Initial support of FST dump format.

15 files changed, 10205 insertions, 3 deletions

diff --git a/src/grt/Makefile.inc b/src/grt/Makefile.inc
index bc59bb5..3bd6ac2 100644
--- a/src/grt/Makefile.inc
+++ b/src/grt/Makefile.inc
@@ -96,8 +96,10 @@ ifndef GRT_TARGET_OBJS
   GRT_EXTRA_LIB=-lpthread -ldl -lm
 endif
 
+GRT_FST_OBJS := fstapi.o lz4.o fastlz.o
+
 # Additionnal object files (C or asm files).
-GRT_ADD_OBJS:=$(GRT_TARGET_OBJS) grt-cbinding.o grt-cvpi.o
+GRT_ADD_OBJS:=$(GRT_TARGET_OBJS) grt-cbinding.o grt-cvpi.o $(GRT_FST_OBJS)
 
 #GRT_USE_PTHREADS=y
 ifeq ($(GRT_USE_PTHREADS),y)
@@ -183,6 +185,15 @@ grt-cvpi.o: $(GRTSRCDIR)/grt-cvpi.c
 grt-cthreads.o: $(GRTSRCDIR)/grt-cthreads.c
 	$(CC) -c $(GRT_FLAGS) -o $@ $<
 
+fstapi.o: $(GRTSRCDIR)/fst/fstapi.c
+	$(CC) -c $(GRT_FLAGS) -o $@ -I$(GRTSRCDIR)/fst $<
+
+lz4.o: $(GRTSRCDIR)/fst/lz4.c
+	$(CC) -c $(GRT_FLAGS) -o $@ $<
+
+fastlz.o: $(GRTSRCDIR)/fst/fastlz.c
+	$(CC) -c $(GRT_FLAGS) -o $@ $<
+
 grt-disp-config:
 	@echo "target: $(target)"
 	@echo "targ: $(targ)"
diff --git a/src/grt/fst/block_format.txt b/src/grt/fst/block_format.txt
new file mode 100644
index 0000000..0cab3a4
--- /dev/null
+++ b/src/grt/fst/block_format.txt
@@ -0,0 +1,130 @@
+See fstapi.h for the values for the FST_BL_XXX enums.
+
+===========================================================================
+
+compressed wrapper (typically over whole file)
+
+uint8_t		FST_BL_ZWRAPPER
+uint64_t        section length
+uint64_t        length of uncompressed data
+[zlib compressed data]
+
+===========================================================================
+
+header block
+
+uint8_t		FST_BL_HDR
+uint64_t	section length
+uint64_t	start time
+uint64_t	end time
+double		endian test for "e"
+uint64_t	memory used by writer
+uint64_t	scope creation count
+uint64_t	var creation count
+uint64_t	max var idcode
+uint64_t	vc section count
+int8_t		timescale exponent
+[128 bytes]	version
+[128 bytes]	date
+
+===========================================================================
+
+geometry block
+
+uint8_t         FST_BL_GEOM
+uint64_t        section length
+uint64_t        length of uncompressed geometry data
+uint64_t        maxhandle
+[compressed data]
+
+(length of compressed data is section length - 24)
+
+===========================================================================
+
+hierarchy block
+
+uint8_t         FST_BL_HIER
+uint64_t        section length
+uint64_t        length of uncompressed hier data
+[zlib compressed data]
+
+or
+
+uint8_t         FST_BL_HIER_LZ4
+uint64_t        section length
+uint64_t        length of uncompressed hier data
+[lz4 compressed data]
+
+uint8_t         FST_BL_HIER_LZ4DUO
+uint64_t        section length
+uint64_t        length of uncompressed hier data
+varint		length of hier data compressed once with lz4
+[lz4 double compressed data]
+
+
+===========================================================================
+
+dumpon/off block
+
+uint8_t         FST_BL_BLACKOUT
+uint64_t        section length
+varint		num blackouts (section below is repeated this # times)
+[
+uint8_t		on/off (nonzero = on)
+varint		delta time
+]
+
+===========================================================================
+
+1..n value change blocks:
+
+// header
+
+uint8_t		FST_BL_VCDATA (or FST_BL_VCDATA_DYN_ALIAS)
+uint64_t	section length
+uint64_t	begin time of section
+uint64_t	end time of section
+uint64_t	amount of buffer memory required in reader for full vc traversal
+varint		maxvalpos (length of uncompressed data)
+varint		length of compressed data
+varint		maxhandle associated with this checkpoint data
+[compressed data]
+
+---
+
+// value changes
+
+varint		maxhandle associated with the value change data
+uint8_t		pack type ('F' is fastlz, '4' is lz4, 
+			others ['Z'/'!'] are zlib)
+
+varint		chain 0 compressed data length (0 = uncompressed)
+[compressed data]	
+...
+varint		chain n compressed data length (0 = uncompressed)
+[compressed data]	
+
+---
+
+// index: chain pointer table (from 0..maxhandle-1)
+
+varint		if &1 == 1, this is <<1 literal delta
+		if &1 == 0, this is <<1 RLE count of zeros
+		if == 0, next varint is handle of prev chain to use,
+			bit only if FST_BL_VCDATA_DYN_ALIAS or
+			later VCDATA format
+
+---
+
+uint64_t	index length (subtract from here to get index position)
+
+---
+
+[compressed data for time section]
+uint64_t	uncompressed data length in bytes
+uint64_t	compressed data length in bytes
+uint64_t	number of time items
+
+// end of section
+
+===========================================================================
diff --git a/src/grt/fst/config.h b/src/grt/fst/config.h
new file mode 100644
index 0000000..71c5a2d
--- /dev/null
+++ b/src/grt/fst/config.h
@@ -0,0 +1,2 @@
+/* config.h for fst.  */
+#define HAVE_FSEEKO 1
diff --git a/src/grt/fst/fastlz.c b/src/grt/fst/fastlz.c
new file mode 100644
index 0000000..50bf56a
--- /dev/null
+++ b/src/grt/fst/fastlz.c
@@ -0,0 +1,547 @@
+/*
+  FastLZ - lightning-fast lossless compression library
+
+  Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)
+  Copyright (C) 2006 Ariya Hidayat (ariya@kde.org)
+  Copyright (C) 2005 Ariya Hidayat (ariya@kde.org)
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/
+
+#include "fastlz.h"
+
+#if !defined(FASTLZ__COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR)
+
+/*
+ * Always check for bound when decompressing.
+ * Generally it is best to leave it defined.
+ */
+#define FASTLZ_SAFE
+
+
+/*
+ * Give hints to the compiler for branch prediction optimization.
+ */
+#if defined(__GNUC__) && (__GNUC__ > 2)
+#define FASTLZ_EXPECT_CONDITIONAL(c)    (__builtin_expect((c), 1))
+#define FASTLZ_UNEXPECT_CONDITIONAL(c)  (__builtin_expect((c), 0))
+#else
+#define FASTLZ_EXPECT_CONDITIONAL(c)    (c)
+#define FASTLZ_UNEXPECT_CONDITIONAL(c)  (c)
+#endif
+
+/*
+ * Use inlined functions for supported systems.
+ */
+#if defined(__GNUC__) || defined(__DMC__) || defined(__POCC__) || defined(__WATCOMC__) || defined(__SUNPRO_C)
+#define FASTLZ_INLINE inline
+#elif defined(__BORLANDC__) || defined(_MSC_VER) || defined(__LCC__)
+#define FASTLZ_INLINE __inline
+#else
+#define FASTLZ_INLINE
+#endif
+
+/*
+ * Prevent accessing more than 8-bit at once, except on x86 architectures.
+ */
+#if !defined(FASTLZ_STRICT_ALIGN)
+#define FASTLZ_STRICT_ALIGN
+#if defined(__i386__) || defined(__386)  /* GNU C, Sun Studio */
+#undef FASTLZ_STRICT_ALIGN
+#elif defined(__i486__) || defined(__i586__) || defined(__i686__) || defined(__amd64) /* GNU C */
+#undef FASTLZ_STRICT_ALIGN
+#elif defined(_M_IX86) /* Intel, MSVC */
+#undef FASTLZ_STRICT_ALIGN
+#elif defined(__386)
+#undef FASTLZ_STRICT_ALIGN
+#elif defined(_X86_) /* MinGW */
+#undef FASTLZ_STRICT_ALIGN
+#elif defined(__I86__) /* Digital Mars */
+#undef FASTLZ_STRICT_ALIGN
+#endif
+#endif
+
+/* prototypes */
+int fastlz_compress(const void* input, int length, void* output);
+int fastlz_compress_level(int level, const void* input, int length, void* output);
+int fastlz_decompress(const void* input, int length, void* output, int maxout);
+
+#define MAX_COPY       32
+#define MAX_LEN       264  /* 256 + 8 */
+#define MAX_DISTANCE 8192
+
+#if !defined(FASTLZ_STRICT_ALIGN)
+#define FASTLZ_READU16(p) *((const flzuint16*)(p))
+#else
+#define FASTLZ_READU16(p) ((p)[0] | (p)[1]<<8)
+#endif
+
+#define HASH_LOG  13
+#define HASH_SIZE (1<< HASH_LOG)
+#define HASH_MASK  (HASH_SIZE-1)
+#define HASH_FUNCTION(v,p) { v = FASTLZ_READU16(p); v ^= FASTLZ_READU16(p+1)^(v>>(16-HASH_LOG));v &= HASH_MASK; }
+
+#undef FASTLZ_LEVEL
+#define FASTLZ_LEVEL 1
+
+#undef FASTLZ_COMPRESSOR
+#undef FASTLZ_DECOMPRESSOR
+#define FASTLZ_COMPRESSOR fastlz1_compress
+#define FASTLZ_DECOMPRESSOR fastlz1_decompress
+static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output);
+static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout);
+#include "fastlz.c"
+
+#undef FASTLZ_LEVEL
+#define FASTLZ_LEVEL 2
+
+#undef MAX_DISTANCE
+#define MAX_DISTANCE 8191
+#define MAX_FARDISTANCE (65535+MAX_DISTANCE-1)
+
+#undef FASTLZ_COMPRESSOR
+#undef FASTLZ_DECOMPRESSOR
+#define FASTLZ_COMPRESSOR fastlz2_compress
+#define FASTLZ_DECOMPRESSOR fastlz2_decompress
+static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output);
+static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout);
+#include "fastlz.c"
+
+int fastlz_compress(const void* input, int length, void* output)
+{
+  /* for short block, choose fastlz1 */
+  if(length < 65536)
+    return fastlz1_compress(input, length, output);
+
+  /* else... */
+  return fastlz2_compress(input, length, output);
+}
+
+int fastlz_decompress(const void* input, int length, void* output, int maxout)
+{
+  /* magic identifier for compression level */
+  int level = ((*(const flzuint8*)input) >> 5) + 1;
+
+  if(level == 1)
+    return fastlz1_decompress(input, length, output, maxout);
+  if(level == 2)
+    return fastlz2_decompress(input, length, output, maxout);
+
+  /* unknown level, trigger error */
+  return 0;
+}
+
+int fastlz_compress_level(int level, const void* input, int length, void* output)
+{
+  if(level == 1)
+    return fastlz1_compress(input, length, output);
+  if(level == 2)
+    return fastlz2_compress(input, length, output);
+
+  return 0;
+}
+
+#else /* !defined(FASTLZ_COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR) */
+
+static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output)
+{
+  const flzuint8* ip = (const flzuint8*) input;
+  const flzuint8* ip_bound = ip + length - 2;
+  const flzuint8* ip_limit = ip + length - 12;
+  flzuint8* op = (flzuint8*) output;
+
+  const flzuint8* htab[HASH_SIZE];
+  const flzuint8** hslot;
+  flzuint32 hval;
+
+  flzuint32 copy;
+
+  /* sanity check */
+  if(FASTLZ_UNEXPECT_CONDITIONAL(length < 4))
+  {
+    if(length)
+    {
+      /* create literal copy only */
+      *op++ = length-1;
+      ip_bound++;
+      while(ip <= ip_bound)
+        *op++ = *ip++;
+      return length+1;
+    }
+    else
+      return 0;
+  }
+
+  /* initializes hash table */
+  for (hslot = htab; hslot < htab + HASH_SIZE; hslot++)
+    *hslot = ip;
+
+  /* we start with literal copy */
+  copy = 2;
+  *op++ = MAX_COPY-1;
+  *op++ = *ip++;
+  *op++ = *ip++;
+
+  /* main loop */
+  while(FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit))
+  {
+    const flzuint8* ref;
+    flzuint32 distance;
+
+    /* minimum match length */
+    flzuint32 len = 3;
+
+    /* comparison starting-point */
+    const flzuint8* anchor = ip;
+
+    /* check for a run */
+#if FASTLZ_LEVEL==2
+    if(ip[0] == ip[-1] && FASTLZ_READU16(ip-1)==FASTLZ_READU16(ip+1))
+    {
+      distance = 1;
+      /* ip += 3; */ /* scan-build, never used */
+      ref = anchor - 1 + 3;
+      goto match;
+    }
+#endif
+
+    /* find potential match */
+    HASH_FUNCTION(hval,ip);
+    hslot = htab + hval;
+    ref = htab[hval];
+
+    /* calculate distance to the match */
+    distance = anchor - ref;
+
+    /* update hash table */
+    *hslot = anchor;
+
+    /* is this a match? check the first 3 bytes */
+    if(distance==0 ||
+#if FASTLZ_LEVEL==1
+    (distance >= MAX_DISTANCE) ||
+#else
+    (distance >= MAX_FARDISTANCE) ||
+#endif
+    *ref++ != *ip++ || *ref++!=*ip++ || *ref++!=*ip++)
+      goto literal;
+
+#if FASTLZ_LEVEL==2
+    /* far, needs at least 5-byte match */
+    if(distance >= MAX_DISTANCE)
+    {
+      if(*ip++ != *ref++ || *ip++!= *ref++)
+        goto literal;
+      len += 2;
+    }
+
+    match:
+#endif
+
+    /* last matched byte */
+    ip = anchor + len;
+
+    /* distance is biased */
+    distance--;
+
+    if(!distance)
+    {
+      /* zero distance means a run */
+      flzuint8 x = ip[-1];
+      while(ip < ip_bound)
+        if(*ref++ != x) break; else ip++;
+    }
+    else
+    for(;;)
+    {
+      /* safe because the outer check against ip limit */
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      if(*ref++ != *ip++) break;
+      while(ip < ip_bound)
+        if(*ref++ != *ip++) break;
+      break;
+    }
+
+    /* if we have copied something, adjust the copy count */
+    if(copy)
+      /* copy is biased, '0' means 1 byte copy */
+      *(op-copy-1) = copy-1;
+    else
+      /* back, to overwrite the copy count */
+      op--;
+
+    /* reset literal counter */
+    copy = 0;
+
+    /* length is biased, '1' means a match of 3 bytes */
+    ip -= 3;
+    len = ip - anchor;
+
+    /* encode the match */
+#if FASTLZ_LEVEL==2
+    if(distance < MAX_DISTANCE)
+    {
+      if(len < 7)
+      {
+        *op++ = (len << 5) + (distance >> 8);
+        *op++ = (distance & 255);
+      }
+      else
+      {
+        *op++ = (7 << 5) + (distance >> 8);
+        for(len-=7; len >= 255; len-= 255)
+          *op++ = 255;
+        *op++ = len;
+        *op++ = (distance & 255);
+      }
+    }
+    else
+    {
+      /* far away, but not yet in the another galaxy... */
+      if(len < 7)
+      {
+        distance -= MAX_DISTANCE;
+        *op++ = (len << 5) + 31;
+        *op++ = 255;
+        *op++ = distance >> 8;
+        *op++ = distance & 255;
+      }
+      else
+      {
+        distance -= MAX_DISTANCE;
+        *op++ = (7 << 5) + 31;
+        for(len-=7; len >= 255; len-= 255)
+          *op++ = 255;
+        *op++ = len;
+        *op++ = 255;
+        *op++ = distance >> 8;
+        *op++ = distance & 255;
+      }
+    }
+#else
+
+    if(FASTLZ_UNEXPECT_CONDITIONAL(len > MAX_LEN-2))
+      while(len > MAX_LEN-2)
+      {
+        *op++ = (7 << 5) + (distance >> 8);
+        *op++ = MAX_LEN - 2 - 7 -2;
+        *op++ = (distance & 255);
+        len -= MAX_LEN-2;
+      }
+
+    if(len < 7)
+    {
+      *op++ = (len << 5) + (distance >> 8);
+      *op++ = (distance & 255);
+    }
+    else
+    {
+      *op++ = (7 << 5) + (distance >> 8);
+      *op++ = len - 7;
+      *op++ = (distance & 255);
+    }
+#endif
+
+    /* update the hash at match boundary */
+    HASH_FUNCTION(hval,ip);
+    htab[hval] = ip++;
+    HASH_FUNCTION(hval,ip);
+    htab[hval] = ip++;
+
+    /* assuming literal copy */
+    *op++ = MAX_COPY-1;
+
+    continue;
+
+    literal:
+      *op++ = *anchor++;
+      ip = anchor;
+      copy++;
+      if(FASTLZ_UNEXPECT_CONDITIONAL(copy == MAX_COPY))
+      {
+        copy = 0;
+        *op++ = MAX_COPY-1;
+      }
+  }
+
+  /* left-over as literal copy */
+  ip_bound++;
+  while(ip <= ip_bound)
+  {
+    *op++ = *ip++;
+    copy++;
+    if(copy == MAX_COPY)
+    {
+      copy = 0;
+      *op++ = MAX_COPY-1;
+    }
+  }
+
+  /* if we have copied something, adjust the copy length */
+  if(copy)
+    *(op-copy-1) = copy-1;
+  else
+    op--;
+
+#if FASTLZ_LEVEL==2
+  /* marker for fastlz2 */
+  *(flzuint8*)output |= (1 << 5);
+#endif
+
+  return op - (flzuint8*)output;
+}
+
+static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout)
+{
+  const flzuint8* ip = (const flzuint8*) input;
+  const flzuint8* ip_limit  = ip + length;
+  flzuint8* op = (flzuint8*) output;
+  flzuint8* op_limit = op + maxout;
+  flzuint32 ctrl = (*ip++) & 31;
+  int loop = 1;
+
+  do
+  {
+    const flzuint8* ref = op;
+    flzuint32 len = ctrl >> 5;
+    flzuint32 ofs = (ctrl & 31) << 8;
+
+    if(ctrl >= 32)
+    {
+#if FASTLZ_LEVEL==2
+      flzuint8 code;
+#endif
+      len--;
+      ref -= ofs;
+      if (len == 7-1)
+#if FASTLZ_LEVEL==1
+        len += *ip++;
+      ref -= *ip++;
+#else
+        do
+        {
+          code = *ip++;
+          len += code;
+        } while (code==255);
+      code = *ip++;
+      ref -= code;
+
+      /* match from 16-bit distance */
+      if(FASTLZ_UNEXPECT_CONDITIONAL(code==255))
+      if(FASTLZ_EXPECT_CONDITIONAL(ofs==(31 << 8)))
+      {
+        ofs = (*ip++) << 8;
+        ofs += *ip++;
+        ref = op - ofs - MAX_DISTANCE;
+      }
+#endif
+
+#ifdef FASTLZ_SAFE
+      if (FASTLZ_UNEXPECT_CONDITIONAL(op + len + 3 > op_limit))
+        return 0;
+
+      if (FASTLZ_UNEXPECT_CONDITIONAL(ref-1 < (flzuint8 *)output))
+        return 0;
+#endif
+
+      if(FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit))
+        ctrl = *ip++;
+      else
+        loop = 0;
+
+      if(ref == op)
+      {
+        /* optimize copy for a run */
+        flzuint8 b = ref[-1];
+        *op++ = b;
+        *op++ = b;
+        *op++ = b;
+        for(; len; --len)
+          *op++ = b;
+      }
+      else
+      {
+#if !defined(FASTLZ_STRICT_ALIGN)
+        const flzuint16* p;
+        flzuint16* q;
+#endif
+        /* copy from reference */
+        ref--;
+        *op++ = *ref++;
+        *op++ = *ref++;
+        *op++ = *ref++;
+
+#if !defined(FASTLZ_STRICT_ALIGN)
+        /* copy a byte, so that now it's word aligned */
+        if(len & 1)
+        {
+          *op++ = *ref++;
+          len--;
+        }
+
+        /* copy 16-bit at once */
+        q = (flzuint16*) op;
+        op += len;
+        p = (const flzuint16*) ref;
+        for(len>>=1; len > 4; len-=4)
+        {
+          *q++ = *p++;
+          *q++ = *p++;
+          *q++ = *p++;
+          *q++ = *p++;
+        }
+        for(; len; --len)
+          *q++ = *p++;
+#else
+        for(; len; --len)
+          *op++ = *ref++;
+#endif
+      }
+    }
+    else
+    {
+      ctrl++;
+#ifdef FASTLZ_SAFE
+      if (FASTLZ_UNEXPECT_CONDITIONAL(op + ctrl > op_limit))
+        return 0;
+      if (FASTLZ_UNEXPECT_CONDITIONAL(ip + ctrl > ip_limit))
+        return 0;
+#endif
+
+      *op++ = *ip++;
+      for(--ctrl; ctrl; ctrl--)
+        *op++ = *ip++;
+
+      loop = FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit);
+      if(loop)
+        ctrl = *ip++;
+    }
+  }
+  while(FASTLZ_EXPECT_CONDITIONAL(loop));
+
+  return op - (flzuint8*)output;
+}
+
+#endif /* !defined(FASTLZ_COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR) */
diff --git a/src/grt/fst/fastlz.h b/src/grt/fst/fastlz.h
new file mode 100644
index 0000000..8b4eac2
--- /dev/null
+++ b/src/grt/fst/fastlz.h
@@ -0,0 +1,107 @@
+/*
+  FastLZ - lightning-fast lossless compression library
+
+  Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)
+  Copyright (C) 2006 Ariya Hidayat (ariya@kde.org)
+  Copyright (C) 2005 Ariya Hidayat (ariya@kde.org)
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/
+
+#ifndef FASTLZ_H
+#define FASTLZ_H
+
+#include <inttypes.h>
+
+#define flzuint8 uint8_t
+#define flzuint16 uint16_t
+#define flzuint32 uint32_t
+
+
+#define FASTLZ_VERSION 0x000100
+
+#define FASTLZ_VERSION_MAJOR     0
+#define FASTLZ_VERSION_MINOR     0
+#define FASTLZ_VERSION_REVISION  0
+
+#define FASTLZ_VERSION_STRING "0.1.0"
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/**
+  Compress a block of data in the input buffer and returns the size of
+  compressed block. The size of input buffer is specified by length. The
+  minimum input buffer size is 16.
+
+  The output buffer must be at least 5% larger than the input buffer
+  and can not be smaller than 66 bytes.
+
+  If the input is not compressible, the return value might be larger than
+  length (input buffer size).
+
+  The input buffer and the output buffer can not overlap.
+*/
+
+int fastlz_compress(const void* input, int length, void* output);
+
+/**
+  Decompress a block of compressed data and returns the size of the
+  decompressed block. If error occurs, e.g. the compressed data is
+  corrupted or the output buffer is not large enough, then 0 (zero)
+  will be returned instead.
+
+  The input buffer and the output buffer can not overlap.
+
+  Decompression is memory safe and guaranteed not to write the output buffer
+  more than what is specified in maxout.
+ */
+
+int fastlz_decompress(const void* input, int length, void* output, int maxout);
+
+/**
+  Compress a block of data in the input buffer and returns the size of
+  compressed block. The size of input buffer is specified by length. The
+  minimum input buffer size is 16.
+
+  The output buffer must be at least 5% larger than the input buffer
+  and can not be smaller than 66 bytes.
+
+  If the input is not compressible, the return value might be larger than
+  length (input buffer size).
+
+  The input buffer and the output buffer can not overlap.
+
+  Compression level can be specified in parameter level. At the moment,
+  only level 1 and level 2 are supported.
+  Level 1 is the fastest compression and generally useful for short data.
+  Level 2 is slightly slower but it gives better compression ratio.
+
+  Note that the compressed data, regardless of the level, can always be
+  decompressed using the function fastlz_decompress above.
+*/
+
+int fastlz_compress_level(int level, const void* input, int length, void* output);
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* FASTLZ_H */
diff --git a/src/grt/fst/fstapi.c b/src/grt/fst/fstapi.c
new file mode 100644
index 0000000..b0d7dfc
--- /dev/null
+++ b/src/grt/fst/fstapi.c
@@ -0,0 +1,6531 @@
+/*
+ * Copyright (c) 2009-2014 Tony Bybell.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * possible disables:
+ *
+ * FST_DYNAMIC_ALIAS_DISABLE : dynamic aliases are not processed
+ * FST_DYNAMIC_ALIAS2_DISABLE : new encoding for dynamic aliases is not generated
+ * FST_WRITEX_DISABLE : fast write I/O routines are disabled
+ *
+ * possible enables:
+ *
+ * FST_DEBUG : not for production use, only enable for development
+ * FST_REMOVE_DUPLICATE_VC : glitch removal (has writer performance impact)
+ * HAVE_LIBPTHREAD -> FST_WRITER_PARALLEL : enables inclusion of parallel writer code
+ * FST_DO_MISALIGNED_OPS (defined automatically for x86 and some others) : CPU architecture can handle misaligned loads/stores
+ * _WAVE_HAVE_JUDY : use Judy arrays instead of Jenkins (undefine if LGPL is not acceptable)
+ *
+ */
+
+#include <config.h>
+
+#include "fstapi.h"
+#include "fastlz.h"
+#include "lz4.h"
+
+#ifndef HAVE_LIBPTHREAD
+#undef FST_WRITER_PARALLEL
+#endif
+
+#ifdef FST_WRITER_PARALLEL
+#include <pthread.h>
+#endif
+
+#ifdef __MINGW32__
+#include <windows.h>
+#endif
+
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#elif defined(__GNUC__)
+#ifndef __MINGW32__
+#ifndef alloca
+#define alloca __builtin_alloca
+#endif
+#else
+#include <malloc.h>
+#endif
+#elif defined(_MSC_VER)
+#include <malloc.h>
+#define alloca _alloca
+#endif
+
+#ifndef PATH_MAX
+#define PATH_MAX (4096)
+#endif
+
+/* note that Judy versus Jenkins requires more experimentation: they are  */
+/* functionally equivalent though it appears Jenkins is slightly faster.  */
+/* in addition, Jenkins is not bound by the LGPL.                         */
+#ifdef _WAVE_HAVE_JUDY
+#include <Judy.h>
+#else
+/* should be more than enough for fstWriterSetSourceStem() */
+#define FST_PATH_HASHMASK               ((1UL << 16) - 1)
+typedef const void *Pcvoid_t;
+typedef void *Pvoid_t;
+typedef void **PPvoid_t;
+#define JudyHSIns(a,b,c,d) JenkinsIns((a),(b),(c),(hashmask))
+#define JudyHSFreeArray(a,b) JenkinsFree((a),(hashmask))
+void JenkinsFree(void *base_i, uint32_t hashmask);
+void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint32_t hashmask);
+#endif
+
+
+#ifndef FST_WRITEX_DISABLE
+#define FST_WRITEX_MAX                  (64 * 1024)
+#else
+#define fstWritex(a,b,c) fstFwrite((b), (c), 1, fv)
+#endif
+
+
+/* these defines have a large impact on writer speed when a model has a */
+/* huge number of symbols.  as a default, use 128MB and increment when  */
+/* every 1M signals are defined.                                        */
+#define FST_BREAK_SIZE                  (1UL << 27)
+#define FST_BREAK_ADD_SIZE              (1UL << 22)
+#define FST_BREAK_SIZE_MAX              (1UL << 31)
+#define FST_ACTIVATE_HUGE_BREAK         (1000000)
+#define FST_ACTIVATE_HUGE_INC           (1000000)
+
+#define FST_WRITER_STR                  "fstWriter"
+#define FST_ID_NAM_SIZ                  (512)
+#define FST_ID_NAM_ATTR_SIZ             (65536+4096)
+#define FST_DOUBLE_ENDTEST              (2.7182818284590452354)
+#define FST_HDR_SIM_VERSION_SIZE        (128)
+#define FST_HDR_DATE_SIZE               (119)
+#define FST_HDR_FILETYPE_SIZE           (1)
+#define FST_HDR_TIMEZERO_SIZE           (8)
+#define FST_GZIO_LEN                    (32768)
+#define FST_HDR_FOURPACK_DUO_SIZE       (4*1024*1024)
+
+#if defined(__i386__) || defined(__x86_64__) || defined(_AIX)
+#define FST_DO_MISALIGNED_OPS
+#endif
+
+#if defined(__APPLE__) && defined(__MACH__)
+#define FST_MACOSX
+#include <sys/sysctl.h>
+#endif
+
+
+/***********************/
+/***                 ***/
+/*** common function ***/
+/***                 ***/
+/***********************/
+
+#ifdef __MINGW32__
+#include <io.h>
+#ifndef HAVE_FSEEKO
+#define ftello ftell
+#define fseeko fseek
+#endif
+#endif
+
+/*
+ * the recoded "extra" values...
+ * note that FST_RCV_Q is currently unused and is for future expansion.
+ * its intended use is as another level of escape such that any arbitrary
+ * value can be stored as the value: { time_delta, 8 bits, FST_RCV_Q }.
+ * this is currently not implemented so that the branchless decode is:
+ * uint32_t shcnt = 2 << (vli & 1); tdelta = vli >> shcnt;
+ */
+#define FST_RCV_X (1 | (0<<1))
+#define FST_RCV_Z (1 | (1<<1))
+#define FST_RCV_H (1 | (2<<1))
+#define FST_RCV_U (1 | (3<<1))
+#define FST_RCV_W (1 | (4<<1))
+#define FST_RCV_L (1 | (5<<1))
+#define FST_RCV_D (1 | (6<<1))
+#define FST_RCV_Q (1 | (7<<1))
+
+#define FST_RCV_STR "xzhuwl-?"
+/*                   01234567 */
+
+
+/*
+ * prevent old file overwrite when currently being read
+ */
+static FILE *unlink_fopen(const char *nam, const char *mode)
+{
+unlink(nam);
+return(fopen(nam, mode));
+}
+
+
+/*
+ * system-specific temp file handling
+ */
+#ifdef __MINGW32__
+
+static FILE* tmpfile_open(char **nam)
+{
+char *fname = NULL;
+TCHAR szTempFileName[MAX_PATH];
+TCHAR lpTempPathBuffer[MAX_PATH];
+DWORD dwRetVal = 0;
+UINT uRetVal = 0;
+FILE *fh = NULL;
+
+if(nam) /* cppcheck warning fix: nam is always defined, so this is not needed */
+        {
+        dwRetVal = GetTempPath(MAX_PATH, lpTempPathBuffer);
+        if((dwRetVal > MAX_PATH) || (dwRetVal == 0))
+                {
+                fprintf(stderr, "GetTempPath() failed in "__FILE__" line %d, exiting.\n", __LINE__);
+                exit(255);
+                }
+                else
+                {
+                uRetVal = GetTempFileName(lpTempPathBuffer, TEXT("FSTW"), 0, szTempFileName);
+                if (uRetVal == 0)
+                        {
+                        fprintf(stderr, "GetTempFileName() failed in "__FILE__" line %d, exiting.\n", __LINE__);
+                        exit(255);
+                        }
+                        else
+                        {
+                        fname = strdup(szTempFileName);
+                        }
+                }
+
+        if(fname)
+                {
+                *nam = fname;
+                fh = unlink_fopen(fname, "w+b");
+                }
+        }
+
+return(fh);
+}
+
+#else
+
+static FILE* tmpfile_open(char **nam)
+{
+FILE *f = tmpfile(); /* replace with mkstemp() + fopen(), etc if this is not good enough */
+if(nam) { *nam = NULL; }
+return(f);
+}
+
+#endif
+
+
+static void tmpfile_close(FILE **f, char **nam)
+{
+if(f)
+        {
+        if(*f) { fclose(*f); *f = NULL; }
+        }
+
+if(nam)
+        {
+        if(*nam)
+                {
+                unlink(*nam);
+                free(*nam);
+                *nam = NULL;
+                }
+        }
+}
+
+/*****************************************/
+
+
+/*
+ * to remove warn_unused_result compile time messages
+ * (in the future there needs to be results checking)
+ */
+static size_t fstFread(void *buf, size_t siz, size_t cnt, FILE *fp)
+{
+return(fread(buf, siz, cnt, fp));
+}
+
+static size_t fstFwrite(const void *buf, size_t siz, size_t cnt, FILE *fp)
+{
+return(fwrite(buf, siz, cnt, fp));
+}
+
+static int fstFtruncate(int fd, off_t length)
+{
+return(ftruncate(fd, length));
+}
+
+
+/*
+ * realpath compatibility
+ */
+static char *fstRealpath(const char *path, char *resolved_path)
+{
+#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __CYGWIN__ || defined HAVE_REALPATH
+
+#if (defined(__MACH__) && defined(__APPLE__))
+if(!resolved_path)
+        {
+        resolved_path = malloc(PATH_MAX+1); /* fixes bug on Leopard when resolved_path == NULL */
+        }
+#endif
+
+return(realpath(path, resolved_path));
+
+#else
+#ifdef __MINGW32__
+if(!resolved_path)
+        {
+        resolved_path = malloc(PATH_MAX+1);
+        }
+return(_fullpath(resolved_path, path, PATH_MAX));
+#else
+return(NULL);
+#endif
+#endif
+}
+
+
+/*
+ * mmap compatibility
+ */
+#if defined __CYGWIN__ || defined __MINGW32__
+#include <limits.h>
+#define fstMmap(__addr,__len,__prot,__flags,__fd,__off) fstMmap2((__len), (__fd), (__off))
+#define fstMunmap(__addr,__len)                         free(__addr)
+
+static void *fstMmap2(size_t __len, int __fd, off_t __off)
+{
+(void)__off;
+
+unsigned char *pnt = malloc(__len);
+off_t cur_offs = lseek(__fd, 0, SEEK_CUR);
+size_t i;
+
+lseek(__fd, 0, SEEK_SET);
+for(i=0;i<__len;i+=SSIZE_MAX)
+        {
+        read(__fd, pnt + i, ((__len - i) >= SSIZE_MAX) ? SSIZE_MAX : (__len - i));
+        }
+lseek(__fd, cur_offs, SEEK_SET);
+return(pnt);
+}
+#else
+#include <sys/mman.h>
+#if defined(__SUNPRO_C)
+#define FST_CADDR_T_CAST (caddr_t)
+#else
+#define FST_CADDR_T_CAST
+#endif
+#define fstMmap(__addr,__len,__prot,__flags,__fd,__off) (void*)mmap(FST_CADDR_T_CAST (__addr),(__len),(__prot),(__flags),(__fd),(__off))
+#define fstMunmap(__addr,__len)                         { if(__addr) munmap(FST_CADDR_T_CAST (__addr),(__len)); }
+#endif
+
+
+/*
+ * regular and variable-length integer access functions
+ */
+#ifdef FST_DO_MISALIGNED_OPS
+#define fstGetUint32(x) (*(uint32_t *)(x))
+#else
+static uint32_t fstGetUint32(unsigned char *mem)
+{
+uint32_t u32;
+unsigned char *buf = (unsigned char *)(&u32);
+
+buf[0] = mem[0];
+buf[1] = mem[1];
+buf[2] = mem[2];
+buf[3] = mem[3];
+
+return(*(uint32_t *)buf);
+}
+#endif
+
+
+static int fstWriterUint64(FILE *handle, uint64_t v)
+{
+unsigned char buf[8];
+int i;
+
+for(i=7;i>=0;i--)
+        {
+        buf[i] = v & 0xff;
+        v >>= 8;
+        }
+
+fstFwrite(buf, 8, 1, handle);
+return(8);
+}
+
+
+static uint64_t fstReaderUint64(FILE *f)
+{
+uint64_t val = 0;
+unsigned char buf[sizeof(uint64_t)];
+unsigned int i;
+
+fstFread(buf, sizeof(uint64_t), 1, f);
+for(i=0;i<sizeof(uint64_t);i++)
+        {
+        val <<= 8;
+        val |= buf[i];
+        }
+
+return(val);
+}
+
+
+static uint32_t fstGetVarint32(unsigned char *mem, int *skiplen)
+{
+unsigned char *mem_orig = mem;
+uint32_t rc = 0;
+while(*mem & 0x80)
+        {
+        mem++;
+        }
+
+*skiplen = mem - mem_orig + 1;
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint32_t)(*mem & 0x7f);
+        if(mem == mem_orig)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static uint32_t fstGetVarint32Length(unsigned char *mem)
+{
+unsigned char *mem_orig = mem;
+
+while(*mem & 0x80)
+        {
+        mem++;
+        }
+
+return(mem - mem_orig + 1);
+}
+
+
+static uint32_t fstGetVarint32NoSkip(unsigned char *mem)
+{
+unsigned char *mem_orig = mem;
+uint32_t rc = 0;
+while(*mem & 0x80)
+        {
+        mem++;
+        }
+
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint32_t)(*mem & 0x7f);
+        if(mem == mem_orig)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static unsigned char *fstCopyVarint32ToLeft(unsigned char *pnt, uint32_t v)
+{
+unsigned char *spnt;
+uint32_t nxt = v;
+int cnt = 1;
+int i;
+
+while((nxt = nxt>>7)) /* determine len to avoid temp buffer copying to cut down on load-hit-store */
+        {
+        cnt++;
+        }
+
+pnt -= cnt;
+spnt = pnt;
+cnt--;
+
+for(i=0;i<cnt;i++) /* now generate left to right as normal */
+        {
+        nxt = v>>7;
+        *(spnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*spnt = (unsigned char)v;
+
+return(pnt);
+}
+
+
+static unsigned char *fstCopyVarint64ToRight(unsigned char *pnt, uint64_t v)
+{
+uint64_t nxt;
+
+while((nxt = v>>7))
+        {
+        *(pnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*(pnt++) = (unsigned char)v;
+
+return(pnt);
+}
+
+
+static uint64_t fstGetVarint64(unsigned char *mem, int *skiplen)
+{
+unsigned char *mem_orig = mem;
+uint64_t rc = 0;
+while(*mem & 0x80)
+        {
+        mem++;
+        }
+
+*skiplen = mem - mem_orig + 1;
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint64_t)(*mem & 0x7f);
+        if(mem == mem_orig)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static uint32_t fstReaderVarint32(FILE *f)
+{
+unsigned char buf[5];
+unsigned char *mem = buf;
+uint32_t rc = 0;
+int ch;
+
+do
+        {
+        ch = fgetc(f);
+        *(mem++) = ch;
+        } while(ch & 0x80);
+mem--;
+
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint32_t)(*mem & 0x7f);
+        if(mem == buf)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static uint32_t fstReaderVarint32WithSkip(FILE *f, uint32_t *skiplen)
+{
+unsigned char buf[5];
+unsigned char *mem = buf;
+uint32_t rc = 0;
+int ch;
+
+do
+        {
+        ch = fgetc(f);
+        *(mem++) = ch;
+        } while(ch & 0x80);
+*skiplen = mem - buf;
+mem--;
+
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint32_t)(*mem & 0x7f);
+        if(mem == buf)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static uint64_t fstReaderVarint64(FILE *f)
+{
+unsigned char buf[16];
+unsigned char *mem = buf;
+uint64_t rc = 0;
+int ch;
+
+do
+        {
+        ch = fgetc(f);
+        *(mem++) = ch;
+        } while(ch & 0x80);
+mem--;
+
+for(;;)
+        {
+        rc <<= 7;
+        rc |= (uint64_t)(*mem & 0x7f);
+        if(mem == buf)
+                {
+                break;
+                }
+        mem--;
+        }
+
+return(rc);
+}
+
+
+static int fstWriterVarint(FILE *handle, uint64_t v)
+{
+uint64_t nxt;
+unsigned char buf[10]; /* ceil(64/7) = 10 */
+unsigned char *pnt = buf;
+int len;
+
+while((nxt = v>>7))
+        {
+        *(pnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*(pnt++) = (unsigned char)v;
+
+len = pnt-buf;
+fstFwrite(buf, len, 1, handle);
+return(len);
+}
+
+
+/* signed integer read/write routines are currently unused */
+static int64_t fstGetSVarint64(unsigned char *mem, int *skiplen)
+{
+unsigned char *mem_orig = mem;
+int64_t rc = 0;
+const int64_t one = 1;
+const int siz = sizeof(int64_t) * 8;
+int shift = 0;
+unsigned char byt;
+
+do      {
+        byt = *(mem++);
+        rc |= ((int64_t)(byt & 0x7f)) << shift;
+        shift += 7;
+
+        } while(byt & 0x80);
+
+if((shift<siz) && (byt & 0x40))
+        {
+        rc |= -(one << shift); /* sign extend */
+        }
+
+*skiplen = mem - mem_orig;
+
+return(rc);
+}
+
+
+static int fstWriterSVarint(FILE *handle, int64_t v)
+{
+unsigned char buf[15]; /* ceil(64/7) = 10 + sign byte padded way up */
+unsigned char byt;
+unsigned char *pnt = buf;
+int more = 1;
+int len;
+
+do      {
+        byt = v | 0x80;
+        v >>= 7;
+
+        if (((!v) && (!(byt & 0x40))) || ((v == -1) && (byt & 0x40)))
+                {
+                more = 0;
+                byt &= 0x7f;
+                }
+
+        *(pnt++) = byt;
+        } while(more);
+
+len = pnt-buf;
+fstFwrite(buf, len, 1, handle);
+return(len);
+}
+
+
+/***********************/
+/***                 ***/
+/*** writer function ***/
+/***                 ***/
+/***********************/
+
+/*
+ * private structs
+ */
+struct fstBlackoutChain
+{
+struct fstBlackoutChain *next;
+uint64_t tim;
+unsigned active : 1;
+};
+
+
+struct fstWriterContext
+{
+FILE *handle;
+FILE *hier_handle;
+FILE *geom_handle;
+FILE *valpos_handle;
+FILE *curval_handle;
+FILE *tchn_handle;
+
+unsigned char *vchg_mem;
+
+off_t hier_file_len;
+
+uint32_t *valpos_mem;
+unsigned char *curval_mem;
+
+char *filename;
+
+fstHandle maxhandle;
+fstHandle numsigs;
+uint32_t maxvalpos;
+
+unsigned vc_emitted : 1;
+unsigned is_initial_time : 1;
+unsigned fourpack : 1;
+unsigned fastpack : 1;
+
+int64_t timezero;
+off_t section_header_truncpos;
+uint32_t tchn_cnt, tchn_idx;
+uint64_t curtime;
+uint64_t firsttime;
+uint32_t vchg_siz;
+uint32_t vchg_alloc_siz;
+
+uint32_t secnum;
+off_t section_start;
+
+uint32_t numscopes;
+double nan; /* nan value for uninitialized doubles */
+
+struct fstBlackoutChain *blackout_head;
+struct fstBlackoutChain *blackout_curr;
+uint32_t num_blackouts;
+
+uint64_t dump_size_limit;
+
+unsigned char filetype; /* default is 0, FST_FT_VERILOG */
+
+unsigned compress_hier : 1;
+unsigned repack_on_close : 1;
+unsigned skip_writing_section_hdr : 1;
+unsigned size_limit_locked : 1;
+unsigned section_header_only : 1;
+unsigned flush_context_pending : 1;
+unsigned parallel_enabled : 1;
+unsigned parallel_was_enabled : 1;
+
+/* should really be semaphores, but are bytes to cut down on read-modify-write window size */
+unsigned char already_in_flush; /* in case control-c handlers interrupt */
+unsigned char already_in_close; /* in case control-c handlers interrupt */
+
+#ifdef FST_WRITER_PARALLEL
+pthread_mutex_t mutex;
+pthread_t thread;
+pthread_attr_t thread_attr;
+struct fstWriterContext *xc_parent;
+#endif
+
+size_t fst_orig_break_size;
+size_t fst_orig_break_add_size;
+
+size_t fst_break_size;
+size_t fst_break_add_size;
+
+size_t fst_huge_break_size;
+
+fstHandle next_huge_break;
+
+Pvoid_t path_array;
+uint32_t path_array_count;
+
+unsigned fseek_failed : 1;
+
+char *geom_handle_nam;
+char *valpos_handle_nam;
+char *curval_handle_nam;
+char *tchn_handle_nam;
+};
+
+
+static int fstWriterFseeko(struct fstWriterContext *xc, FILE *stream, off_t offset, int whence)
+{
+int rc = fseeko(stream, offset, whence);
+
+if(rc<0)
+        {
+        xc->fseek_failed = 1;
+#ifdef FST_DEBUG
+        fprintf(stderr, "Seek to #%"PRId64" (whence = %d) failed!\n", offset, whence);
+        perror("Why");
+#endif
+        }
+
+return(rc);
+}
+
+
+static uint32_t fstWriterUint32WithVarint32(struct fstWriterContext *xc, uint32_t *u, uint32_t v, const void *dbuf, uint32_t siz)
+{
+unsigned char *buf = xc->vchg_mem + xc->vchg_siz;
+unsigned char *pnt = buf;
+uint32_t nxt;
+uint32_t len;
+
+#ifdef FST_DO_MISALIGNED_OPS
+(*(uint32_t *)(pnt)) = (*(uint32_t *)(u));
+#else
+memcpy(pnt, u, sizeof(uint32_t));
+#endif
+pnt += 4;
+
+while((nxt = v>>7))
+        {
+        *(pnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*(pnt++) = (unsigned char)v;
+memcpy(pnt, dbuf, siz);
+
+len = pnt-buf + siz;
+return(len);
+}
+
+
+static uint32_t fstWriterUint32WithVarint32AndLength(struct fstWriterContext *xc, uint32_t *u, uint32_t v, const void *dbuf, uint32_t siz)
+{
+unsigned char *buf = xc->vchg_mem + xc->vchg_siz;
+unsigned char *pnt = buf;
+uint32_t nxt;
+uint32_t len;
+
+#ifdef FST_DO_MISALIGNED_OPS
+(*(uint32_t *)(pnt)) = (*(uint32_t *)(u));
+#else
+memcpy(pnt, u, sizeof(uint32_t));
+#endif
+pnt += 4;
+
+while((nxt = v>>7))
+        {
+        *(pnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*(pnt++) = (unsigned char)v;
+
+v = siz;
+while((nxt = v>>7))
+        {
+        *(pnt++) = ((unsigned char)v) | 0x80;
+        v = nxt;
+        }
+*(pnt++) = (unsigned char)v;
+
+memcpy(pnt, dbuf, siz);
+
+len = pnt-buf + siz;
+return(len);
+}
+
+
+/*
+ * header bytes, write here so defines are set up before anything else
+ * that needs to use them
+ */
+static void fstWriterEmitHdrBytes(struct fstWriterContext *xc)
+{
+char vbuf[FST_HDR_SIM_VERSION_SIZE];
+char dbuf[FST_HDR_DATE_SIZE];
+double endtest = FST_DOUBLE_ENDTEST;
+time_t walltime;
+
+#define FST_HDR_OFFS_TAG                        (0)
+fputc(FST_BL_HDR, xc->handle);                  /* +0 tag */
+
+#define FST_HDR_OFFS_SECLEN                     (FST_HDR_OFFS_TAG + 1)
+fstWriterUint64(xc->handle, 329);               /* +1 section length */
+
+#define FST_HDR_OFFS_START_TIME                 (FST_HDR_OFFS_SECLEN + 8)
+fstWriterUint64(xc->handle, 0);                 /* +9 start time */
+
+#define FST_HDR_OFFS_END_TIME                   (FST_HDR_OFFS_START_TIME + 8)
+fstWriterUint64(xc->handle, 0);                 /* +17 end time */
+
+#define FST_HDR_OFFS_ENDIAN_TEST                (FST_HDR_OFFS_END_TIME + 8)
+fstFwrite(&endtest, 8, 1, xc->handle);          /* +25 endian test for reals */
+
+#define FST_HDR_OFFS_MEM_USED                   (FST_HDR_OFFS_ENDIAN_TEST + 8)
+fstWriterUint64(xc->handle, xc->fst_break_size);/* +33 memory used by writer */
+
+#define FST_HDR_OFFS_NUM_SCOPES                 (FST_HDR_OFFS_MEM_USED + 8)
+fstWriterUint64(xc->handle, 0);                 /* +41 scope creation count */
+
+#define FST_HDR_OFFS_NUM_VARS                   (FST_HDR_OFFS_NUM_SCOPES + 8)
+fstWriterUint64(xc->handle, 0);                 /* +49 var creation count */
+
+#define FST_HDR_OFFS_MAXHANDLE                  (FST_HDR_OFFS_NUM_VARS + 8)
+fstWriterUint64(xc->handle, 0);                 /* +57 max var idcode */
+
+#define FST_HDR_OFFS_SECTION_CNT                (FST_HDR_OFFS_MAXHANDLE + 8)
+fstWriterUint64(xc->handle, 0);                 /* +65 vc section count */
+
+#define FST_HDR_OFFS_TIMESCALE                  (FST_HDR_OFFS_SECTION_CNT + 8)
+fputc((-9)&255, xc->handle);                    /* +73 timescale 1ns */
+
+#define FST_HDR_OFFS_SIM_VERSION                (FST_HDR_OFFS_TIMESCALE + 1)
+memset(vbuf, 0, FST_HDR_SIM_VERSION_SIZE);
+strcpy(vbuf, FST_WRITER_STR);
+fstFwrite(vbuf, FST_HDR_SIM_VERSION_SIZE, 1, xc->handle); /* +74 version */
+
+#define FST_HDR_OFFS_DATE                       (FST_HDR_OFFS_SIM_VERSION + FST_HDR_SIM_VERSION_SIZE)
+memset(dbuf, 0, FST_HDR_DATE_SIZE);
+time(&walltime);
+strcpy(dbuf, asctime(localtime(&walltime)));
+fstFwrite(dbuf, FST_HDR_DATE_SIZE, 1, xc->handle);      /* +202 date */
+
+/* date size is deliberately overspecified at 119 bytes (originally 128) in order to provide backfill for new args */
+
+#define FST_HDR_OFFS_FILETYPE                   (FST_HDR_OFFS_DATE + FST_HDR_DATE_SIZE)
+fputc(xc->filetype, xc->handle);                /* +321 filetype */
+
+#define FST_HDR_OFFS_TIMEZERO                   (FST_HDR_OFFS_FILETYPE + FST_HDR_FILETYPE_SIZE)
+fstWriterUint64(xc->handle, xc->timezero);      /* +322 timezero */
+
+#define FST_HDR_LENGTH                          (FST_HDR_OFFS_TIMEZERO + FST_HDR_TIMEZERO_SIZE)
+                                                /* +330 next section starts here */
+fflush(xc->handle);
+}
+
+
+/*
+ * mmap functions
+ */
+static void fstWriterCreateMmaps(struct fstWriterContext *xc)
+{
+off_t curpos = ftello(xc->handle);
+
+fflush(xc->hier_handle);
+
+/* write out intermediate header */
+fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_START_TIME, SEEK_SET);
+fstWriterUint64(xc->handle, xc->firsttime);
+fstWriterUint64(xc->handle, xc->curtime);
+fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_NUM_SCOPES, SEEK_SET);
+fstWriterUint64(xc->handle, xc->numscopes);
+fstWriterUint64(xc->handle, xc->numsigs);
+fstWriterUint64(xc->handle, xc->maxhandle);
+fstWriterUint64(xc->handle, xc->secnum);
+fstWriterFseeko(xc, xc->handle, curpos, SEEK_SET);
+fflush(xc->handle);
+
+/* do mappings */
+if(!xc->valpos_mem)
+        {
+        fflush(xc->valpos_handle);
+        xc->valpos_mem = fstMmap(NULL, xc->maxhandle * 4 * sizeof(uint32_t), PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->valpos_handle), 0);
+        }
+if(!xc->curval_mem)
+        {
+        fflush(xc->curval_handle);
+        xc->curval_mem = fstMmap(NULL, xc->maxvalpos, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->curval_handle), 0);
+        }
+}
+
+
+static void fstDestroyMmaps(struct fstWriterContext *xc, int is_closing)
+{
+(void)is_closing;
+
+fstMunmap(xc->valpos_mem, xc->maxhandle * 4 * sizeof(uint32_t));
+xc->valpos_mem = NULL;
+
+#if defined __CYGWIN__ || defined __MINGW32__
+if(xc->curval_mem)
+        {
+        if(!is_closing) /* need to flush out for next emulated mmap() read */
+                {
+                unsigned char *pnt = xc->curval_mem;
+                int __fd = fileno(xc->curval_handle);
+                off_t cur_offs = lseek(__fd, 0, SEEK_CUR);
+                size_t i;
+                size_t __len = xc->maxvalpos;
+
+                lseek(__fd, 0, SEEK_SET);
+                for(i=0;i<__len;i+=SSIZE_MAX)
+                        {
+                        write(__fd, pnt + i, ((__len - i) >= SSIZE_MAX) ? SSIZE_MAX : (__len - i));
+                        }
+                lseek(__fd, cur_offs, SEEK_SET);
+                }
+        }
+#endif
+
+fstMunmap(xc->curval_mem, xc->maxvalpos);
+xc->curval_mem = NULL;
+}
+
+
+/*
+ * set up large and small memory usages
+ * crossover point in model is FST_ACTIVATE_HUGE_BREAK number of signals
+ */
+static void fstDetermineBreakSize(struct fstWriterContext *xc)
+{
+#if defined(__linux__) || defined(FST_MACOSX)
+int was_set = 0;
+
+#ifdef __linux__
+FILE *f = fopen("/proc/meminfo", "rb");
+
+if(f)
+        {
+        char buf[257];
+        char *s;
+        while(!feof(f))
+                {
+                buf[0] = 0;
+                s = fgets(buf, 256, f);
+                if(s && *s)
+                        {
+                        if(!strncmp(s, "MemTotal:", 9))
+                                {
+                                size_t v = atol(s+10);
+                                v *= 1024; /* convert to bytes */
+                                v /= 8; /* chop down to 1/8 physical memory */
+                                if(v > FST_BREAK_SIZE)
+                                        {
+                                        if(v > FST_BREAK_SIZE_MAX)
+                                                {
+                                                v = FST_BREAK_SIZE_MAX;
+                                                }
+
+                                        xc->fst_huge_break_size = v;
+                                        was_set = 1;
+                                        break;
+                                        }
+                                }
+                        }
+                }
+
+        fclose(f);
+        }
+
+if(!was_set)
+        {
+        xc->fst_huge_break_size = FST_BREAK_SIZE;
+        }
+#else
+int mib[2];
+int64_t v;
+size_t length;
+
+mib[0] = CTL_HW;
+mib[1] = HW_MEMSIZE;
+length = sizeof(int64_t);
+if(!sysctl(mib, 2, &v, &length, NULL, 0))
+        {
+        v /= 8;
+
+        if(v > (int64_t)FST_BREAK_SIZE)
+                {
+                if(v > (int64_t)FST_BREAK_SIZE_MAX)
+                        {
+                        v = FST_BREAK_SIZE_MAX;
+                        }
+
+                xc->fst_huge_break_size = v;
+                was_set = 1;
+                }
+        }
+
+if(!was_set)
+        {
+        xc->fst_huge_break_size = FST_BREAK_SIZE;
+        }
+#endif
+#else
+xc->fst_huge_break_size = FST_BREAK_SIZE;
+#endif
+
+xc->fst_break_size = xc->fst_orig_break_size = FST_BREAK_SIZE;
+xc->fst_break_add_size = xc->fst_orig_break_add_size = FST_BREAK_ADD_SIZE;
+xc->next_huge_break = FST_ACTIVATE_HUGE_BREAK;
+}
+
+
+/*
+ * file creation and close
+ */
+void *fstWriterCreate(const char *nam, int use_compressed_hier)
+{
+struct fstWriterContext *xc = calloc(1, sizeof(struct fstWriterContext));
+
+xc->compress_hier = use_compressed_hier;
+fstDetermineBreakSize(xc);
+
+if((!nam)||
+        (!(xc->handle=unlink_fopen(nam, "w+b"))))
+        {
+        free(xc);
+        xc=NULL;
+        }
+        else
+        {
+        int flen = strlen(nam);
+        char *hf = calloc(1, flen + 6);
+
+        memcpy(hf, nam, flen);
+        strcpy(hf + flen, ".hier");
+        xc->hier_handle = unlink_fopen(hf, "w+b");
+
+        xc->geom_handle = tmpfile_open(&xc->geom_handle_nam);           /* .geom */
+        xc->valpos_handle = tmpfile_open(&xc->valpos_handle_nam);       /* .offs */
+        xc->curval_handle = tmpfile_open(&xc->curval_handle_nam);       /* .bits */
+        xc->tchn_handle = tmpfile_open(&xc->tchn_handle_nam);           /* .tchn */
+        xc->vchg_alloc_siz = xc->fst_break_size + xc->fst_break_add_size;
+        xc->vchg_mem = malloc(xc->vchg_alloc_siz);
+
+        if(xc->hier_handle && xc->geom_handle && xc->valpos_handle && xc->curval_handle && xc->vchg_mem && xc->tchn_handle)
+                {
+                xc->filename = strdup(nam);
+                xc->is_initial_time = 1;
+
+                fstWriterEmitHdrBytes(xc);
+                xc->nan = strtod("NaN", NULL);
+#ifdef FST_WRITER_PARALLEL
+                pthread_mutex_init(&xc->mutex, NULL);
+                pthread_attr_init(&xc->thread_attr);
+                pthread_attr_setdetachstate(&xc->thread_attr, PTHREAD_CREATE_DETACHED);
+#endif
+                }
+                else
+                {
+                fclose(xc->handle);
+                if(xc->hier_handle) { fclose(xc->hier_handle); unlink(hf); }
+                tmpfile_close(&xc->geom_handle, &xc->geom_handle_nam);
+                tmpfile_close(&xc->valpos_handle, &xc->valpos_handle_nam);
+                tmpfile_close(&xc->curval_handle, &xc->curval_handle_nam);
+                tmpfile_close(&xc->tchn_handle, &xc->tchn_handle_nam);
+                free(xc->vchg_mem);
+                free(xc);
+                xc=NULL;
+                }
+
+        free(hf);
+        }
+
+return(xc);
+}
+
+
+/*
+ * generation and writing out of value change data sections
+ */
+static void fstWriterEmitSectionHeader(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        unsigned long destlen;
+        unsigned char *dmem;
+        int rc;
+
+        destlen = xc->maxvalpos;
+        dmem = malloc(compressBound(destlen));
+        rc = compress2(dmem, &destlen, xc->curval_mem, xc->maxvalpos, 4); /* was 9...which caused performance drag on traces with many signals */
+
+        fputc(FST_BL_SKIP, xc->handle);                 /* temporarily tag the section, use FST_BL_VCDATA on finalize */
+        xc->section_start = ftello(xc->handle);
+#ifdef FST_WRITER_PARALLEL
+        if(xc->xc_parent) xc->xc_parent->section_start = xc->section_start;
+#endif
+        xc->section_header_only = 1;                    /* indicates truncate might be needed */
+        fstWriterUint64(xc->handle, 0);                 /* placeholder = section length */
+        fstWriterUint64(xc->handle, xc->is_initial_time ? xc->firsttime : xc->curtime);         /* begin time of section */
+        fstWriterUint64(xc->handle, xc->curtime);       /* end time of section (placeholder) */
+        fstWriterUint64(xc->handle, 0);                 /* placeholder = amount of buffer memory required in reader for full vc traversal */
+        fstWriterVarint(xc->handle, xc->maxvalpos);     /* maxvalpos = length of uncompressed data */
+
+        if((rc == Z_OK) && (destlen < xc->maxvalpos))
+                {
+                fstWriterVarint(xc->handle, destlen);   /* length of compressed data */
+                }
+                else
+                {
+                fstWriterVarint(xc->handle, xc->maxvalpos); /* length of (unable to be) compressed data */
+                }
+        fstWriterVarint(xc->handle, xc->maxhandle);     /* max handle associated with this data (in case of dynamic facility adds) */
+
+        if((rc == Z_OK) && (destlen < xc->maxvalpos))
+                {
+                fstFwrite(dmem, destlen, 1, xc->handle);
+                }
+                else /* comparison between compressed / decompressed len tells if compressed */
+                {
+                fstFwrite(xc->curval_mem, xc->maxvalpos, 1, xc->handle);
+                }
+
+        free(dmem);
+        }
+}
+
+
+/*
+ * only to be called directly by fst code...otherwise must
+ * be synced up with time changes
+ */
+#ifdef FST_WRITER_PARALLEL
+static void fstWriterFlushContextPrivate2(void *ctx)
+#else
+static void fstWriterFlushContextPrivate(void *ctx)
+#endif
+{
+#ifdef FST_DEBUG
+int cnt = 0;
+#endif
+unsigned int i;
+unsigned char *vchg_mem;
+FILE *f;
+off_t fpos, indxpos, endpos;
+uint32_t prevpos;
+int zerocnt;
+unsigned char *scratchpad;
+unsigned char *scratchpnt;
+unsigned char *tmem;
+off_t tlen;
+off_t unc_memreq = 0; /* for reader */
+unsigned char *packmem;
+unsigned int packmemlen;
+uint32_t *vm4ip;
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+#ifdef FST_WRITER_PARALLEL
+struct fstWriterContext *xc2 = xc->xc_parent;
+#else
+struct fstWriterContext *xc2 = xc;
+#endif
+
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+Pvoid_t PJHSArray = (Pvoid_t) NULL;
+#ifndef _WAVE_HAVE_JUDY
+uint32_t hashmask =  xc->maxhandle;
+hashmask |= hashmask >> 1;
+hashmask |= hashmask >> 2;
+hashmask |= hashmask >> 4;
+hashmask |= hashmask >> 8;
+hashmask |= hashmask >> 16;
+#endif
+#endif
+
+if((xc->vchg_siz <= 1)||(xc->already_in_flush)) return;
+xc->already_in_flush = 1; /* should really do this with a semaphore */
+
+xc->section_header_only = 0;
+scratchpad = malloc(xc->vchg_siz);
+
+vchg_mem = xc->vchg_mem;
+
+f = xc->handle;
+fstWriterVarint(f, xc->maxhandle);      /* emit current number of handles */
+fputc(xc->fourpack ? '4' : (xc->fastpack ? 'F' : 'Z'), f);
+fpos = 1;
+
+packmemlen = 1024;                      /* maintain a running "longest" allocation to */
+packmem = malloc(packmemlen);           /* prevent continual malloc...free every loop iter */
+
+for(i=0;i<xc->maxhandle;i++)
+        {
+        vm4ip = &(xc->valpos_mem[4*i]);
+
+        if(vm4ip[2])
+                {
+                uint32_t offs = vm4ip[2];
+                uint32_t next_offs;
+                unsigned int wrlen;
+
+                vm4ip[2] = fpos;
+
+                scratchpnt = scratchpad + xc->vchg_siz;         /* build this buffer backwards */
+                if(vm4ip[1] <= 1)
+                        {
+                        if(vm4ip[1] == 1)
+                                {
+                                wrlen = fstGetVarint32Length(vchg_mem + offs + 4); /* used to advance and determine wrlen */
+#ifndef FST_REMOVE_DUPLICATE_VC
+                                xc->curval_mem[vm4ip[0]] = vchg_mem[offs + 4 + wrlen]; /* checkpoint variable */
+#endif
+                                while(offs)
+                                        {
+                                        unsigned char val;
+                                        uint32_t time_delta, rcv;
+                                        next_offs = fstGetUint32(vchg_mem + offs);
+                                        offs += 4;
+
+                                        time_delta = fstGetVarint32(vchg_mem + offs, (int *)&wrlen);
+                                        val = vchg_mem[offs+wrlen];
+                                        offs = next_offs;
+
+                                        switch(val)
+                                                {
+                                                case '0':
+                                                case '1':               rcv = ((val&1)<<1) | (time_delta<<2);
+                                                                        break; /* pack more delta bits in for 0/1 vchs */
+
+                                                case 'x': case 'X':     rcv = FST_RCV_X | (time_delta<<4); break;
+                                                case 'z': case 'Z':     rcv = FST_RCV_Z | (time_delta<<4); break;
+                                                case 'h': case 'H':     rcv = FST_RCV_H | (time_delta<<4); break;
+                                                case 'u': case 'U':     rcv = FST_RCV_U | (time_delta<<4); break;
+                                                case 'w': case 'W':     rcv = FST_RCV_W | (time_delta<<4); break;
+                                                case 'l': case 'L':     rcv = FST_RCV_L | (time_delta<<4); break;
+                                                default:                rcv = FST_RCV_D | (time_delta<<4); break;
+                                                }
+
+                                        scratchpnt = fstCopyVarint32ToLeft(scratchpnt, rcv);
+                                        }
+                                }
+                                else
+                                {
+                                /* variable length */
+                                /* fstGetUint32 (next_offs) + fstGetVarint32 (time_delta) + fstGetVarint32 (len) + payload */
+                                unsigned char *pnt;
+                                uint32_t record_len;
+                                uint32_t time_delta;
+
+                                while(offs)
+                                        {
+                                        next_offs = fstGetUint32(vchg_mem + offs);
+                                        offs += 4;
+                                        pnt = vchg_mem + offs;
+                                        offs = next_offs;
+                                        time_delta = fstGetVarint32(pnt, (int *)&wrlen);
+                                        pnt += wrlen;
+                                        record_len = fstGetVarint32(pnt, (int *)&wrlen);
+                                        pnt += wrlen;
+
+                                        scratchpnt -= record_len;
+                                        memcpy(scratchpnt, pnt, record_len);
+
+                                        scratchpnt = fstCopyVarint32ToLeft(scratchpnt, record_len);
+                                        scratchpnt = fstCopyVarint32ToLeft(scratchpnt, (time_delta << 1)); /* reserve | 1 case for future expansion */
+                                        }
+                                }
+                        }
+                        else
+                        {
+                        wrlen = fstGetVarint32Length(vchg_mem + offs + 4); /* used to advance and determine wrlen */
+#ifndef FST_REMOVE_DUPLICATE_VC
+                        memcpy(xc->curval_mem + vm4ip[0], vchg_mem + offs + 4 + wrlen, vm4ip[1]); /* checkpoint variable */
+#endif
+                        while(offs)
+                                {
+                                unsigned int idx;
+                                char is_binary = 1;
+                                unsigned char *pnt;
+                                uint32_t time_delta;
+
+                                next_offs = fstGetUint32(vchg_mem + offs);
+                                offs += 4;
+
+                                time_delta = fstGetVarint32(vchg_mem + offs, (int *)&wrlen);
+
+                                pnt = vchg_mem+offs+wrlen;
+                                offs = next_offs;
+
+                                for(idx=0;idx<vm4ip[1];idx++)
+                                        {
+                                        if((pnt[idx] == '0') || (pnt[idx] == '1'))
+                                                {
+                                                continue;
+                                                }
+                                                else
+                                                {
+                                                is_binary = 0;
+                                                break;
+                                                }
+                                        }
+
+                                if(is_binary)
+                                        {
+                                        unsigned char acc = 0;
+                                        /* new algorithm */
+                                        idx = ((vm4ip[1]+7) & ~7);
+                                        switch(vm4ip[1] & 7)
+                                                {
+                                                case 0: do {    acc  = (pnt[idx+7-8] & 1) << 0;
+                                                case 7:         acc |= (pnt[idx+6-8] & 1) << 1;
+                                                case 6:         acc |= (pnt[idx+5-8] & 1) << 2;
+                                                case 5:         acc |= (pnt[idx+4-8] & 1) << 3;
+                                                case 4:         acc |= (pnt[idx+3-8] & 1) << 4;
+                                                case 3:         acc |= (pnt[idx+2-8] & 1) << 5;
+                                                case 2:         acc |= (pnt[idx+1-8] & 1) << 6;
+                                                case 1:         acc |= (pnt[idx+0-8] & 1) << 7;
+                                                                *(--scratchpnt) = acc;
+                                                                idx -= 8;
+                                                        } while(idx);
+                                                }
+
+                                        scratchpnt = fstCopyVarint32ToLeft(scratchpnt, (time_delta << 1));
+                                        }
+                                        else
+                                        {
+                                        scratchpnt -= vm4ip[1];
+                                        memcpy(scratchpnt, pnt, vm4ip[1]);
+
+                                        scratchpnt = fstCopyVarint32ToLeft(scratchpnt, (time_delta << 1) | 1);
+                                        }
+                                }
+                        }
+
+                wrlen = scratchpad + xc->vchg_siz - scratchpnt;
+                unc_memreq += wrlen;
+                if(wrlen > 32)
+                        {
+                        unsigned long destlen = wrlen;
+                        unsigned char *dmem;
+                        unsigned int rc;
+
+                        if(!xc->fastpack)
+                                {
+                                if(wrlen <= packmemlen)
+                                        {
+                                        dmem = packmem;
+                                        }
+                                        else
+                                        {
+                                        free(packmem);
+                                        dmem = packmem = malloc(compressBound(packmemlen = wrlen));
+                                        }
+
+                                rc = compress2(dmem, &destlen, scratchpnt, wrlen, 4);
+                                if(rc == Z_OK)
+                                        {
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                        PPvoid_t pv = JudyHSIns(&PJHSArray, dmem, destlen, NULL);
+                                        if(*pv)
+                                                {
+                                                uint32_t pvi = (long)(*pv);
+                                                vm4ip[2] = -pvi;
+                                                }
+                                                else
+                                                {
+                                                *pv = (void *)(long)(i+1);
+#endif
+                                                fpos += fstWriterVarint(f, wrlen);
+                                                fpos += destlen;
+                                                fstFwrite(dmem, destlen, 1, f);
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                                }
+#endif
+                                        }
+                                        else
+                                        {
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                        PPvoid_t pv = JudyHSIns(&PJHSArray, scratchpnt, wrlen, NULL);
+                                        if(*pv)
+                                                {
+                                                uint32_t pvi = (long)(*pv);
+                                                vm4ip[2] = -pvi;
+                                                }
+                                                else
+                                                {
+                                                *pv = (void *)(long)(i+1);
+#endif
+                                                fpos += fstWriterVarint(f, 0);
+                                                fpos += wrlen;
+                                                fstFwrite(scratchpnt, wrlen, 1, f);
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                                }
+#endif
+                                        }
+                                }
+                                else
+                                {
+                                /* this is extremely conservative: fastlz needs +5% for worst case, lz4 needs siz+(siz/255)+16 */
+                                if(((wrlen * 2) + 2) <= packmemlen)
+                                        {
+                                        dmem = packmem;
+                                        }
+                                        else
+                                        {
+                                        free(packmem);
+                                        dmem = packmem = malloc(packmemlen = (wrlen * 2) + 2);
+                                        }
+
+                                rc = (xc->fourpack) ? LZ4_compress((char *)scratchpnt, (char *)dmem, wrlen) : fastlz_compress(scratchpnt, wrlen, dmem);
+                                if(rc < destlen)
+                                        {
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                        PPvoid_t pv = JudyHSIns(&PJHSArray, dmem, rc, NULL);
+                                        if(*pv)
+                                                {
+                                                uint32_t pvi = (long)(*pv);
+                                                vm4ip[2] = -pvi;
+                                                }
+                                                else
+                                                {
+                                                *pv = (void *)(long)(i+1);
+#endif
+                                                fpos += fstWriterVarint(f, wrlen);
+                                                fpos += rc;
+                                                fstFwrite(dmem, rc, 1, f);
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                                }
+#endif
+                                        }
+                                        else
+                                        {
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                        PPvoid_t pv = JudyHSIns(&PJHSArray, scratchpnt, wrlen, NULL);
+                                        if(*pv)
+                                                {
+                                                uint32_t pvi = (long)(*pv);
+                                                vm4ip[2] = -pvi;
+                                                }
+                                                else
+                                                {
+                                                *pv = (void *)(long)(i+1);
+#endif
+                                                fpos += fstWriterVarint(f, 0);
+                                                fpos += wrlen;
+                                                fstFwrite(scratchpnt, wrlen, 1, f);
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                                }
+#endif
+                                        }
+                                }
+                        }
+                        else
+                        {
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                        PPvoid_t pv = JudyHSIns(&PJHSArray, scratchpnt, wrlen, NULL);
+                        if(*pv)
+                                {
+                                uint32_t pvi = (long)(*pv);
+                                vm4ip[2] = -pvi;
+                                }
+                                else
+                                {
+                                *pv = (void *)(long)(i+1);
+#endif
+                                fpos += fstWriterVarint(f, 0);
+                                fpos += wrlen;
+                                fstFwrite(scratchpnt, wrlen, 1, f);
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+                                }
+#endif
+                        }
+
+                /* vm4ip[3] = 0; ...redundant with clearing below */
+#ifdef FST_DEBUG
+                cnt++;
+#endif
+                }
+        }
+
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+JudyHSFreeArray(&PJHSArray, NULL);
+#endif
+
+free(packmem); packmem = NULL; /* packmemlen = 0; */ /* scan-build */
+
+prevpos = 0; zerocnt = 0;
+free(scratchpad); scratchpad = NULL;
+
+indxpos = ftello(f);
+xc->secnum++;
+
+#ifndef FST_DYNAMIC_ALIAS2_DISABLE
+if(1)
+        {
+        uint32_t prev_alias = 0;
+
+        for(i=0;i<xc->maxhandle;i++)
+                {
+                vm4ip = &(xc->valpos_mem[4*i]);
+
+                if(vm4ip[2])
+                        {
+                        if(zerocnt)
+                                {
+                                fpos += fstWriterVarint(f, (zerocnt << 1));
+                                zerocnt = 0;
+                                }
+
+                        if(vm4ip[2] & 0x80000000)
+                                {
+                                if(vm4ip[2] != prev_alias)
+                                        {
+                                        fpos += fstWriterSVarint(f, (((int64_t)((int32_t)(prev_alias = vm4ip[2]))) << 1) | 1);
+                                        }
+                                        else
+                                        {
+                                        fpos += fstWriterSVarint(f, (0 << 1) | 1);
+                                        }
+                                }
+                                else
+                                {
+                                fpos += fstWriterSVarint(f, ((vm4ip[2] - prevpos) << 1) | 1);
+                                prevpos = vm4ip[2];
+                                }
+                        vm4ip[2] = 0;
+                        vm4ip[3] = 0; /* clear out tchn idx */
+                        }
+                        else
+                        {
+                        zerocnt++;
+                        }
+                }
+        }
+        else
+#endif
+        {
+        for(i=0;i<xc->maxhandle;i++)
+                {
+                vm4ip = &(xc->valpos_mem[4*i]);
+
+                if(vm4ip[2])
+                        {
+                        if(zerocnt)
+                                {
+                                fpos += fstWriterVarint(f, (zerocnt << 1));
+                                zerocnt = 0;
+                                }
+
+                        if(vm4ip[2] & 0x80000000)
+                                {
+                                fpos += fstWriterVarint(f, 0); /* signal, note that using a *signed* varint would be more efficient than this byte escape! */
+                                fpos += fstWriterVarint(f, (-(int32_t)vm4ip[2]));
+                                }
+                                else
+                                {
+                                fpos += fstWriterVarint(f, ((vm4ip[2] - prevpos) << 1) | 1);
+                                prevpos = vm4ip[2];
+                                }
+                        vm4ip[2] = 0;
+                        vm4ip[3] = 0; /* clear out tchn idx */
+                        }
+                        else
+                        {
+                        zerocnt++;
+                        }
+                }
+        }
+
+if(zerocnt)
+        {
+        /* fpos += */ fstWriterVarint(f, (zerocnt << 1)); /* scan-build */
+        }
+#ifdef FST_DEBUG
+fprintf(stderr, "value chains: %d\n", cnt);
+#endif
+
+xc->vchg_mem[0] = '!';
+xc->vchg_siz = 1;
+
+endpos = ftello(xc->handle);
+fstWriterUint64(xc->handle, endpos-indxpos);            /* write delta index position at very end of block */
+
+/*emit time changes for block */
+fflush(xc->tchn_handle);
+tlen = ftello(xc->tchn_handle);
+fstWriterFseeko(xc, xc->tchn_handle, 0, SEEK_SET);
+
+tmem = fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->tchn_handle), 0);
+if(tmem)
+        {
+        unsigned long destlen = tlen;
+        unsigned char *dmem = malloc(compressBound(destlen));
+        int rc = compress2(dmem, &destlen, tmem, tlen, 9);
+
+        if((rc == Z_OK) && (((off_t)destlen) < tlen))
+                {
+                fstFwrite(dmem, destlen, 1, xc->handle);
+                }
+                else /* comparison between compressed / decompressed len tells if compressed */
+                {
+                fstFwrite(tmem, tlen, 1, xc->handle);
+                destlen = tlen;
+                }
+        free(dmem);
+        fstMunmap(tmem, tlen);
+        fstWriterUint64(xc->handle, tlen);              /* uncompressed */
+        fstWriterUint64(xc->handle, destlen);           /* compressed */
+        fstWriterUint64(xc->handle, xc->tchn_cnt);      /* number of time items */
+        }
+
+xc->tchn_cnt = xc->tchn_idx = 0;
+fstWriterFseeko(xc, xc->tchn_handle, 0, SEEK_SET);
+fstFtruncate(fileno(xc->tchn_handle), 0);
+
+/* write block trailer */
+endpos = ftello(xc->handle);
+fstWriterFseeko(xc, xc->handle, xc->section_start, SEEK_SET);
+fstWriterUint64(xc->handle, endpos - xc->section_start);        /* write block length */
+fstWriterFseeko(xc, xc->handle, 8, SEEK_CUR);                           /* skip begin time */
+fstWriterUint64(xc->handle, xc->curtime);                       /* write end time for section */
+fstWriterUint64(xc->handle, unc_memreq);                        /* amount of buffer memory required in reader for full traversal */
+fflush(xc->handle);
+
+fstWriterFseeko(xc, xc->handle, xc->section_start-1, SEEK_SET);         /* write out FST_BL_VCDATA over FST_BL_SKIP */
+
+#ifndef FST_DYNAMIC_ALIAS_DISABLE
+#ifndef FST_DYNAMIC_ALIAS2_DISABLE
+fputc(FST_BL_VCDATA_DYN_ALIAS2, xc->handle);
+#else
+fputc(FST_BL_VCDATA_DYN_ALIAS, xc->handle);
+#endif
+#else
+fputc(FST_BL_VCDATA, xc->handle);
+#endif
+
+fflush(xc->handle);
+
+fstWriterFseeko(xc, xc->handle, endpos, SEEK_SET);                              /* seek to end of file */
+
+xc2->section_header_truncpos = endpos;                          /* cache in case of need to truncate */
+if(xc->dump_size_limit)
+        {
+        if(endpos >= ((off_t)xc->dump_size_limit))
+                {
+                xc2->skip_writing_section_hdr = 1;
+                xc2->size_limit_locked = 1;
+                xc2->is_initial_time = 1; /* to trick emit value and emit time change */
+#ifdef FST_DEBUG
+                fprintf(stderr, "<< dump file size limit reached, stopping dumping >>\n");
+#endif
+                }
+        }
+
+if(!xc2->skip_writing_section_hdr)
+        {
+        fstWriterEmitSectionHeader(xc);                         /* emit next section header */
+        }
+fflush(xc->handle);
+
+xc->already_in_flush = 0;
+}
+
+
+#ifdef FST_WRITER_PARALLEL
+static void *fstWriterFlushContextPrivate1(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+fstWriterFlushContextPrivate2(xc);
+
+pthread_mutex_unlock(&(xc->xc_parent->mutex));
+
+#ifdef FST_REMOVE_DUPLICATE_VC
+free(xc->curval_mem);
+#endif
+free(xc->valpos_mem);
+free(xc->vchg_mem);
+tmpfile_close(&xc->tchn_handle, &xc->tchn_handle_nam);
+free(xc);
+
+return(NULL);
+}
+
+
+static void fstWriterFlushContextPrivate(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc->parallel_enabled)
+        {
+        struct fstWriterContext *xc2 = malloc(sizeof(struct fstWriterContext));
+        unsigned int i;
+
+        pthread_mutex_lock(&xc->mutex);
+        pthread_mutex_unlock(&xc->mutex);
+
+        xc->xc_parent = xc;
+        memcpy(xc2, xc, sizeof(struct fstWriterContext));
+
+        xc2->valpos_mem = malloc(xc->maxhandle * 4 * sizeof(uint32_t));
+        memcpy(xc2->valpos_mem, xc->valpos_mem, xc->maxhandle * 4 * sizeof(uint32_t));
+
+        /* curval mem is updated in the thread */
+#ifdef FST_REMOVE_DUPLICATE_VC
+        xc2->curval_mem = malloc(xc->maxvalpos);
+        memcpy(xc2->curval_mem, xc->curval_mem, xc->maxvalpos);
+#endif
+
+        xc->vchg_mem = malloc(xc->vchg_alloc_siz);
+        xc->vchg_mem[0] = '!';
+        xc->vchg_siz = 1;
+
+        for(i=0;i<xc->maxhandle;i++)
+                {
+                uint32_t *vm4ip = &(xc->valpos_mem[4*i]);
+                vm4ip[2] = 0; /* zero out offset val */
+                vm4ip[3] = 0; /* zero out last time change val */
+                }
+
+        xc->tchn_cnt = xc->tchn_idx = 0;
+        xc->tchn_handle = tmpfile_open(&xc->tchn_handle_nam); /* child thread will deallocate file/name */
+        fstWriterFseeko(xc, xc->tchn_handle, 0, SEEK_SET);
+        fstFtruncate(fileno(xc->tchn_handle), 0);
+
+        xc->section_header_only = 0;
+        xc->secnum++;
+
+        pthread_mutex_lock(&xc->mutex);
+
+        pthread_create(&xc->thread, &xc->thread_attr, fstWriterFlushContextPrivate1, xc2);
+        }
+        else
+        {
+        if(xc->parallel_was_enabled) /* conservatively block */
+                {
+                pthread_mutex_lock(&xc->mutex);
+                pthread_mutex_unlock(&xc->mutex);
+                }
+
+        xc->xc_parent = xc;
+        fstWriterFlushContextPrivate2(xc);
+        }
+}
+#endif
+
+
+/*
+ * queues up a flush context operation
+ */
+void fstWriterFlushContext(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        if(xc->tchn_idx > 1)
+                {
+                xc->flush_context_pending = 1;
+                }
+        }
+}
+
+
+/*
+ * close out FST file
+ */
+void fstWriterClose(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+#ifdef FST_WRITER_PARALLEL
+if(xc)
+        {
+        pthread_mutex_lock(&xc->mutex);
+        pthread_mutex_unlock(&xc->mutex);
+        }
+#endif
+
+if(xc && !xc->already_in_close && !xc->already_in_flush)
+        {
+        unsigned char *tmem;
+        off_t fixup_offs, tlen, hlen;
+
+        xc->already_in_close = 1; /* never need to zero this out as it is freed at bottom */
+
+        if(xc->section_header_only && xc->section_header_truncpos && (xc->vchg_siz <= 1) && (!xc->is_initial_time))
+                {
+                fstFtruncate(fileno(xc->handle), xc->section_header_truncpos);
+                fstWriterFseeko(xc, xc->handle, xc->section_header_truncpos, SEEK_SET);
+                xc->section_header_only = 0;
+                }
+                else
+                {
+                xc->skip_writing_section_hdr = 1;
+                if(!xc->size_limit_locked)
+                        {
+                        if(xc->is_initial_time) /* simulation time never advanced so mock up the changes as time zero ones */
+                                {
+                                fstHandle dupe_idx;
+
+                                fstWriterEmitTimeChange(xc, 0); /* emit some time change just to have one */
+                                for(dupe_idx = 0; dupe_idx < xc->maxhandle; dupe_idx++) /* now clone the values */
+                                        {
+                                        fstWriterEmitValueChange(xc, dupe_idx+1, xc->curval_mem + xc->valpos_mem[4*dupe_idx]);
+                                        }
+                                }
+                        fstWriterFlushContextPrivate(xc);
+#ifdef FST_WRITER_PARALLEL
+                        pthread_mutex_lock(&xc->mutex);
+                        pthread_mutex_unlock(&xc->mutex);
+#endif
+                        }
+                }
+        fstDestroyMmaps(xc, 1);
+
+        /* write out geom section */
+        fflush(xc->geom_handle);
+        tlen = ftello(xc->geom_handle);
+        tmem = fstMmap(NULL, tlen, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->geom_handle), 0);
+        if(tmem)
+                {
+                unsigned long destlen = tlen;
+                unsigned char *dmem = malloc(compressBound(destlen));
+                int rc = compress2(dmem, &destlen, tmem, tlen, 9);
+
+                if((rc != Z_OK) || (((off_t)destlen) > tlen))
+                        {
+                        destlen = tlen;
+                        }
+
+                fixup_offs = ftello(xc->handle);
+                fputc(FST_BL_SKIP, xc->handle);                 /* temporary tag */
+                fstWriterUint64(xc->handle, destlen + 24);      /* section length */
+                fstWriterUint64(xc->handle, tlen);              /* uncompressed */
+                                                                /* compressed len is section length - 24 */
+                fstWriterUint64(xc->handle, xc->maxhandle);     /* maxhandle */
+                fstFwrite((((off_t)destlen) != tlen) ? dmem : tmem, destlen, 1, xc->handle);
+                fflush(xc->handle);
+
+                fstWriterFseeko(xc, xc->handle, fixup_offs, SEEK_SET);
+                fputc(FST_BL_GEOM, xc->handle);                 /* actual tag */
+
+                fstWriterFseeko(xc, xc->handle, 0, SEEK_END);           /* move file pointer to end for any section adds */
+                fflush(xc->handle);
+
+                free(dmem);
+                fstMunmap(tmem, tlen);
+                }
+
+        if(xc->num_blackouts)
+                {
+                uint64_t cur_bl = 0;
+                off_t bpos, eos;
+                uint32_t i;
+
+                fixup_offs = ftello(xc->handle);
+                fputc(FST_BL_SKIP, xc->handle);                 /* temporary tag */
+                bpos = fixup_offs + 1;
+                fstWriterUint64(xc->handle, 0);                 /* section length */
+                fstWriterVarint(xc->handle, xc->num_blackouts);
+
+                for(i=0;i<xc->num_blackouts;i++)
+                        {
+                        fputc(xc->blackout_head->active, xc->handle);
+                        fstWriterVarint(xc->handle, xc->blackout_head->tim - cur_bl);
+                        cur_bl = xc->blackout_head->tim;
+                        xc->blackout_curr = xc->blackout_head->next;
+                        free(xc->blackout_head);
+                        xc->blackout_head = xc->blackout_curr;
+                        }
+
+                eos = ftello(xc->handle);
+                fstWriterFseeko(xc, xc->handle, bpos, SEEK_SET);
+                fstWriterUint64(xc->handle, eos - bpos);
+                fflush(xc->handle);
+
+                fstWriterFseeko(xc, xc->handle, fixup_offs, SEEK_SET);
+                fputc(FST_BL_BLACKOUT, xc->handle);     /* actual tag */
+
+                fstWriterFseeko(xc, xc->handle, 0, SEEK_END);   /* move file pointer to end for any section adds */
+                fflush(xc->handle);
+                }
+
+        if(xc->compress_hier)
+                {
+                off_t hl, eos;
+                gzFile zhandle;
+                int zfd;
+                int fourpack_duo = 0;
+#ifndef __MINGW32__
+                char *fnam = malloc(strlen(xc->filename) + 5 + 1);
+#endif
+
+                fixup_offs = ftello(xc->handle);
+                fputc(FST_BL_SKIP, xc->handle);                 /* temporary tag */
+                hlen = ftello(xc->handle);
+                fstWriterUint64(xc->handle, 0);                 /* section length */
+                fstWriterUint64(xc->handle, xc->hier_file_len); /* uncompressed length */
+
+                if(!xc->fourpack)
+                        {
+                        unsigned char *mem = malloc(FST_GZIO_LEN);
+                        zfd = dup(fileno(xc->handle));
+                        fflush(xc->handle);
+                        zhandle = gzdopen(zfd, "wb4");
+                        if(zhandle)
+                                {
+                                fstWriterFseeko(xc, xc->hier_handle, 0, SEEK_SET);
+                                for(hl = 0; hl < xc->hier_file_len; hl += FST_GZIO_LEN)
+                                        {
+                                        unsigned len = ((xc->hier_file_len - hl) > FST_GZIO_LEN) ? FST_GZIO_LEN : (xc->hier_file_len - hl);
+                                        fstFread(mem, len, 1, xc->hier_handle);
+                                        gzwrite(zhandle, mem, len);
+                                        }
+                                gzclose(zhandle);
+                                }
+                                else
+                                {
+                                close(zfd);
+                                }
+                        free(mem);
+                        }
+                        else
+                        {
+                        int lz4_maxlen;
+                        unsigned char *mem;
+                        unsigned char *hmem;
+                        int packed_len;
+
+                        fflush(xc->handle);
+
+                        lz4_maxlen = LZ4_compressBound(xc->hier_file_len);
+                        mem = malloc(lz4_maxlen);
+                        hmem = fstMmap(NULL, xc->hier_file_len, PROT_READ|PROT_WRITE, MAP_SHARED, fileno(xc->hier_handle), 0);
+                        packed_len = LZ4_compress((char *)hmem, (char *)mem, xc->hier_file_len);
+                        fstMunmap(hmem, xc->hier_file_len);
+
+                        fourpack_duo = (!xc->repack_on_close) && (xc->hier_file_len > FST_HDR_FOURPACK_DUO_SIZE); /* double pack when hierarchy is large */
+
+                        if(fourpack_duo)        /* double packing with LZ4 is faster than gzip */
+                                {
+                                unsigned char *mem_duo;
+                                int lz4_maxlen_duo;
+                                int packed_len_duo;
+
+                                lz4_maxlen_duo = LZ4_compressBound(packed_len);
+                                mem_duo = malloc(lz4_maxlen_duo);
+                                packed_len_duo = LZ4_compress((char *)mem, (char *)mem_duo, packed_len);
+
+                                fstWriterVarint(xc->handle, packed_len); /* 1st round compressed length */
+                                fstFwrite(mem_duo, packed_len_duo, 1, xc->handle);
+                                free(mem_duo);
+                                }
+                                else
+                                {
+                                fstFwrite(mem, packed_len, 1, xc->handle);
+                                }
+
+                        free(mem);
+                        }
+
+                fstWriterFseeko(xc, xc->handle, 0, SEEK_END);
+                eos = ftello(xc->handle);
+                fstWriterFseeko(xc, xc->handle, hlen, SEEK_SET);
+                fstWriterUint64(xc->handle, eos - hlen);
+                fflush(xc->handle);
+
+                fstWriterFseeko(xc, xc->handle, fixup_offs, SEEK_SET);
+                fputc(xc->fourpack ?
+                        ( fourpack_duo ? FST_BL_HIER_LZ4DUO : FST_BL_HIER_LZ4) :
+                        FST_BL_HIER, xc->handle); /* actual tag now also == compression type */
+
+                fstWriterFseeko(xc, xc->handle, 0, SEEK_END);   /* move file pointer to end for any section adds */
+                fflush(xc->handle);
+
+#ifndef __MINGW32__
+                sprintf(fnam, "%s.hier", xc->filename);
+                unlink(fnam);
+                free(fnam);
+#endif
+                }
+
+        /* finalize out header */
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_START_TIME, SEEK_SET);
+        fstWriterUint64(xc->handle, xc->firsttime);
+        fstWriterUint64(xc->handle, xc->curtime);
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_NUM_SCOPES, SEEK_SET);
+        fstWriterUint64(xc->handle, xc->numscopes);
+        fstWriterUint64(xc->handle, xc->numsigs);
+        fstWriterUint64(xc->handle, xc->maxhandle);
+        fstWriterUint64(xc->handle, xc->secnum);
+        fflush(xc->handle);
+
+        tmpfile_close(&xc->tchn_handle, &xc->tchn_handle_nam);
+        free(xc->vchg_mem); xc->vchg_mem = NULL;
+        tmpfile_close(&xc->curval_handle, &xc->curval_handle_nam);
+        tmpfile_close(&xc->valpos_handle, &xc->valpos_handle_nam);
+        tmpfile_close(&xc->geom_handle, &xc->geom_handle_nam);
+        if(xc->hier_handle) { fclose(xc->hier_handle); xc->hier_handle = NULL; }
+        if(xc->handle)
+                {
+                if(xc->repack_on_close)
+                        {
+                        FILE *fp;
+                        off_t offpnt, uclen;
+                        int flen = strlen(xc->filename);
+                        char *hf = calloc(1, flen + 5);
+
+                        strcpy(hf, xc->filename);
+                        strcpy(hf+flen, ".pak");
+                        fp = fopen(hf, "wb");
+
+                        if(fp)
+                                {
+                                void *dsth;
+                                int zfd;
+                                char gz_membuf[FST_GZIO_LEN];
+
+                                fstWriterFseeko(xc, xc->handle, 0, SEEK_END);
+                                uclen = ftello(xc->handle);
+
+                                fputc(FST_BL_ZWRAPPER, fp);
+                                fstWriterUint64(fp, 0);
+                                fstWriterUint64(fp, uclen);
+                                fflush(fp);
+
+                                fstWriterFseeko(xc, xc->handle, 0, SEEK_SET);
+                                zfd = dup(fileno(fp));
+                                dsth = gzdopen(zfd, "wb4");
+                                if(dsth)
+                                        {
+                                        for(offpnt = 0; offpnt < uclen; offpnt += FST_GZIO_LEN)
+                                                {
+                                                size_t this_len = ((uclen - offpnt) > FST_GZIO_LEN) ? FST_GZIO_LEN : (uclen - offpnt);
+                                                fstFread(gz_membuf, this_len, 1, xc->handle);
+                                                gzwrite(dsth, gz_membuf, this_len);
+                                                }
+                                        gzclose(dsth);
+                                        }
+                                        else
+                                        {
+                                        close(zfd);
+                                        }
+                                fstWriterFseeko(xc, fp, 0, SEEK_END);
+                                offpnt = ftello(fp);
+                                fstWriterFseeko(xc, fp, 1, SEEK_SET);
+                                fstWriterUint64(fp, offpnt - 1);
+                                fclose(fp);
+                                fclose(xc->handle); xc->handle = NULL;
+
+                                unlink(xc->filename);
+                                rename(hf, xc->filename);
+                                }
+                                else
+                                {
+                                xc->repack_on_close = 0;
+                                fclose(xc->handle); xc->handle = NULL;
+                                }
+
+                        free(hf);
+                        }
+                        else
+                        {
+                        fclose(xc->handle); xc->handle = NULL;
+                        }
+                }
+
+#ifdef __MINGW32__
+        {
+        int flen = strlen(xc->filename);
+        char *hf = calloc(1, flen + 6);
+        strcpy(hf, xc->filename);
+
+        if(xc->compress_hier)
+                {
+                strcpy(hf + flen, ".hier");
+                unlink(hf); /* no longer needed as a section now exists for this */
+                }
+
+        free(hf);
+        }
+#endif
+
+#ifdef FST_WRITER_PARALLEL
+        pthread_mutex_destroy(&xc->mutex);
+        pthread_attr_destroy(&xc->thread_attr);
+#endif
+
+        if(xc->path_array)
+                {
+#ifndef _WAVE_HAVE_JUDY
+                const uint32_t hashmask = FST_PATH_HASHMASK;
+#endif
+                JudyHSFreeArray(&(xc->path_array), NULL);
+                }
+
+        free(xc->filename); xc->filename = NULL;
+        free(xc);
+        }
+}
+
+
+/*
+ * functions to set miscellaneous header/block information
+ */
+void fstWriterSetDate(void *ctx, const char *dat)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        char s[FST_HDR_DATE_SIZE];
+        off_t fpos = ftello(xc->handle);
+        int len = strlen(dat);
+
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_DATE, SEEK_SET);
+        memset(s, 0, FST_HDR_DATE_SIZE);
+        memcpy(s, dat, (len < FST_HDR_DATE_SIZE) ? len : FST_HDR_DATE_SIZE);
+        fstFwrite(s, FST_HDR_DATE_SIZE, 1, xc->handle);
+        fflush(xc->handle);
+        fstWriterFseeko(xc, xc->handle, fpos, SEEK_SET);
+        }
+}
+
+
+void fstWriterSetVersion(void *ctx, const char *vers)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc && vers)
+        {
+        char s[FST_HDR_SIM_VERSION_SIZE];
+        off_t fpos = ftello(xc->handle);
+        int len = strlen(vers);
+
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_SIM_VERSION, SEEK_SET);
+        memset(s, 0, FST_HDR_SIM_VERSION_SIZE);
+        memcpy(s, vers, (len < FST_HDR_SIM_VERSION_SIZE) ? len : FST_HDR_SIM_VERSION_SIZE);
+        fstFwrite(s, FST_HDR_SIM_VERSION_SIZE, 1, xc->handle);
+        fflush(xc->handle);
+        fstWriterFseeko(xc, xc->handle, fpos, SEEK_SET);
+        }
+}
+
+
+void fstWriterSetFileType(void *ctx, enum fstFileType filetype)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        if(/*(filetype >= FST_FT_MIN) &&*/ (filetype <= FST_FT_MAX))
+                {
+                off_t fpos = ftello(xc->handle);
+
+                xc->filetype = filetype;
+
+                fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_FILETYPE, SEEK_SET);
+                fputc(xc->filetype, xc->handle);
+                fflush(xc->handle);
+                fstWriterFseeko(xc, xc->handle, fpos, SEEK_SET);
+                }
+        }
+}
+
+
+static void fstWriterSetAttrDoubleArgGeneric(void *ctx, int typ, uint64_t arg1, uint64_t arg2)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        unsigned char buf[11]; /* ceil(64/7) = 10 + null term */
+        unsigned char *pnt = fstCopyVarint64ToRight(buf, arg1);
+        if(arg1)
+                {
+                *pnt = 0; /* this converts any *nonzero* arg1 when made a varint into a null-term string */
+                }
+
+        fstWriterSetAttrBegin(xc, FST_AT_MISC, typ, (char *)buf, arg2);
+        }
+}
+
+
+static void fstWriterSetAttrGeneric(void *ctx, const char *comm, int typ, uint64_t arg)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc && comm)
+        {
+        char *s = strdup(comm);
+        char *sf = s;
+
+        while(*s)
+                {
+                if((*s == '\n') || (*s == '\r')) *s = ' ';
+                s++;
+                }
+
+        fstWriterSetAttrBegin(xc, FST_AT_MISC, typ, sf, arg);
+        free(sf);
+        }
+}
+
+
+static void fstWriterSetSourceStem_2(void *ctx, const char *path, unsigned int line, unsigned int use_realpath, int typ)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc && path && path[0])
+        {
+        uint64_t sidx = 0;
+        int slen = strlen(path);
+#ifndef _WAVE_HAVE_JUDY
+        const uint32_t hashmask = FST_PATH_HASHMASK;
+        const unsigned char *path2 = (const unsigned char *)path;
+#else
+        char *path2 = alloca(slen + 1); /* judy lacks const qualifier in its JudyHSIns definition */
+        strcpy(path2, path);
+#endif
+
+        PPvoid_t pv = JudyHSIns(&(xc->path_array), path2, slen, NULL);
+        if(*pv)
+                {
+                sidx = (long)(*pv);
+                }
+                else
+                {
+                char *rp = NULL;
+
+                sidx = ++xc->path_array_count;
+                *pv = (void *)(long)(xc->path_array_count);
+
+                if(use_realpath)
+                        {
+                        rp = fstRealpath(
+#ifndef _WAVE_HAVE_JUDY
+                                (const char *)
+#endif
+                                path2, NULL);
+                        }
+
+                fstWriterSetAttrGeneric(xc, rp ? rp :
+#ifndef _WAVE_HAVE_JUDY
+                        (const char *)
+#endif
+                        path2, FST_MT_PATHNAME, sidx);
+
+                if(rp)
+                        {
+                        free(rp);
+                        }
+                }
+
+        fstWriterSetAttrDoubleArgGeneric(xc, typ, sidx, line);
+        }
+}
+
+
+void fstWriterSetSourceStem(void *ctx, const char *path, unsigned int line, unsigned int use_realpath)
+{
+fstWriterSetSourceStem_2(ctx, path, line, use_realpath, FST_MT_SOURCESTEM);
+}
+
+
+void fstWriterSetSourceInstantiationStem(void *ctx, const char *path, unsigned int line, unsigned int use_realpath)
+{
+fstWriterSetSourceStem_2(ctx, path, line, use_realpath, FST_MT_SOURCEISTEM);
+}
+
+
+void fstWriterSetComment(void *ctx, const char *comm)
+{
+fstWriterSetAttrGeneric(ctx, comm, FST_MT_COMMENT, 0);
+}
+
+
+void fstWriterSetEnvVar(void *ctx, const char *envvar)
+{
+fstWriterSetAttrGeneric(ctx, envvar, FST_MT_ENVVAR, 0);
+}
+
+
+void fstWriterSetTimescale(void *ctx, int ts)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        off_t fpos = ftello(xc->handle);
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_TIMESCALE, SEEK_SET);
+        fputc(ts & 255, xc->handle);
+        fflush(xc->handle);
+        fstWriterFseeko(xc, xc->handle, fpos, SEEK_SET);
+        }
+}
+
+
+void fstWriterSetTimescaleFromString(void *ctx, const char *s)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc && s)
+        {
+        int mat = 0;
+        int seconds_exp = -9;
+        int tv = atoi(s);
+        const char *pnt = s;
+
+        while(*pnt)
+                {
+                switch(*pnt)
+                        {
+                        case 'm': seconds_exp =  -3; mat = 1; break;
+                        case 'u': seconds_exp =  -6; mat = 1; break;
+                        case 'n': seconds_exp =  -9; mat = 1; break;
+                        case 'p': seconds_exp = -12; mat = 1; break;
+                        case 'f': seconds_exp = -15; mat = 1; break;
+                        case 'a': seconds_exp = -18; mat = 1; break;
+                        case 'z': seconds_exp = -21; mat = 1; break;
+                        case 's': seconds_exp =   0; mat = 1; break;
+                        default: break;
+                        }
+
+                if(mat) break;
+                pnt++;
+                }
+
+        if(tv == 10)
+                {
+                seconds_exp++;
+                }
+        else
+        if(tv == 100)
+                {
+                seconds_exp+=2;
+                }
+
+        fstWriterSetTimescale(ctx, seconds_exp);
+        }
+}
+
+
+void fstWriterSetTimezero(void *ctx, int64_t tim)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        off_t fpos = ftello(xc->handle);
+        fstWriterFseeko(xc, xc->handle, FST_HDR_OFFS_TIMEZERO, SEEK_SET);
+        fstWriterUint64(xc->handle, (xc->timezero = tim));
+        fflush(xc->handle);
+        fstWriterFseeko(xc, xc->handle, fpos, SEEK_SET);
+        }
+}
+
+
+void fstWriterSetPackType(void *ctx, enum fstWriterPackType typ)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        xc->fastpack     = (typ != FST_WR_PT_ZLIB);
+        xc->fourpack     = (typ == FST_WR_PT_LZ4);
+        }
+}
+
+
+void fstWriterSetRepackOnClose(void *ctx, int enable)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        xc->repack_on_close = (enable != 0);
+        }
+}
+
+
+void fstWriterSetParallelMode(void *ctx, int enable)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        xc->parallel_was_enabled |= xc->parallel_enabled; /* make sticky */
+        xc->parallel_enabled = (enable != 0);
+#ifndef FST_WRITER_PARALLEL
+        if(xc->parallel_enabled)
+                {
+                fprintf(stderr, "ERROR: fstWriterSetParallelMode(), FST_WRITER_PARALLEL not enabled during compile, exiting.\n");
+                exit(255);
+                }
+#endif
+        }
+}
+
+
+void fstWriterSetDumpSizeLimit(void *ctx, uint64_t numbytes)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        xc->dump_size_limit = numbytes;
+        }
+}
+
+
+int fstWriterGetDumpSizeLimitReached(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        return(xc->size_limit_locked != 0);
+        }
+
+return(0);
+}
+
+
+int fstWriterGetFseekFailed(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+if(xc)
+        {
+        return(xc->fseek_failed != 0);
+        }
+
+return(0);
+}
+
+
+/*
+ * writer attr/scope/var creation:
+ * fstWriterCreateVar2() is used to dump VHDL or other languages, but the
+ * underlying variable needs to map to Verilog/SV via the proper fstVarType vt
+ */
+fstHandle fstWriterCreateVar2(void *ctx, enum fstVarType vt, enum fstVarDir vd,
+        uint32_t len, const char *nam, fstHandle aliasHandle,
+        const char *type, enum fstSupplementalVarType svt, enum fstSupplementalDataType sdt)
+{
+fstWriterSetAttrGeneric(ctx, type ? type : "", FST_MT_SUPVAR, (svt<<FST_SDT_SVT_SHIFT_COUNT) | (sdt & FST_SDT_ABS_MAX));
+return(fstWriterCreateVar(ctx, vt, vd, len, nam, aliasHandle));
+}
+
+
+fstHandle fstWriterCreateVar(void *ctx, enum fstVarType vt, enum fstVarDir vd,
+        uint32_t len, const char *nam, fstHandle aliasHandle)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+unsigned int i;
+int nlen, is_real;
+
+if(xc && nam)
+        {
+        if(xc->valpos_mem)
+                {
+                fstDestroyMmaps(xc, 0);
+                }
+
+        fputc(vt, xc->hier_handle);
+        fputc(vd, xc->hier_handle);
+        nlen = strlen(nam);
+        fstFwrite(nam, nlen, 1, xc->hier_handle);
+        fputc(0, xc->hier_handle);
+        xc->hier_file_len += (nlen+3);
+
+        if((vt == FST_VT_VCD_REAL) || (vt == FST_VT_VCD_REAL_PARAMETER) || (vt == FST_VT_VCD_REALTIME) || (vt == FST_VT_SV_SHORTREAL))
+                {
+                is_real = 1;
+                len = 8; /* recast number of bytes to that of what a double is */
+                }
+                else
+                {
+                is_real = 0;
+                if(vt == FST_VT_GEN_STRING)
+                        {
+                        len = 0;
+                        }
+                }
+
+        xc->hier_file_len += fstWriterVarint(xc->hier_handle, len);
+
+        if(aliasHandle > xc->maxhandle) aliasHandle = 0;
+        xc->hier_file_len += fstWriterVarint(xc->hier_handle, aliasHandle);
+        xc->numsigs++;
+        if(xc->numsigs == xc->next_huge_break)
+                {
+                if(xc->fst_break_size < xc->fst_huge_break_size)
+                        {
+                        xc->next_huge_break += FST_ACTIVATE_HUGE_INC;
+                        xc->fst_break_size += xc->fst_orig_break_size;
+                        xc->fst_break_add_size += xc->fst_orig_break_add_size;
+
+                        xc->vchg_alloc_siz = xc->fst_break_size + xc->fst_break_add_size;
+                        if(xc->vchg_mem)
+                                {
+                                xc->vchg_mem = realloc(xc->vchg_mem, xc->vchg_alloc_siz);
+                                }
+                        }
+                }
+
+        if(!aliasHandle)
+                {
+                uint32_t zero = 0;
+
+                if(len)
+                        {
+                        fstWriterVarint(xc->geom_handle, !is_real ? len : 0); /* geom section encodes reals as zero byte */
+                        }
+                        else
+                        {
+                        fstWriterVarint(xc->geom_handle, 0xFFFFFFFF);         /* geom section encodes zero len as 32b -1 */
+                        }
+
+                fstFwrite(&xc->maxvalpos, sizeof(uint32_t), 1, xc->valpos_handle);
+                fstFwrite(&len, sizeof(uint32_t), 1, xc->valpos_handle);
+                fstFwrite(&zero, sizeof(uint32_t), 1, xc->valpos_handle);
+                fstFwrite(&zero, sizeof(uint32_t), 1, xc->valpos_handle);
+
+                if(!is_real)
+                        {
+                        for(i=0;i<len;i++)
+                                {
+                                fputc('x', xc->curval_handle);
+                                }
+                        }
+                        else
+                        {
+                        fstFwrite(&xc->nan, 8, 1, xc->curval_handle); /* initialize doubles to NaN rather than x */
+                        }
+
+                xc->maxvalpos+=len;
+                xc->maxhandle++;
+                return(xc->maxhandle);
+                }
+                else
+                {
+                return(aliasHandle);
+                }
+        }
+
+return(0);
+}
+
+
+void fstWriterSetScope(void *ctx, enum fstScopeType scopetype,
+                const char *scopename, const char *scopecomp)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        fputc(FST_ST_VCD_SCOPE, xc->hier_handle);
+        if(/*(scopetype < FST_ST_VCD_MODULE) ||*/ (scopetype > FST_ST_MAX)) { scopetype = FST_ST_VCD_MODULE; }
+        fputc(scopetype, xc->hier_handle);
+        fprintf(xc->hier_handle, "%s%c%s%c",
+                scopename ? scopename : "", 0,
+                scopecomp ? scopecomp : "", 0);
+
+        if(scopename)
+                {
+                xc->hier_file_len += strlen(scopename);
+                }
+        if(scopecomp)
+                {
+                xc->hier_file_len += strlen(scopecomp);
+                }
+
+        xc->hier_file_len += 4; /* FST_ST_VCD_SCOPE + scopetype + two string terminating zeros */
+        xc->numscopes++;
+        }
+}
+
+
+void fstWriterSetUpscope(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        fputc(FST_ST_VCD_UPSCOPE, xc->hier_handle);
+        xc->hier_file_len++;
+        }
+}
+
+
+void fstWriterSetAttrBegin(void *ctx, enum fstAttrType attrtype, int subtype,
+                const char *attrname, uint64_t arg)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        fputc(FST_ST_GEN_ATTRBEGIN, xc->hier_handle);
+        if(/*(attrtype < FST_AT_MISC) ||*/ (attrtype > FST_AT_MAX)) { attrtype = FST_AT_MISC; subtype = FST_MT_UNKNOWN; }
+        fputc(attrtype, xc->hier_handle);
+
+        switch(attrtype)
+                {
+                case FST_AT_ARRAY:      if((subtype < FST_AR_NONE) || (subtype > FST_AR_MAX)) subtype = FST_AR_NONE; break;
+                case FST_AT_ENUM:       if((subtype < FST_EV_SV_INTEGER) || (subtype > FST_EV_MAX)) subtype = FST_EV_SV_INTEGER; break;
+                case FST_AT_PACK:       if((subtype < FST_PT_NONE) || (subtype > FST_PT_MAX)) subtype = FST_PT_NONE; break;
+
+                case FST_AT_MISC:
+                default:                break;
+                }
+
+        fputc(subtype, xc->hier_handle);
+        fprintf(xc->hier_handle, "%s%c",
+                attrname ? attrname : "", 0);
+
+        if(attrname)
+                {
+                xc->hier_file_len += strlen(attrname);
+                }
+
+        xc->hier_file_len += 4; /* FST_ST_GEN_ATTRBEGIN + type + subtype + string terminating zero */
+        xc->hier_file_len += fstWriterVarint(xc->hier_handle, arg);
+        }
+}
+
+
+void fstWriterSetAttrEnd(void *ctx)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        fputc(FST_ST_GEN_ATTREND, xc->hier_handle);
+        xc->hier_file_len++;
+        }
+}
+
+
+/*
+ * value and time change emission
+ */
+void fstWriterEmitValueChange(void *ctx, fstHandle handle, const void *val)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+const unsigned char *buf = (const unsigned char *)val;
+uint32_t offs;
+int len;
+
+if((xc) && (handle <= xc->maxhandle))
+        {
+        uint32_t fpos;
+        uint32_t *vm4ip;
+
+        if(!xc->valpos_mem)
+                {
+                xc->vc_emitted = 1;
+                fstWriterCreateMmaps(xc);
+                }
+
+        handle--; /* move starting at 1 index to starting at 0 */
+        vm4ip = &(xc->valpos_mem[4*handle]);
+
+        len  = vm4ip[1];
+        if(len) /* len of zero = variable length, use fstWriterEmitVariableLengthValueChange */
+                {
+                if(!xc->is_initial_time)
+                        {
+                        fpos = xc->vchg_siz;
+
+                        if((fpos + len + 10) > xc->vchg_alloc_siz)
+                                {
+                                xc->vchg_alloc_siz += (xc->fst_break_add_size + len); /* +len added in the case of extremely long vectors and small break add sizes */
+                                xc->vchg_mem = realloc(xc->vchg_mem, xc->vchg_alloc_siz);
+                                if(!xc->vchg_mem)
+                                        {
+                                        fprintf(stderr, "FATAL ERROR, could not realloc() in fstWriterEmitValueChange, exiting.\n");
+                                        exit(255);
+                                        }
+                                }
+#ifdef FST_REMOVE_DUPLICATE_VC
+                        offs = vm4ip[0];
+
+                        if(len != 1)
+                                {
+                                if((vm4ip[3]==xc->tchn_idx)&&(vm4ip[2]))
+                                        {
+                                        unsigned char *old_value = xc->vchg_mem + vm4ip[2] + 4; /* the +4 skips old vm4ip[2] value */
+                                        while(*(old_value++) & 0x80) { /* skips over varint encoded "xc->tchn_idx - vm4ip[3]" */ }
+                                        memcpy(old_value, buf, len); /* overlay new value */
+
+                                        memcpy(xc->curval_mem + offs, buf, len);
+                                        return;
+                                        }
+                                else
+                                        {
+                                        if(!memcmp(xc->curval_mem + offs, buf, len))
+                                                {
+                                                if(!xc->curtime)
+                                                        {
+                                                        int i;
+                                                        for(i=0;i<len;i++)
+                                                                {
+                                                                if(buf[i]!='x') break;
+                                                                }
+
+                                                        if(i<len) return;
+                                                        }
+                                                        else
+                                                        {
+                                                        return;
+                                                        }
+                                                }
+                                        }
+
+                                memcpy(xc->curval_mem + offs, buf, len);
+                                }
+                                else
+                                {
+                                if((vm4ip[3]==xc->tchn_idx)&&(vm4ip[2]))
+                                        {
+                                        unsigned char *old_value = xc->vchg_mem + vm4ip[2] + 4; /* the +4 skips old vm4ip[2] value */
+                                        while(*(old_value++) & 0x80) { /* skips over varint encoded "xc->tchn_idx - vm4ip[3]" */ }
+                                        *old_value = *buf; /* overlay new value */
+
+                                        *(xc->curval_mem + offs) = *buf;
+                                        return;
+                                        }
+                                else
+                                        {
+                                        if((*(xc->curval_mem + offs)) == (*buf))
+                                                {
+                                                if(!xc->curtime)
+                                                        {
+                                                        if(*buf != 'x') return;
+                                                        }
+                                                        else
+                                                        {
+                                                        return;
+                                                        }
+                                                }
+                                        }
+
+                                *(xc->curval_mem + offs) = *buf;
+                                }
+#endif
+                        xc->vchg_siz += fstWriterUint32WithVarint32(xc, &vm4ip[2], xc->tchn_idx - vm4ip[3], buf, len); /* do one fwrite op only */
+                        vm4ip[3] = xc->tchn_idx;
+                        vm4ip[2] = fpos;
+                        }
+                        else
+                        {
+                        offs = vm4ip[0];
+                        memcpy(xc->curval_mem + offs, buf, len);
+                        }
+                }
+        }
+}
+
+
+void fstWriterEmitVariableLengthValueChange(void *ctx, fstHandle handle, const void *val, uint32_t len)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+const unsigned char *buf = (const unsigned char *)val;
+
+if((xc) && (handle <= xc->maxhandle))
+        {
+        uint32_t fpos;
+        uint32_t *vm4ip;
+
+        if(!xc->valpos_mem)
+                {
+                xc->vc_emitted = 1;
+                fstWriterCreateMmaps(xc);
+                }
+
+        handle--; /* move starting at 1 index to starting at 0 */
+        vm4ip = &(xc->valpos_mem[4*handle]);
+
+        /* there is no initial time dump for variable length value changes */
+        if(!vm4ip[1]) /* len of zero = variable length */
+                {
+                fpos = xc->vchg_siz;
+
+                if((fpos + len + 10 + 5) > xc->vchg_alloc_siz)
+                        {
+                        xc->vchg_alloc_siz += (xc->fst_break_add_size + len + 5); /* +len added in the case of extremely long vectors and small break add sizes */
+                        xc->vchg_mem = realloc(xc->vchg_mem, xc->vchg_alloc_siz);
+                        if(!xc->vchg_mem)
+                                {
+                                fprintf(stderr, "FATAL ERROR, could not realloc() in fstWriterEmitVariableLengthValueChange, exiting.\n");
+                                exit(255);
+                                }
+                        }
+
+                xc->vchg_siz += fstWriterUint32WithVarint32AndLength(xc, &vm4ip[2], xc->tchn_idx - vm4ip[3], buf, len); /* do one fwrite op only */
+                vm4ip[3] = xc->tchn_idx;
+                vm4ip[2] = fpos;
+                }
+        }
+}
+
+
+void fstWriterEmitTimeChange(void *ctx, uint64_t tim)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+unsigned int i;
+int skip = 0;
+if(xc)
+        {
+        if(xc->is_initial_time)
+                {
+                if(xc->size_limit_locked)       /* this resets xc->is_initial_time to one */
+                        {
+                        return;
+                        }
+
+                if(!xc->valpos_mem)
+                        {
+                        fstWriterCreateMmaps(xc);
+                        }
+
+                skip = 1;
+
+                xc->firsttime = (xc->vc_emitted) ? 0: tim;
+                xc->curtime = 0;
+                xc->vchg_mem[0] = '!';
+                xc->vchg_siz = 1;
+                fstWriterEmitSectionHeader(xc);
+                for(i=0;i<xc->maxhandle;i++)
+                        {
+                        xc->valpos_mem[4*i+2] = 0; /* zero out offset val */
+                        xc->valpos_mem[4*i+3] = 0; /* zero out last time change val */
+                        }
+                xc->is_initial_time = 0;
+                }
+                else
+                {
+                if((xc->vchg_siz >= xc->fst_break_size) || (xc->flush_context_pending))
+                        {
+                        xc->flush_context_pending = 0;
+                        fstWriterFlushContextPrivate(xc);
+                        xc->tchn_cnt++;
+                        fstWriterVarint(xc->tchn_handle, xc->curtime);
+                        }
+                }
+
+        if(!skip)
+                {
+                xc->tchn_idx++;
+                }
+        fstWriterVarint(xc->tchn_handle, tim - xc->curtime);
+        xc->tchn_cnt++;
+        xc->curtime = tim;
+        }
+}
+
+
+void fstWriterEmitDumpActive(void *ctx, int enable)
+{
+struct fstWriterContext *xc = (struct fstWriterContext *)ctx;
+
+if(xc)
+        {
+        struct fstBlackoutChain *b = calloc(1, sizeof(struct fstBlackoutChain));
+
+        b->tim = xc->curtime;
+        b->active = (enable != 0);
+
+        xc->num_blackouts++;
+        if(xc->blackout_curr)
+                {
+                xc->blackout_curr->next = b;
+                xc->blackout_curr = b;
+                }
+                else
+                {
+                xc->blackout_head = b;
+                xc->blackout_curr = b;
+                }
+        }
+}
+
+
+/***********************/
+/***                 ***/
+/*** reader function ***/
+/***                 ***/
+/***********************/
+
+/*
+ * private structs
+ */
+static const char *vartypes[] = {
+        "event", "integer", "parameter", "real", "real_parameter",
+        "reg", "supply0", "supply1", "time", "tri",
+        "triand", "trior", "trireg", "tri0", "tri1",
+        "wand", "wire", "wor", "port", "sparray", "realtime",
+        "string",
+        "bit", "logic", "int", "shortint", "longint", "byte", "enum", "shortreal"
+        };
+
+static const char *modtypes[] = {
+        "module", "task", "function", "begin", "fork", "generate", "struct", "union", "class", "interface", "package", "program",
+        "vhdl_architecture", "vhdl_procedure", "vhdl_function", "vhdl_record", "vhdl_process", "vhdl_block", "vhdl_for_generate", "vhdl_if_generate", "vhdl_generate", "vhdl_package"
+        };
+
+static const char *attrtypes[] = {
+        "misc", "array", "enum", "class"
+        };
+
+static const char *arraytypes[] = {
+        "none", "unpacked", "packed", "sparse"
+        };
+
+static const char *enumvaluetypes[] = {
+        "integer", "bit", "logic", "int", "shortint", "longint", "byte",
+        "unsigned_integer", "unsigned_bit", "unsigned_logic", "unsigned_int", "unsigned_shortint", "unsigned_longint", "unsigned_byte"
+        };
+
+static const char *packtypes[] = {
+        "none", "unpacked", "packed", "tagged_packed"
+        };
+
+
+struct fstCurrHier
+{
+struct fstCurrHier *prev;
+void *user_info;
+int len;
+};
+
+
+struct fstReaderContext
+{
+/* common entries */
+
+FILE *f, *fh;
+
+uint64_t start_time, end_time;
+uint64_t mem_used_by_writer;
+uint64_t scope_count;
+uint64_t var_count;
+fstHandle maxhandle;
+uint64_t num_alias;
+uint64_t vc_section_count;
+
+uint32_t *signal_lens;                  /* maxhandle sized */
+unsigned char *signal_typs;             /* maxhandle sized */
+unsigned char *process_mask;            /* maxhandle-based, bitwise sized */
+uint32_t longest_signal_value_len;      /* longest len value encountered */
+unsigned char *temp_signal_value_buf;   /* malloced for len in longest_signal_value_len */
+
+signed char timescale;
+unsigned char filetype;
+
+unsigned use_vcd_extensions : 1;
+unsigned double_endian_match : 1;
+unsigned native_doubles_for_cb : 1;
+unsigned contains_geom_section : 1;
+unsigned contains_hier_section : 1;        /* valid for hier_pos */
+unsigned contains_hier_section_lz4duo : 1; /* valid for hier_pos (contains_hier_section_lz4 always also set) */
+unsigned contains_hier_section_lz4 : 1;    /* valid for hier_pos */
+unsigned limit_range_valid : 1;            /* valid for limit_range_start, limit_range_end */
+
+char version[FST_HDR_SIM_VERSION_SIZE + 1];
+char date[FST_HDR_DATE_SIZE + 1];
+int64_t timezero;
+
+char *filename, *filename_unpacked;
+off_t hier_pos;
+
+uint32_t num_blackouts;
+uint64_t *blackout_times;
+unsigned char *blackout_activity;
+
+uint64_t limit_range_start, limit_range_end;
+
+/* entries specific to read value at time functions */
+
+unsigned rvat_data_valid : 1;
+uint64_t *rvat_time_table;
+uint64_t rvat_beg_tim, rvat_end_tim;
+unsigned char *rvat_frame_data;
+uint64_t rvat_frame_maxhandle;
+off_t *rvat_chain_table;
+uint32_t *rvat_chain_table_lengths;
+uint64_t rvat_vc_maxhandle;
+off_t rvat_vc_start;
+uint32_t *rvat_sig_offs;
+
+uint32_t rvat_chain_len;
+unsigned char *rvat_chain_mem;
+fstHandle rvat_chain_facidx;
+
+uint32_t rvat_chain_pos_tidx;
+uint32_t rvat_chain_pos_idx;
+uint64_t rvat_chain_pos_time;
+unsigned rvat_chain_pos_valid : 1;
+
+/* entries specific to hierarchy traversal */
+
+struct fstHier hier;
+struct fstCurrHier *curr_hier;
+fstHandle current_handle;
+char *curr_flat_hier_nam;
+int flat_hier_alloc_len;
+unsigned do_rewind : 1;
+char str_scope_nam[FST_ID_NAM_SIZ+1];
+char str_scope_comp[FST_ID_NAM_SIZ+1];
+
+unsigned fseek_failed : 1;
+
+/* self-buffered I/O for writes */
+
+#ifndef FST_WRITEX_DISABLE
+int writex_pos;
+int writex_fd;
+unsigned char writex_buf[FST_WRITEX_MAX];
+#endif
+
+char *f_nam;
+char *fh_nam;
+};
+
+
+int fstReaderFseeko(struct fstReaderContext *xc, FILE *stream, off_t offset, int whence)
+{
+int rc = fseeko(stream, offset, whence);
+
+if(rc<0)
+        {
+        xc->fseek_failed = 1;
+#ifdef FST_DEBUG
+        fprintf(stderr, "Seek to #%"PRId64" (whence = %d) failed!\n", offset, whence);
+        perror("Why");
+#endif
+        }
+
+return(rc);
+}
+
+
+#ifndef FST_WRITEX_DISABLE
+static void fstWritex(struct fstReaderContext *xc, void *v, int len)
+{
+unsigned char *s = (unsigned char *)v;
+
+if(len)
+        {
+        if(len < FST_WRITEX_MAX)
+                {
+                if(xc->writex_pos + len >= FST_WRITEX_MAX)
+                        {
+                        fstWritex(xc, NULL, 0);
+                        }
+
+                memcpy(xc->writex_buf + xc->writex_pos, s, len);
+                xc->writex_pos += len;
+                }
+                else
+                {
+                fstWritex(xc, NULL, 0);
+                if (write(xc->writex_fd, s, len)) { };
+                }
+        }
+        else
+        {
+        if(xc->writex_pos)
+                {
+                if(write(xc->writex_fd, xc->writex_buf, xc->writex_pos)) { };
+                xc->writex_pos = 0;
+                }
+        }
+}
+#endif
+
+
+/*
+ * scope -> flat name handling
+ */
+static void fstReaderDeallocateScopeData(struct fstReaderContext *xc)
+{
+struct fstCurrHier *chp;
+
+free(xc->curr_flat_hier_nam); xc->curr_flat_hier_nam = NULL;
+while(xc->curr_hier)
+        {
+        chp = xc->curr_hier->prev;
+        free(xc->curr_hier);
+        xc->curr_hier = chp;
+        }
+}
+
+
+const char *fstReaderGetCurrentFlatScope(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        return(xc->curr_flat_hier_nam ? xc->curr_flat_hier_nam : "");
+        }
+        else
+        {
+        return(NULL);
+        }
+}
+
+
+void *fstReaderGetCurrentScopeUserInfo(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        return(xc->curr_hier ? xc->curr_hier->user_info : NULL);
+        }
+        else
+        {
+        return(NULL);
+        }
+}
+
+
+const char *fstReaderPopScope(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc && xc->curr_hier)
+        {
+        struct fstCurrHier *ch = xc->curr_hier;
+        if(xc->curr_hier->prev)
+                {
+                xc->curr_flat_hier_nam[xc->curr_hier->prev->len] = 0;
+                }
+                else
+                {
+                *xc->curr_flat_hier_nam = 0;
+                }
+        xc->curr_hier = xc->curr_hier->prev;
+        free(ch);
+        return(xc->curr_flat_hier_nam ? xc->curr_flat_hier_nam : "");
+        }
+
+return(NULL);
+}
+
+
+void fstReaderResetScope(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        while(fstReaderPopScope(xc)); /* remove any already-built scoping info */
+        }
+}
+
+
+const char *fstReaderPushScope(void *ctx, const char *nam, void *user_info)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        struct fstCurrHier *ch = malloc(sizeof(struct fstCurrHier));
+        int chl = xc->curr_hier ? xc->curr_hier->len : 0;
+        int len = chl + 1 + strlen(nam);
+        if(len >= xc->flat_hier_alloc_len)
+                {
+                xc->curr_flat_hier_nam = xc->curr_flat_hier_nam ? realloc(xc->curr_flat_hier_nam, len+1) : malloc(len+1);
+                }
+
+        if(chl)
+                {
+                xc->curr_flat_hier_nam[chl] = '.';
+                strcpy(xc->curr_flat_hier_nam + chl + 1, nam);
+                }
+                else
+                {
+                strcpy(xc->curr_flat_hier_nam, nam);
+                len--;
+                }
+
+        ch->len = len;
+        ch->prev = xc->curr_hier;
+        ch->user_info = user_info;
+        xc->curr_hier = ch;
+        return(xc->curr_flat_hier_nam);
+        }
+
+return(NULL);
+}
+
+
+int fstReaderGetCurrentScopeLen(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc && xc->curr_hier)
+        {
+        return(xc->curr_hier->len);
+        }
+
+return(0);
+}
+
+
+int fstReaderGetFseekFailed(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        return(xc->fseek_failed != 0);
+        }
+
+return(0);
+}
+
+
+/*
+ * iter mask manipulation util functions
+ */
+int fstReaderGetFacProcessMask(void *ctx, fstHandle facidx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        facidx--;
+        if(facidx<xc->maxhandle)
+                {
+                int process_idx = facidx/8;
+                int process_bit = facidx&7;
+
+                return( (xc->process_mask[process_idx]&(1<<process_bit)) != 0 );
+                }
+        }
+return(0);
+}
+
+
+void fstReaderSetFacProcessMask(void *ctx, fstHandle facidx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        facidx--;
+        if(facidx<xc->maxhandle)
+                {
+                int idx = facidx/8;
+                int bitpos = facidx&7;
+
+                xc->process_mask[idx] |= (1<<bitpos);
+                }
+        }
+}
+
+
+void fstReaderClrFacProcessMask(void *ctx, fstHandle facidx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        facidx--;
+        if(facidx<xc->maxhandle)
+                {
+                int idx = facidx/8;
+                int bitpos = facidx&7;
+
+                xc->process_mask[idx] &= (~(1<<bitpos));
+                }
+        }
+}
+
+
+void fstReaderSetFacProcessMaskAll(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        memset(xc->process_mask, 0xff, (xc->maxhandle+7)/8);
+        }
+}
+
+
+void fstReaderClrFacProcessMaskAll(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        memset(xc->process_mask, 0x00, (xc->maxhandle+7)/8);
+        }
+}
+
+
+/*
+ * various utility read/write functions
+ */
+signed char fstReaderGetTimescale(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->timescale : 0);
+}
+
+
+uint64_t fstReaderGetStartTime(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->start_time : 0);
+}
+
+
+uint64_t fstReaderGetEndTime(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->end_time : 0);
+}
+
+
+uint64_t fstReaderGetMemoryUsedByWriter(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->mem_used_by_writer : 0);
+}
+
+
+uint64_t fstReaderGetScopeCount(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->scope_count : 0);
+}
+
+
+uint64_t fstReaderGetVarCount(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->var_count : 0);
+}
+
+
+fstHandle fstReaderGetMaxHandle(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->maxhandle : 0);
+}
+
+
+uint64_t fstReaderGetAliasCount(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->num_alias : 0);
+}
+
+
+uint64_t fstReaderGetValueChangeSectionCount(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->vc_section_count : 0);
+}
+
+
+int fstReaderGetDoubleEndianMatchState(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->double_endian_match : 0);
+}
+
+
+const char *fstReaderGetVersionString(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->version : NULL);
+}
+
+
+const char *fstReaderGetDateString(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->date : NULL);
+}
+
+
+int fstReaderGetFileType(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->filetype : FST_FT_VERILOG);
+}
+
+
+int64_t fstReaderGetTimezero(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->timezero : 0);
+}
+
+
+uint32_t fstReaderGetNumberDumpActivityChanges(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+return(xc ? xc->num_blackouts : 0);
+}
+
+
+uint64_t fstReaderGetDumpActivityChangeTime(void *ctx, uint32_t idx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc && (idx < xc->num_blackouts) && (xc->blackout_times))
+        {
+        return(xc->blackout_times[idx]);
+        }
+        else
+        {
+        return(0);
+        }
+}
+
+
+unsigned char fstReaderGetDumpActivityChangeValue(void *ctx, uint32_t idx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc && (idx < xc->num_blackouts) && (xc->blackout_activity))
+        {
+        return(xc->blackout_activity[idx]);
+        }
+        else
+        {
+        return(0);
+        }
+}
+
+
+void fstReaderSetLimitTimeRange(void *ctx, uint64_t start_time, uint64_t end_time)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        xc->limit_range_valid = 1;
+        xc->limit_range_start = start_time;
+        xc->limit_range_end = end_time;
+        }
+}
+
+
+void fstReaderSetUnlimitedTimeRange(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        xc->limit_range_valid = 0;
+        }
+}
+
+
+void fstReaderSetVcdExtensions(void *ctx, int enable)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        xc->use_vcd_extensions = (enable != 0);
+        }
+}
+
+
+void fstReaderIterBlocksSetNativeDoublesOnCallback(void *ctx, int enable)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        xc->native_doubles_for_cb = (enable != 0);
+        }
+}
+
+/*
+ * hierarchy processing
+ */
+static void fstVcdID(char *buf, unsigned int value)
+{
+char *pnt = buf;
+
+/* zero is illegal for a value...it is assumed they start at one */
+while (value)
+        {
+        value--;
+        *(pnt++) = (char)('!' + value % 94);
+        value = value / 94;
+        }
+
+*pnt = 0;
+}
+
+static int fstVcdIDForFwrite(char *buf, unsigned int value)
+{
+char *pnt = buf;
+
+/* zero is illegal for a value...it is assumed they start at one */
+while (value)
+        {
+        value--;
+        *(pnt++) = (char)('!' + value % 94);
+        value = value / 94;
+        }
+
+return(pnt - buf);
+}
+
+
+static int fstReaderRecreateHierFile(struct fstReaderContext *xc)
+{
+int pass_status = 1;
+
+if(!xc->fh)
+        {
+        off_t offs_cache = ftello(xc->f);
+        char *fnam = malloc(strlen(xc->filename) + 6 + 16 + 32 + 1);
+        unsigned char *mem = malloc(FST_GZIO_LEN);
+        off_t hl, uclen;
+        off_t clen = 0;
+        gzFile zhandle = NULL;
+        int zfd;
+        int htyp = FST_BL_SKIP;
+
+        /* can't handle both set at once should never happen in a real file */
+        if(!xc->contains_hier_section_lz4 && xc->contains_hier_section)
+                {
+                htyp = FST_BL_HIER;
+                }
+        else
+        if(xc->contains_hier_section_lz4 && !xc->contains_hier_section)
+                {
+                htyp = xc->contains_hier_section_lz4duo ? FST_BL_HIER_LZ4DUO : FST_BL_HIER_LZ4;
+                }
+
+        sprintf(fnam, "%s.hier_%d_%p", xc->filename, getpid(), (void *)xc);
+        fstReaderFseeko(xc, xc->f, xc->hier_pos, SEEK_SET);
+        uclen = fstReaderUint64(xc->f);
+#ifndef __MINGW32__
+        fflush(xc->f);
+#endif
+        if(htyp == FST_BL_HIER)
+                {
+                fstReaderFseeko(xc, xc->f, xc->hier_pos, SEEK_SET);
+                uclen = fstReaderUint64(xc->f);
+#ifndef __MINGW32__
+                fflush(xc->f);
+#endif
+                zfd = dup(fileno(xc->f));
+                zhandle = gzdopen(zfd, "rb");
+                if(!zhandle)
+                        {
+                        close(zfd);
+                        free(mem);
+                        free(fnam);
+                        return(0);
+                        }
+                }
+        else
+        if((htyp == FST_BL_HIER_LZ4) || (htyp == FST_BL_HIER_LZ4DUO))
+                {
+                fstReaderFseeko(xc, xc->f, xc->hier_pos - 8, SEEK_SET); /* get section len */
+                clen =  fstReaderUint64(xc->f) - 16;
+                uclen = fstReaderUint64(xc->f);
+#ifndef __MINGW32__
+                fflush(xc->f);
+#endif
+                }
+
+#ifndef __MINGW32__
+        xc->fh = fopen(fnam, "w+b");
+        if(!xc->fh)
+#endif
+                {
+                xc->fh = tmpfile_open(&xc->fh_nam);
+                free(fnam); fnam = NULL;
+                if(!xc->fh)
+                        {
+                        tmpfile_close(&xc->fh, &xc->fh_nam);
+                        free(mem);
+                        return(0);
+                        }
+                }
+
+#ifndef __MINGW32__
+        if(fnam) unlink(fnam);
+#endif
+
+        if(htyp == FST_BL_HIER)
+                {
+                for(hl = 0; hl < uclen; hl += FST_GZIO_LEN)
+                        {
+                        size_t len = ((uclen - hl) > FST_GZIO_LEN) ? FST_GZIO_LEN : (uclen - hl);
+                        size_t gzreadlen = gzread(zhandle, mem, len); /* rc should equal len... */
+                        size_t fwlen;
+
+                        if(gzreadlen != len)
+                                {
+                                pass_status = 0;
+                                break;
+                                }
+
+                        fwlen = fstFwrite(mem, len, 1, xc->fh);
+                        if(fwlen != 1)
+                                {
+                                pass_status = 0;
+                                break;
+                                }
+                        }
+                gzclose(zhandle);
+                }
+        else
+        if(htyp == FST_BL_HIER_LZ4DUO)
+                {
+                unsigned char *lz4_cmem  = malloc(clen);
+                unsigned char *lz4_ucmem = malloc(uclen);
+                unsigned char *lz4_ucmem2;
+                uint64_t uclen2;
+                int skiplen2 = 0;
+
+                fstFread(lz4_cmem, clen, 1, xc->f);
+
+                uclen2 = fstGetVarint64(lz4_cmem, &skiplen2);
+                lz4_ucmem2 = malloc(uclen2);
+                pass_status = (uclen2 == (uint64_t)LZ4_decompress_safe_partial ((char *)lz4_cmem + skiplen2, (char *)lz4_ucmem2, clen - skiplen2, uclen2, uclen2));
+                if(pass_status)
+                        {
+                        pass_status = (uclen == LZ4_decompress_safe_partial ((char *)lz4_ucmem2, (char *)lz4_ucmem, uclen2, uclen, uclen));
+
+                        if(fstFwrite(lz4_ucmem, uclen, 1, xc->fh) != 1)
+                                {
+                                pass_status = 0;
+                                }
+                        }
+
+                free(lz4_ucmem2);
+                free(lz4_ucmem);
+                free(lz4_cmem);
+                }
+        else
+        if(htyp == FST_BL_HIER_LZ4)
+                {
+                unsigned char *lz4_cmem  = malloc(clen);
+                unsigned char *lz4_ucmem = malloc(uclen);
+
+                fstFread(lz4_cmem, clen, 1, xc->f);
+                pass_status = (uclen == LZ4_decompress_safe_partial ((char *)lz4_cmem, (char *)lz4_ucmem, clen, uclen, uclen));
+
+                if(fstFwrite(lz4_ucmem, uclen, 1, xc->fh) != 1)
+                        {
+                        pass_status = 0;
+                        }
+
+                free(lz4_ucmem);
+                free(lz4_cmem);
+                }
+        else /* FST_BL_SKIP */
+                {
+                pass_status = 0;
+                }
+
+        free(mem);
+        free(fnam);
+
+        fstReaderFseeko(xc, xc->f, offs_cache, SEEK_SET);
+        }
+
+return(pass_status);
+}
+
+
+int fstReaderIterateHierRewind(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+int pass_status = 0;
+
+if(xc)
+        {
+        pass_status = 1;
+        if(!xc->fh)
+                {
+                pass_status = fstReaderRecreateHierFile(xc);
+                }
+
+        xc->do_rewind = 1;
+        }
+
+return(pass_status);
+}
+
+
+struct fstHier *fstReaderIterateHier(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+int isfeof;
+fstHandle alias;
+char *pnt;
+int ch;
+
+if(!xc) return(NULL);
+
+if(!xc->fh)
+        {
+        if(!fstReaderRecreateHierFile(xc))
+                {
+                return(NULL);
+                }
+        }
+
+if(xc->do_rewind)
+        {
+        xc->do_rewind = 0;
+        xc->current_handle = 0;
+        fstReaderFseeko(xc, xc->fh, 0, SEEK_SET);
+        clearerr(xc->fh);
+        }
+
+if(!(isfeof=feof(xc->fh)))
+        {
+        int tag = fgetc(xc->fh);
+        switch(tag)
+                {
+                case FST_ST_VCD_SCOPE:
+                        xc->hier.htyp = FST_HT_SCOPE;
+                        xc->hier.u.scope.typ = fgetc(xc->fh);
+                        xc->hier.u.scope.name = pnt = xc->str_scope_nam;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* scopename */
+                        *pnt = 0;
+                        xc->hier.u.scope.name_length = pnt - xc->hier.u.scope.name;
+
+                        xc->hier.u.scope.component = pnt = xc->str_scope_comp;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* scopecomp */
+                        *pnt = 0;
+                        xc->hier.u.scope.component_length = pnt - xc->hier.u.scope.component;
+                        break;
+
+                case FST_ST_VCD_UPSCOPE:
+                        xc->hier.htyp = FST_HT_UPSCOPE;
+                        break;
+
+                case FST_ST_GEN_ATTRBEGIN:
+                        xc->hier.htyp = FST_HT_ATTRBEGIN;
+                        xc->hier.u.attr.typ = fgetc(xc->fh);
+                        xc->hier.u.attr.subtype = fgetc(xc->fh);
+                        xc->hier.u.attr.name = pnt = xc->str_scope_nam;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* scopename */
+                        *pnt = 0;
+                        xc->hier.u.attr.name_length = pnt - xc->hier.u.scope.name;
+
+                        xc->hier.u.attr.arg = fstReaderVarint64(xc->fh);
+
+                        if(xc->hier.u.attr.typ == FST_AT_MISC)
+                                {
+                                if((xc->hier.u.attr.subtype == FST_MT_SOURCESTEM)||(xc->hier.u.attr.subtype == FST_MT_SOURCEISTEM))
+                                        {
+                                        int sidx_skiplen_dummy = 0;
+                                        xc->hier.u.attr.arg_from_name = fstGetVarint64((unsigned char *)xc->str_scope_nam, &sidx_skiplen_dummy);
+                                        }
+                                }
+                        break;
+
+                case FST_ST_GEN_ATTREND:
+                        xc->hier.htyp = FST_HT_ATTREND;
+                        break;
+
+                case FST_VT_VCD_EVENT:
+                case FST_VT_VCD_INTEGER:
+                case FST_VT_VCD_PARAMETER:
+                case FST_VT_VCD_REAL:
+                case FST_VT_VCD_REAL_PARAMETER:
+                case FST_VT_VCD_REG:
+                case FST_VT_VCD_SUPPLY0:
+                case FST_VT_VCD_SUPPLY1:
+                case FST_VT_VCD_TIME:
+                case FST_VT_VCD_TRI:
+                case FST_VT_VCD_TRIAND:
+                case FST_VT_VCD_TRIOR:
+                case FST_VT_VCD_TRIREG:
+                case FST_VT_VCD_TRI0:
+                case FST_VT_VCD_TRI1:
+                case FST_VT_VCD_WAND:
+                case FST_VT_VCD_WIRE:
+                case FST_VT_VCD_WOR:
+                case FST_VT_VCD_PORT:
+                case FST_VT_VCD_SPARRAY:
+                case FST_VT_VCD_REALTIME:
+                case FST_VT_GEN_STRING:
+                case FST_VT_SV_BIT:
+                case FST_VT_SV_LOGIC:
+                case FST_VT_SV_INT:
+                case FST_VT_SV_SHORTINT:
+                case FST_VT_SV_LONGINT:
+                case FST_VT_SV_BYTE:
+                case FST_VT_SV_ENUM:
+                case FST_VT_SV_SHORTREAL:
+                        xc->hier.htyp = FST_HT_VAR;
+                        xc->hier.u.var.svt_workspace = FST_SVT_NONE;
+                        xc->hier.u.var.sdt_workspace = FST_SDT_NONE;
+                        xc->hier.u.var.sxt_workspace = 0;
+                        xc->hier.u.var.typ = tag;
+                        xc->hier.u.var.direction = fgetc(xc->fh);
+                        xc->hier.u.var.name = pnt = xc->str_scope_nam;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* varname */
+                        *pnt = 0;
+                        xc->hier.u.var.name_length = pnt - xc->hier.u.var.name;
+                        xc->hier.u.var.length = fstReaderVarint32(xc->fh);
+                        if(tag == FST_VT_VCD_PORT)
+                                {
+                                xc->hier.u.var.length -= 2; /* removal of delimiting spaces */
+                                xc->hier.u.var.length /= 3; /* port -> signal size adjust */
+                                }
+
+                        alias = fstReaderVarint32(xc->fh);
+
+                        if(!alias)
+                                {
+                                xc->current_handle++;
+                                xc->hier.u.var.handle = xc->current_handle;
+                                xc->hier.u.var.is_alias = 0;
+                                }
+                                else
+                                {
+                                xc->hier.u.var.handle = alias;
+                                xc->hier.u.var.is_alias = 1;
+                                }
+
+                        break;
+
+                default:
+                        isfeof = 1;
+                        break;
+                }
+        }
+
+return(!isfeof ? &xc->hier : NULL);
+}
+
+
+int fstReaderProcessHier(void *ctx, FILE *fv)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+char *str;
+char *pnt;
+int ch, scopetype;
+int vartype;
+uint32_t len, alias;
+/* uint32_t maxvalpos=0; */
+unsigned int num_signal_dyn = 65536;
+int attrtype, subtype;
+uint64_t attrarg;
+fstHandle maxhandle_scanbuild;
+
+if(!xc) return(0);
+
+xc->longest_signal_value_len = 32; /* arbitrarily set at 32...this is much longer than an expanded double */
+
+if(!xc->fh)
+        {
+        if(!fstReaderRecreateHierFile(xc))
+                {
+                return(0);
+                }
+        }
+
+str = malloc(FST_ID_NAM_ATTR_SIZ+1);
+
+if(fv)
+        {
+        char time_dimension[2] = {0, 0};
+        int time_scale = 1;
+
+        fprintf(fv, "$date\n\t%s\n$end\n", xc->date);
+        fprintf(fv, "$version\n\t%s\n$end\n", xc->version);
+        if(xc->timezero) fprintf(fv, "$timezero\n\t%"PRId64"\n$end\n", xc->timezero);
+
+        switch(xc->timescale)
+                {
+                case  2:        time_scale = 100;               time_dimension[0] = 0;   break;
+                case  1:        time_scale = 10;
+                case  0:                                        time_dimension[0] = 0;   break;
+
+                case -1:        time_scale = 100;               time_dimension[0] = 'm'; break;
+                case -2:        time_scale = 10;
+                case -3:                                        time_dimension[0] = 'm'; break;
+
+                case -4:        time_scale = 100;               time_dimension[0] = 'u'; break;
+                case -5:        time_scale = 10;
+                case -6:                                        time_dimension[0] = 'u'; break;
+
+                case -10:       time_scale = 100;               time_dimension[0] = 'p'; break;
+                case -11:       time_scale = 10;
+                case -12:                                       time_dimension[0] = 'p'; break;
+
+                case -13:       time_scale = 100;               time_dimension[0] = 'f'; break;
+                case -14:       time_scale = 10;
+                case -15:                                       time_dimension[0] = 'f'; break;
+
+                case -16:       time_scale = 100;               time_dimension[0] = 'a'; break;
+                case -17:       time_scale = 10;
+                case -18:                                       time_dimension[0] = 'a'; break;
+
+                case -19:       time_scale = 100;               time_dimension[0] = 'z'; break;
+                case -20:       time_scale = 10;
+                case -21:                                       time_dimension[0] = 'z'; break;
+
+                case -7:        time_scale = 100;               time_dimension[0] = 'n'; break;
+                case -8:        time_scale = 10;
+                case -9:
+                default:                                        time_dimension[0] = 'n'; break;
+                }
+
+        if(fv) fprintf(fv, "$timescale\n\t%d%ss\n$end\n", time_scale, time_dimension);
+        }
+
+xc->maxhandle = 0;
+xc->num_alias = 0;
+
+free(xc->signal_lens);
+xc->signal_lens = malloc(num_signal_dyn*sizeof(uint32_t));
+
+free(xc->signal_typs);
+xc->signal_typs = malloc(num_signal_dyn*sizeof(unsigned char));
+
+fstReaderFseeko(xc, xc->fh, 0, SEEK_SET);
+while(!feof(xc->fh))
+        {
+        int tag = fgetc(xc->fh);
+        switch(tag)
+                {
+                case FST_ST_VCD_SCOPE:
+                        scopetype = fgetc(xc->fh);
+                        if((scopetype < FST_ST_MIN) || (scopetype > FST_ST_MAX)) scopetype = FST_ST_VCD_MODULE;
+                        pnt = str;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* scopename */
+                        *pnt = 0;
+                        while(fgetc(xc->fh)) { }; /* scopecomp */
+
+                        if(fv) fprintf(fv, "$scope %s %s $end\n", modtypes[scopetype], str);
+                        break;
+
+                case FST_ST_VCD_UPSCOPE:
+                        if(fv) fprintf(fv, "$upscope $end\n");
+                        break;
+
+                case FST_ST_GEN_ATTRBEGIN:
+                        attrtype = fgetc(xc->fh);
+                        subtype = fgetc(xc->fh);
+                        pnt = str;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* attrname */
+                        *pnt = 0;
+
+                        if(!str[0]) { strcpy(str, "\"\""); }
+
+                        attrarg = fstReaderVarint64(xc->fh);
+
+                        if(fv && xc->use_vcd_extensions)
+                                {
+                                switch(attrtype)
+                                        {
+                                        case FST_AT_ARRAY:      if((subtype < FST_AR_NONE) || (subtype > FST_AR_MAX)) subtype = FST_AR_NONE;
+                                                                fprintf(fv, "$attrbegin %s %s %s %"PRId64" $end\n", attrtypes[attrtype], arraytypes[subtype], str, attrarg);
+                                                                break;
+                                        case FST_AT_ENUM:       if((subtype < FST_EV_SV_INTEGER) || (subtype > FST_EV_MAX)) subtype = FST_EV_SV_INTEGER;
+                                                                fprintf(fv, "$attrbegin %s %s %s %"PRId64" $end\n", attrtypes[attrtype], enumvaluetypes[subtype], str, attrarg);
+                                                                break;
+                                        case FST_AT_PACK:       if((subtype < FST_PT_NONE) || (subtype > FST_PT_MAX)) subtype = FST_PT_NONE;
+                                                                fprintf(fv, "$attrbegin %s %s %s %"PRId64" $end\n", attrtypes[attrtype], packtypes[subtype], str, attrarg);
+                                                                break;
+                                        case FST_AT_MISC:
+                                        default:                attrtype = FST_AT_MISC;
+                                                                if(subtype == FST_MT_COMMENT)
+                                                                        {
+                                                                        fprintf(fv, "$comment\n\t%s\n$end\n", str);
+                                                                        }
+                                                                        else
+                                                                        {
+                                                                        if((subtype == FST_MT_SOURCESTEM)||(subtype == FST_MT_SOURCEISTEM))
+                                                                                {
+                                                                                int sidx_skiplen_dummy = 0;
+                                                                                uint64_t sidx = fstGetVarint64((unsigned char *)str, &sidx_skiplen_dummy);
+
+                                                                                fprintf(fv, "$attrbegin %s %02x %"PRId64" %"PRId64" $end\n", attrtypes[attrtype], subtype, sidx, attrarg);
+                                                                                }
+                                                                                else
+                                                                                {
+                                                                                fprintf(fv, "$attrbegin %s %02x %s %"PRId64" $end\n", attrtypes[attrtype], subtype, str, attrarg);
+                                                                                }
+                                                                        }
+                                                                break;
+                                        }
+                                }
+                        break;
+
+                case FST_ST_GEN_ATTREND:
+                        if(fv && xc->use_vcd_extensions) fprintf(fv, "$attrend $end\n");
+                        break;
+
+                case FST_VT_VCD_EVENT:
+                case FST_VT_VCD_INTEGER:
+                case FST_VT_VCD_PARAMETER:
+                case FST_VT_VCD_REAL:
+                case FST_VT_VCD_REAL_PARAMETER:
+                case FST_VT_VCD_REG:
+                case FST_VT_VCD_SUPPLY0:
+                case FST_VT_VCD_SUPPLY1:
+                case FST_VT_VCD_TIME:
+                case FST_VT_VCD_TRI:
+                case FST_VT_VCD_TRIAND:
+                case FST_VT_VCD_TRIOR:
+                case FST_VT_VCD_TRIREG:
+                case FST_VT_VCD_TRI0:
+                case FST_VT_VCD_TRI1:
+                case FST_VT_VCD_WAND:
+                case FST_VT_VCD_WIRE:
+                case FST_VT_VCD_WOR:
+                case FST_VT_VCD_PORT:
+                case FST_VT_VCD_SPARRAY:
+                case FST_VT_VCD_REALTIME:
+                case FST_VT_GEN_STRING:
+                case FST_VT_SV_BIT:
+                case FST_VT_SV_LOGIC:
+                case FST_VT_SV_INT:
+                case FST_VT_SV_SHORTINT:
+                case FST_VT_SV_LONGINT:
+                case FST_VT_SV_BYTE:
+                case FST_VT_SV_ENUM:
+                case FST_VT_SV_SHORTREAL:
+                        vartype = tag;
+                        /* vardir = */ fgetc(xc->fh); /* unused in VCD reader, but need to advance read pointer */
+                        pnt = str;
+                        while((ch = fgetc(xc->fh)))
+                                {
+                                *(pnt++) = ch;
+                                }; /* varname */
+                        *pnt = 0;
+                        len = fstReaderVarint32(xc->fh);
+                        alias = fstReaderVarint32(xc->fh);
+
+                        if(!alias)
+                                {
+                                if(xc->maxhandle == num_signal_dyn)
+                                        {
+                                        num_signal_dyn *= 2;
+                                        xc->signal_lens = realloc(xc->signal_lens, num_signal_dyn*sizeof(uint32_t));
+                                        xc->signal_typs = realloc(xc->signal_typs, num_signal_dyn*sizeof(unsigned char));
+                                        }
+                                xc->signal_lens[xc->maxhandle] = len;
+                                xc->signal_typs[xc->maxhandle] = vartype;
+
+                                /* maxvalpos+=len; */
+                                if(len > xc->longest_signal_value_len)
+                                        {
+                                        xc->longest_signal_value_len = len;
+                                        }
+
+                                if((vartype == FST_VT_VCD_REAL) || (vartype == FST_VT_VCD_REAL_PARAMETER) || (vartype == FST_VT_VCD_REALTIME) || (vartype == FST_VT_SV_SHORTREAL))
+                                        {
+                                        len = (vartype != FST_VT_SV_SHORTREAL) ? 64 : 32;
+                                        xc->signal_typs[xc->maxhandle] = FST_VT_VCD_REAL;
+                                        }
+                                if(fv)
+                                        {
+                                        char vcdid_buf[16];
+                                        uint32_t modlen = (vartype != FST_VT_VCD_PORT) ? len : ((len - 2) / 3);
+                                        fstVcdID(vcdid_buf, xc->maxhandle+1);
+                                        fprintf(fv, "$var %s %"PRIu32" %s %s $end\n", vartypes[vartype], modlen, vcdid_buf, str);
+                                        }
+                                xc->maxhandle++;
+                                }
+                                else
+                                {
+                                if((vartype == FST_VT_VCD_REAL) || (vartype == FST_VT_VCD_REAL_PARAMETER) || (vartype == FST_VT_VCD_REALTIME) || (vartype == FST_VT_SV_SHORTREAL))
+                                        {
+                                        len = (vartype != FST_VT_SV_SHORTREAL) ? 64 : 32;
+                                        xc->signal_typs[xc->maxhandle] = FST_VT_VCD_REAL;
+                                        }
+                                if(fv)
+                                        {
+                                        char vcdid_buf[16];
+                                        uint32_t modlen = (vartype != FST_VT_VCD_PORT) ? len : ((len - 2) / 3);
+                                        fstVcdID(vcdid_buf, alias);
+                                        fprintf(fv, "$var %s %"PRIu32" %s %s $end\n", vartypes[vartype], modlen, vcdid_buf, str);
+                                        }
+                                xc->num_alias++;
+                                }
+
+                        break;
+
+                default:
+                        break;
+                }
+        }
+if(fv) fprintf(fv, "$enddefinitions $end\n");
+
+maxhandle_scanbuild = xc->maxhandle ? xc->maxhandle : 1; /*scan-build warning suppression, in reality we have at least one signal */
+
+xc->signal_lens = realloc(xc->signal_lens, maxhandle_scanbuild*sizeof(uint32_t));
+xc->signal_typs = realloc(xc->signal_typs, maxhandle_scanbuild*sizeof(unsigned char));
+
+free(xc->process_mask);
+xc->process_mask = calloc(1, (maxhandle_scanbuild+7)/8);
+
+free(xc->temp_signal_value_buf);
+xc->temp_signal_value_buf = malloc(xc->longest_signal_value_len + 1);
+
+xc->var_count = xc->maxhandle + xc->num_alias;
+
+free(str);
+return(1);
+}
+
+
+/*
+ * reader file open/close functions
+ */
+int fstReaderInit(struct fstReaderContext *xc)
+{
+off_t blkpos = 0;
+off_t endfile;
+uint64_t seclen;
+int sectype;
+uint64_t vc_section_count_actual = 0;
+int hdr_incomplete = 0;
+int hdr_seen = 0;
+int gzread_pass_status = 1;
+
+sectype = fgetc(xc->f);
+if(sectype == FST_BL_ZWRAPPER)
+        {
+        FILE *fcomp;
+        off_t offpnt, uclen;
+        char gz_membuf[FST_GZIO_LEN];
+        void *zhandle;
+        int zfd;
+        int flen = strlen(xc->filename);
+        char *hf;
+
+        seclen = fstReaderUint64(xc->f);
+        uclen = fstReaderUint64(xc->f);
+
+        if(!seclen) return(0); /* not finished compressing, this is a failed read */
+
+        hf = calloc(1, flen + 16 + 32 + 1);
+
+        sprintf(hf, "%s.upk_%d_%p", xc->filename, getpid(), (void *)xc);
+        fcomp = fopen(hf, "w+b");
+        if(!fcomp)
+                {
+                fcomp = tmpfile_open(&xc->f_nam);
+                free(hf); hf = NULL;
+                if(!fcomp) { tmpfile_close(&fcomp, &xc->f_nam); return(0); }
+                }
+
+#if defined(FST_MACOSX)
+        setvbuf(fcomp, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
+#endif
+
+#ifdef __MINGW32__
+        setvbuf(fcomp, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
+        xc->filename_unpacked = hf;
+#else
+        if(hf)
+                {
+                unlink(hf);
+                free(hf);
+                }
+#endif
+
+        fstReaderFseeko(xc, xc->f, 1+8+8, SEEK_SET);
+#ifndef __MINGW32__
+        fflush(xc->f);
+#endif
+
+        zfd = dup(fileno(xc->f));
+        zhandle = gzdopen(zfd, "rb");
+        if(zhandle)
+                {
+                for(offpnt = 0; offpnt < uclen; offpnt += FST_GZIO_LEN)
+                        {
+                        size_t this_len = ((uclen - offpnt) > FST_GZIO_LEN) ? FST_GZIO_LEN : (uclen - offpnt);
+                        size_t gzreadlen = gzread(zhandle, gz_membuf, this_len);
+                        size_t fwlen;
+
+                        if(gzreadlen != this_len)
+                                {
+                                gzread_pass_status = 0;
+                                break;
+                                }
+                        fwlen = fstFwrite(gz_membuf, this_len, 1, fcomp);
+                        if(fwlen != 1)
+                                {
+                                gzread_pass_status = 0;
+                                break;
+                                }
+                        }
+                gzclose(zhandle);
+                }
+                else
+                {
+                close(zfd);
+                }
+        fflush(fcomp);
+        fclose(xc->f);
+        xc->f = fcomp;
+        }
+
+if(gzread_pass_status)
+        {
+        fstReaderFseeko(xc, xc->f, 0, SEEK_END);
+        endfile = ftello(xc->f);
+
+        while(blkpos < endfile)
+                {
+                fstReaderFseeko(xc, xc->f, blkpos, SEEK_SET);
+
+                sectype = fgetc(xc->f);
+                seclen = fstReaderUint64(xc->f);
+
+                if(sectype == EOF)
+                        {
+                        break;
+                        }
+
+                if((hdr_incomplete) && (!seclen))
+                        {
+                        break;
+                        }
+
+                if(!hdr_seen && (sectype != FST_BL_HDR))
+                        {
+                        break;
+                        }
+
+                blkpos++;
+                if(sectype == FST_BL_HDR)
+                        {
+                        if(!hdr_seen)
+                                {
+                                int ch;
+                                double dcheck;
+
+                                xc->start_time = fstReaderUint64(xc->f);
+                                xc->end_time = fstReaderUint64(xc->f);
+
+                                hdr_incomplete = (xc->start_time == 0) && (xc->end_time == 0);
+
+                                fstFread(&dcheck, 8, 1, xc->f);
+                                xc->double_endian_match = (dcheck == FST_DOUBLE_ENDTEST);
+                                if(!xc->double_endian_match)
+                                        {
+                                        union   {
+                                                unsigned char rvs_buf[8];
+                                                double d;
+                                                } vu;
+
+                                        unsigned char *dcheck_alias = (unsigned char *)&dcheck;
+                                        int rvs_idx;
+
+                                        for(rvs_idx=0;rvs_idx<8;rvs_idx++)
+                                                {
+                                                vu.rvs_buf[rvs_idx] = dcheck_alias[7-rvs_idx];
+                                                }
+                                        if(vu.d != FST_DOUBLE_ENDTEST)
+                                                {
+                                                break; /* either corrupt file or wrong architecture (offset +33 also functions as matchword) */
+                                                }
+                                        }
+
+                                hdr_seen = 1;
+
+                                xc->mem_used_by_writer = fstReaderUint64(xc->f);
+                                xc->scope_count = fstReaderUint64(xc->f);
+                                xc->var_count = fstReaderUint64(xc->f);
+                                xc->maxhandle = fstReaderUint64(xc->f);
+                                xc->num_alias = xc->var_count - xc->maxhandle;
+                                xc->vc_section_count = fstReaderUint64(xc->f);
+                                ch = fgetc(xc->f);
+                                xc->timescale = (signed char)ch;
+                                fstFread(xc->version, FST_HDR_SIM_VERSION_SIZE, 1, xc->f);
+                                xc->version[FST_HDR_SIM_VERSION_SIZE] = 0;
+                                fstFread(xc->date, FST_HDR_DATE_SIZE, 1, xc->f);
+                                xc->date[FST_HDR_DATE_SIZE] = 0;
+                                ch = fgetc(xc->f);
+                                xc->filetype = (unsigned char)ch;
+                                xc->timezero = fstReaderUint64(xc->f);
+                                }
+                        }
+                else if((sectype == FST_BL_VCDATA) || (sectype == FST_BL_VCDATA_DYN_ALIAS) || (sectype == FST_BL_VCDATA_DYN_ALIAS2))
+                        {
+                        if(hdr_incomplete)
+                                {
+                                uint64_t bt = fstReaderUint64(xc->f);
+                                xc->end_time = fstReaderUint64(xc->f);
+
+                                if(!vc_section_count_actual) { xc->start_time = bt; }
+                                }
+
+                        vc_section_count_actual++;
+                        }
+                else if(sectype == FST_BL_GEOM)
+                        {
+                        if(!hdr_incomplete)
+                                {
+                                uint64_t clen = seclen - 24;
+                                uint64_t uclen = fstReaderUint64(xc->f);
+                                unsigned char *ucdata = malloc(uclen);
+                                unsigned char *pnt = ucdata;
+                                unsigned int i;
+
+                                xc->contains_geom_section = 1;
+                                xc->maxhandle = fstReaderUint64(xc->f);
+                                xc->longest_signal_value_len = 32; /* arbitrarily set at 32...this is much longer than an expanded double */
+
+                                free(xc->process_mask);
+                                xc->process_mask = calloc(1, (xc->maxhandle+7)/8);
+
+                                if(clen != uclen)
+                                        {
+                                        unsigned char *cdata = malloc(clen);
+                                        unsigned long destlen = uclen;
+                                        unsigned long sourcelen = clen;
+                                        int rc;
+
+                                        fstFread(cdata, clen, 1, xc->f);
+                                        rc = uncompress(ucdata, &destlen, cdata, sourcelen);
+
+                                        if(rc != Z_OK)
+                                                {
+                                                printf("geom uncompress rc = %d\n", rc);
+                                                exit(255);
+                                                }
+
+                                        free(cdata);
+                                        }
+                                        else
+                                        {
+                                        fstFread(ucdata, uclen, 1, xc->f);
+                                        }
+
+                                free(xc->signal_lens);
+                                xc->signal_lens = malloc(sizeof(uint32_t) * xc->maxhandle);
+                                free(xc->signal_typs);
+                                xc->signal_typs = malloc(sizeof(unsigned char) * xc->maxhandle);
+
+                                for(i=0;i<xc->maxhandle;i++)
+                                        {
+                                        int skiplen;
+                                        uint64_t val = fstGetVarint32(pnt, &skiplen);
+
+                                        pnt += skiplen;
+
+                                        if(val)
+                                                {
+                                                xc->signal_lens[i] = (val != 0xFFFFFFFF) ? val : 0;
+                                                xc->signal_typs[i] = FST_VT_VCD_WIRE;
+                                                if(xc->signal_lens[i] > xc->longest_signal_value_len)
+                                                        {
+                                                        xc->longest_signal_value_len = xc->signal_lens[i];
+                                                        }
+                                                }
+                                                else
+                                                {
+                                                xc->signal_lens[i] = 8; /* backpatch in real */
+                                                xc->signal_typs[i] = FST_VT_VCD_REAL;
+                                                /* xc->longest_signal_value_len handled above by overly large init size */
+                                                }
+                                        }
+
+                                free(xc->temp_signal_value_buf);
+                                xc->temp_signal_value_buf = malloc(xc->longest_signal_value_len + 1);
+
+                                free(ucdata);
+                                }
+                        }
+                else if(sectype == FST_BL_HIER)
+                        {
+                        xc->contains_hier_section = 1;
+                        xc->hier_pos = ftello(xc->f);
+                        }
+                else if(sectype == FST_BL_HIER_LZ4DUO)
+                        {
+                        xc->contains_hier_section_lz4    = 1;
+                        xc->contains_hier_section_lz4duo = 1;
+                        xc->hier_pos = ftello(xc->f);
+                        }
+                else if(sectype == FST_BL_HIER_LZ4)
+                        {
+                        xc->contains_hier_section_lz4 = 1;
+                        xc->hier_pos = ftello(xc->f);
+                        }
+                else if(sectype == FST_BL_BLACKOUT)
+                        {
+                        uint32_t i;
+                        uint64_t cur_bl = 0;
+                        uint64_t delta;
+
+                        xc->num_blackouts = fstReaderVarint32(xc->f);
+                        free(xc->blackout_times);
+                        xc->blackout_times = calloc(xc->num_blackouts, sizeof(uint64_t));
+                        free(xc->blackout_activity);
+                        xc->blackout_activity = calloc(xc->num_blackouts, sizeof(unsigned char));
+
+                        for(i=0;i<xc->num_blackouts;i++)
+                                {
+                                xc->blackout_activity[i] = fgetc(xc->f) != 0;
+                                delta = fstReaderVarint64(xc->f);
+                                cur_bl += delta;
+                                xc->blackout_times[i] = cur_bl;
+                                }
+                        }
+
+                blkpos += seclen;
+                if(!hdr_seen) break;
+                }
+
+        if(hdr_seen)
+                {
+                if(xc->vc_section_count != vc_section_count_actual)
+                        {
+                        xc->vc_section_count = vc_section_count_actual;
+                        }
+
+                if(!xc->contains_geom_section)
+                        {
+                        fstReaderProcessHier(xc, NULL); /* recreate signal_lens/signal_typs info */
+                        }
+                }
+        }
+
+return(hdr_seen);
+}
+
+
+void *fstReaderOpenForUtilitiesOnly(void)
+{
+struct fstReaderContext *xc = calloc(1, sizeof(struct fstReaderContext));
+
+return(xc);
+}
+
+
+void *fstReaderOpen(const char *nam)
+{
+struct fstReaderContext *xc = calloc(1, sizeof(struct fstReaderContext));
+
+if((!nam)||(!(xc->f=fopen(nam, "rb"))))
+        {
+        free(xc);
+        xc=NULL;
+        }
+        else
+        {
+        int flen = strlen(nam);
+        char *hf = calloc(1, flen + 6);
+        int rc;
+
+#if defined(__MINGW32__) || defined(FST_MACOSX)
+        setvbuf(xc->f, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
+#endif
+
+        memcpy(hf, nam, flen);
+        strcpy(hf + flen, ".hier");
+        xc->fh = fopen(hf, "rb");
+
+        free(hf);
+        xc->filename = strdup(nam);
+        rc = fstReaderInit(xc);
+
+        if((rc) && (xc->vc_section_count) && (xc->maxhandle) && ((xc->fh)||(xc->contains_hier_section||(xc->contains_hier_section_lz4))))
+                {
+                /* more init */
+                xc->do_rewind = 1;
+                }
+                else
+                {
+                fstReaderClose(xc);
+                xc = NULL;
+                }
+        }
+
+return(xc);
+}
+
+
+static void fstReaderDeallocateRvatData(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+if(xc)
+        {
+        free(xc->rvat_chain_mem); xc->rvat_chain_mem = NULL;
+        free(xc->rvat_frame_data); xc->rvat_frame_data = NULL;
+        free(xc->rvat_time_table); xc->rvat_time_table = NULL;
+        free(xc->rvat_chain_table); xc->rvat_chain_table = NULL;
+        free(xc->rvat_chain_table_lengths); xc->rvat_chain_table_lengths = NULL;
+
+        xc->rvat_data_valid = 0;
+        }
+}
+
+
+void fstReaderClose(void *ctx)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+if(xc)
+        {
+        fstReaderDeallocateScopeData(xc);
+        fstReaderDeallocateRvatData(xc);
+        free(xc->rvat_sig_offs); xc->rvat_sig_offs = NULL;
+
+        free(xc->process_mask); xc->process_mask = NULL;
+        free(xc->blackout_times); xc->blackout_times = NULL;
+        free(xc->blackout_activity); xc->blackout_activity = NULL;
+        free(xc->temp_signal_value_buf); xc->temp_signal_value_buf = NULL;
+        free(xc->signal_typs); xc->signal_typs = NULL;
+        free(xc->signal_lens); xc->signal_lens = NULL;
+        free(xc->filename); xc->filename = NULL;
+
+        if(xc->fh)
+                {
+                tmpfile_close(&xc->fh, &xc->fh_nam);
+                }
+
+        if(xc->f)
+                {
+                tmpfile_close(&xc->f, &xc->f_nam);
+                if(xc->filename_unpacked)
+                        {
+                        unlink(xc->filename_unpacked);
+                        free(xc->filename_unpacked);
+                        }
+                }
+
+        free(xc);
+        }
+}
+
+
+/*
+ * read processing
+ */
+
+/* normal read which re-interleaves the value change data */
+int fstReaderIterBlocks(void *ctx,
+        void (*value_change_callback)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value),
+        void *user_callback_data_pointer, FILE *fv)
+{
+return(fstReaderIterBlocks2(ctx, value_change_callback, NULL, user_callback_data_pointer, fv));
+}
+
+
+int fstReaderIterBlocks2(void *ctx,
+        void (*value_change_callback)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value),
+        void (*value_change_callback_varlen)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value, uint32_t len),
+        void *user_callback_data_pointer, FILE *fv)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+
+uint64_t previous_time = UINT64_MAX;
+uint64_t *time_table = NULL;
+uint64_t tsec_nitems;
+unsigned int secnum = 0;
+int blocks_skipped = 0;
+off_t blkpos = 0;
+uint64_t seclen, beg_tim;
+#ifdef FST_DEBUG
+uint64_t end_tim;
+#endif
+uint64_t frame_uclen, frame_clen, frame_maxhandle, vc_maxhandle;
+off_t vc_start;
+off_t indx_pntr, indx_pos;
+off_t *chain_table = NULL;
+uint32_t *chain_table_lengths = NULL;
+unsigned char *chain_cmem;
+unsigned char *pnt;
+long chain_clen;
+fstHandle idx, pidx=0, i;
+uint64_t pval;
+uint64_t vc_maxhandle_largest = 0;
+uint64_t tsec_uclen = 0, tsec_clen = 0;
+int sectype;
+uint64_t mem_required_for_traversal;
+unsigned char *mem_for_traversal = NULL;
+uint32_t traversal_mem_offs;
+uint32_t *scatterptr, *headptr, *length_remaining;
+uint32_t cur_blackout = 0;
+int packtype;
+unsigned char *mc_mem = NULL;
+uint32_t mc_mem_len; /* corresponds to largest value encountered in chain_table_lengths[i] */
+
+if(!xc) return(0);
+
+scatterptr = calloc(xc->maxhandle, sizeof(uint32_t));
+headptr = calloc(xc->maxhandle, sizeof(uint32_t));
+length_remaining = calloc(xc->maxhandle, sizeof(uint32_t));
+
+if(fv)
+        {
+        fprintf(fv, "$dumpvars\n");
+#ifndef FST_WRITEX_DISABLE
+        fflush(fv);
+        setvbuf(fv, (char *) NULL, _IONBF, 0); /* even buffered IO is slow so disable it and use our own routines that don't need seeking */
+        xc->writex_fd = fileno(fv);
+#endif
+        }
+
+for(;;)
+        {
+        uint32_t *tc_head = NULL;
+        traversal_mem_offs = 0;
+
+        fstReaderFseeko(xc, xc->f, blkpos, SEEK_SET);
+
+        sectype = fgetc(xc->f);
+        seclen = fstReaderUint64(xc->f);
+
+        if((sectype == EOF) || (sectype == FST_BL_SKIP))
+                {
+#ifdef FST_DEBUG
+                fprintf(stderr, "<< EOF >>\n");
+#endif
+                break;
+                }
+
+        blkpos++;
+        if((sectype != FST_BL_VCDATA) && (sectype != FST_BL_VCDATA_DYN_ALIAS) && (sectype != FST_BL_VCDATA_DYN_ALIAS2))
+                {
+                blkpos += seclen;
+                continue;
+                }
+
+        if(!seclen) break;
+
+        beg_tim = fstReaderUint64(xc->f);
+#ifdef FST_DEBUG
+        end_tim =
+#endif
+        fstReaderUint64(xc->f);
+
+        if(xc->limit_range_valid)
+                {
+                if(beg_tim < xc->limit_range_start)
+                        {
+                        blocks_skipped++;
+                        blkpos += seclen;
+                        continue;
+                        }
+
+                if(beg_tim > xc->limit_range_end) /* likely the compare in for(i=0;i<tsec_nitems;i++) below would do this earlier */
+                        {
+                        break;
+                        }
+                }
+
+
+        mem_required_for_traversal = fstReaderUint64(xc->f);
+        mem_for_traversal = malloc(mem_required_for_traversal + 66); /* add in potential fastlz overhead */
+#ifdef FST_DEBUG
+        fprintf(stderr, "sec: %u seclen: %d begtim: %d endtim: %d\n",
+                secnum, (int)seclen, (int)beg_tim, (int)end_tim);
+        fprintf(stderr, "\tmem_required_for_traversal: %d\n", (int)mem_required_for_traversal);
+#endif
+        /* process time block */
+        {
+        unsigned char *ucdata;
+        unsigned char *cdata;
+        unsigned long destlen /* = tsec_uclen */; /* scan-build */
+        unsigned long sourcelen /*= tsec_clen */; /* scan-build */
+        int rc;
+        unsigned char *tpnt;
+        uint64_t tpval;
+        unsigned int ti;
+
+        if(fstReaderFseeko(xc, xc->f, blkpos + seclen - 24, SEEK_SET) != 0) break;
+        tsec_uclen = fstReaderUint64(xc->f);
+        tsec_clen = fstReaderUint64(xc->f);
+        tsec_nitems = fstReaderUint64(xc->f);
+#ifdef FST_DEBUG
+        fprintf(stderr, "\ttime section unc: %d, com: %d (%d items)\n",
+                (int)tsec_uclen, (int)tsec_clen, (int)tsec_nitems);
+#endif
+        if(tsec_clen > seclen) break; /* corrupted tsec_clen: by definition it can't be larger than size of section */
+        ucdata = malloc(tsec_uclen);
+        if(!ucdata) break; /* malloc fail as tsec_uclen out of range from corrupted file */
+        destlen = tsec_uclen;
+        sourcelen = tsec_clen;
+
+        fstReaderFseeko(xc, xc->f, -24 - ((off_t)tsec_clen), SEEK_CUR);
+
+        if(tsec_uclen != tsec_clen)
+                {
+                cdata = malloc(tsec_clen);
+                fstFread(cdata, tsec_clen, 1, xc->f);
+
+                rc = uncompress(ucdata, &destlen, cdata, sourcelen);
+
+                if(rc != Z_OK)
+                        {
+                        printf("tsec uncompress rc = %d\n", rc);
+                        exit(255);
+                        }
+
+                free(cdata);
+                }
+                else
+                {
+                fstFread(ucdata, tsec_uclen, 1, xc->f);
+                }
+
+        free(time_table);
+        time_table = calloc(tsec_nitems, sizeof(uint64_t));
+        tpnt = ucdata;
+        tpval = 0;
+        for(ti=0;ti<tsec_nitems;ti++)
+                {
+                int skiplen;
+                uint64_t val = fstGetVarint64(tpnt, &skiplen);
+                tpval = time_table[ti] = tpval + val;
+                tpnt += skiplen;
+                }
+
+        tc_head = calloc(tsec_nitems /* scan-build */ ? tsec_nitems : 1, sizeof(uint32_t));
+        free(ucdata);
+        }
+
+        fstReaderFseeko(xc, xc->f, blkpos+32, SEEK_SET);
+
+        frame_uclen = fstReaderVarint64(xc->f);
+        frame_clen = fstReaderVarint64(xc->f);
+        frame_maxhandle = fstReaderVarint64(xc->f);
+
+        if(secnum == 0)
+                {
+                if((beg_tim != time_table[0]) || (blocks_skipped))
+                        {
+                        unsigned char *mu = malloc(frame_uclen);
+                        uint32_t sig_offs = 0;
+
+                        if(fv)
+                                {
+                                char wx_buf[32];
+                                int wx_len;
+
+                                if(beg_tim)
+                                        {
+                                        wx_len = sprintf(wx_buf, "#%"PRIu64"\n", beg_tim);
+                                        fstWritex(xc, wx_buf, wx_len);
+                                        }
+                                if((xc->num_blackouts)&&(cur_blackout != xc->num_blackouts))
+                                        {
+                                        if(beg_tim == xc->blackout_times[cur_blackout])
+                                                {
+                                                wx_len = sprintf(wx_buf, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
+                                                fstWritex(xc, wx_buf, wx_len);
+                                                }
+                                        }
+                                }
+
+                        if(frame_uclen == frame_clen)
+                                {
+                                fstFread(mu, frame_uclen, 1, xc->f);
+                                }
+                                else
+                                {
+                                unsigned char *mc = malloc(frame_clen);
+                                int rc;
+
+                                unsigned long destlen = frame_uclen;
+                                unsigned long sourcelen = frame_clen;
+
+                                fstFread(mc, sourcelen, 1, xc->f);
+                                rc = uncompress(mu, &destlen, mc, sourcelen);
+                                if(rc != Z_OK)
+                                        {
+                                        printf("rc: %d\n", rc);
+                                        exit(255);
+                                        }
+                                free(mc);
+                                }
+
+
+                        for(idx=0;idx<frame_maxhandle;idx++)
+                                {
+                                int process_idx = idx/8;
+                                int process_bit = idx&7;
+
+                                if(xc->process_mask[process_idx]&(1<<process_bit))
+                                        {
+                                        if(xc->signal_lens[idx] <= 1)
+                                                {
+                                                if(xc->signal_lens[idx] == 1)
+                                                        {
+                                                        unsigned char val = mu[sig_offs];
+                                                        if(value_change_callback)
+                                                                {
+                                                                xc->temp_signal_value_buf[0] = val;
+                                                                xc->temp_signal_value_buf[1] = 0;
+                                                                value_change_callback(user_callback_data_pointer, beg_tim, idx+1, xc->temp_signal_value_buf);
+                                                                }
+                                                                else
+                                                                {
+                                                                if(fv)
+                                                                        {
+                                                                        char vcd_id[16];
+
+                                                                        int vcdid_len = fstVcdIDForFwrite(vcd_id+1, idx+1);
+                                                                        vcd_id[0] = val; /* collapse 3 writes into one I/O call */
+                                                                        vcd_id[vcdid_len + 1] = '\n';
+                                                                        fstWritex(xc, vcd_id, vcdid_len + 2);
+                                                                        }
+                                                                }
+                                                        }
+                                                        else
+                                                        {
+                                                        /* variable-length ("0" length) records have no initial state */
+                                                        }
+                                                }
+                                                else
+                                                {
+                                                if(xc->signal_typs[idx] != FST_VT_VCD_REAL)
+                                                        {
+                                                        if(value_change_callback)
+                                                                {
+                                                                memcpy(xc->temp_signal_value_buf, mu+sig_offs, xc->signal_lens[idx]);
+                                                                xc->temp_signal_value_buf[xc->signal_lens[idx]] = 0;
+                                                                value_change_callback(user_callback_data_pointer, beg_tim, idx+1, xc->temp_signal_value_buf);
+                                                                }
+                                                                else
+                                                                {
+                                                                if(fv)
+                                                                        {
+                                                                        char vcd_id[16];
+                                                                        int vcdid_len = fstVcdIDForFwrite(vcd_id+1, idx+1);
+
+                                                                        vcd_id[0] = (xc->signal_typs[idx] != FST_VT_VCD_PORT) ? 'b' : 'p';
+                                                                        fstWritex(xc, vcd_id, 1);
+                                                                        fstWritex(xc,mu+sig_offs, xc->signal_lens[idx]);
+
+                                                                        vcd_id[0] = ' '; /* collapse 3 writes into one I/O call */
+                                                                        vcd_id[vcdid_len + 1] = '\n';
+                                                                        fstWritex(xc, vcd_id, vcdid_len + 2);
+                                                                        }
+                                                                }
+                                                        }
+                                                        else
+                                                        {
+                                                        double d;
+                                                        unsigned char *clone_d;
+                                                        unsigned char *srcdata = mu+sig_offs;
+
+                                                        if(value_change_callback)
+                                                                {
+                                                                if(xc->native_doubles_for_cb)
+                                                                        {
+                                                                        if(xc->double_endian_match)
+                                                                                {
+                                                                                clone_d = srcdata;
+                                                                                }
+                                                                                else
+                                                                                {
+                                                                                int j;
+
+                                                                                clone_d = (unsigned char *)&d;
+                                                                                for(j=0;j<8;j++)
+                                                                                        {
+                                                                                        clone_d[j] = srcdata[7-j];
+                                                                                        }
+                                                                                }
+                                                                        value_change_callback(user_callback_data_pointer, beg_tim, idx+1, clone_d);
+                                                                        }
+                                                                        else
+                                                                        {
+                                                                        clone_d = (unsigned char *)&d;
+                                                                        if(xc->double_endian_match)
+                                                                                {
+                                                                                memcpy(clone_d, srcdata, 8);
+                                                                                }
+                                                                                else
+                                                                                {
+                                                                                int j;
+
+                                                                                for(j=0;j<8;j++)
+                                                                                        {
+                                                                                        clone_d[j] = srcdata[7-j];
+                                                                                        }
+                                                                                }
+                                                                        sprintf((char *)xc->temp_signal_value_buf, "%.16g", d);
+                                                                        value_change_callback(user_callback_data_pointer, beg_tim, idx+1, xc->temp_signal_value_buf);
+                                                                        }
+                                                                }
+                                                                else
+                                                                {
+                                                                if(fv)
+                                                                        {
+                                                                        char vcdid_buf[16];
+                                                                        char wx_buf[64];
+                                                                        int wx_len;
+
+                                                                        clone_d = (unsigned char *)&d;
+                                                                        if(xc->double_endian_match)
+                                                                                {
+                                                                                memcpy(clone_d, srcdata, 8);
+                                                                                }
+                                                                                else
+                                                                                {
+                                                                                int j;
+
+                                                                                for(j=0;j<8;j++)
+                                                                                        {
+                                                                                        clone_d[j] = srcdata[7-j];
+                                                                                        }
+                                                                                }
+
+                                                                        fstVcdID(vcdid_buf, idx+1);
+                                                                        wx_len = sprintf(wx_buf, "r%.16g %s\n", d, vcdid_buf);
+                                                                        fstWritex(xc, wx_buf, wx_len);
+                                                                        }
+                                                                }
+                                                        }
+                                                }
+                                        }
+
+                                sig_offs += xc->signal_lens[idx];
+                                }
+
+                        free(mu);
+                        fstReaderFseeko(xc, xc->f, -((off_t)frame_clen), SEEK_CUR);
+                        }
+                }
+
+        fstReaderFseeko(xc, xc->f, (off_t)frame_clen, SEEK_CUR); /* skip past compressed data */
+
+        vc_maxhandle = fstReaderVarint64(xc->f);
+        vc_start = ftello(xc->f);       /* points to '!' character */
+        packtype = fgetc(xc->f);
+
+#ifdef FST_DEBUG
+        fprintf(stderr, "\tframe_uclen: %d, frame_clen: %d, frame_maxhandle: %d\n",
+                (int)frame_uclen, (int)frame_clen, (int)frame_maxhandle);
+        fprintf(stderr, "\tvc_maxhandle: %d, packtype: %c\n", (int)vc_maxhandle, packtype);
+#endif
+
+        indx_pntr = blkpos + seclen - 24 -tsec_clen -8;
+        fstReaderFseeko(xc, xc->f, indx_pntr, SEEK_SET);
+        chain_clen = fstReaderUint64(xc->f);
+        indx_pos = indx_pntr - chain_clen;
+#ifdef FST_DEBUG
+        fprintf(stderr, "\tindx_pos: %d (%d bytes)\n", (int)indx_pos, (int)chain_clen);
+#endif
+        chain_cmem = malloc(chain_clen);
+        if(!chain_cmem) goto block_err;
+        fstReaderFseeko(xc, xc->f, indx_pos, SEEK_SET);
+        fstFread(chain_cmem, chain_clen, 1, xc->f);
+
+        if(vc_maxhandle > vc_maxhandle_largest)
+                {
+                free(chain_table);
+                free(chain_table_lengths);
+
+                vc_maxhandle_largest = vc_maxhandle;
+                chain_table = calloc((vc_maxhandle+1), sizeof(off_t));
+                chain_table_lengths = calloc((vc_maxhandle+1), sizeof(uint32_t));
+                }
+
+        if(!chain_table || !chain_table_lengths) goto block_err;
+
+        pnt = chain_cmem;
+        idx = 0;
+        pval = 0;
+
+        if(sectype == FST_BL_VCDATA_DYN_ALIAS2)
+                {
+                uint32_t prev_alias = 0;
+
+                do      {
+                        int skiplen;
+
+                        if(*pnt & 0x01)
+                                {
+                                int64_t shval = fstGetSVarint64(pnt, &skiplen) >> 1;
+                                if(shval > 0)
+                                        {
+                                        pval = chain_table[idx] = pval + shval;
+                                        if(idx) { chain_table_lengths[pidx] = pval - chain_table[pidx]; }
+                                        pidx = idx++;
+                                        }
+                                else if(shval < 0)
+                                        {
+                                        chain_table[idx] = 0;                                   /* need to explicitly zero as calloc above might not run */
+                                        chain_table_lengths[idx] = prev_alias = shval;          /* because during this loop iter would give stale data! */
+                                        idx++;
+                                        }
+                                else
+                                        {
+                                        chain_table[idx] = 0;                                   /* need to explicitly zero as calloc above might not run */
+                                        chain_table_lengths[idx] = prev_alias;                  /* because during this loop iter would give stale data! */
+                                        idx++;
+                                        }
+                                }
+                                else
+                                {
+                                uint64_t val = fstGetVarint32(pnt, &skiplen);
+
+                                fstHandle loopcnt = val >> 1;
+                                for(i=0;i<loopcnt;i++)
+                                        {
+                                        chain_table[idx++] = 0;
+                                        }
+                                }
+
+                        pnt += skiplen;
+                        } while (pnt != (chain_cmem + chain_clen));
+                }
+                else
+                {
+                do      {
+                        int skiplen;
+                        uint64_t val = fstGetVarint32(pnt, &skiplen);
+
+                        if(!val)
+                                {
+                                pnt += skiplen;
+                                val = fstGetVarint32(pnt, &skiplen);
+                                chain_table[idx] = 0;                   /* need to explicitly zero as calloc above might not run */
+                                chain_table_lengths[idx] = -val;        /* because during this loop iter would give stale data! */
+                                idx++;
+                                }
+                        else
+                        if(val&1)
+                                {
+                                pval = chain_table[idx] = pval + (val >> 1);
+                                if(idx) { chain_table_lengths[pidx] = pval - chain_table[pidx]; }
+                                pidx = idx++;
+                                }
+                        else
+                                {
+                                fstHandle loopcnt = val >> 1;
+                                for(i=0;i<loopcnt;i++)
+                                        {
+                                        chain_table[idx++] = 0;
+                                        }
+                                }
+
+                        pnt += skiplen;
+                        } while (pnt != (chain_cmem + chain_clen));
+                }
+
+        chain_table[idx] = indx_pos - vc_start;
+        chain_table_lengths[pidx] = chain_table[idx] - chain_table[pidx];
+
+        for(i=0;i<idx;i++)
+                {
+                int32_t v32 = chain_table_lengths[i];
+                if((v32 < 0) && (!chain_table[i]))
+                        {
+                        v32 = -v32;
+                        v32--;
+                        if(((uint32_t)v32) < i) /* sanity check */
+                                {
+                                chain_table[i] = chain_table[v32];
+                                chain_table_lengths[i] = chain_table_lengths[v32];
+                                }
+                        }
+                }
+
+#ifdef FST_DEBUG
+        fprintf(stderr, "\tdecompressed chain idx len: %"PRIu32"\n", idx);
+#endif
+
+        mc_mem_len = 16384;
+        mc_mem = malloc(mc_mem_len); /* buffer for compressed reads */
+
+        /* check compressed VC data */
+        if(idx > xc->maxhandle) idx = xc->maxhandle;
+        for(i=0;i<idx;i++)
+                {
+                if(chain_table[i])
+                        {
+                        int process_idx = i/8;
+                        int process_bit = i&7;
+
+                        if(xc->process_mask[process_idx]&(1<<process_bit))
+                                {
+                                int rc = Z_OK;
+                                uint32_t val;
+                                uint32_t skiplen;
+                                uint32_t tdelta;
+
+                                fstReaderFseeko(xc, xc->f, vc_start + chain_table[i], SEEK_SET);
+                                val = fstReaderVarint32WithSkip(xc->f, &skiplen);
+                                if(val)
+                                        {
+                                        unsigned char *mu = mem_for_traversal + traversal_mem_offs; /* uncomp: dst */
+                                        unsigned char *mc;                                          /* comp:   src */
+                                        unsigned long destlen = val;
+                                        unsigned long sourcelen = chain_table_lengths[i];
+
+                                        if(mc_mem_len < chain_table_lengths[i])
+                                                {
+                                                free(mc_mem);
+                                                mc_mem = malloc(mc_mem_len = chain_table_lengths[i]);
+                                                }
+                                        mc = mc_mem;
+
+                                        fstFread(mc, chain_table_lengths[i], 1, xc->f);
+
+                                        switch(packtype)
+                                                {
+                                                case '4': rc = (destlen == (unsigned long)LZ4_decompress_safe_partial((char *)mc, (char *)mu, sourcelen, destlen, destlen)) ? Z_OK : Z_DATA_ERROR;
+                                                          break;
+                                                case 'F': fastlz_decompress(mc, sourcelen, mu, destlen); /* rc appears unreliable */
+                                                          break;
+                                                default:  rc = uncompress(mu, &destlen, mc, sourcelen);
+                                                          break;
+                                                }
+
+                                        /* data to process is for(j=0;j<destlen;j++) in mu[j] */
+                                        headptr[i] = traversal_mem_offs;
+                                        length_remaining[i] = val;
+                                        traversal_mem_offs += val;
+                                        }
+                                        else
+                                        {
+                                        int destlen = chain_table_lengths[i] - skiplen;
+                                        unsigned char *mu = mem_for_traversal + traversal_mem_offs;
+                                        fstFread(mu, destlen, 1, xc->f);
+                                        /* data to process is for(j=0;j<destlen;j++) in mu[j] */
+                                        headptr[i] = traversal_mem_offs;
+                                        length_remaining[i] = destlen;
+                                        traversal_mem_offs += destlen;
+                                        }
+
+                                if(rc != Z_OK)
+                                        {
+                                        printf("\tfac: %d clen: %d (rc=%d)\n", (int)i, (int)val, rc);
+                                        exit(255);
+                                        }
+
+                                if(xc->signal_lens[i] == 1)
+                                        {
+                                        uint32_t vli = fstGetVarint32NoSkip(mem_for_traversal + headptr[i]);
+                                        uint32_t shcnt = 2 << (vli & 1);
+                                        tdelta = vli >> shcnt;
+                                        }
+                                        else
+                                        {
+                                        uint32_t vli = fstGetVarint32NoSkip(mem_for_traversal + headptr[i]);
+                                        tdelta = vli >> 1;
+                                        }
+
+                                scatterptr[i] = tc_head[tdelta];
+                                tc_head[tdelta] = i+1;
+                                }
+                        }
+                }
+
+        free(mc_mem); /* there is no usage below for this, no real need to clear out mc_mem or mc_mem_len */
+
+        for(i=0;i<tsec_nitems;i++)
+                {
+                uint32_t tdelta;
+                int skiplen, skiplen2;
+                uint32_t vli;
+
+                if(fv)
+                        {
+                        char wx_buf[32];
+                        int wx_len;
+
+                        if(time_table[i] != previous_time)
+                                {
+                                if(xc->limit_range_valid)
+                                        {
+                                        if(time_table[i] > xc->limit_range_end)
+                                                {
+                                                break;
+                                                }
+                                        }
+
+                                wx_len = sprintf(wx_buf, "#%"PRIu64"\n", time_table[i]);
+                                fstWritex(xc, wx_buf, wx_len);
+
+                                if((xc->num_blackouts)&&(cur_blackout != xc->num_blackouts))
+                                        {
+                                        if(time_table[i] == xc->blackout_times[cur_blackout])
+                                                {
+                                                wx_len = sprintf(wx_buf, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
+                                                fstWritex(xc, wx_buf, wx_len);
+                                                }
+                                        }
+                                previous_time = time_table[i];
+                                }
+                        }
+
+                while(tc_head[i])
+                        {
+                        idx = tc_head[i] - 1;
+                        vli = fstGetVarint32(mem_for_traversal + headptr[idx], &skiplen);
+
+                        if(xc->signal_lens[idx] <= 1)
+                                {
+                                if(xc->signal_lens[idx] == 1)
+                                        {
+                                        unsigned char val;
+                                        if(!(vli & 1))
+                                                {
+                                                /* tdelta = vli >> 2; */ /* scan-build */
+                                                val = ((vli >> 1) & 1) | '0';
+                                                }
+                                                else
+                                                {
+                                                /* tdelta = vli >> 4; */ /* scan-build */
+                                                val = FST_RCV_STR[((vli >> 1) & 7)];
+                                                }
+
+                                        if(value_change_callback)
+                                                {
+                                                xc->temp_signal_value_buf[0] = val;
+                                                xc->temp_signal_value_buf[1] = 0;
+                                                value_change_callback(user_callback_data_pointer, time_table[i], idx+1, xc->temp_signal_value_buf);
+                                                }
+                                                else
+                                                {
+                                                if(fv)
+                                                        {
+                                                        char vcd_id[16];
+                                                        int vcdid_len = fstVcdIDForFwrite(vcd_id+1, idx+1);
+
+                                                        vcd_id[0] = val;
+                                                        vcd_id[vcdid_len+1] = '\n';
+                                                        fstWritex(xc, vcd_id, vcdid_len+2);
+                                                        }
+                                                }
+                                        headptr[idx] += skiplen;
+                                        length_remaining[idx] -= skiplen;
+
+                                        tc_head[i] = scatterptr[idx];
+                                        scatterptr[idx] = 0;
+
+                                        if(length_remaining[idx])
+                                                {
+                                                int shamt;
+                                                vli = fstGetVarint32NoSkip(mem_for_traversal + headptr[idx]);
+                                                shamt = 2 << (vli & 1);
+                                                tdelta = vli >> shamt;
+
+                                                scatterptr[idx] = tc_head[i+tdelta];
+                                                tc_head[i+tdelta] = idx+1;
+                                                }
+                                        }
+                                        else
+                                        {
+                                        unsigned char *vdata;
+                                        uint32_t len;
+
+                                        vli = fstGetVarint32(mem_for_traversal + headptr[idx], &skiplen);
+                                        len = fstGetVarint32(mem_for_traversal + headptr[idx] + skiplen, &skiplen2);
+                                        /* tdelta = vli >> 1; */ /* scan-build */
+                                        skiplen += skiplen2;
+                                        vdata = mem_for_traversal + headptr[idx] + skiplen;
+
+                                        if(!(vli & 1))
+                                                {
+                                                if(value_change_callback_varlen)
+                                                        {
+                                                        value_change_callback_varlen(user_callback_data_pointer, time_table[i], idx+1, vdata, len);
+                                                        }
+                                                        else
+                                                        {
+                                                        if(fv)
+                                                                {
+                                                                char vcd_id[16];
+                                                                int vcdid_len;
+
+                                                                vcd_id[0] = 's';
+                                                                fstWritex(xc, vcd_id, 1);
+
+                                                                vcdid_len = fstVcdIDForFwrite(vcd_id+1, idx+1);
+                                                                {
+                                                                unsigned char *vesc = malloc(len*4 + 1);
+                                                                int vlen = fstUtilityBinToEsc(vesc, vdata, len);
+                                                                fstWritex(xc, vesc, vlen);
+                                                                free(vesc);
+                                                                }
+
+                                                                vcd_id[0] = ' ';
+                                                                vcd_id[vcdid_len + 1] = '\n';
+                                                                fstWritex(xc, vcd_id, vcdid_len+2);
+                                                                }
+                                                        }
+                                                }
+
+                                        skiplen += len;
+                                        headptr[idx] += skiplen;
+                                        length_remaining[idx] -= skiplen;
+
+                                        tc_head[i] = scatterptr[idx];
+                                        scatterptr[idx] = 0;
+
+                                        if(length_remaining[idx])
+                                                {
+                                                vli = fstGetVarint32NoSkip(mem_for_traversal + headptr[idx]);
+                                                tdelta = vli >> 1;
+
+                                                scatterptr[idx] = tc_head[i+tdelta];
+                                                tc_head[i+tdelta] = idx+1;
+                                                }
+                                        }
+                                }
+                                else
+                                {
+                                uint32_t len = xc->signal_lens[idx];
+                                unsigned char *vdata;
+
+                                vli = fstGetVarint32(mem_for_traversal + headptr[idx], &skiplen);
+                                /* tdelta = vli >> 1; */ /* scan-build */
+                                vdata = mem_for_traversal + headptr[idx] + skiplen;
+
+                                if(xc->signal_typs[idx] != FST_VT_VCD_REAL)
+                                        {
+                                        if(!(vli & 1))
+                                                {
+                                                int byte = 0;
+                                                int bit;
+                                                unsigned int j;
+
+                                                for(j=0;j<len;j++)
+                                                        {
+                                                        unsigned char ch;
+                                                        byte = j/8;
+                                                        bit = 7 - (j & 7);
+                                                        ch = ((vdata[byte] >> bit) & 1) | '0';
+                                                        xc->temp_signal_value_buf[j] = ch;
+                                                        }
+                                                xc->temp_signal_value_buf[j] = 0;
+
+                                                if(value_change_callback)
+                                                        {
+                                                        value_change_callback(user_callback_data_pointer, time_table[i], idx+1, xc->temp_signal_value_buf);
+                                                        }
+                                                        else
+                                                        {
+                                                        if(fv)  {
+                                                                unsigned char ch_bp = (xc->signal_typs[idx] != FST_VT_VCD_PORT) ? 'b' : 'p';
+
+                                                                fstWritex(xc, &ch_bp, 1);
+                                                                fstWritex(xc, xc->temp_signal_value_buf, len);
+                                                                }
+                                                        }
+
+                                                len = byte+1;
+                                                }
+                                                else
+                                                {
+                                                if(value_change_callback)
+                                                        {
+                                                        memcpy(xc->temp_signal_value_buf, vdata, len);
+                                                        xc->temp_signal_value_buf[len] = 0;
+                                                        value_change_callback(user_callback_data_pointer, time_table[i], idx+1, xc->temp_signal_value_buf);
+                                                        }
+                                                        else
+                                                        {
+                                                        if(fv)
+                                                                {
+                                                                unsigned char ch_bp =  (xc->signal_typs[idx] != FST_VT_VCD_PORT) ? 'b' : 'p';
+
+                                                                fstWritex(xc, &ch_bp, 1);
+                                                                fstWritex(xc, vdata, len);
+                                                                }
+                                                        }
+                                                }
+                                        }
+                                        else
+                                        {
+                                        double d;
+                                        unsigned char *clone_d /*= (unsigned char *)&d */; /* scan-build */
+                                        unsigned char buf[8];
+                                        unsigned char *srcdata;
+
+                                        if(!(vli & 1))  /* very rare case, but possible */
+                                                {
+                                                int bit;
+                                                int j;
+
+                                                for(j=0;j<8;j++)
+                                                        {
+                                                        unsigned char ch;
+                                                        bit = 7 - (j & 7);
+                                                        ch = ((vdata[0] >> bit) & 1) | '0';
+                                                        buf[j] = ch;
+                                                        }
+
+                                                len = 1;
+                                                srcdata = buf;
+                                                }
+                                                else
+                                                {
+                                                srcdata = vdata;
+                                                }
+
+                                        if(value_change_callback)
+                                                {
+                                                if(xc->native_doubles_for_cb)
+                                                        {
+                                                        if(xc->double_endian_match)
+                                                                {
+                                                                clone_d = srcdata;
+                                                                }
+                                                                else
+                                                                {
+                                                                int j;
+
+                                                                clone_d = (unsigned char *)&d;
+                                                                for(j=0;j<8;j++)
+                                                                        {
+                                                                        clone_d[j] = srcdata[7-j];
+                                                                        }
+                                                                }
+                                                        value_change_callback(user_callback_data_pointer, time_table[i], idx+1, clone_d);
+                                                        }
+                                                        else
+                                                        {
+                                                        clone_d = (unsigned char *)&d;
+                                                        if(xc->double_endian_match)
+                                                                {
+                                                                memcpy(clone_d, srcdata, 8);
+                                                                }
+                                                                else
+                                                                {
+                                                                int j;
+
+                                                                for(j=0;j<8;j++)
+                                                                        {
+                                                                        clone_d[j] = srcdata[7-j];
+                                                                        }
+                                                                }
+                                                        sprintf((char *)xc->temp_signal_value_buf, "%.16g", d);
+                                                        value_change_callback(user_callback_data_pointer, time_table[i], idx+1, xc->temp_signal_value_buf);
+                                                        }
+                                                }
+                                                else
+                                                {
+                                                if(fv)
+                                                        {
+                                                        char wx_buf[32];
+                                                        int wx_len;
+
+                                                        clone_d = (unsigned char *)&d;
+                                                        if(xc->double_endian_match)
+                                                                {
+                                                                memcpy(clone_d, srcdata, 8);
+                                                                }
+                                                                else
+                                                                {
+                                                                int j;
+
+                                                                for(j=0;j<8;j++)
+                                                                        {
+                                                                        clone_d[j] = srcdata[7-j];
+                                                                        }
+                                                                }
+
+                                                        wx_len = sprintf(wx_buf, "r%.16g", d);
+                                                        fstWritex(xc, wx_buf, wx_len);
+                                                        }
+                                                }
+                                        }
+
+                                if(fv)
+                                        {
+                                        char vcd_id[16];
+                                        int vcdid_len = fstVcdIDForFwrite(vcd_id+1, idx+1);
+                                        vcd_id[0] = ' ';
+                                        vcd_id[vcdid_len+1] = '\n';
+                                        fstWritex(xc, vcd_id, vcdid_len+2);
+                                        }
+
+                                skiplen += len;
+                                headptr[idx] += skiplen;
+                                length_remaining[idx] -= skiplen;
+
+                                tc_head[i] = scatterptr[idx];
+                                scatterptr[idx] = 0;
+
+                                if(length_remaining[idx])
+                                        {
+                                        vli = fstGetVarint32NoSkip(mem_for_traversal + headptr[idx]);
+                                        tdelta = vli >> 1;
+
+                                        scatterptr[idx] = tc_head[i+tdelta];
+                                        tc_head[i+tdelta] = idx+1;
+                                        }
+                                }
+                        }
+                }
+
+block_err:
+        free(tc_head);
+        free(chain_cmem);
+        free(mem_for_traversal); mem_for_traversal = NULL;
+
+        secnum++;
+        if(secnum == xc->vc_section_count) break; /* in case file is growing, keep with original block count */
+        blkpos += seclen;
+        }
+
+if(mem_for_traversal) free(mem_for_traversal); /* scan-build */
+free(length_remaining);
+free(headptr);
+free(scatterptr);
+
+if(chain_table) free(chain_table);
+if(chain_table_lengths) free(chain_table_lengths);
+
+free(time_table);
+
+#ifndef FST_WRITEX_DISABLE
+if(fv)
+        {
+        fstWritex(xc, NULL, 0);
+        }
+#endif
+
+return(1);
+}
+
+
+/* rvat functions */
+
+static char *fstExtractRvatDataFromFrame(struct fstReaderContext *xc, fstHandle facidx, char *buf)
+{
+if(facidx >= xc->rvat_frame_maxhandle)
+        {
+        return(NULL);
+        }
+
+if(xc->signal_lens[facidx] == 1)
+        {
+        buf[0] = (char)xc->rvat_frame_data[xc->rvat_sig_offs[facidx]];
+        buf[1] = 0;
+        }
+        else
+        {
+        if(xc->signal_typs[facidx] != FST_VT_VCD_REAL)
+                {
+                memcpy(buf, xc->rvat_frame_data + xc->rvat_sig_offs[facidx], xc->signal_lens[facidx]);
+                buf[xc->signal_lens[facidx]] = 0;
+                }
+                else
+                {
+                double d;
+                unsigned char *clone_d = (unsigned char *)&d;
+                unsigned char *srcdata = xc->rvat_frame_data + xc->rvat_sig_offs[facidx];
+
+                if(xc->double_endian_match)
+                        {
+                        memcpy(clone_d, srcdata, 8);
+                        }
+                        else
+                        {
+                        int j;
+
+                        for(j=0;j<8;j++)
+                                {
+                                clone_d[j] = srcdata[7-j];
+                                }
+                        }
+
+                sprintf((char *)buf, "%.16g", d);
+                }
+        }
+
+return(buf);
+}
+
+
+char *fstReaderGetValueFromHandleAtTime(void *ctx, uint64_t tim, fstHandle facidx, char *buf)
+{
+struct fstReaderContext *xc = (struct fstReaderContext *)ctx;
+off_t blkpos = 0, prev_blkpos;
+uint64_t beg_tim, end_tim, beg_tim2, end_tim2;
+int sectype;
+unsigned int secnum = 0;
+uint64_t seclen;
+uint64_t tsec_uclen = 0, tsec_clen = 0;
+uint64_t tsec_nitems;
+uint64_t frame_uclen, frame_clen;
+#ifdef FST_DEBUG
+uint64_t mem_required_for_traversal;
+#endif
+off_t indx_pntr, indx_pos;
+long chain_clen;
+unsigned char *chain_cmem;
+unsigned char *pnt;
+fstHandle idx, pidx=0, i;
+uint64_t pval;
+
+if((!xc) || (!facidx) || (facidx > xc->maxhandle) || (!buf) || (!xc->signal_lens[facidx-1]))
+        {
+        return(NULL);
+        }
+
+if(!xc->rvat_sig_offs)
+        {
+        uint32_t cur_offs = 0;
+
+        xc->rvat_sig_offs = calloc(xc->maxhandle, sizeof(uint32_t));
+        for(i=0;i<xc->maxhandle;i++)
+                {
+                xc->rvat_sig_offs[i] = cur_offs;
+                cur_offs += xc->signal_lens[i];
+                }
+        }
+
+if(xc->rvat_data_valid)
+        {
+        if((xc->rvat_beg_tim <= tim) && (tim <= xc->rvat_end_tim))
+                {
+                goto process_value;
+                }
+
+        fstReaderDeallocateRvatData(xc);
+        }
+
+xc->rvat_chain_pos_valid = 0;
+
+for(;;)
+        {
+        fstReaderFseeko(xc, xc->f, (prev_blkpos = blkpos), SEEK_SET);
+
+        sectype = fgetc(xc->f);
+        seclen = fstReaderUint64(xc->f);
+
+        if((sectype == EOF) || (sectype == FST_BL_SKIP) || (!seclen))
+                {
+                return(NULL); /* if this loop exits on break, it's successful */
+                }
+
+        blkpos++;
+        if((sectype != FST_BL_VCDATA) && (sectype != FST_BL_VCDATA_DYN_ALIAS) && (sectype != FST_BL_VCDATA_DYN_ALIAS2))
+                {
+                blkpos += seclen;
+                continue;
+                }
+
+        beg_tim = fstReaderUint64(xc->f);
+        end_tim = fstReaderUint64(xc->f);
+
+        if((beg_tim <= tim) && (tim <= end_tim))
+                {
+                if((tim == end_tim) && (tim != xc->end_time))
+                        {
+                        off_t cached_pos = ftello(xc->f);
+                        fstReaderFseeko(xc, xc->f, blkpos, SEEK_SET);
+
+                        sectype = fgetc(xc->f);
+                        seclen = fstReaderUint64(xc->f);
+
+                        beg_tim2 = fstReaderUint64(xc->f);
+                        end_tim2 = fstReaderUint64(xc->f);
+
+                        if(((sectype != FST_BL_VCDATA)&&(sectype != FST_BL_VCDATA_DYN_ALIAS)&&(sectype != FST_BL_VCDATA_DYN_ALIAS2)) || (!seclen) || (beg_tim2 != tim))
+                                {
+                                blkpos = prev_blkpos;
+                                break;
+                                }
+                        beg_tim = beg_tim2;
+                        end_tim = end_tim2;
+                        fstReaderFseeko(xc, xc->f, cached_pos, SEEK_SET);
+                        }
+                break;
+                }
+
+        blkpos += seclen;
+        secnum++;
+        }
+
+xc->rvat_beg_tim = beg_tim;
+xc->rvat_end_tim = end_tim;
+
+#ifdef FST_DEBUG
+mem_required_for_traversal =
+#endif
+        fstReaderUint64(xc->f);
+
+#ifdef FST_DEBUG
+fprintf(stderr, "rvat sec: %u seclen: %d begtim: %d endtim: %d\n",
+        secnum, (int)seclen, (int)beg_tim, (int)end_tim);
+fprintf(stderr, "\tmem_required_for_traversal: %d\n", (int)mem_required_for_traversal);
+#endif
+
+/* process time block */
+{
+unsigned char *ucdata;
+unsigned char *cdata;
+unsigned long destlen /* = tsec_uclen */; /* scan-build */
+unsigned long sourcelen /* = tsec_clen */; /* scan-build */
+int rc;
+unsigned char *tpnt;
+uint64_t tpval;
+unsigned int ti;
+
+fstReaderFseeko(xc, xc->f, blkpos + seclen - 24, SEEK_SET);
+tsec_uclen = fstReaderUint64(xc->f);
+tsec_clen = fstReaderUint64(xc->f);
+tsec_nitems = fstReaderUint64(xc->f);
+#ifdef FST_DEBUG
+fprintf(stderr, "\ttime section unc: %d, com: %d (%d items)\n",
+        (int)tsec_uclen, (int)tsec_clen, (int)tsec_nitems);
+#endif
+ucdata = malloc(tsec_uclen);
+destlen = tsec_uclen;
+sourcelen = tsec_clen;
+
+fstReaderFseeko(xc, xc->f, -24 - ((off_t)tsec_clen), SEEK_CUR);
+if(tsec_uclen != tsec_clen)
+        {
+        cdata = malloc(tsec_clen);
+        fstFread(cdata, tsec_clen, 1, xc->f);
+
+        rc = uncompress(ucdata, &destlen, cdata, sourcelen);
+
+        if(rc != Z_OK)
+                {
+                printf("tsec uncompress rc = %d\n", rc);
+                exit(255);
+                }
+
+        free(cdata);
+        }
+        else
+        {
+        fstFread(ucdata, tsec_uclen, 1, xc->f);
+        }
+
+xc->rvat_time_table = calloc(tsec_nitems, sizeof(uint64_t));
+tpnt = ucdata;
+tpval = 0;
+for(ti=0;ti<tsec_nitems;ti++)
+        {
+        int skiplen;
+        uint64_t val = fstGetVarint64(tpnt, &skiplen);
+        tpval = xc->rvat_time_table[ti] = tpval + val;
+        tpnt += skiplen;
+        }
+
+free(ucdata);
+}
+
+fstReaderFseeko(xc, xc->f, blkpos+32, SEEK_SET);
+
+frame_uclen = fstReaderVarint64(xc->f);
+frame_clen = fstReaderVarint64(xc->f);
+xc->rvat_frame_maxhandle = fstReaderVarint64(xc->f);
+xc->rvat_frame_data = malloc(frame_uclen);
+
+if(frame_uclen == frame_clen)
+        {
+        fstFread(xc->rvat_frame_data, frame_uclen, 1, xc->f);
+        }
+        else
+        {
+        unsigned char *mc = malloc(frame_clen);
+        int rc;
+
+        unsigned long destlen = frame_uclen;
+        unsigned long sourcelen = frame_clen;
+
+        fstFread(mc, sourcelen, 1, xc->f);
+        rc = uncompress(xc->rvat_frame_data, &destlen, mc, sourcelen);
+        if(rc != Z_OK)
+                {
+                printf("decompress rc: %d\n", rc);
+                exit(255);
+                }
+        free(mc);
+        }
+
+xc->rvat_vc_maxhandle = fstReaderVarint64(xc->f);
+xc->rvat_vc_start = ftello(xc->f);      /* points to '!' character */
+
+#ifdef FST_DEBUG
+fprintf(stderr, "\tframe_uclen: %d, frame_clen: %d, frame_maxhandle: %d\n",
+        (int)frame_uclen, (int)frame_clen, (int)xc->rvat_frame_maxhandle);
+fprintf(stderr, "\tvc_maxhandle: %d\n", (int)xc->rvat_vc_maxhandle);
+#endif
+
+indx_pntr = blkpos + seclen - 24 -tsec_clen -8;
+fstReaderFseeko(xc, xc->f, indx_pntr, SEEK_SET);
+chain_clen = fstReaderUint64(xc->f);
+indx_pos = indx_pntr - chain_clen;
+#ifdef FST_DEBUG
+fprintf(stderr, "\tindx_pos: %d (%d bytes)\n", (int)indx_pos, (int)chain_clen);
+#endif
+chain_cmem = malloc(chain_clen);
+fstReaderFseeko(xc, xc->f, indx_pos, SEEK_SET);
+fstFread(chain_cmem, chain_clen, 1, xc->f);
+
+xc->rvat_chain_table = calloc((xc->rvat_vc_maxhandle+1), sizeof(off_t));
+xc->rvat_chain_table_lengths = calloc((xc->rvat_vc_maxhandle+1), sizeof(uint32_t));
+
+pnt = chain_cmem;
+idx = 0;
+pval = 0;
+do
+        {
+        int skiplen;
+        uint64_t val = fstGetVarint32(pnt, &skiplen);
+
+        if(!val)
+                {
+                pnt += skiplen;
+                val = fstGetVarint32(pnt, &skiplen);
+                xc->rvat_chain_table[idx] = 0;
+                xc->rvat_chain_table_lengths[idx] = -val;
+                idx++;
+                }
+        else
+        if(val&1)
+                {
+                pval = xc->rvat_chain_table[idx] = pval + (val >> 1);
+                if(idx) { xc->rvat_chain_table_lengths[pidx] = pval - xc->rvat_chain_table[pidx]; }
+                pidx = idx++;
+                }
+                else
+                {
+                fstHandle loopcnt = val >> 1;
+                for(i=0;i<loopcnt;i++)
+                        {
+                        xc->rvat_chain_table[idx++] = 0;
+                        }
+                }
+
+        pnt += skiplen;
+        } while (pnt != (chain_cmem + chain_clen));
+
+free(chain_cmem);
+xc->rvat_chain_table[idx] = indx_pos - xc->rvat_vc_start;
+xc->rvat_chain_table_lengths[pidx] = xc->rvat_chain_table[idx] - xc->rvat_chain_table[pidx];
+
+for(i=0;i<idx;i++)
+        {
+        int32_t v32 = xc->rvat_chain_table_lengths[i];
+        if((v32 < 0) && (!xc->rvat_chain_table[i]))
+                {
+                v32 = -v32;
+                v32--;
+                if(((uint32_t)v32) < i) /* sanity check */
+                        {
+                        xc->rvat_chain_table[i] = xc->rvat_chain_table[v32];
+                        xc->rvat_chain_table_lengths[i] = xc->rvat_chain_table_lengths[v32];
+                        }
+                }
+        }
+
+#ifdef FST_DEBUG
+fprintf(stderr, "\tdecompressed chain idx len: %"PRIu32"\n", idx);
+#endif
+
+xc->rvat_data_valid = 1;
+
+/* all data at this point is loaded or resident in fst cache, process and return appropriate value */
+process_value:
+if(facidx > xc->rvat_vc_maxhandle)
+        {
+        return(NULL);
+        }
+
+facidx--; /* scale down for array which starts at zero */
+
+
+if(((tim == xc->rvat_beg_tim)&&(!xc->rvat_chain_table[facidx])) || (!xc->rvat_chain_table[facidx]))
+        {
+        return(fstExtractRvatDataFromFrame(xc, facidx, buf));
+        }
+
+if(facidx != xc->rvat_chain_facidx)
+        {
+        if(xc->rvat_chain_mem)
+                {
+                free(xc->rvat_chain_mem);
+                xc->rvat_chain_mem = NULL;
+
+                xc->rvat_chain_pos_valid = 0;
+                }
+        }
+
+if(!xc->rvat_chain_mem)
+        {
+        uint32_t skiplen;
+        fstReaderFseeko(xc, xc->f, xc->rvat_vc_start + xc->rvat_chain_table[facidx], SEEK_SET);
+        xc->rvat_chain_len = fstReaderVarint32WithSkip(xc->f, &skiplen);
+        if(xc->rvat_chain_len)
+                {
+                unsigned char *mu = malloc(xc->rvat_chain_len);
+                unsigned char *mc = malloc(xc->rvat_chain_table_lengths[facidx]);
+                unsigned long destlen = xc->rvat_chain_len;
+                unsigned long sourcelen = xc->rvat_chain_table_lengths[facidx];
+                int rc;
+
+                fstFread(mc, xc->rvat_chain_table_lengths[facidx], 1, xc->f);
+                rc = uncompress(mu, &destlen, mc, sourcelen);
+                free(mc);
+
+                if(rc != Z_OK)
+                        {
+                        printf("\tclen: %d (rc=%d)\n", (int)xc->rvat_chain_len, rc);
+                        exit(255);
+                        }
+
+                /* data to process is for(j=0;j<destlen;j++) in mu[j] */
+                xc->rvat_chain_mem = mu;
+                }
+                else
+                {
+                int destlen = xc->rvat_chain_table_lengths[facidx] - skiplen;
+                unsigned char *mu = malloc(xc->rvat_chain_len = destlen);
+                fstFread(mu, destlen, 1, xc->f);
+                /* data to process is for(j=0;j<destlen;j++) in mu[j] */
+                xc->rvat_chain_mem = mu;
+                }
+
+        xc->rvat_chain_facidx = facidx;
+        }
+
+/* process value chain here */
+
+{
+uint32_t tidx = 0, ptidx = 0;
+uint32_t tdelta;
+int skiplen;
+unsigned int iprev = xc->rvat_chain_len;
+uint32_t pvli = 0;
+int pskip = 0;
+
+if((xc->rvat_chain_pos_valid)&&(tim >= xc->rvat_chain_pos_time))
+        {
+        i = xc->rvat_chain_pos_idx;
+        tidx = xc->rvat_chain_pos_tidx;
+        }
+        else
+        {
+        i = 0;
+        tidx = 0;
+        xc->rvat_chain_pos_time = xc->rvat_beg_tim;
+        }
+
+if(xc->signal_lens[facidx] == 1)
+        {
+        while(i<xc->rvat_chain_len)
+                {
+                uint32_t vli = fstGetVarint32(xc->rvat_chain_mem + i, &skiplen);
+                uint32_t shcnt = 2 << (vli & 1);
+                tdelta = vli >> shcnt;
+
+                if(xc->rvat_time_table[tidx + tdelta] <= tim)
+                        {
+                        iprev = i;
+                        pvli = vli;
+                        ptidx = tidx;
+                        /* pskip = skiplen; */ /* scan-build */
+
+                        tidx += tdelta;
+                        i+=skiplen;
+                        }
+                        else
+                        {
+                        break;
+                        }
+                }
+        if(iprev != xc->rvat_chain_len)
+                {
+                xc->rvat_chain_pos_tidx = ptidx;
+                xc->rvat_chain_pos_idx = iprev;
+                xc->rvat_chain_pos_time = tim;
+                xc->rvat_chain_pos_valid = 1;
+
+                if(!(pvli & 1))
+                        {
+                        buf[0] = ((pvli >> 1) & 1) | '0';
+                        }
+                        else
+                        {
+                        buf[0] = FST_RCV_STR[((pvli >> 1) & 7)];
+                        }
+                buf[1] = 0;
+                return(buf);
+                }
+                else
+                {
+                return(fstExtractRvatDataFromFrame(xc, facidx, buf));
+                }
+        }
+        else
+        {
+        while(i<xc->rvat_chain_len)
+                {
+                uint32_t vli = fstGetVarint32(xc->rvat_chain_mem + i, &skiplen);
+                tdelta = vli >> 1;
+
+                if(xc->rvat_time_table[tidx + tdelta] <= tim)
+                        {
+                        iprev = i;
+                        pvli = vli;
+                        ptidx = tidx;
+                        pskip = skiplen;
+
+                        tidx += tdelta;
+                        i+=skiplen;
+
+                        if(!(pvli & 1))
+                                {
+                                i+=((xc->signal_lens[facidx]+7)/8);
+                                }
+                                else
+                                {
+                                i+=xc->signal_lens[facidx];
+                                }
+                        }
+                        else
+                        {
+                        break;
+                        }
+                }
+
+        if(iprev != xc->rvat_chain_len)
+                {
+                unsigned char *vdata = xc->rvat_chain_mem + iprev + pskip;
+
+                xc->rvat_chain_pos_tidx = ptidx;
+                xc->rvat_chain_pos_idx = iprev;
+                xc->rvat_chain_pos_time = tim;
+                xc->rvat_chain_pos_valid = 1;
+
+                if(xc->signal_typs[facidx] != FST_VT_VCD_REAL)
+                        {
+                        if(!(pvli & 1))
+                                {
+                                int byte = 0;
+                                int bit;
+                                unsigned int j;
+
+                                for(j=0;j<xc->signal_lens[facidx];j++)
+                                        {
+                                        unsigned char ch;
+                                        byte = j/8;
+                                        bit = 7 - (j & 7);
+                                        ch = ((vdata[byte] >> bit) & 1) | '0';
+                                        buf[j] = ch;
+                                        }
+                                buf[j] = 0;
+
+                                return(buf);
+                                }
+                                else
+                                {
+                                memcpy(buf, vdata, xc->signal_lens[facidx]);
+                                buf[xc->signal_lens[facidx]] = 0;
+                                return(buf);
+                                }
+                        }
+                        else
+                        {
+                        double d;
+                        unsigned char *clone_d = (unsigned char *)&d;
+                        unsigned char bufd[8];
+                        unsigned char *srcdata;
+
+                        if(!(pvli & 1)) /* very rare case, but possible */
+                                {
+                                int bit;
+                                int j;
+
+                                for(j=0;j<8;j++)
+                                        {
+                                        unsigned char ch;
+                                        bit = 7 - (j & 7);
+                                        ch = ((vdata[0] >> bit) & 1) | '0';
+                                        bufd[j] = ch;
+                                        }
+
+                                srcdata = bufd;
+                                }
+                                else
+                                {
+                                srcdata = vdata;
+                                }
+
+                        if(xc->double_endian_match)
+                                {
+                                memcpy(clone_d, srcdata, 8);
+                                }
+                                else
+                                {
+                                int j;
+
+                                for(j=0;j<8;j++)
+                                        {
+                                        clone_d[j] = srcdata[7-j];
+                                        }
+                                }
+
+                        sprintf(buf, "r%.16g", d);
+                        return(buf);
+                        }
+                }
+                else
+                {
+                return(fstExtractRvatDataFromFrame(xc, facidx, buf));
+                }
+        }
+}
+
+/* return(NULL); */
+}
+
+
+
+/**********************************************************************/
+#ifndef _WAVE_HAVE_JUDY
+
+/***********************/
+/***                 ***/
+/***  jenkins hash   ***/
+/***                 ***/
+/***********************/
+
+/*
+--------------------------------------------------------------------
+mix -- mix 3 32-bit values reversibly.
+For every delta with one or two bits set, and the deltas of all three
+  high bits or all three low bits, whether the original value of a,b,c
+  is almost all zero or is uniformly distributed,
+* If mix() is run forward or backward, at least 32 bits in a,b,c
+  have at least 1/4 probability of changing.
+* If mix() is run forward, every bit of c will change between 1/3 and
+  2/3 of the time.  (Well, 22/100 and 78/100 for some 2-bit deltas.)
+mix() was built out of 36 single-cycle latency instructions in a
+  structure that could supported 2x parallelism, like so:
+      a -= b;
+      a -= c; x = (c>>13);
+      b -= c; a ^= x;
+      b -= a; x = (a<<8);
+      c -= a; b ^= x;
+      c -= b; x = (b>>13);
+      ...
+  Unfortunately, superscalar Pentiums and Sparcs can't take advantage
+  of that parallelism.  They've also turned some of those single-cycle
+  latency instructions into multi-cycle latency instructions.  Still,
+  this is the fastest good hash I could find.  There were about 2^^68
+  to choose from.  I only looked at a billion or so.
+--------------------------------------------------------------------
+*/
+#define mix(a,b,c) \
+{ \
+  a -= b; a -= c; a ^= (c>>13); \
+  b -= c; b -= a; b ^= (a<<8); \
+  c -= a; c -= b; c ^= (b>>13); \
+  a -= b; a -= c; a ^= (c>>12);  \
+  b -= c; b -= a; b ^= (a<<16); \
+  c -= a; c -= b; c ^= (b>>5); \
+  a -= b; a -= c; a ^= (c>>3);  \
+  b -= c; b -= a; b ^= (a<<10); \
+  c -= a; c -= b; c ^= (b>>15); \
+}
+
+/*
+--------------------------------------------------------------------
+j_hash() -- hash a variable-length key into a 32-bit value
+  k       : the key (the unaligned variable-length array of bytes)
+  len     : the length of the key, counting by bytes
+  initval : can be any 4-byte value
+Returns a 32-bit value.  Every bit of the key affects every bit of
+the return value.  Every 1-bit and 2-bit delta achieves avalanche.
+About 6*len+35 instructions.
+
+The best hash table sizes are powers of 2.  There is no need to do
+mod a prime (mod is sooo slow!).  If you need less than 32 bits,
+use a bitmask.  For example, if you need only 10 bits, do
+  h = (h & hashmask(10));
+In which case, the hash table should have hashsize(10) elements.
+
+If you are hashing n strings (uint8_t **)k, do it like this:
+  for (i=0, h=0; i<n; ++i) h = hash( k[i], len[i], h);
+
+By Bob Jenkins, 1996.  bob_jenkins@burtleburtle.net.  You may use this
+code any way you wish, private, educational, or commercial.  It's free.
+
+See http://burtleburtle.net/bob/hash/evahash.html
+Use for hash table lookup, or anything where one collision in 2^^32 is
+acceptable.  Do NOT use for cryptographic purposes.
+--------------------------------------------------------------------
+*/
+
+static uint32_t j_hash(const uint8_t *k, uint32_t length, uint32_t initval)
+{
+   uint32_t a,b,c,len;
+
+   /* Set up the internal state */
+   len = length;
+   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
+   c = initval;         /* the previous hash value */
+
+   /*---------------------------------------- handle most of the key */
+   while (len >= 12)
+   {
+      a += (k[0] +((uint32_t)k[1]<<8) +((uint32_t)k[2]<<16) +((uint32_t)k[3]<<24));
+      b += (k[4] +((uint32_t)k[5]<<8) +((uint32_t)k[6]<<16) +((uint32_t)k[7]<<24));
+      c += (k[8] +((uint32_t)k[9]<<8) +((uint32_t)k[10]<<16)+((uint32_t)k[11]<<24));
+      mix(a,b,c);
+      k += 12; len -= 12;
+   }
+
+   /*------------------------------------- handle the last 11 bytes */
+   c += length;
+   switch(len)              /* all the case statements fall through */
+   {
+   case 11: c+=((uint32_t)k[10]<<24);
+   case 10: c+=((uint32_t)k[9]<<16);
+   case 9 : c+=((uint32_t)k[8]<<8);
+      /* the first byte of c is reserved for the length */
+   case 8 : b+=((uint32_t)k[7]<<24);
+   case 7 : b+=((uint32_t)k[6]<<16);
+   case 6 : b+=((uint32_t)k[5]<<8);
+   case 5 : b+=k[4];
+   case 4 : a+=((uint32_t)k[3]<<24);
+   case 3 : a+=((uint32_t)k[2]<<16);
+   case 2 : a+=((uint32_t)k[1]<<8);
+   case 1 : a+=k[0];
+     /* case 0: nothing left to add */
+   }
+   mix(a,b,c);
+   /*-------------------------------------------- report the result */
+   return(c);
+}
+
+/********************************************************************/
+
+/***************************/
+/***                     ***/
+/***  judy HS emulation  ***/
+/***                     ***/
+/***************************/
+
+struct collchain_t
+{
+struct collchain_t *next;
+void *payload;
+uint32_t fullhash, length;
+unsigned char mem[1];
+};
+
+
+void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint32_t hashmask)
+{
+struct collchain_t ***base = (struct collchain_t ***)base_i;
+uint32_t hf, h;
+struct collchain_t **ar;
+struct collchain_t *chain, *pchain;
+
+if(!*base)
+        {
+        *base = calloc(1, (hashmask + 1) * sizeof(void *));
+        }
+ar = *base;
+
+h = (hf = j_hash(mem, length, length)) & hashmask;
+pchain = chain = ar[h];
+while(chain)
+        {
+        if((chain->fullhash == hf) && (chain->length == length) && !memcmp(chain->mem, mem, length))
+                {
+                if(pchain != chain) /* move hit to front */
+                        {
+                        pchain->next = chain->next;
+                        chain->next = ar[h];
+                        ar[h] = chain;
+                        }
+                return(&(chain->payload));
+                }
+
+        pchain = chain;
+        chain = chain->next;
+        }
+
+chain = calloc(1, sizeof(struct collchain_t) + length - 1);
+memcpy(chain->mem, mem, length);
+chain->fullhash = hf;
+chain->length = length;
+chain->next = ar[h];
+ar[h] = chain;
+return(&(chain->payload));
+}
+
+
+void JenkinsFree(void *base_i, uint32_t hashmask)
+{
+struct collchain_t ***base = (struct collchain_t ***)base_i;
+uint32_t h;
+struct collchain_t **ar;
+struct collchain_t *chain, *chain_next;
+
+if(base && *base)
+        {
+        ar = *base;
+        for(h=0;h<=hashmask;h++)
+                {
+                chain = ar[h];
+                while(chain)
+                        {
+                        chain_next = chain->next;
+                        free(chain);
+                        chain = chain_next;
+                        }
+                }
+
+        free(*base);
+        *base = NULL;
+        }
+}
+
+#endif
+
+/**********************************************************************/
+
+/************************/
+/***                  ***/
+/*** utility function ***/
+/***                  ***/
+/************************/
+
+int fstUtilityBinToEsc(unsigned char *d, unsigned char *s, int len)
+{
+unsigned char *src = s;
+unsigned char *dst = d;
+unsigned char val;
+int i;
+
+for(i=0;i<len;i++)
+        {
+        switch(src[i])
+                {
+                case '\a':      *(dst++) = '\\'; *(dst++) = 'a'; break;
+                case '\b':      *(dst++) = '\\'; *(dst++) = 'b'; break;
+                case '\f':      *(dst++) = '\\'; *(dst++) = 'f'; break;
+                case '\n':      *(dst++) = '\\'; *(dst++) = 'n'; break;
+                case '\r':      *(dst++) = '\\'; *(dst++) = 'r'; break;
+                case '\t':      *(dst++) = '\\'; *(dst++) = 't'; break;
+                case '\v':      *(dst++) = '\\'; *(dst++) = 'v'; break;
+                case '\'':      *(dst++) = '\\'; *(dst++) = '\''; break;
+                case '\"':      *(dst++) = '\\'; *(dst++) = '\"'; break;
+                case '\\':      *(dst++) = '\\'; *(dst++) = '\\'; break;
+                case '\?':      *(dst++) = '\\'; *(dst++) = '\?'; break;
+                default:        if((src[i] > ' ') && (src[i] <= '~')) /* no white spaces in output */
+                                        {
+                                        *(dst++) = src[i];
+                                        }
+                                        else
+                                        {
+                                        val = src[i];
+                                        *(dst++) = '\\';
+                                        *(dst++) = (val/64) + '0'; val = val & 63;
+                                        *(dst++) = (val/8)  + '0'; val = val & 7;
+                                        *(dst++) = (val) + '0';
+                                        }
+                                break;
+                }
+        }
+
+return(dst - d);
+}
+
+
+/*
+ * this overwrites the original string if the destination pointer is NULL
+ */
+int fstUtilityEscToBin(unsigned char *d, unsigned char *s, int len)
+{
+unsigned char *src = s;
+unsigned char *dst = (!d) ? s : (s = d);
+unsigned char val[3];
+int i;
+
+for(i=0;i<len;i++)
+        {
+        if(src[i] != '\\')
+                {
+                *(dst++) = src[i];
+                }
+                else
+                {
+                switch(src[++i])
+                        {
+                        case 'a':       *(dst++) = '\a'; break;
+                        case 'b':       *(dst++) = '\b'; break;
+                        case 'f':       *(dst++) = '\f'; break;
+                        case 'n':       *(dst++) = '\n'; break;
+                        case 'r':       *(dst++) = '\r'; break;
+                        case 't':       *(dst++) = '\t'; break;
+                        case 'v':       *(dst++) = '\v'; break;
+                        case '\'':      *(dst++) = '\''; break;
+                        case '\"':      *(dst++) = '\"'; break;
+                        case '\\':      *(dst++) = '\\'; break;
+                        case '\?':      *(dst++) = '\?'; break;
+
+                        case 'x':       val[0] = toupper(src[++i]);
+                                        val[1] = toupper(src[++i]);
+                                        val[0] = ((val[0]>='A')&&(val[0]<='F')) ? (val[0] - 'A' + 10) : (val[0] - '0');
+                                        val[1] = ((val[1]>='A')&&(val[1]<='F')) ? (val[1] - 'A' + 10) : (val[1] - '0');
+                                        *(dst++) = val[0] * 16 + val[1];
+                                        break;
+
+                        case '0':
+                        case '1':
+                        case '2':
+                        case '3':
+                        case '4':
+                        case '5':
+                        case '6':
+                        case '7':       val[0] = src[  i] - '0';
+                                        val[1] = src[++i] - '0';
+                                        val[2] = src[++i] - '0';
+                                        *(dst++) = val[0] * 64 + val[1] * 8 + val[2];
+                                        break;
+
+                        default:        *(dst++) = src[i]; break;
+                        }
+                }
+        }
+
+return(dst - s);
+}
diff --git a/src/grt/fst/fstapi.h b/src/grt/fst/fstapi.h
new file mode 100644
index 0000000..83daac4
--- /dev/null
+++ b/src/grt/fst/fstapi.h
@@ -0,0 +1,426 @@
+/*
+ * Copyright (c) 2009-2014 Tony Bybell.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef FST_API_H
+#define FST_API_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <zlib.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <time.h>
+
+#define FST_RDLOAD "FSTLOAD | "
+
+typedef uint32_t fstHandle;
+
+enum fstWriterPackType {
+    FST_WR_PT_ZLIB             = 0,
+    FST_WR_PT_FASTLZ           = 1,
+    FST_WR_PT_LZ4              = 2
+};
+
+enum fstFileType {
+    FST_FT_MIN                 = 0,
+
+    FST_FT_VERILOG             = 0,
+    FST_FT_VHDL                = 1,
+    FST_FT_VERILOG_VHDL        = 2,
+
+    FST_FT_MAX                 = 2
+};
+
+enum fstBlockType {
+    FST_BL_HDR                 = 0,
+    FST_BL_VCDATA              = 1,
+    FST_BL_BLACKOUT            = 2,
+    FST_BL_GEOM                = 3,
+    FST_BL_HIER                = 4,
+    FST_BL_VCDATA_DYN_ALIAS    = 5,
+    FST_BL_HIER_LZ4            = 6,
+    FST_BL_HIER_LZ4DUO         = 7,
+    FST_BL_VCDATA_DYN_ALIAS2   = 8,
+
+    FST_BL_ZWRAPPER            = 254,   /* indicates that whole trace is gz wrapped */
+    FST_BL_SKIP                = 255    /* used while block is being written */
+};
+
+enum fstScopeType {
+    FST_ST_MIN                 = 0,
+
+    FST_ST_VCD_MODULE          = 0,
+    FST_ST_VCD_TASK            = 1,
+    FST_ST_VCD_FUNCTION        = 2,
+    FST_ST_VCD_BEGIN           = 3,
+    FST_ST_VCD_FORK            = 4,
+    FST_ST_VCD_GENERATE        = 5,
+    FST_ST_VCD_STRUCT          = 6,
+    FST_ST_VCD_UNION           = 7,
+    FST_ST_VCD_CLASS           = 8,
+    FST_ST_VCD_INTERFACE       = 9,
+    FST_ST_VCD_PACKAGE         = 10,
+    FST_ST_VCD_PROGRAM         = 11,
+
+    FST_ST_VHDL_ARCHITECTURE   = 12,
+    FST_ST_VHDL_PROCEDURE      = 13,
+    FST_ST_VHDL_FUNCTION       = 14,
+    FST_ST_VHDL_RECORD         = 15,
+    FST_ST_VHDL_PROCESS        = 16,
+    FST_ST_VHDL_BLOCK          = 17,
+    FST_ST_VHDL_FOR_GENERATE   = 18,
+    FST_ST_VHDL_IF_GENERATE    = 19,
+    FST_ST_VHDL_GENERATE       = 20,
+    FST_ST_VHDL_PACKAGE        = 21,
+
+    FST_ST_MAX                 = 21,
+
+    FST_ST_GEN_ATTRBEGIN       = 252,
+    FST_ST_GEN_ATTREND         = 253,
+
+    FST_ST_VCD_SCOPE           = 254,
+    FST_ST_VCD_UPSCOPE         = 255
+};
+
+enum fstVarType {
+    FST_VT_MIN                 = 0,     /* start of vartypes */
+
+    FST_VT_VCD_EVENT           = 0,
+    FST_VT_VCD_INTEGER         = 1,
+    FST_VT_VCD_PARAMETER       = 2,
+    FST_VT_VCD_REAL            = 3,
+    FST_VT_VCD_REAL_PARAMETER  = 4,
+    FST_VT_VCD_REG             = 5,
+    FST_VT_VCD_SUPPLY0         = 6,
+    FST_VT_VCD_SUPPLY1         = 7,
+    FST_VT_VCD_TIME            = 8,
+    FST_VT_VCD_TRI             = 9,
+    FST_VT_VCD_TRIAND          = 10,
+    FST_VT_VCD_TRIOR           = 11,
+    FST_VT_VCD_TRIREG          = 12,
+    FST_VT_VCD_TRI0            = 13,
+    FST_VT_VCD_TRI1            = 14,
+    FST_VT_VCD_WAND            = 15,
+    FST_VT_VCD_WIRE            = 16,
+    FST_VT_VCD_WOR             = 17,
+    FST_VT_VCD_PORT            = 18,
+    FST_VT_VCD_SPARRAY         = 19,    /* used to define the rownum (index) port for a sparse array */
+    FST_VT_VCD_REALTIME        = 20,
+
+    FST_VT_GEN_STRING          = 21,    /* generic string type   (max len is defined dynamically via fstWriterEmitVariableLengthValueChange) */
+
+    FST_VT_SV_BIT              = 22,
+    FST_VT_SV_LOGIC            = 23,
+    FST_VT_SV_INT              = 24,    /* declare as size = 32 */
+    FST_VT_SV_SHORTINT         = 25,    /* declare as size = 16 */
+    FST_VT_SV_LONGINT          = 26,    /* declare as size = 64 */
+    FST_VT_SV_BYTE             = 27,    /* declare as size = 8  */
+    FST_VT_SV_ENUM             = 28,    /* declare as appropriate type range */
+    FST_VT_SV_SHORTREAL        = 29,    /* declare and emit same as FST_VT_VCD_REAL (needs to be emitted as double, not a float) */
+
+    FST_VT_MAX                 = 29     /* end of vartypes */
+};
+
+enum fstVarDir {
+    FST_VD_MIN         = 0,
+
+    FST_VD_IMPLICIT    = 0,
+    FST_VD_INPUT       = 1,
+    FST_VD_OUTPUT      = 2,
+    FST_VD_INOUT       = 3,
+    FST_VD_BUFFER      = 4,
+    FST_VD_LINKAGE     = 5,
+
+    FST_VD_MAX         = 5
+};
+
+enum fstHierType {
+    FST_HT_MIN         = 0,
+
+    FST_HT_SCOPE       = 0,
+    FST_HT_UPSCOPE     = 1,
+    FST_HT_VAR         = 2,
+    FST_HT_ATTRBEGIN   = 3,
+    FST_HT_ATTREND     = 4,
+
+    FST_HT_MAX         = 4
+};
+
+enum fstAttrType {
+    FST_AT_MIN         = 0,
+
+    FST_AT_MISC        = 0,     /* self-contained: does not need matching FST_HT_ATTREND */
+    FST_AT_ARRAY       = 1,
+    FST_AT_ENUM        = 2,
+    FST_AT_PACK        = 3,
+
+    FST_AT_MAX         = 3
+};
+
+enum fstMiscType {
+    FST_MT_MIN         = 0,
+
+    FST_MT_COMMENT     = 0,     /* use fstWriterSetComment() to emit */
+    FST_MT_ENVVAR      = 1,     /* use fstWriterSetEnvVar() to emit */
+    FST_MT_SUPVAR      = 2,     /* use fstWriterCreateVar2() to emit */
+    FST_MT_PATHNAME    = 3,     /* reserved for fstWriterSetSourceStem() string -> number management */
+    FST_MT_SOURCESTEM  = 4,     /* use fstWriterSetSourceStem() to emit */
+    FST_MT_SOURCEISTEM = 5,     /* use fstWriterSetSourceInstantiationStem() to emit */
+    FST_MT_UNKNOWN     = 6,
+
+    FST_MT_MAX         = 6
+};
+
+enum fstArrayType {
+    FST_AR_MIN         = 0,
+
+    FST_AR_NONE        = 0,
+    FST_AR_UNPACKED    = 1,
+    FST_AR_PACKED      = 2,
+    FST_AR_SPARSE      = 3,
+
+    FST_AR_MAX         = 3
+};
+
+enum fstEnumValueType {
+    FST_EV_SV_INTEGER           = 0,
+    FST_EV_SV_BIT               = 1,
+    FST_EV_SV_LOGIC             = 2,
+    FST_EV_SV_INT               = 3,
+    FST_EV_SV_SHORTINT          = 4,
+    FST_EV_SV_LONGINT           = 5,
+    FST_EV_SV_BYTE              = 6,
+    FST_EV_SV_UNSIGNED_INTEGER  = 7,
+    FST_EV_SV_UNSIGNED_BIT      = 8,
+    FST_EV_SV_UNSIGNED_LOGIC    = 9,
+    FST_EV_SV_UNSIGNED_INT      = 10,
+    FST_EV_SV_UNSIGNED_SHORTINT = 11,
+    FST_EV_SV_UNSIGNED_LONGINT  = 12,
+    FST_EV_SV_UNSIGNED_BYTE     = 13,
+
+    FST_EV_MAX                  = 13
+};
+
+enum fstPackType {
+    FST_PT_NONE          = 0,
+    FST_PT_UNPACKED      = 1,
+    FST_PT_PACKED        = 2,
+    FST_PT_TAGGED_PACKED = 3,
+
+    FST_PT_MAX           = 3
+};
+
+enum fstSupplementalVarType {
+    FST_SVT_MIN                    = 0,
+
+    FST_SVT_NONE                   = 0,
+
+    FST_SVT_VHDL_SIGNAL            = 1,
+    FST_SVT_VHDL_VARIABLE          = 2,
+    FST_SVT_VHDL_CONSTANT          = 3,
+    FST_SVT_VHDL_FILE              = 4,
+    FST_SVT_VHDL_MEMORY            = 5,
+
+    FST_SVT_MAX                    = 5,
+};
+
+enum fstSupplementalDataType {
+    FST_SDT_MIN                    = 0,
+
+    FST_SDT_NONE                   = 0,
+
+    FST_SDT_VHDL_BOOLEAN           = 1,
+    FST_SDT_VHDL_BIT               = 2,
+    FST_SDT_VHDL_BIT_VECTOR        = 3,
+    FST_SDT_VHDL_STD_ULOGIC        = 4,
+    FST_SDT_VHDL_STD_ULOGIC_VECTOR = 5,
+    FST_SDT_VHDL_STD_LOGIC         = 6,
+    FST_SDT_VHDL_STD_LOGIC_VECTOR  = 7,
+    FST_SDT_VHDL_UNSIGNED          = 8,
+    FST_SDT_VHDL_SIGNED            = 9,
+    FST_SDT_VHDL_INTEGER           = 10,
+    FST_SDT_VHDL_REAL              = 11,
+    FST_SDT_VHDL_NATURAL           = 12,
+    FST_SDT_VHDL_POSITIVE          = 13,
+    FST_SDT_VHDL_TIME              = 14,
+    FST_SDT_VHDL_CHARACTER         = 15,
+    FST_SDT_VHDL_STRING            = 16,
+
+    FST_SDT_MAX                    = 16,
+
+    FST_SDT_SVT_SHIFT_COUNT        = 10, /* FST_SVT_* is ORed in by fstWriterCreateVar2() to the left after shifting FST_SDT_SVT_SHIFT_COUNT */
+    FST_SDT_ABS_MAX                = ((1<<(FST_SDT_SVT_SHIFT_COUNT))-1)
+};
+
+
+struct fstHier
+{
+unsigned char htyp;
+
+union {
+        /* if htyp == FST_HT_SCOPE */
+        struct fstHierScope {
+                unsigned char typ; /* FST_ST_MIN ... FST_ST_MAX */
+                const char *name;
+                const char *component;
+                uint32_t name_length;           /* strlen(u.scope.name) */
+                uint32_t component_length;      /* strlen(u.scope.component) */
+                } scope;
+
+        /* if htyp == FST_HT_VAR */
+        struct fstHierVar {
+                unsigned char typ; /* FST_VT_MIN ... FST_VT_MAX */
+                unsigned char direction; /* FST_VD_MIN ... FST_VD_MAX */
+                unsigned char svt_workspace; /* zeroed out by FST reader, for client code use */
+                unsigned char sdt_workspace; /* zeroed out by FST reader, for client code use */
+                unsigned int  sxt_workspace; /* zeroed out by FST reader, for client code use */
+                const char *name;
+                uint32_t length;
+                fstHandle handle;
+                uint32_t name_length; /* strlen(u.var.name) */
+                unsigned is_alias : 1;
+                } var;
+
+        /* if htyp == FST_HT_ATTRBEGIN */
+        struct fstHierAttr {
+                unsigned char typ; /* FST_AT_MIN ... FST_AT_MAX */
+                unsigned char subtype; /* from fstMiscType, fstArrayType, fstEnumValueType, fstPackType */
+                const char *name;
+                uint64_t arg; /* number of array elements, struct members, or some other payload (possibly ignored) */
+                uint64_t arg_from_name; /* for when name is overloaded as a variable-length integer (FST_AT_MISC + FST_MT_SOURCESTEM) */
+                uint32_t name_length; /* strlen(u.attr.name) */
+                } attr;
+        } u;
+};
+
+
+/*
+ * writer functions
+ */
+void            fstWriterClose(void *ctx);
+void *          fstWriterCreate(const char *nam, int use_compressed_hier);
+                /* used for Verilog/SV */
+fstHandle       fstWriterCreateVar(void *ctx, enum fstVarType vt, enum fstVarDir vd,
+                        uint32_t len, const char *nam, fstHandle aliasHandle);
+                /* future expansion for VHDL and other languages.  The variable type, data type, etc map onto
+                   the current Verilog/SV one.  The "type" string is optional for a more verbose or custom description */
+fstHandle       fstWriterCreateVar2(void *ctx, enum fstVarType vt, enum fstVarDir vd,
+                        uint32_t len, const char *nam, fstHandle aliasHandle,
+                        const char *type, enum fstSupplementalVarType svt, enum fstSupplementalDataType sdt);
+void            fstWriterEmitValueChange(void *ctx, fstHandle handle, const void *val);
+void            fstWriterEmitVariableLengthValueChange(void *ctx, fstHandle handle, const void *val, uint32_t len);
+void            fstWriterEmitDumpActive(void *ctx, int enable);
+void            fstWriterEmitTimeChange(void *ctx, uint64_t tim);
+void            fstWriterFlushContext(void *ctx);
+int             fstWriterGetDumpSizeLimitReached(void *ctx);
+int             fstWriterGetFseekFailed(void *ctx);
+void            fstWriterSetAttrBegin(void *ctx, enum fstAttrType attrtype, int subtype,
+                        const char *attrname, uint64_t arg);
+void            fstWriterSetAttrEnd(void *ctx);
+void            fstWriterSetComment(void *ctx, const char *comm);
+void            fstWriterSetDate(void *ctx, const char *dat);
+void            fstWriterSetDumpSizeLimit(void *ctx, uint64_t numbytes);
+void            fstWriterSetEnvVar(void *ctx, const char *envvar);
+void            fstWriterSetFileType(void *ctx, enum fstFileType filetype);
+void            fstWriterSetPackType(void *ctx, enum fstWriterPackType typ);
+void            fstWriterSetParallelMode(void *ctx, int enable);
+void            fstWriterSetRepackOnClose(void *ctx, int enable);       /* type = 0 (none), 1 (libz) */
+void            fstWriterSetScope(void *ctx, enum fstScopeType scopetype,
+                        const char *scopename, const char *scopecomp);
+void            fstWriterSetSourceInstantiationStem(void *ctx, const char *path, unsigned int line, unsigned int use_realpath);
+void            fstWriterSetSourceStem(void *ctx, const char *path, unsigned int line, unsigned int use_realpath);
+void            fstWriterSetTimescale(void *ctx, int ts);
+void            fstWriterSetTimescaleFromString(void *ctx, const char *s);
+void            fstWriterSetTimezero(void *ctx, int64_t tim);
+void            fstWriterSetUpscope(void *ctx);
+void            fstWriterSetVersion(void *ctx, const char *vers);
+
+
+/*
+ * reader functions
+ */
+void            fstReaderClose(void *ctx);
+void            fstReaderClrFacProcessMask(void *ctx, fstHandle facidx);
+void            fstReaderClrFacProcessMaskAll(void *ctx);
+uint64_t        fstReaderGetAliasCount(void *ctx);
+const char *    fstReaderGetCurrentFlatScope(void *ctx);
+void *          fstReaderGetCurrentScopeUserInfo(void *ctx);
+int             fstReaderGetCurrentScopeLen(void *ctx);
+const char *    fstReaderGetDateString(void *ctx);
+int             fstReaderGetDoubleEndianMatchState(void *ctx);
+uint64_t        fstReaderGetDumpActivityChangeTime(void *ctx, uint32_t idx);
+unsigned char   fstReaderGetDumpActivityChangeValue(void *ctx, uint32_t idx);
+uint64_t        fstReaderGetEndTime(void *ctx);
+int             fstReaderGetFacProcessMask(void *ctx, fstHandle facidx);
+int             fstReaderGetFileType(void *ctx);
+int             fstReaderGetFseekFailed(void *ctx);
+fstHandle       fstReaderGetMaxHandle(void *ctx);
+uint64_t        fstReaderGetMemoryUsedByWriter(void *ctx);
+uint32_t        fstReaderGetNumberDumpActivityChanges(void *ctx);
+uint64_t        fstReaderGetScopeCount(void *ctx);
+uint64_t        fstReaderGetStartTime(void *ctx);
+signed char     fstReaderGetTimescale(void *ctx);
+int64_t         fstReaderGetTimezero(void *ctx);
+uint64_t        fstReaderGetValueChangeSectionCount(void *ctx);
+char *          fstReaderGetValueFromHandleAtTime(void *ctx, uint64_t tim, fstHandle facidx, char *buf);
+uint64_t        fstReaderGetVarCount(void *ctx);
+const char *    fstReaderGetVersionString(void *ctx);
+struct fstHier *fstReaderIterateHier(void *ctx);
+int             fstReaderIterateHierRewind(void *ctx);
+int             fstReaderIterBlocks(void *ctx,
+                        void (*value_change_callback)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value),
+                        void *user_callback_data_pointer, FILE *vcdhandle);
+int             fstReaderIterBlocks2(void *ctx,
+                        void (*value_change_callback)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value),
+                        void (*value_change_callback_varlen)(void *user_callback_data_pointer, uint64_t time, fstHandle facidx, const unsigned char *value, uint32_t len),
+                        void *user_callback_data_pointer, FILE *vcdhandle);
+void            fstReaderIterBlocksSetNativeDoublesOnCallback(void *ctx, int enable);
+void *          fstReaderOpen(const char *nam);
+void *          fstReaderOpenForUtilitiesOnly(void);
+const char *    fstReaderPopScope(void *ctx);
+int             fstReaderProcessHier(void *ctx, FILE *vcdhandle);
+const char *    fstReaderPushScope(void *ctx, const char *nam, void *user_info);
+void            fstReaderResetScope(void *ctx);
+void            fstReaderSetFacProcessMask(void *ctx, fstHandle facidx);
+void            fstReaderSetFacProcessMaskAll(void *ctx);
+void            fstReaderSetLimitTimeRange(void *ctx, uint64_t start_time, uint64_t end_time);
+void            fstReaderSetUnlimitedTimeRange(void *ctx);
+void            fstReaderSetVcdExtensions(void *ctx, int enable);
+
+
+/*
+ * utility functions
+ */
+int             fstUtilityBinToEsc(unsigned char *d, unsigned char *s, int len);
+int             fstUtilityEscToBin(unsigned char *d, unsigned char *s, int len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/grt/fst/lz4.c b/src/grt/fst/lz4.c
new file mode 100644
index 0000000..39f176f
--- /dev/null
+++ b/src/grt/fst/lz4.c
@@ -0,0 +1,1267 @@
+/*
+   LZ4 - Fast LZ compression algorithm
+   Copyright (C) 2011-2014, Yann Collet.
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - LZ4 source repository : http://code.google.com/p/lz4/
+   - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
+*/
+
+/**************************************
+   Tuning parameters
+**************************************/
+/*
+ * HEAPMODE :
+ * Select how default compression functions will allocate memory for their hash table,
+ * in memory stack (0:default, fastest), or in memory heap (1:requires memory allocation (malloc)).
+ */
+#define HEAPMODE 0
+
+
+/**************************************
+   CPU Feature Detection
+**************************************/
+/* 32 or 64 bits ? */
+#if (defined(__x86_64__) || defined(_M_X64) || defined(_WIN64) \
+  || defined(__64BIT__)  || defined(__mips64) \
+  || defined(__powerpc64__) || defined(__powerpc64le__) \
+  || defined(__ppc64__) || defined(__ppc64le__) \
+  || defined(__PPC64__) || defined(__PPC64LE__) \
+  || defined(__ia64) || defined(__itanium__) || defined(_M_IA64) \
+  || defined(__s390x__) )   /* Detects 64 bits mode */
+#  define LZ4_ARCH64 1
+#else
+#  define LZ4_ARCH64 0
+#endif
+#define LZ4_32BITS (sizeof(void*)==4)
+#define LZ4_64BITS (sizeof(void*)==8)
+
+/*
+ * Little Endian or Big Endian ?
+ * Overwrite the #define below if you know your architecture endianess
+ */
+#include <stdlib.h>   /* Apparently required to detect endianess */
+#if defined (__GLIBC__)
+#  include <endian.h>
+#  if (__BYTE_ORDER == __BIG_ENDIAN)
+#     define LZ4_BIG_ENDIAN 1
+#  endif
+#elif (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(__LITTLE_ENDIAN__) || defined(__LITTLE_ENDIAN) || defined(_LITTLE_ENDIAN))
+#  define LZ4_BIG_ENDIAN 1
+#elif defined(__sparc) || defined(__sparc__) \
+   || defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) \
+   || defined(__hpux)  || defined(__hppa) \
+   || defined(_MIPSEB) || defined(__s390__)
+#  define LZ4_BIG_ENDIAN 1
+#else
+/* Little Endian assumed. PDP Endian and other very rare endian format are unsupported. */
+#endif
+
+/*
+ * Unaligned memory access is automatically enabled for "common" CPU, such as x86.
+ * For others CPU, such as ARM, the compiler may be more cautious, inserting unnecessary extra code to ensure aligned access property
+ * If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance
+ */
+#if defined(__ARM_FEATURE_UNALIGNED)
+#  define LZ4_FORCE_UNALIGNED_ACCESS 1
+#endif
+
+/* Define this parameter if your target system or compiler does not support hardware bit count */
+#if defined(_MSC_VER) && defined(_WIN32_WCE)   /* Visual Studio for Windows CE does not support Hardware bit count */
+#  define LZ4_FORCE_SW_BITCOUNT
+#endif
+
+/*
+ * BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
+ * This option may provide a small boost to performance for some big endian cpu, although probably modest.
+ * You may set this option to 1 if data will remain within closed environment.
+ * This option is useless on Little_Endian CPU (such as x86)
+ */
+
+/* #define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1 */
+
+
+/**************************************
+ Compiler Options
+**************************************/
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)   /* C99 */
+/* "restrict" is a known keyword */
+#else
+#  define restrict /* Disable restrict */
+#endif
+
+#ifdef _MSC_VER    /* Visual Studio */
+#  define FORCE_INLINE static __forceinline
+#  include <intrin.h>                    /* For Visual 2005 */
+#  if LZ4_ARCH64   /* 64-bits */
+#    pragma intrinsic(_BitScanForward64) /* For Visual 2005 */
+#    pragma intrinsic(_BitScanReverse64) /* For Visual 2005 */
+#  else            /* 32-bits */
+#    pragma intrinsic(_BitScanForward)   /* For Visual 2005 */
+#    pragma intrinsic(_BitScanReverse)   /* For Visual 2005 */
+#  endif
+#  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
+#else
+#  ifdef __GNUC__
+#    define FORCE_INLINE static inline __attribute__((always_inline))
+#  else
+#    define FORCE_INLINE static inline
+#  endif
+#endif
+
+#ifdef _MSC_VER  /* Visual Studio */
+#  define lz4_bswap16(x) _byteswap_ushort(x)
+#else
+#  define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
+#endif
+
+#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
+#  define expect(expr,value)    (__builtin_expect ((expr),(value)) )
+#else
+#  define expect(expr,value)    (expr)
+#endif
+
+#define likely(expr)     expect((expr) != 0, 1)
+#define unlikely(expr)   expect((expr) != 0, 0)
+
+
+/**************************************
+   Memory routines
+**************************************/
+#include <stdlib.h>   /* malloc, calloc, free */
+#define ALLOCATOR(n,s) calloc(n,s)
+#define FREEMEM        free
+#include <string.h>   /* memset, memcpy */
+#define MEM_INIT       memset
+
+
+/**************************************
+   Includes
+**************************************/
+#include "lz4.h"
+
+
+/**************************************
+   Basic Types
+**************************************/
+#if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)   /* C99 */
+# include <stdint.h>
+  typedef  uint8_t BYTE;
+  typedef uint16_t U16;
+  typedef uint32_t U32;
+  typedef  int32_t S32;
+  typedef uint64_t U64;
+#else
+  typedef unsigned char       BYTE;
+  typedef unsigned short      U16;
+  typedef unsigned int        U32;
+  typedef   signed int        S32;
+  typedef unsigned long long  U64;
+#endif
+
+#if defined(__GNUC__)  && !defined(LZ4_FORCE_UNALIGNED_ACCESS)
+#  define _PACKED __attribute__ ((packed))
+#else
+#  define _PACKED
+#endif
+
+#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
+#  if defined(__IBMC__) || defined(__SUNPRO_C) || defined(__SUNPRO_CC)
+#    pragma pack(1)
+#  else
+#    pragma pack(push, 1)
+#  endif
+#endif
+
+typedef struct { U16 v; }  _PACKED U16_S;
+typedef struct { U32 v; }  _PACKED U32_S;
+typedef struct { U64 v; }  _PACKED U64_S;
+typedef struct {size_t v;} _PACKED size_t_S;
+
+#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
+#  if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
+#    pragma pack(0)
+#  else
+#    pragma pack(pop)
+#  endif
+#endif
+
+#define A16(x)   (((U16_S *)(x))->v)
+#define A32(x)   (((U32_S *)(x))->v)
+#define A64(x)   (((U64_S *)(x))->v)
+#define AARCH(x) (((size_t_S *)(x))->v)
+
+
+/**************************************
+   Constants
+**************************************/
+#define LZ4_HASHLOG   (LZ4_MEMORY_USAGE-2)
+#define HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
+#define HASH_SIZE_U32 (1 << LZ4_HASHLOG)
+
+#define MINMATCH 4
+
+#define COPYLENGTH 8
+#define LASTLITERALS 5
+#define MFLIMIT (COPYLENGTH+MINMATCH)
+static const int LZ4_minLength = (MFLIMIT+1);
+
+#define KB *(1U<<10)
+#define MB *(1U<<20)
+#define GB *(1U<<30)
+
+#define LZ4_64KLIMIT ((64 KB) + (MFLIMIT-1))
+#define SKIPSTRENGTH 6   /* Increasing this value will make the compression run slower on incompressible data */
+
+#define MAXD_LOG 16
+#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
+
+#define ML_BITS  4
+#define ML_MASK  ((1U<<ML_BITS)-1)
+#define RUN_BITS (8-ML_BITS)
+#define RUN_MASK ((1U<<RUN_BITS)-1)
+
+
+/**************************************
+   Structures and local types
+**************************************/
+typedef struct {
+    U32  hashTable[HASH_SIZE_U32];
+    U32  currentOffset;
+    U32  initCheck;
+    const BYTE* dictionary;
+    const BYTE* bufferStart;
+    U32  dictSize;
+} LZ4_stream_t_internal;
+
+typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
+typedef enum { byPtr, byU32, byU16 } tableType_t;
+
+typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
+typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
+
+typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
+typedef enum { full = 0, partial = 1 } earlyEnd_directive;
+
+
+/**************************************
+   Architecture-specific macros
+**************************************/
+#define STEPSIZE                  sizeof(size_t)
+#define LZ4_COPYSTEP(d,s)         { AARCH(d) = AARCH(s); d+=STEPSIZE; s+=STEPSIZE; }
+#define LZ4_COPY8(d,s)            { LZ4_COPYSTEP(d,s); if (STEPSIZE<8) LZ4_COPYSTEP(d,s); }
+
+#if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
+#  define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
+#  define LZ4_WRITE_LITTLEENDIAN_16(p,i)  { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
+#else      /* Little Endian */
+#  define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
+#  define LZ4_WRITE_LITTLEENDIAN_16(p,v)  { A16(p) = v; p+=2; }
+#endif
+
+
+/**************************************
+   Macros
+**************************************/
+#define LZ4_STATIC_ASSERT(c)    { enum { LZ4_static_assert = 1/(!!(c)) }; }   /* use only *after* variable declarations */
+#if LZ4_ARCH64 || !defined(__GNUC__)
+#  define LZ4_WILDCOPY(d,s,e)   { do { LZ4_COPY8(d,s) } while (d<e); }        /* at the end, d>=e; */
+#else
+#  define LZ4_WILDCOPY(d,s,e)   { if (likely(e-d <= 8)) LZ4_COPY8(d,s) else do { LZ4_COPY8(d,s) } while (d<e); }
+#endif
+
+
+/****************************
+   Private local functions
+****************************/
+#if LZ4_ARCH64
+
+static int LZ4_NbCommonBytes (register U64 val)
+{
+# if defined(LZ4_BIG_ENDIAN)
+#   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    unsigned long r = 0;
+    _BitScanReverse64( &r, val );
+    return (int)(r>>3);
+#   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    return (__builtin_clzll(val) >> 3);
+#   else
+    int r;
+    if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
+    if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
+    r += (!val);
+    return r;
+#   endif
+# else
+#   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    unsigned long r = 0;
+    _BitScanForward64( &r, val );
+    return (int)(r>>3);
+#   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    return (__builtin_ctzll(val) >> 3);
+#   else
+    static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
+    return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
+#   endif
+# endif
+}
+
+#else
+
+static int LZ4_NbCommonBytes (register U32 val)
+{
+# if defined(LZ4_BIG_ENDIAN)
+#   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    unsigned long r = 0;
+    _BitScanReverse( &r, val );
+    return (int)(r>>3);
+#   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    return (__builtin_clz(val) >> 3);
+#   else
+    int r;
+    if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
+    r += (!val);
+    return r;
+#   endif
+# else
+#   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    unsigned long r;
+    _BitScanForward( &r, val );
+    return (int)(r>>3);
+#   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
+    return (__builtin_ctz(val) >> 3);
+#   else
+    static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
+    return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
+#   endif
+# endif
+}
+
+#endif
+
+
+/********************************
+   Compression functions
+********************************/
+int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; }
+int LZ4_compressBound(int isize)  { return LZ4_COMPRESSBOUND(isize); }
+
+static int LZ4_hashSequence(U32 sequence, tableType_t tableType)
+{
+    if (tableType == byU16)
+        return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
+    else
+        return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
+}
+
+static int LZ4_hashPosition(const BYTE* p, tableType_t tableType) { return LZ4_hashSequence(A32(p), tableType); }
+
+static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+    switch (tableType)
+    {
+    case byPtr: { const BYTE** hashTable = (const BYTE**) tableBase; hashTable[h] = p; break; }
+    case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); break; }
+    case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); break; }
+    }
+}
+
+static void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+    U32 h = LZ4_hashPosition(p, tableType);
+    LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
+}
+
+static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+    if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
+    if (tableType == byU32) { U32* hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
+    { U16* hashTable = (U16*) tableBase; return hashTable[h] + srcBase; }   /* default, to ensure a return */
+}
+
+static const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+    U32 h = LZ4_hashPosition(p, tableType);
+    return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
+}
+
+static unsigned LZ4_count(const BYTE* pIn, const BYTE* pRef, const BYTE* pInLimit)
+{
+    const BYTE* const pStart = pIn;
+
+    while (likely(pIn<pInLimit-(STEPSIZE-1)))
+    {
+        size_t diff = AARCH(pRef) ^ AARCH(pIn);
+        if (!diff) { pIn+=STEPSIZE; pRef+=STEPSIZE; continue; }
+        pIn += LZ4_NbCommonBytes(diff);
+        return (unsigned)(pIn - pStart);
+    }
+    if (LZ4_64BITS) if ((pIn<(pInLimit-3)) && (A32(pRef) == A32(pIn))) { pIn+=4; pRef+=4; }
+    if ((pIn<(pInLimit-1)) && (A16(pRef) == A16(pIn))) { pIn+=2; pRef+=2; }
+    if ((pIn<pInLimit) && (*pRef == *pIn)) pIn++;
+
+    return (unsigned)(pIn - pStart);
+}
+
+
+static int LZ4_compress_generic(
+                 void* ctx,
+                 const char* source,
+                 char* dest,
+                 int inputSize,
+                 int maxOutputSize,
+
+                 limitedOutput_directive outputLimited,
+                 tableType_t tableType,
+                 dict_directive dict,
+                 dictIssue_directive dictIssue)
+{
+    LZ4_stream_t_internal* const dictPtr = (LZ4_stream_t_internal*)ctx;
+
+    const BYTE* ip = (const BYTE*) source;
+    const BYTE* base;
+    const BYTE* lowLimit;
+    const BYTE* const lowRefLimit = ip - dictPtr->dictSize;
+    const BYTE* const dictionary = dictPtr->dictionary;
+    const BYTE* const dictEnd = dictionary + dictPtr->dictSize;
+    const size_t dictDelta = dictEnd - (const BYTE*)source;
+    const BYTE* anchor = (const BYTE*) source;
+    const BYTE* const iend = ip + inputSize;
+    const BYTE* const mflimit = iend - MFLIMIT;
+    const BYTE* const matchlimit = iend - LASTLITERALS;
+
+    BYTE* op = (BYTE*) dest;
+    BYTE* const olimit = op + maxOutputSize;
+
+    const int skipStrength = SKIPSTRENGTH;
+    U32 forwardH;
+    size_t refDelta=0;
+
+    /* Init conditions */
+    if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0;          /* Unsupported input size, too large (or negative) */
+    switch(dict)
+    {
+    case noDict:
+    default:
+        base = (const BYTE*)source;
+        lowLimit = (const BYTE*)source;
+        break;
+    case withPrefix64k:
+        base = (const BYTE*)source - dictPtr->currentOffset;
+        lowLimit = (const BYTE*)source - dictPtr->dictSize;
+        break;
+    case usingExtDict:
+        base = (const BYTE*)source - dictPtr->currentOffset;
+        lowLimit = (const BYTE*)source;
+        break;
+    }
+    if ((tableType == byU16) && (inputSize>=(int)LZ4_64KLIMIT)) return 0;   /* Size too large (not within 64K limit) */
+    if (inputSize<LZ4_minLength) goto _last_literals;                       /* Input too small, no compression (all literals) */
+
+    /* First Byte */
+    LZ4_putPosition(ip, ctx, tableType, base);
+    ip++; forwardH = LZ4_hashPosition(ip, tableType);
+
+    /* Main Loop */
+    for ( ; ; )
+    {
+        const BYTE* ref;
+        BYTE* token;
+        {
+            const BYTE* forwardIp = ip;
+            unsigned step=1;
+            unsigned searchMatchNb = (1U << skipStrength);
+
+            /* Find a match */
+            do {
+                U32 h = forwardH;
+                ip = forwardIp;
+                forwardIp += step;
+                step = searchMatchNb++ >> skipStrength;
+
+                if (unlikely(forwardIp > mflimit)) goto _last_literals;
+
+                ref = LZ4_getPositionOnHash(h, ctx, tableType, base);
+                if (dict==usingExtDict)
+                {
+                    if (ref<(const BYTE*)source)
+                    {
+                        refDelta = dictDelta;
+                        lowLimit = dictionary;
+                    }
+                    else
+                    {
+                        refDelta = 0;
+                        lowLimit = (const BYTE*)source;
+                    }
+                }
+                forwardH = LZ4_hashPosition(forwardIp, tableType);
+                LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
+
+            } while ( ((dictIssue==dictSmall) ? (ref < lowRefLimit) : 0)
+                || ((tableType==byU16) ? 0 : (ref + MAX_DISTANCE < ip))
+                || (A32(ref+refDelta) != A32(ip)) );
+        }
+
+        /* Catch up */
+        while ((ip>anchor) && (ref+refDelta > lowLimit) && (unlikely(ip[-1]==ref[refDelta-1]))) { ip--; ref--; }
+
+        {
+            /* Encode Literal length */
+            unsigned litLength = (unsigned)(ip - anchor);
+            token = op++;
+            if ((outputLimited) && (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
+                return 0;   /* Check output limit */
+            if (litLength>=RUN_MASK)
+            {
+                int len = (int)litLength-RUN_MASK;
+                *token=(RUN_MASK<<ML_BITS);
+                for(; len >= 255 ; len-=255) *op++ = 255;
+                *op++ = (BYTE)len;
+            }
+            else *token = (BYTE)(litLength<<ML_BITS);
+
+            /* Copy Literals */
+            { BYTE* end = op+litLength; LZ4_WILDCOPY(op,anchor,end); op=end; }
+        }
+
+_next_match:
+        /* Encode Offset */
+        LZ4_WRITE_LITTLEENDIAN_16(op, (U16)(ip-ref));
+
+        /* Encode MatchLength */
+        {
+            unsigned matchLength;
+
+            if ((dict==usingExtDict) && (lowLimit==dictionary))
+            {
+                const BYTE* limit;
+                ref += refDelta;
+                limit = ip + (dictEnd-ref);
+                if (limit > matchlimit) limit = matchlimit;
+                matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, limit);
+                ip += MINMATCH + matchLength;
+                if (ip==limit)
+                {
+                    unsigned more = LZ4_count(ip, (const BYTE*)source, matchlimit);
+                    matchLength += more;
+                    ip += more;
+                }
+            }
+            else
+            {
+                matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, matchlimit);
+                ip += MINMATCH + matchLength;
+            }
+
+            if (matchLength>=ML_MASK)
+            {
+                if ((outputLimited) && (unlikely(op + (1 + LASTLITERALS) + (matchLength>>8) > olimit)))
+                    return 0;    /* Check output limit */
+                *token += ML_MASK;
+                matchLength -= ML_MASK;
+                for (; matchLength >= 510 ; matchLength-=510) { *op++ = 255; *op++ = 255; }
+                if (matchLength >= 255) { matchLength-=255; *op++ = 255; }
+                *op++ = (BYTE)matchLength;
+            }
+            else *token += (BYTE)(matchLength);
+        }
+
+        anchor = ip;
+
+        /* Test end of chunk */
+        if (ip > mflimit) break;
+
+        /* Fill table */
+        LZ4_putPosition(ip-2, ctx, tableType, base);
+
+        /* Test next position */
+        ref = LZ4_getPosition(ip, ctx, tableType, base);
+        if (dict==usingExtDict)
+        {
+            if (ref<(const BYTE*)source)
+            {
+                refDelta = dictDelta;
+                lowLimit = dictionary;
+            }
+            else
+            {
+                refDelta = 0;
+                lowLimit = (const BYTE*)source;
+            }
+        }
+        LZ4_putPosition(ip, ctx, tableType, base);
+        if ( ((dictIssue==dictSmall) ? (ref>=lowRefLimit) : 1)
+            && (ref+MAX_DISTANCE>=ip)
+            && (A32(ref+refDelta)==A32(ip)) )
+        { token=op++; *token=0; goto _next_match; }
+
+        /* Prepare next loop */
+        forwardH = LZ4_hashPosition(++ip, tableType);
+    }
+
+_last_literals:
+    /* Encode Last Literals */
+    {
+        int lastRun = (int)(iend - anchor);
+        if ((outputLimited) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize))
+            return 0;   /* Check output limit */
+        if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun >= 255 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
+        else *op++ = (BYTE)(lastRun<<ML_BITS);
+        memcpy(op, anchor, iend - anchor);
+        op += iend-anchor;
+    }
+
+    /* End */
+    return (int) (((char*)op)-dest);
+}
+
+
+int LZ4_compress(const char* source, char* dest, int inputSize)
+{
+#if (HEAPMODE)
+    void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4);   /* Aligned on 4-bytes boundaries */
+#else
+    U32 ctx[LZ4_STREAMSIZE_U32] = {0};      /* Ensure data is aligned on 4-bytes boundaries */
+#endif
+    int result;
+
+    if (inputSize < (int)LZ4_64KLIMIT)
+        result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue);
+    else
+        result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, LZ4_64BITS ? byU32 : byPtr, noDict, noDictIssue);
+
+#if (HEAPMODE)
+    FREEMEM(ctx);
+#endif
+    return result;
+}
+
+int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
+{
+#if (HEAPMODE)
+    void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4);   /* Aligned on 4-bytes boundaries */
+#else
+    U32 ctx[LZ4_STREAMSIZE_U32] = {0};      /* Ensure data is aligned on 4-bytes boundaries */
+#endif
+    int result;
+
+    if (inputSize < (int)LZ4_64KLIMIT)
+        result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue);
+    else
+        result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, LZ4_64BITS ? byU32 : byPtr, noDict, noDictIssue);
+
+#if (HEAPMODE)
+    FREEMEM(ctx);
+#endif
+    return result;
+}
+
+
+/*****************************************
+   Experimental : Streaming functions
+*****************************************/
+
+/*
+ * LZ4_initStream
+ * Use this function once, to init a newly allocated LZ4_stream_t structure
+ * Return : 1 if OK, 0 if error
+ */
+void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
+{
+    MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
+}
+
+LZ4_stream_t* LZ4_createStream(void)
+{
+    LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOCATOR(4, LZ4_STREAMSIZE_U32);
+    LZ4_resetStream(lz4s);
+    return lz4s;
+}
+
+int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
+{
+    FREEMEM(LZ4_stream);
+    return (0);
+}
+
+
+int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
+{
+    LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
+    const BYTE* p = (const BYTE*)dictionary;
+    const BYTE* const dictEnd = p + dictSize;
+    const BYTE* base;
+
+    LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal));    /* A compilation error here means LZ4_STREAMSIZE is not large enough */
+    if (dict->initCheck) LZ4_resetStream(LZ4_dict);                         /* Uninitialized structure detected */
+
+    if (dictSize < MINMATCH)
+    {
+        dict->dictionary = NULL;
+        dict->dictSize = 0;
+        return 1;
+    }
+
+    if (p <= dictEnd - 64 KB) p = dictEnd - 64 KB;
+    base = p - dict->currentOffset;
+    dict->dictionary = p;
+    dict->dictSize = (U32)(dictEnd - p);
+    dict->currentOffset += dict->dictSize;
+
+    while (p <= dictEnd-MINMATCH)
+    {
+        LZ4_putPosition(p, dict, byU32, base);
+        p+=3;
+    }
+
+    return 1;
+}
+
+
+static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
+{
+    if ((LZ4_dict->currentOffset > 0x80000000) ||
+        ((size_t)LZ4_dict->currentOffset > (size_t)src))   /* address space overflow */
+    {
+        /* rescale hash table */
+        U32 delta = LZ4_dict->currentOffset - 64 KB;
+        const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
+        int i;
+        for (i=0; i<HASH_SIZE_U32; i++)
+        {
+            if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0;
+            else LZ4_dict->hashTable[i] -= delta;
+        }
+        LZ4_dict->currentOffset = 64 KB;
+        if (LZ4_dict->dictSize > 64 KB) LZ4_dict->dictSize = 64 KB;
+        LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
+    }
+}
+
+
+FORCE_INLINE int LZ4_compress_continue_generic (void* LZ4_stream, const char* source, char* dest, int inputSize,
+                                                int maxOutputSize, limitedOutput_directive limit)
+{
+    LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_stream;
+    const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
+
+    const BYTE* smallest = (const BYTE*) source;
+    if (streamPtr->initCheck) return 0;   /* Uninitialized structure detected */
+    if ((streamPtr->dictSize>0) && (smallest>dictEnd)) smallest = dictEnd;
+    LZ4_renormDictT(streamPtr, smallest);
+
+    /* Check overlapping input/dictionary space */
+    {
+        const BYTE* sourceEnd = (const BYTE*) source + inputSize;
+        if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd))
+        {
+            streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
+            if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB;
+            if (streamPtr->dictSize < 4) streamPtr->dictSize = 0;
+            streamPtr->dictionary = dictEnd - streamPtr->dictSize;
+        }
+    }
+
+    /* prefix mode : source data follows dictionary */
+    if (dictEnd == (const BYTE*)source)
+    {
+        int result;
+        if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
+            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, dictSmall);
+        else
+            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, noDictIssue);
+        streamPtr->dictSize += (U32)inputSize;
+        streamPtr->currentOffset += (U32)inputSize;
+        return result;
+    }
+
+    /* external dictionary mode */
+    {
+        int result;
+        if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
+            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, dictSmall);
+        else
+            result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, noDictIssue);
+        streamPtr->dictionary = (const BYTE*)source;
+        streamPtr->dictSize = (U32)inputSize;
+        streamPtr->currentOffset += (U32)inputSize;
+        return result;
+    }
+}
+
+int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize)
+{
+    return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, 0, notLimited);
+}
+
+int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize)
+{
+    return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput);
+}
+
+
+/* Hidden debug function, to force separate dictionary mode */
+int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int inputSize)
+{
+    LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_dict;
+    int result;
+    const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
+
+    const BYTE* smallest = dictEnd;
+    if (smallest > (const BYTE*) source) smallest = (const BYTE*) source;
+    LZ4_renormDictT((LZ4_stream_t_internal*)LZ4_dict, smallest);
+
+    result = LZ4_compress_generic(LZ4_dict, source, dest, inputSize, 0, notLimited, byU32, usingExtDict, noDictIssue);
+
+    streamPtr->dictionary = (const BYTE*)source;
+    streamPtr->dictSize = (U32)inputSize;
+    streamPtr->currentOffset += (U32)inputSize;
+
+    return result;
+}
+
+
+int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize)
+{
+    LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
+    const BYTE* previousDictEnd = dict->dictionary + dict->dictSize;
+
+    if ((U32)dictSize > 64 KB) dictSize = 64 KB;   /* useless to define a dictionary > 64 KB */
+    if ((U32)dictSize > dict->dictSize) dictSize = dict->dictSize;
+
+    memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
+
+    dict->dictionary = (const BYTE*)safeBuffer;
+    dict->dictSize = (U32)dictSize;
+
+    return dictSize;
+}
+
+
+
+/****************************
+   Decompression functions
+****************************/
+/*
+ * This generic decompression function cover all use cases.
+ * It shall be instantiated several times, using different sets of directives
+ * Note that it is essential this generic function is really inlined,
+ * in order to remove useless branches during compilation optimization.
+ */
+FORCE_INLINE int LZ4_decompress_generic(
+                 const char* source,
+                 char* dest,
+                 int inputSize,
+                 int outputSize,         /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */
+
+                 int endOnInput,         /* endOnOutputSize, endOnInputSize */
+                 int partialDecoding,    /* full, partial */
+                 int targetOutputSize,   /* only used if partialDecoding==partial */
+                 int dict,               /* noDict, withPrefix64k, usingExtDict */
+                 const char* dictStart,  /* only if dict==usingExtDict */
+                 int dictSize            /* note : = 0 if noDict */
+                 )
+{
+    /* Local Variables */
+    const BYTE* restrict ip = (const BYTE*) source;
+    const BYTE* ref;
+    const BYTE* const iend = ip + inputSize;
+
+    BYTE* op = (BYTE*) dest;
+    BYTE* const oend = op + outputSize;
+    BYTE* cpy;
+    BYTE* oexit = op + targetOutputSize;
+    const BYTE* const lowLimit = (const BYTE*)dest - dictSize;
+
+    const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
+    const size_t dec32table[] = {4, 1, 2, 1, 4, 4, 4, 4};
+    const size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
+
+    const int safeDecode = (endOnInput==endOnInputSize);
+    const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));
+
+
+    /* Special cases */
+    if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT;                         /* targetOutputSize too high => decode everything */
+    if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1;  /* Empty output buffer */
+    if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);
+
+
+    /* Main Loop */
+    while (1)
+    {
+        unsigned token;
+        size_t length;
+
+        /* get runlength */
+        token = *ip++;
+        if ((length=(token>>ML_BITS)) == RUN_MASK)
+        {
+            unsigned s;
+            do
+            {
+                s = *ip++;
+                length += s;
+            }
+            while (likely((endOnInput)?ip<iend-RUN_MASK:1) && (s==255));
+            if ((safeDecode) && LZ4_32BITS && unlikely((size_t)(op+length)<(size_t)(op))) goto _output_error;   /* overflow detection */
+            if ((safeDecode) && LZ4_32BITS && unlikely((size_t)(ip+length)<(size_t)(ip))) goto _output_error;   /* overflow detection */
+        }
+
+        /* copy literals */
+        cpy = op+length;
+        if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
+            || ((!endOnInput) && (cpy>oend-COPYLENGTH)))
+        {
+            if (partialDecoding)
+            {
+                if (cpy > oend) goto _output_error;                           /* Error : write attempt beyond end of output buffer */
+                if ((endOnInput) && (ip+length > iend)) goto _output_error;   /* Error : read attempt beyond end of input buffer */
+            }
+            else
+            {
+                if ((!endOnInput) && (cpy != oend)) goto _output_error;       /* Error : block decoding must stop exactly there */
+                if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error;   /* Error : input must be consumed */
+            }
+            memcpy(op, ip, length);
+            ip += length;
+            op += length;
+            break;     /* Necessarily EOF, due to parsing restrictions */
+        }
+        LZ4_WILDCOPY(op, ip, cpy); ip -= (op-cpy); op = cpy;
+
+        /* get offset */
+        LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
+        if ((checkOffset) && (unlikely(ref < lowLimit))) goto _output_error;   /* Error : offset outside destination buffer */
+
+        /* get matchlength */
+        if ((length=(token&ML_MASK)) == ML_MASK)
+        {
+            unsigned s;
+            do
+            {
+                if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error;
+                s = *ip++;
+                length += s;
+            } while (s==255);
+            if ((safeDecode) && LZ4_32BITS && unlikely((size_t)(op+length)<(size_t)op)) goto _output_error;   /* overflow detection */
+        }
+        length += MINMATCH;
+
+        /* check external dictionary */
+        if ((dict==usingExtDict) && (ref < (BYTE* const)dest))
+        {
+            if (unlikely(op+length > oend-LASTLITERALS)) goto _output_error;
+
+            if (length <= (size_t)(dest-(char*)ref))
+            {
+                ref = dictEnd - (dest-(char*)ref);
+                memcpy(op, ref, length);
+                op += length;
+            }
+            else
+            {
+                size_t copySize = (size_t)(dest-(char*)ref);
+                memcpy(op, dictEnd - copySize, copySize);
+                op += copySize;
+                copySize = length - copySize;
+                if (copySize > (size_t)((char*)op-dest))   /* overlap */
+                {
+                    BYTE* const endOfMatch = op + copySize;
+                    const BYTE* copyFrom = (BYTE*)dest;
+                    while (op < endOfMatch) *op++ = *copyFrom++;
+                }
+                else
+                {
+                    memcpy(op, dest, copySize);
+                    op += copySize;
+                }
+            }
+            continue;
+        }
+
+        /* copy repeated sequence */
+        cpy = op + length;
+        if (unlikely((op-ref)<(int)STEPSIZE))
+        {
+            const size_t dec64 = dec64table[op-ref];
+            op[0] = ref[0];
+            op[1] = ref[1];
+            op[2] = ref[2];
+            op[3] = ref[3];
+            ref += dec32table[op-ref];
+            A32(op+4) = A32(ref);
+            op += 8; ref -= dec64;
+        } else { LZ4_COPY8(op,ref); }
+
+        if (unlikely(cpy>oend-12))
+        {
+            if (cpy > oend-LASTLITERALS) goto _output_error;    /* Error : last 5 bytes must be literals */
+            if (op<oend-COPYLENGTH) LZ4_WILDCOPY(op, ref, (oend-COPYLENGTH));
+            while(op<cpy) *op++=*ref++;
+        }
+        else LZ4_WILDCOPY(op, ref, cpy);
+        op=cpy;   /* correction */
+    }
+
+    /* end of decoding */
+    if (endOnInput)
+       return (int) (((char*)op)-dest);     /* Nb of output bytes decoded */
+    else
+       return (int) (((char*)ip)-source);   /* Nb of input bytes read */
+
+    /* Overflow error detected */
+_output_error:
+    return (int) (-(((char*)ip)-source))-1;
+}
+
+
+int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
+{
+    return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, full, 0, noDict, NULL, 0);
+}
+
+int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize)
+{
+    return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, partial, targetOutputSize, noDict, NULL, 0);
+}
+
+int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
+{
+    return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, NULL, 64 KB);
+}
+
+/* streaming decompression functions */
+
+typedef struct
+{
+    const char* dictionary;
+    int dictSize;
+} LZ4_streamDecode_t_internal;
+
+/*
+ * If you prefer dynamic allocation methods,
+ * LZ4_createStreamDecode()
+ * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
+ */
+LZ4_streamDecode_t* LZ4_createStreamDecode(void)
+{
+    LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOCATOR(sizeof(U32), LZ4_STREAMDECODESIZE_U32);
+    MEM_INIT(lz4s, 0, LZ4_STREAMDECODESIZE);
+    return lz4s;
+}
+
+int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
+{
+    FREEMEM(LZ4_stream);
+    return 0;
+}
+
+/*
+ * LZ4_setStreamDecode
+ * Use this function to instruct where to find the dictionary
+ * This function is not necessary if previous data is still available where it was decoded.
+ * Loading a size of 0 is allowed (same effect as no dictionary).
+ * Return : 1 if OK, 0 if error
+ */
+int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize)
+{
+    LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
+    lz4sd->dictionary = dictionary;
+    lz4sd->dictSize = dictSize;
+    return 1;
+}
+
+/*
+*_continue() :
+    These decoding functions allow decompression of multiple blocks in "streaming" mode.
+    Previously decoded blocks must still be available at the memory position where they were decoded.
+    If it's not possible, save the relevant part of decoded data into a safe buffer,
+    and indicate where it stands using LZ4_setDictDecode()
+*/
+int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
+{
+    LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
+    int result;
+
+    result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
+    if (result <= 0) return result;
+    if (lz4sd->dictionary + lz4sd->dictSize == dest)
+    {
+        lz4sd->dictSize += result;
+    }
+    else
+    {
+        lz4sd->dictionary = dest;
+        lz4sd->dictSize = result;
+    }
+
+    return result;
+}
+
+int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize)
+{
+    LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
+    int result;
+
+    result = LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
+    if (result <= 0) return result;
+    if (lz4sd->dictionary + lz4sd->dictSize == dest)
+    {
+        lz4sd->dictSize += result;
+    }
+    else
+    {
+        lz4sd->dictionary = dest;
+        lz4sd->dictSize = result;
+    }
+
+    return result;
+}
+
+
+/*
+Advanced decoding functions :
+*_usingDict() :
+    These decoding functions work the same as "_continue" ones,
+    the dictionary must be explicitly provided within parameters
+*/
+
+FORCE_INLINE int LZ4_decompress_usingDict_generic(const char* source, char* dest, int compressedSize, int maxOutputSize, int safe, const char* dictStart, int dictSize)
+{
+    if (dictSize==0)
+        return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, NULL, 64 KB);
+    if ((dictStart+dictSize == dest) && (dictSize >= (int)(64 KB - 1)))
+        return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, withPrefix64k, NULL, 64 KB);
+    return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, usingExtDict, dictStart, dictSize);
+}
+
+int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
+{
+    //return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, dictStart, dictSize);
+    return LZ4_decompress_usingDict_generic(source, dest, compressedSize, maxOutputSize, 1, dictStart, dictSize);
+}
+
+int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
+{
+    //return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, dictStart, dictSize);
+    return LZ4_decompress_usingDict_generic(source, dest, 0, originalSize, 0, dictStart, dictSize);
+}
+
+/* debug function */
+int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
+{
+    return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, dictStart, dictSize);
+}
+
+
+/***************************************************
+    Obsolete Functions
+***************************************************/
+/*
+These function names are deprecated and should no longer be used.
+They are only provided here for compatibility with older user programs.
+- LZ4_uncompress is totally equivalent to LZ4_decompress_fast
+- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
+*/
+int LZ4_uncompress (const char* source, char* dest, int outputSize) { return LZ4_decompress_fast(source, dest, outputSize); }
+int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) { return LZ4_decompress_safe(source, dest, isize, maxOutputSize); }
+
+
+/* Obsolete Streaming functions */
+
+int LZ4_sizeofStreamState() { return LZ4_STREAMSIZE; }
+
+static void LZ4_init(LZ4_stream_t_internal* lz4ds, const BYTE* base)
+{
+    MEM_INIT(lz4ds, 0, LZ4_STREAMSIZE);
+    lz4ds->bufferStart = base;
+}
+
+int LZ4_resetStreamState(void* state, const char* inputBuffer)
+{
+    if ((((size_t)state) & 3) != 0) return 1;   /* Error : pointer is not aligned on 4-bytes boundary */
+    LZ4_init((LZ4_stream_t_internal*)state, (const BYTE*)inputBuffer);
+    return 0;
+}
+
+void* LZ4_create (const char* inputBuffer)
+{
+    void* lz4ds = ALLOCATOR(4, LZ4_STREAMSIZE_U32);
+    LZ4_init ((LZ4_stream_t_internal*)lz4ds, (const BYTE*)inputBuffer);
+    return lz4ds;
+}
+
+char* LZ4_slideInputBuffer (void* LZ4_Data)
+{
+    LZ4_stream_t_internal* lz4ds = (LZ4_stream_t_internal*)LZ4_Data;
+
+    LZ4_saveDict((LZ4_stream_t*)LZ4_Data, (char*)lz4ds->bufferStart, 64 KB);
+
+    return (char*)(lz4ds->bufferStart + 64 KB);
+}
+
+/*  Obsolete compresson functions using User-allocated state */
+
+int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
+
+int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize)
+{
+    if (((size_t)(state)&3) != 0) return 0;   /* Error : state is not aligned on 4-bytes boundary */
+    MEM_INIT(state, 0, LZ4_STREAMSIZE);
+
+    if (inputSize < (int)LZ4_64KLIMIT)
+        return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue);
+    else
+        return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, LZ4_64BITS ? byU32 : byPtr, noDict, noDictIssue);
+}
+
+int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize)
+{
+    if (((size_t)(state)&3) != 0) return 0;   /* Error : state is not aligned on 4-bytes boundary */
+    MEM_INIT(state, 0, LZ4_STREAMSIZE);
+
+    if (inputSize < (int)LZ4_64KLIMIT)
+        return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue);
+    else
+        return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, LZ4_64BITS ? byU32 : byPtr, noDict, noDictIssue);
+}
+
+/* Obsolete streaming decompression functions */
+
+int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
+{
+    return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, withPrefix64k, NULL, 64 KB);
+}
+
+int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
+{
+    return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, NULL, 64 KB);
+}
diff --git a/src/grt/fst/lz4.h b/src/grt/fst/lz4.h
new file mode 100644
index 0000000..44ada14
--- /dev/null
+++ b/src/grt/fst/lz4.h
@@ -0,0 +1,323 @@
+/*
+   LZ4 - Fast LZ compression algorithm
+   Header File
+   Copyright (C) 2011-2014, Yann Collet.
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - LZ4 source repository : http://code.google.com/p/lz4/
+   - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
+*/
+#pragma once
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/*
+ * lz4.h provides raw compression format functions, for optimal performance and integration into programs.
+ * If you need to generate data using an inter-operable format (respecting the framing specification),
+ * please use lz4frame.h instead.
+*/
+
+/**************************************
+   Version
+**************************************/
+#define LZ4_VERSION_MAJOR    1    /* for major interface/format changes  */
+#define LZ4_VERSION_MINOR    3    /* for minor interface/format changes  */
+#define LZ4_VERSION_RELEASE  1    /* for tweaks, bug-fixes, or development */
+#define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
+int LZ4_versionNumber (void);
+
+/**************************************
+   Tuning parameter
+**************************************/
+/*
+ * LZ4_MEMORY_USAGE :
+ * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
+ * Increasing memory usage improves compression ratio
+ * Reduced memory usage can improve speed, due to cache effect
+ * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
+ */
+#define LZ4_MEMORY_USAGE 14
+
+
+/**************************************
+   Simple Functions
+**************************************/
+
+int LZ4_compress        (const char* source, char* dest, int sourceSize);
+int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
+
+/*
+LZ4_compress() :
+    Compresses 'sourceSize' bytes from 'source' into 'dest'.
+    Destination buffer must be already allocated,
+    and must be sized to handle worst cases situations (input data not compressible)
+    Worst case size evaluation is provided by function LZ4_compressBound()
+    inputSize : Max supported value is LZ4_MAX_INPUT_SIZE
+    return : the number of bytes written in buffer dest
+             or 0 if the compression fails
+
+LZ4_decompress_safe() :
+    compressedSize : is obviously the source size
+    maxDecompressedSize : is the size of the destination buffer, which must be already allocated.
+    return : the number of bytes decompressed into the destination buffer (necessarily <= maxDecompressedSize)
+             If the destination buffer is not large enough, decoding will stop and output an error code (<0).
+             If the source stream is detected malformed, the function will stop decoding and return a negative result.
+             This function is protected against buffer overflow exploits,
+             and never writes outside of output buffer, nor reads outside of input buffer.
+             It is also protected against malicious data packets.
+*/
+
+
+/**************************************
+   Advanced Functions
+**************************************/
+#define LZ4_MAX_INPUT_SIZE        0x7E000000   /* 2 113 929 216 bytes */
+#define LZ4_COMPRESSBOUND(isize)  ((unsigned int)(isize) > (unsigned int)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
+
+/*
+LZ4_compressBound() :
+    Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
+    This function is primarily useful for memory allocation purposes (output buffer size).
+    Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
+
+    isize  : is the input size. Max supported value is LZ4_MAX_INPUT_SIZE
+    return : maximum output size in a "worst case" scenario
+             or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
+*/
+int LZ4_compressBound(int isize);
+
+
+/*
+LZ4_compress_limitedOutput() :
+    Compress 'sourceSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
+    If it cannot achieve it, compression will stop, and result of the function will be zero.
+    This saves time and memory on detecting non-compressible (or barely compressible) data.
+    This function never writes outside of provided output buffer.
+
+    sourceSize  : Max supported value is LZ4_MAX_INPUT_VALUE
+    maxOutputSize : is the size of the destination buffer (which must be already allocated)
+    return : the number of bytes written in buffer 'dest'
+             or 0 if compression fails
+*/
+int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
+
+
+/*
+LZ4_compress_withState() :
+    Same compression functions, but using an externally allocated memory space to store compression state.
+    Use LZ4_sizeofState() to know how much memory must be allocated,
+    and then, provide it as 'void* state' to compression functions.
+*/
+int LZ4_sizeofState(void);
+int LZ4_compress_withState               (void* state, const char* source, char* dest, int inputSize);
+int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+
+
+/*
+LZ4_decompress_fast() :
+    originalSize : is the original and therefore uncompressed size
+    return : the number of bytes read from the source buffer (in other words, the compressed size)
+             If the source stream is detected malformed, the function will stop decoding and return a negative result.
+             Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
+    note : This function fully respect memory boundaries for properly formed compressed data.
+           It is a bit faster than LZ4_decompress_safe().
+           However, it does not provide any protection against intentionally modified data stream (malicious input).
+           Use this function in trusted environment only (data to decode comes from a trusted source).
+*/
+int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
+
+
+/*
+LZ4_decompress_safe_partial() :
+    This function decompress a compressed block of size 'compressedSize' at position 'source'
+    into destination buffer 'dest' of size 'maxDecompressedSize'.
+    The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
+    reducing decompression time.
+    return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
+       Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
+             Always control how many bytes were decoded.
+             If the source stream is detected malformed, the function will stop decoding and return a negative result.
+             This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
+*/
+int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
+
+
+/***********************************************
+   Experimental Streaming Compression Functions
+***********************************************/
+
+#define LZ4_STREAMSIZE_U32 ((1 << (LZ4_MEMORY_USAGE-2)) + 8)
+#define LZ4_STREAMSIZE     (LZ4_STREAMSIZE_U32 * sizeof(unsigned int))
+/*
+ * LZ4_stream_t
+ * information structure to track an LZ4 stream.
+ * important : init this structure content before first use !
+ */
+typedef struct { unsigned int table[LZ4_STREAMSIZE_U32]; } LZ4_stream_t;
+
+/*
+ * LZ4_resetStream
+ * Use this function to init an allocated LZ4_stream_t structure
+ */
+void LZ4_resetStream (LZ4_stream_t* LZ4_streamPtr);
+
+/*
+ * If you prefer dynamic allocation methods,
+ * LZ4_createStream will allocate and initialize an LZ4_stream_t structure
+ * LZ4_freeStream releases its memory.
+ */
+LZ4_stream_t* LZ4_createStream(void);
+int           LZ4_freeStream (LZ4_stream_t* LZ4_stream);
+
+/*
+ * LZ4_loadDict
+ * Use this function to load a static dictionary into LZ4_stream.
+ * Any previous data will be forgotten, only 'dictionary' will remain in memory.
+ * Loading a size of 0 is allowed.
+ * Return : 1 if OK, 0 if error
+ */
+int LZ4_loadDict (LZ4_stream_t* LZ4_stream, const char* dictionary, int dictSize);
+
+/*
+ * LZ4_compress_continue
+ * Compress data block 'source', using blocks compressed before as dictionary to improve compression ratio
+ * Previous data blocks are assumed to still be present at their previous location.
+ */
+int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize);
+
+/*
+ * LZ4_compress_limitedOutput_continue
+ * Same as before, but also specify a maximum target compressed size (maxOutputSize)
+ * If objective cannot be met, compression exits, and returns a zero.
+ */
+int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize);
+
+/*
+ * LZ4_saveDict
+ * If previously compressed data block is not guaranteed to remain available at its memory location
+ * save it into a safer place (char* safeBuffer)
+ * Note : you don't need to call LZ4_loadDict() afterwards,
+ *        dictionary is immediately usable, you can therefore call again LZ4_compress_continue()
+ * Return : dictionary size in bytes, or 0 if error
+ * Note : any dictSize > 64 KB will be interpreted as 64KB.
+ */
+int LZ4_saveDict (LZ4_stream_t* LZ4_stream, char* safeBuffer, int dictSize);
+
+
+/************************************************
+  Experimental Streaming Decompression Functions
+************************************************/
+
+#define LZ4_STREAMDECODESIZE_U32 4
+#define LZ4_STREAMDECODESIZE     (LZ4_STREAMDECODESIZE_U32 * sizeof(unsigned int))
+/*
+ * LZ4_streamDecode_t
+ * information structure to track an LZ4 stream.
+ * important : init this structure content using LZ4_setStreamDecode or memset() before first use !
+ */
+typedef struct { unsigned int table[LZ4_STREAMDECODESIZE_U32]; } LZ4_streamDecode_t;
+
+/*
+ * LZ4_setStreamDecode
+ * Use this function to instruct where to find the dictionary.
+ * This function can be used to specify a static dictionary,
+ * or to instruct where to find some previously decoded data saved into a different memory space.
+ * Setting a size of 0 is allowed (same effect as no dictionary).
+ * Return : 1 if OK, 0 if error
+ */
+int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
+
+/*
+ * If you prefer dynamic allocation methods,
+ * LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure
+ * LZ4_freeStreamDecode releases its memory.
+ */
+LZ4_streamDecode_t* LZ4_createStreamDecode(void);
+int                 LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
+
+/*
+*_continue() :
+    These decoding functions allow decompression of multiple blocks in "streaming" mode.
+    Previously decoded blocks must still be available at the memory position where they were decoded.
+    If it's not possible, save the relevant part of decoded data into a safe buffer,
+    and indicate where its new address using LZ4_setStreamDecode()
+*/
+int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
+int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
+
+
+/*
+Advanced decoding functions :
+*_usingDict() :
+    These decoding functions work the same as
+    a combination of LZ4_setDictDecode() followed by LZ4_decompress_x_continue()
+    They don't use nor update an LZ4_streamDecode_t structure.
+*/
+int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
+int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
+
+
+
+/**************************************
+   Obsolete Functions
+**************************************/
+/*
+Obsolete decompression functions
+These function names are deprecated and should no longer be used.
+They are only provided here for compatibility with older user programs.
+- LZ4_uncompress is the same as LZ4_decompress_fast
+- LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
+These function prototypes are now disabled; uncomment them if you really need them.
+It is highly recommended to stop using these functions and migrated to newer ones */
+/* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
+/* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
+
+/*
+ * If you prefer dynamic allocation methods,
+ * LZ4_createStreamDecode()
+ * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
+ * LZ4_free just frees it.
+ */
+/* void* LZ4_createStreamDecode(void); */
+/*int   LZ4_free (void* LZ4_stream);    yes, it's the same one as for compression */
+
+/* Obsolete streaming functions; use new streaming interface whenever possible */
+void* LZ4_create (const char* inputBuffer);
+int   LZ4_sizeofStreamState(void);
+int   LZ4_resetStreamState(void* state, const char* inputBuffer);
+char* LZ4_slideInputBuffer (void* state);
+
+/* Obsolete streaming decoding functions */
+int LZ4_decompress_safe_withPrefix64k (const char* source, char* dest, int compressedSize, int maxOutputSize);
+int LZ4_decompress_fast_withPrefix64k (const char* source, char* dest, int originalSize);
+
+
+#if defined (__cplusplus)
+}
+#endif
diff --git a/src/grt/grt-fst.adb b/src/grt/grt-fst.adb
new file mode 100644
index 0000000..bd7b9a9
--- /dev/null
+++ b/src/grt/grt-fst.adb
@@ -0,0 +1,474 @@
+--  GHDL Run Time (GRT) - FST generator.
+--  Copyright (C) 2014 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+--  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+--  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+--  for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+--
+--  As a special exception, if other files instantiate generics from this
+--  unit, or you link this unit with other files to produce an executable,
+--  this unit does not by itself cause the resulting executable to be
+--  covered by the GNU General Public License. This exception does not
+--  however invalidate any other reasons why the executable file might be
+--  covered by the GNU Public License.
+with Interfaces; use Interfaces;
+with Interfaces.C;
+with System; use System;
+with Grt.Types; use Grt.Types;
+with Grt.Fst_Api; use Grt.Fst_Api;
+with Grt.Vcd; use Grt.Vcd;
+with Grt.Avhpi; use Grt.Avhpi;
+with System.Storage_Elements; --  Work around GNAT bug.
+pragma Unreferenced (System.Storage_Elements);
+with Grt.Errors; use Grt.Errors;
+with Grt.Signals; use Grt.Signals;
+with Grt.Table;
+with Grt.Astdio; use Grt.Astdio;
+with Grt.Hooks; use Grt.Hooks;
+with Grt.Rtis; use Grt.Rtis;
+with Grt.Rtis_Types; use Grt.Rtis_Types;
+with Grt.Vstrings;
+pragma Elaborate_All (Grt.Table);
+
+package body Grt.Fst is
+   Context : fstContext := Null_fstContext;
+
+   --  Index type of the table of vcd variables to dump.
+   type Fst_Index_Type is new Integer;
+
+   --  Return TRUE if OPT is an option for FST.
+   function Fst_Option (Opt : String) return Boolean
+   is
+      F : constant Natural := Opt'First;
+      Fst_Filename : String_Access;
+   begin
+      if Opt'Length < 6 or else Opt (F .. F + 5) /= "--fst=" then
+         return False;
+      end if;
+      if Context /= Null_fstContext then
+         Error ("--fst: file already set");
+         return True;
+      end if;
+
+      --  Add an extra NUL character.
+      Fst_Filename := new String (1 .. Opt'Length - 6 + 1);
+      Fst_Filename (1 .. Opt'Length - 6) := Opt (F + 6 .. Opt'Last);
+      Fst_Filename (Fst_Filename'Last) := NUL;
+
+      Context := fstWriterCreate
+        (To_Ghdl_C_String (Fst_Filename.all'Address), 1);
+      if Context = Null_fstContext then
+         Error_C ("fst: cannot open ");
+         Error_E (Fst_Filename (Fst_Filename'First .. Fst_Filename'Last - 1));
+      end if;
+      return True;
+   end Fst_Option;
+
+   procedure Fst_Help is
+   begin
+      Put_Line (" --fst=FILENAME     dump signal values into an FST file");
+   end Fst_Help;
+
+   --  Called before elaboration.
+   procedure Fst_Init
+   is
+      Version : constant String := "GHDL FST v0" & NUL;
+   begin
+      if Context = Null_fstContext then
+         return;
+      end if;
+
+      fstWriterSetFileType (Context, FST_FT_VHDL);
+      fstWriterSetPackType (Context, FST_WR_PT_LZ4);
+      fstWriterSetTimescale (Context, -15); --  fs
+      fstWriterSetVersion (Context, To_Ghdl_C_String (Version'Address));
+      fstWriterSetRepackOnClose (Context, 1);
+      fstWriterSetParallelMode (Context, 0);
+   end Fst_Init;
+
+   type Fst_Sig_Info is record
+      Wire : Verilog_Wire_Info;
+      Hand : fstHandle;
+   end record;
+
+   package Fst_Table is new Grt.Table
+     (Table_Component_Type => Fst_Sig_Info,
+      Table_Index_Type => Fst_Index_Type,
+      Table_Low_Bound => 0,
+      Table_Initial => 32);
+
+   procedure Avhpi_Error (Err : AvhpiErrorT)
+   is
+      pragma Unreferenced (Err);
+   begin
+      Put_Line ("Fst.Avhpi_Error!");
+   end Avhpi_Error;
+
+   procedure Fst_Add_Signal (Sig : VhpiHandleT)
+   is
+      Vcd_El : Verilog_Wire_Info;
+      Vt : fstVarType;
+      Sdt : fstSupplementalDataType;
+      Dir : fstVarDir;
+      Len : Interfaces.C.unsigned;
+      Name : String (1 .. 128);
+      Name_Len : Natural;
+      Hand : fstHandle;
+   begin
+      Get_Verilog_Wire (Sig, Vcd_El);
+
+      if Vcd_El.Kind = Vcd_Bad then
+         --  Not handled.
+         return;
+      end if;
+
+
+      case Vcd_El.Kind is
+         when Vcd_Bad =>
+            raise Program_Error;
+         when Vcd_Bool =>
+            Vt := FST_VT_VCD_REG;
+            Len := 1;
+            Sdt := FST_SDT_VHDL_BOOLEAN;
+         when Vcd_Integer32 =>
+            Vt := FST_VT_VCD_INTEGER;
+            Len := 1;
+            Sdt := FST_SDT_VHDL_INTEGER;
+         when Vcd_Float64 =>
+            Vt := FST_VT_VCD_REAL;
+            Len := 1;
+            Sdt := FST_SDT_VHDL_REAL;
+         when Vcd_Bit =>
+            Vt := FST_VT_VCD_REG;
+            Len := 1;
+            Sdt := FST_SDT_VHDL_BIT;
+         when Vcd_Stdlogic =>
+            Vt := FST_VT_VCD_REG;
+            Len := 1;
+            Sdt := FST_SDT_VHDL_STD_LOGIC;
+         when Vcd_Bitvector =>
+            Vt := FST_VT_VCD_REG;
+            Len := Interfaces.C.unsigned (Vcd_El.Irange.I32.Len);
+            Sdt := FST_SDT_VHDL_BIT_VECTOR;
+         when Vcd_Stdlogic_Vector =>
+            Vt := FST_VT_VCD_REG;
+            Len := Interfaces.C.unsigned (Vcd_El.Irange.I32.Len);
+            Sdt := FST_SDT_VHDL_STD_LOGIC_VECTOR;
+      end case;
+
+      if Vhpi_Get_Kind (Sig) = VhpiPortDeclK then
+         case Vhpi_Get_Mode (Sig) is
+            when VhpiInMode =>
+               Dir := FST_VD_INPUT;
+            when VhpiInoutMode =>
+               Dir := FST_VD_INOUT;
+            when VhpiBufferMode =>
+               Dir := FST_VD_BUFFER;
+            when VhpiLinkageMode =>
+               Dir := FST_VD_LINKAGE;
+            when VhpiOutMode =>
+               Dir := FST_VD_OUTPUT;
+            when VhpiErrorMode =>
+               Dir := FST_VD_IMPLICIT;
+         end case;
+      else
+         Dir := FST_VD_IMPLICIT;
+      end if;
+
+      Vhpi_Get_Str (VhpiNameP, Sig, Name, Name_Len);
+      if Name_Len >= Name'Length
+        or else Vcd_El.Irange /= null
+      then
+         declare
+            Name2 : String (1 .. Name_Len + 3 + 2 * 11 + 1);
+
+            procedure Append (N : Ghdl_I32)
+            is
+               Num : String (1 .. 11);
+               Num_First : Natural;
+               Num_Len : Natural;
+            begin
+               Grt.Vstrings.To_String (Num, Num_First, N);
+               Num_Len := Num'Last - Num_First + 1;
+               Name2 (Name_Len + 1 .. Name_Len + Num_Len) :=
+                 Num (Num_First .. Num'Last);
+               Name_Len := Name_Len + Num_Len;
+            end Append;
+         begin
+            Vhpi_Get_Str (VhpiNameP, Sig, Name2, Name_Len);
+            if Vcd_El.Irange /= null then
+               Name2 (Name_Len + 1) := '[';
+               Name_Len := Name_Len + 1;
+               Append (Vcd_El.Irange.I32.Left);
+               Name2 (Name_Len + 1) := ':';
+               Name_Len := Name_Len + 1;
+               Append (Vcd_El.Irange.I32.Right);
+               Name2 (Name_Len + 1) := ']';
+               Name_Len := Name_Len + 1;
+            end if;
+            Name2 (Name_Len + 1) := NUL;
+            Name_Len := Name_Len + 1;
+
+            Hand := fstWriterCreateVar2
+              (Context, Vt, Dir, Len, To_Ghdl_C_String (Name2'Address),
+               Null_fstHandle, null, FST_SVT_VHDL_SIGNAL, Sdt);
+         end;
+      else
+         Name (Name_Len) := NUL;
+         Hand := fstWriterCreateVar2
+           (Context, Vt, Dir, Len, To_Ghdl_C_String (Name'Address),
+            Null_fstHandle, null, FST_SVT_VHDL_SIGNAL, Sdt);
+      end if;
+
+      Fst_Table.Append (Fst_Sig_Info'(Wire => Vcd_El, Hand => Hand));
+   end Fst_Add_Signal;
+
+   procedure Fst_Put_Hierarchy (Inst : VhpiHandleT);
+
+   procedure Fst_Put_Scope (Scope : fstScopeType; Decl : VhpiHandleT)
+   is
+      Name : String (1 .. 128);
+      Name_Len : Integer;
+   begin
+      Vhpi_Get_Str (VhpiNameP, Decl, Name, Name_Len);
+      if Name_Len < Name'Last then
+         Name (Name_Len + 1) := NUL;
+      else
+         --  Truncate
+         Name (Name'Last) := NUL;
+      end if;
+
+      fstWriterSetScope
+        (Context, Scope, To_Ghdl_C_String (Name'Address), null);
+      Fst_Put_Hierarchy (Decl);
+      fstWriterSetUpscope (Context);
+   end Fst_Put_Scope;
+
+   procedure Fst_Put_Hierarchy (Inst : VhpiHandleT)
+   is
+      Decl_It : VhpiHandleT;
+      Decl : VhpiHandleT;
+      Error : AvhpiErrorT;
+   begin
+      Vhpi_Iterator (VhpiDecls, Inst, Decl_It, Error);
+      if Error /= AvhpiErrorOk then
+         Avhpi_Error (Error);
+         return;
+      end if;
+
+      --  Extract signals.
+      loop
+         Vhpi_Scan (Decl_It, Decl, Error);
+         exit when Error = AvhpiErrorIteratorEnd;
+         if Error /= AvhpiErrorOk then
+            Avhpi_Error (Error);
+            return;
+         end if;
+
+         case Vhpi_Get_Kind (Decl) is
+            when VhpiPortDeclK
+              | VhpiSigDeclK =>
+               Fst_Add_Signal (Decl);
+            when others =>
+               null;
+         end case;
+      end loop;
+
+      --  Extract sub-scopes.
+      Vhpi_Iterator (VhpiInternalRegions, Inst, Decl_It, Error);
+      if Error /= AvhpiErrorOk then
+         Avhpi_Error (Error);
+         return;
+      end if;
+
+      loop
+         Vhpi_Scan (Decl_It, Decl, Error);
+         exit when Error = AvhpiErrorIteratorEnd;
+         if Error /= AvhpiErrorOk then
+            Avhpi_Error (Error);
+            return;
+         end if;
+
+         case Vhpi_Get_Kind (Decl) is
+            when VhpiIfGenerateK =>
+               Fst_Put_Scope (FST_ST_VHDL_IF_GENERATE, Decl);
+            when VhpiForGenerateK =>
+               Fst_Put_Scope (FST_ST_VHDL_FOR_GENERATE, Decl);
+            when  VhpiBlockStmtK =>
+               Fst_Put_Scope (FST_ST_VHDL_BLOCK, Decl);
+            when VhpiCompInstStmtK =>
+               Fst_Put_Scope (FST_ST_VHDL_ARCHITECTURE, Decl);
+            when others =>
+               null;
+         end case;
+      end loop;
+   end Fst_Put_Hierarchy;
+
+   procedure Fst_Put_Integer32 (Hand : fstHandle; V : Ghdl_U32)
+   is
+      Str : String (1 .. 32);
+      Val : Ghdl_U32;
+   begin
+      Val := V;
+      for I in Str'Range loop
+         Str (I) := Character'Val (Character'Pos ('0') + (Val and 1));
+         Val := Val / 2;
+      end loop;
+      fstWriterEmitValueChange (Context, Hand, Str'Address);
+   end Fst_Put_Integer32;
+
+   procedure Fst_Put_Var (I : Fst_Index_Type)
+   is
+      From_Bit : constant array (Ghdl_B1) of Character := "01";
+      type Map_Type is array (Ghdl_E8 range 0 .. 8) of Character;
+      From_Std : constant Map_Type := "UX01ZWLH-";
+      Sig : Signal_Arr_Ptr;
+      V : Fst_Sig_Info renames Fst_Table.Table (I);
+      Len : Ghdl_Index_Type;
+      Hand : constant fstHandle := V.Hand;
+   begin
+      Sig := To_Signal_Arr_Ptr (V.Wire.Addr);
+      if V.Wire.Irange = null then
+         Len := 1;
+      else
+         Len := V.Wire.Irange.I32.Len;
+      end if;
+      case V.Wire.Val is
+         when Vcd_Effective =>
+            case V.Wire.Kind is
+               when Vcd_Bit
+                 | Vcd_Bool
+                 | Vcd_Bitvector =>
+                  declare
+                     Str : Std_String_Uncons (0 .. Len - 1);
+                  begin
+                     for I in Str'Range loop
+                        Str (I) := From_Bit (Sig (I).Value.B1);
+                     end loop;
+                     fstWriterEmitValueChange (Context, Hand, Str'Address);
+                  end;
+               when Vcd_Stdlogic
+                 | Vcd_Stdlogic_Vector =>
+                  declare
+                     Str : Std_String_Uncons (0 .. Len - 1);
+                  begin
+                     for I in Str'Range loop
+                        Str (I) := From_Std (Sig (I).Value.E8);
+                     end loop;
+                     fstWriterEmitValueChange (Context, Hand, Str'Address);
+                  end;
+               when Vcd_Integer32 =>
+                  Fst_Put_Integer32 (Hand, Sig (0).Value.E32);
+               when Vcd_Float64 =>
+                  null;
+               when Vcd_Bad =>
+                  null;
+            end case;
+         when Vcd_Driving =>
+            case V.Wire.Kind is
+               when Vcd_Bit
+                 | Vcd_Bool
+                 | Vcd_Bitvector =>
+                  declare
+                     Str : Std_String_Uncons (0 .. Len - 1);
+                  begin
+                     for I in Str'Range loop
+                        Str (I) := From_Bit (Sig (I).Driving_Value.B1);
+                     end loop;
+                     fstWriterEmitValueChange (Context, Hand, Str'Address);
+                  end;
+               when Vcd_Stdlogic
+                 | Vcd_Stdlogic_Vector =>
+                  declare
+                     Str : Std_String_Uncons (0 .. Len - 1);
+                  begin
+                     for I in Str'Range loop
+                        Str (I) := From_Std (Sig (I).Driving_Value.E8);
+                     end loop;
+                     fstWriterEmitValueChange (Context, Hand, Str'Address);
+                  end;
+               when Vcd_Integer32 =>
+                  Fst_Put_Integer32 (Hand, Sig (0).Driving_Value.E32);
+               when Vcd_Float64 =>
+                  null;
+               when Vcd_Bad =>
+                  null;
+            end case;
+      end case;
+   end Fst_Put_Var;
+
+   procedure Fst_Cycle;
+
+   --  Called after elaboration.
+   procedure Fst_Start
+   is
+      Root : VhpiHandleT;
+   begin
+      --  Do nothing if there is no VCD file to generate.
+      if Context = Null_fstContext then
+         return;
+      end if;
+
+      --  Be sure the RTI of std_ulogic is set.
+      Search_Types_RTI;
+
+      --  Put hierarchy.
+      Get_Root_Inst (Root);
+      Fst_Put_Hierarchy (Root);
+
+      Register_Cycle_Hook (Fst_Cycle'Access);
+   end Fst_Start;
+
+   --  Called before each non delta cycle.
+   procedure Fst_Cycle is
+   begin
+      --  Disp values.
+      fstWriterEmitTimeChange (Context, Unsigned_64 (Cycle_Time));
+
+      if Cycle_Time = 0 then
+         --  Disp all values.
+         for I in Fst_Table.First .. Fst_Table.Last loop
+            Fst_Put_Var (I);
+         end loop;
+      else
+         --  Disp only values changed.
+         for I in Fst_Table.First .. Fst_Table.Last loop
+            if Verilog_Wire_Changed (Fst_Table.Table (I).Wire, Cycle_Time) then
+               Fst_Put_Var (I);
+            end if;
+         end loop;
+      end if;
+   end Fst_Cycle;
+
+   --  Called at the end of the simulation.
+   procedure Fst_End is
+   begin
+      if Context /= Null_fstContext then
+         fstWriterClose (Context);
+         Context := Null_fstContext;
+      end if;
+   end Fst_End;
+
+   Fst_Hooks : aliased constant Hooks_Type :=
+     (Option => Fst_Option'Access,
+      Help => Fst_Help'Access,
+      Init => Fst_Init'Access,
+      Start => Fst_Start'Access,
+      Finish => Fst_End'Access);
+
+   procedure Register is
+   begin
+      Register_Hooks (Fst_Hooks'Access);
+   end Register;
+end Grt.Fst;
diff --git a/src/grt/grt-fst.ads b/src/grt/grt-fst.ads
new file mode 100644
index 0000000..81b6abd
--- /dev/null
+++ b/src/grt/grt-fst.ads
@@ -0,0 +1,28 @@
+--  GHDL Run Time (GRT) - FST generator.
+--  Copyright (C) 2014 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+--  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+--  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+--  for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+--
+--  As a special exception, if other files instantiate generics from this
+--  unit, or you link this unit with other files to produce an executable,
+--  this unit does not by itself cause the resulting executable to be
+--  covered by the GNU General Public License. This exception does not
+--  however invalidate any other reasons why the executable file might be
+--  covered by the GNU Public License.
+
+package Grt.Fst is
+   procedure Register;
+end Grt.Fst;
diff --git a/src/grt/grt-fst_api.ads b/src/grt/grt-fst_api.ads
new file mode 100644
index 0000000..ba0ec0c
--- /dev/null
+++ b/src/grt/grt-fst_api.ads
@@ -0,0 +1,353 @@
+with Interfaces; use Interfaces;
+with Interfaces.C; use Interfaces.C;
+with System;
+with Grt.Types; use Grt.Types;
+
+package Grt.Fst_Api is
+
+   subtype fstHandle is unsigned;
+   Null_fstHandle : constant fstHandle := 0;
+
+   type fstWriterPackType is
+     (FST_WR_PT_ZLIB,
+      FST_WR_PT_FASTLZ,
+      FST_WR_PT_LZ4);
+   pragma Convention (C, fstWriterPackType);
+
+   subtype fstFileType is unsigned;
+   FST_FT_MIN          : constant fstFileType := 0;
+   FST_FT_VERILOG      : constant fstFileType := 0;
+   FST_FT_VHDL         : constant fstFileType := 1;
+   FST_FT_VERILOG_VHDL : constant fstFileType := 2;
+   FST_FT_MAX          : constant fstFileType := 2;
+
+   subtype fstBlockType is unsigned;
+   FST_BL_HDR               : constant fstBlockType := 0;
+   FST_BL_VCDATA            : constant fstBlockType := 1;
+   FST_BL_BLACKOUT          : constant fstBlockType := 2;
+   FST_BL_GEOM              : constant fstBlockType := 3;
+   FST_BL_HIER              : constant fstBlockType := 4;
+   FST_BL_VCDATA_DYN_ALIAS  : constant fstBlockType := 5;
+   FST_BL_HIER_LZ4          : constant fstBlockType := 6;
+   FST_BL_HIER_LZ4DUO       : constant fstBlockType := 7;
+   FST_BL_VCDATA_DYN_ALIAS2 : constant fstBlockType := 8;
+   FST_BL_ZWRAPPER          : constant fstBlockType := 254;
+   FST_BL_SKIP              : constant fstBlockType := 255;
+
+   subtype fstScopeType is unsigned;
+   FST_ST_MIN               : constant fstScopeType := 0;
+   FST_ST_VCD_MODULE        : constant fstScopeType := 0;
+   FST_ST_VCD_TASK          : constant fstScopeType := 1;
+   FST_ST_VCD_FUNCTION      : constant fstScopeType := 2;
+   FST_ST_VCD_BEGIN         : constant fstScopeType := 3;
+   FST_ST_VCD_FORK          : constant fstScopeType := 4;
+   FST_ST_VCD_GENERATE      : constant fstScopeType := 5;
+   FST_ST_VCD_STRUCT        : constant fstScopeType := 6;
+   FST_ST_VCD_UNION         : constant fstScopeType := 7;
+   FST_ST_VCD_CLASS         : constant fstScopeType := 8;
+   FST_ST_VCD_INTERFACE     : constant fstScopeType := 9;
+   FST_ST_VCD_PACKAGE       : constant fstScopeType := 10;
+   FST_ST_VCD_PROGRAM       : constant fstScopeType := 11;
+   FST_ST_VHDL_ARCHITECTURE : constant fstScopeType := 12;
+   FST_ST_VHDL_PROCEDURE    : constant fstScopeType := 13;
+   FST_ST_VHDL_FUNCTION     : constant fstScopeType := 14;
+   FST_ST_VHDL_RECORD       : constant fstScopeType := 15;
+   FST_ST_VHDL_PROCESS      : constant fstScopeType := 16;
+   FST_ST_VHDL_BLOCK        : constant fstScopeType := 17;
+   FST_ST_VHDL_FOR_GENERATE : constant fstScopeType := 18;
+   FST_ST_VHDL_IF_GENERATE  : constant fstScopeType := 19;
+   FST_ST_VHDL_GENERATE     : constant fstScopeType := 20;
+   FST_ST_VHDL_PACKAGE      : constant fstScopeType := 21;
+   FST_ST_MAX               : constant fstScopeType := 21;
+   FST_ST_GEN_ATTRBEGIN     : constant fstScopeType := 252;
+   FST_ST_GEN_ATTREND       : constant fstScopeType := 253;
+   FST_ST_VCD_SCOPE         : constant fstScopeType := 254;
+   FST_ST_VCD_UPSCOPE       : constant fstScopeType := 255;
+
+   subtype fstVarType is unsigned;
+   FST_VT_MIN                : constant fstVarType := 0;
+   FST_VT_VCD_EVENT          : constant fstVarType := 0;
+   FST_VT_VCD_INTEGER        : constant fstVarType := 1;
+   FST_VT_VCD_PARAMETER      : constant fstVarType := 2;
+   FST_VT_VCD_REAL           : constant fstVarType := 3;
+   FST_VT_VCD_REAL_PARAMETER : constant fstVarType := 4;
+   FST_VT_VCD_REG            : constant fstVarType := 5;
+   FST_VT_VCD_SUPPLY0        : constant fstVarType := 6;
+   FST_VT_VCD_SUPPLY1        : constant fstVarType := 7;
+   FST_VT_VCD_TIME           : constant fstVarType := 8;
+   FST_VT_VCD_TRI            : constant fstVarType := 9;
+   FST_VT_VCD_TRIAND         : constant fstVarType := 10;
+   FST_VT_VCD_TRIOR          : constant fstVarType := 11;
+   FST_VT_VCD_TRIREG         : constant fstVarType := 12;
+   FST_VT_VCD_TRI0           : constant fstVarType := 13;
+   FST_VT_VCD_TRI1           : constant fstVarType := 14;
+   FST_VT_VCD_WAND           : constant fstVarType := 15;
+   FST_VT_VCD_WIRE           : constant fstVarType := 16;
+   FST_VT_VCD_WOR            : constant fstVarType := 17;
+   FST_VT_VCD_PORT           : constant fstVarType := 18;
+   FST_VT_VCD_SPARRAY        : constant fstVarType := 19;
+   FST_VT_VCD_REALTIME       : constant fstVarType := 20;
+   FST_VT_GEN_STRING         : constant fstVarType := 21;
+   FST_VT_SV_BIT             : constant fstVarType := 22;
+   FST_VT_SV_LOGIC           : constant fstVarType := 23;
+   FST_VT_SV_INT             : constant fstVarType := 24;
+   FST_VT_SV_SHORTINT        : constant fstVarType := 25;
+   FST_VT_SV_LONGINT         : constant fstVarType := 26;
+   FST_VT_SV_BYTE            : constant fstVarType := 27;
+   FST_VT_SV_ENUM            : constant fstVarType := 28;
+   FST_VT_SV_SHORTREAL       : constant fstVarType := 29;
+   FST_VT_MAX                : constant fstVarType := 29;
+
+   subtype fstVarDir is unsigned;
+   FST_VD_MIN      : constant fstVarDir := 0;
+   FST_VD_IMPLICIT : constant fstVarDir := 0;
+   FST_VD_INPUT    : constant fstVarDir := 1;
+   FST_VD_OUTPUT   : constant fstVarDir := 2;
+   FST_VD_INOUT    : constant fstVarDir := 3;
+   FST_VD_BUFFER   : constant fstVarDir := 4;
+   FST_VD_LINKAGE  : constant fstVarDir := 5;
+   FST_VD_MAX      : constant fstVarDir := 5;
+
+   subtype fstHierType is unsigned;
+   FST_HT_MIN       : constant fstHierType := 0;
+   FST_HT_SCOPE     : constant fstHierType := 0;
+   FST_HT_UPSCOPE   : constant fstHierType := 1;
+   FST_HT_VAR       : constant fstHierType := 2;
+   FST_HT_ATTRBEGIN : constant fstHierType := 3;
+   FST_HT_ATTREND   : constant fstHierType := 4;
+   FST_HT_MAX       : constant fstHierType := 4;
+
+   subtype fstAttrType is unsigned;
+   FST_AT_MIN   : constant fstAttrType := 0;
+   FST_AT_MISC  : constant fstAttrType := 0;
+   FST_AT_ARRAY : constant fstAttrType := 1;
+   FST_AT_ENUM  : constant fstAttrType := 2;
+   FST_AT_PACK  : constant fstAttrType := 3;
+   FST_AT_MAX   : constant fstAttrType := 3;
+
+   subtype fstMiscType is unsigned;
+   FST_MT_MIN         : constant fstMiscType := 0;
+   FST_MT_COMMENT     : constant fstMiscType := 0;
+   FST_MT_ENVVAR      : constant fstMiscType := 1;
+   FST_MT_SUPVAR      : constant fstMiscType := 2;
+   FST_MT_PATHNAME    : constant fstMiscType := 3;
+   FST_MT_SOURCESTEM  : constant fstMiscType := 4;
+   FST_MT_SOURCEISTEM : constant fstMiscType := 5;
+   FST_MT_UNKNOWN     : constant fstMiscType := 6;
+   FST_MT_MAX         : constant fstMiscType := 6;
+
+   subtype fstArrayType is unsigned;
+   FST_AR_MIN      : constant fstArrayType := 0;
+   FST_AR_NONE     : constant fstArrayType := 0;
+   FST_AR_UNPACKED : constant fstArrayType := 1;
+   FST_AR_PACKED   : constant fstArrayType := 2;
+   FST_AR_SPARSE   : constant fstArrayType := 3;
+   FST_AR_MAX      : constant fstArrayType := 3;
+
+   subtype fstEnumValueType is unsigned;
+   FST_EV_SV_INTEGER           : constant fstEnumValueType := 0;
+   FST_EV_SV_BIT               : constant fstEnumValueType := 1;
+   FST_EV_SV_LOGIC             : constant fstEnumValueType := 2;
+   FST_EV_SV_INT               : constant fstEnumValueType := 3;
+   FST_EV_SV_SHORTINT          : constant fstEnumValueType := 4;
+   FST_EV_SV_LONGINT           : constant fstEnumValueType := 5;
+   FST_EV_SV_BYTE              : constant fstEnumValueType := 6;
+   FST_EV_SV_UNSIGNED_INTEGER  : constant fstEnumValueType := 7;
+   FST_EV_SV_UNSIGNED_BIT      : constant fstEnumValueType := 8;
+   FST_EV_SV_UNSIGNED_LOGIC    : constant fstEnumValueType := 9;
+   FST_EV_SV_UNSIGNED_INT      : constant fstEnumValueType := 10;
+   FST_EV_SV_UNSIGNED_SHORTINT : constant fstEnumValueType := 11;
+   FST_EV_SV_UNSIGNED_LONGINT  : constant fstEnumValueType := 12;
+   FST_EV_SV_UNSIGNED_BYTE     : constant fstEnumValueType := 13;
+   FST_EV_MAX                  : constant fstEnumValueType := 13;
+
+   subtype fstPackType is unsigned;
+   FST_PT_NONE          : constant fstPackType := 0;
+   FST_PT_UNPACKED      : constant fstPackType := 1;
+   FST_PT_PACKED        : constant fstPackType := 2;
+   FST_PT_TAGGED_PACKED : constant fstPackType := 3;
+   FST_PT_MAX           : constant fstPackType := 3;
+
+   subtype fstSupplementalVarType is unsigned;
+   FST_SVT_MIN           : constant fstSupplementalVarType := 0;
+   FST_SVT_NONE          : constant fstSupplementalVarType := 0;
+   FST_SVT_VHDL_SIGNAL   : constant fstSupplementalVarType := 1;
+   FST_SVT_VHDL_VARIABLE : constant fstSupplementalVarType := 2;
+   FST_SVT_VHDL_CONSTANT : constant fstSupplementalVarType := 3;
+   FST_SVT_VHDL_FILE     : constant fstSupplementalVarType := 4;
+   FST_SVT_VHDL_MEMORY   : constant fstSupplementalVarType := 5;
+   FST_SVT_MAX           : constant fstSupplementalVarType := 5;
+
+   subtype fstSupplementalDataType is unsigned;
+   FST_SDT_MIN                    : constant fstSupplementalDataType := 0;
+   FST_SDT_NONE                   : constant fstSupplementalDataType := 0;
+   FST_SDT_VHDL_BOOLEAN           : constant fstSupplementalDataType := 1;
+   FST_SDT_VHDL_BIT               : constant fstSupplementalDataType := 2;
+   FST_SDT_VHDL_BIT_VECTOR        : constant fstSupplementalDataType := 3;
+   FST_SDT_VHDL_STD_ULOGIC        : constant fstSupplementalDataType := 4;
+   FST_SDT_VHDL_STD_ULOGIC_VECTOR : constant fstSupplementalDataType := 5;
+   FST_SDT_VHDL_STD_LOGIC         : constant fstSupplementalDataType := 6;
+   FST_SDT_VHDL_STD_LOGIC_VECTOR  : constant fstSupplementalDataType := 7;
+   FST_SDT_VHDL_UNSIGNED          : constant fstSupplementalDataType := 8;
+   FST_SDT_VHDL_SIGNED            : constant fstSupplementalDataType := 9;
+   FST_SDT_VHDL_INTEGER           : constant fstSupplementalDataType := 10;
+   FST_SDT_VHDL_REAL              : constant fstSupplementalDataType := 11;
+   FST_SDT_VHDL_NATURAL           : constant fstSupplementalDataType := 12;
+   FST_SDT_VHDL_POSITIVE          : constant fstSupplementalDataType := 13;
+   FST_SDT_VHDL_TIME              : constant fstSupplementalDataType := 14;
+   FST_SDT_VHDL_CHARACTER         : constant fstSupplementalDataType := 15;
+   FST_SDT_VHDL_STRING            : constant fstSupplementalDataType := 16;
+   FST_SDT_MAX                    : constant fstSupplementalDataType := 16;
+   FST_SDT_SVT_SHIFT_COUNT        : constant fstSupplementalDataType := 10;
+   FST_SDT_ABS_MAX                : constant fstSupplementalDataType := 1023;
+
+   type fstContext is new System.Address;
+   Null_fstContext : constant fstContext := fstContext (System.Null_Address);
+
+   procedure fstWriterClose (ctx : fstContext);
+   pragma Import (C, fstWriterClose, "fstWriterClose");
+
+   function fstWriterCreate (nam : Ghdl_C_String; use_compressed_hier : int)
+                             return fstContext;
+   pragma Import (C, fstWriterCreate, "fstWriterCreate");
+
+   function fstWriterCreateVar
+     (ctx : fstContext;
+      vt : fstVarType;
+      vd : fstVarDir;
+      len : unsigned;
+      nam : Ghdl_C_String;
+      aliasHandle : fstHandle) return fstHandle;
+   pragma Import (C, fstWriterCreateVar, "fstWriterCreateVar");
+
+   function fstWriterCreateVar2
+     (ctx : fstContext;
+      vt : fstVarType;
+      vd : fstVarDir;
+      len : unsigned;
+      nam : Ghdl_C_String;
+      aliasHandle : fstHandle;
+      c_type : Ghdl_C_String;
+      svt : fstSupplementalVarType;
+      sdt : fstSupplementalDataType) return fstHandle;
+   pragma Import (C, fstWriterCreateVar2, "fstWriterCreateVar2");
+
+   procedure fstWriterEmitValueChange
+     (ctx : fstContext;
+      handle : fstHandle;
+      val : System.Address);
+   pragma Import (C, fstWriterEmitValueChange, "fstWriterEmitValueChange");
+
+   procedure fstWriterEmitVariableLengthValueChange
+     (ctx : fstContext;
+      handle : fstHandle;
+      val : System.Address;
+      len : unsigned);
+   pragma Import (C, fstWriterEmitVariableLengthValueChange,
+                  "fstWriterEmitVariableLengthValueChange");
+
+   procedure fstWriterEmitDumpActive (ctx : fstContext; enable : int);
+   pragma Import (C, fstWriterEmitDumpActive, "fstWriterEmitDumpActive");
+
+   procedure fstWriterEmitTimeChange
+     (ctx : fstContext; tim : Unsigned_64);
+   pragma Import (C, fstWriterEmitTimeChange, "fstWriterEmitTimeChange");
+
+   procedure fstWriterFlushContext (ctx : fstContext);
+   pragma Import (C, fstWriterFlushContext, "fstWriterFlushContext");
+
+   function fstWriterGetDumpSizeLimitReached (ctx : fstContext) return int;
+   pragma Import (C, fstWriterGetDumpSizeLimitReached,
+                  "fstWriterGetDumpSizeLimitReached");
+
+   function fstWriterGetFseekFailed (ctx : fstContext) return int;
+   pragma Import (C, fstWriterGetFseekFailed, "fstWriterGetFseekFailed");
+
+   procedure fstWriterSetAttrBegin
+     (ctx : fstContext;
+      attrtype : fstAttrType;
+      c_subtype : int;
+      attrname : Ghdl_C_String;
+      arg : Unsigned_64);
+   pragma Import (C, fstWriterSetAttrBegin, "fstWriterSetAttrBegin");
+
+   procedure fstWriterSetAttrEnd (ctx : fstContext);
+   pragma Import (C, fstWriterSetAttrEnd, "fstWriterSetAttrEnd");
+
+   procedure fstWriterSetComment (ctx : fstContext; comm : Ghdl_C_String);
+   pragma Import (C, fstWriterSetComment, "fstWriterSetComment");
+
+   procedure fstWriterSetDate (ctx : fstContext; dat : Ghdl_C_String);
+   pragma Import (C, fstWriterSetDate, "fstWriterSetDate");
+
+   procedure fstWriterSetDumpSizeLimit
+     (ctx : Ghdl_C_String; numbytes : Unsigned_64);
+   pragma Import (C, fstWriterSetDumpSizeLimit, "fstWriterSetDumpSizeLimit");
+
+   procedure fstWriterSetEnvVar (ctx : fstContext; envvar : Ghdl_C_String);
+   pragma Import (C, fstWriterSetEnvVar, "fstWriterSetEnvVar");
+
+   procedure fstWriterSetFileType (ctx : fstContext; filetype : fstFileType);
+   pragma Import (C, fstWriterSetFileType, "fstWriterSetFileType");
+
+   procedure fstWriterSetPackType (ctx : fstContext; typ : fstWriterPackType);
+   pragma Import (C, fstWriterSetPackType, "fstWriterSetPackType");
+
+   procedure fstWriterSetParallelMode (ctx : fstContext; enable : int);
+   pragma Import (C, fstWriterSetParallelMode, "fstWriterSetParallelMode");
+
+   procedure fstWriterSetRepackOnClose (ctx : fstContext; enable : int);
+   pragma Import (C, fstWriterSetRepackOnClose, "fstWriterSetRepackOnClose");
+
+   procedure fstWriterSetScope
+     (ctx : fstContext;
+      scopetype : fstScopeType;
+      scopename : Ghdl_C_String;
+      scopecomp : Ghdl_C_String);
+   pragma Import (C, fstWriterSetScope, "fstWriterSetScope");
+
+   procedure fstWriterSetSourceInstantiationStem
+     (ctx : fstContext;
+      path : Ghdl_C_String;
+      line : unsigned;
+      use_realpath : unsigned);
+   pragma Import (C, fstWriterSetSourceInstantiationStem,
+                  "fstWriterSetSourceInstantiationStem");
+
+   procedure fstWriterSetSourceStem
+     (ctx : fstContext;
+      path : Ghdl_C_String;
+      line : unsigned;
+      use_realpath : unsigned);
+   pragma Import (C, fstWriterSetSourceStem, "fstWriterSetSourceStem");
+
+   procedure fstWriterSetTimescale (ctx : fstContext; ts : Integer);
+   pragma Import (C, fstWriterSetTimescale, "fstWriterSetTimescale");
+
+   procedure fstWriterSetTimescaleFromString
+     (ctx : fstContext; s : Ghdl_C_String);
+   pragma Import (C, fstWriterSetTimescaleFromString,
+                  "fstWriterSetTimescaleFromString");
+
+   procedure fstWriterSetTimezero (ctx : fstContext; tim : Unsigned_64);
+   pragma Import (C, fstWriterSetTimezero, "fstWriterSetTimezero");
+
+   procedure fstWriterSetUpscope (ctx : fstContext);
+   pragma Import (C, fstWriterSetUpscope, "fstWriterSetUpscope");
+
+   procedure fstWriterSetVersion (ctx : fstContext; vers : Ghdl_C_String);
+   pragma Import (C, fstWriterSetVersion, "fstWriterSetVersion");
+
+   function fstUtilityBinToEsc
+     (d : access unsigned_char;
+      s : access unsigned_char;
+      len : int) return int;
+   pragma Import (C, fstUtilityBinToEsc, "fstUtilityBinToEsc");
+
+   function fstUtilityEscToBin
+     (d : access unsigned_char;
+      s : access unsigned_char;
+      len : int) return int;
+   pragma Import (C, fstUtilityEscToBin, "fstUtilityEscToBin");
+
+end Grt.Fst_Api;
diff --git a/src/grt/grt-modules.adb b/src/grt/grt-modules.adb
index e5304f0..3fc6c4e 100644
--- a/src/grt/grt-modules.adb
+++ b/src/grt/grt-modules.adb
@@ -27,6 +27,7 @@ pragma Unreferenced (System.Storage_Elements);
 with Grt.Vcd;
 with Grt.Vcdz;
 with Grt.Vpi;
+with Grt.Fst;
 with Grt.Waves;
 with Grt.Vital_Annotate;
 with Grt.Disp_Tree;
@@ -40,6 +41,7 @@ package body Grt.Modules is
       Grt.Vcd.Register;
       Grt.Vcdz.Register;
       Grt.Waves.Register;
+      Grt.Fst.Register;
       Grt.Vpi.Register;
       Grt.Vital_Annotate.Register;
       Grt.Disp_Rti.Register;
diff --git a/src/grt/grt-vcd.adb b/src/grt/grt-vcd.adb
index d4a9ea0..13c1f20 100644
--- a/src/grt/grt-vcd.adb
+++ b/src/grt/grt-vcd.adb
@@ -714,8 +714,7 @@ package body Grt.Vcd is
       Vcd_Newline;
    end Vcd_Put_Var;
 
-   function Verilog_Wire_Changed (Info : Verilog_Wire_Info;
-                                  Last : Std_Time)
+   function Verilog_Wire_Changed (Info : Verilog_Wire_Info; Last : Std_Time)
                                  return Boolean
    is
       Len : Ghdl_Index_Type;
diff --git a/src/grt/grt-vcd.ads b/src/grt/grt-vcd.ads
index ed015af..73096c5 100644
--- a/src/grt/grt-vcd.ads
+++ b/src/grt/grt-vcd.ads
@@ -47,7 +47,9 @@ package Grt.Vcd is
    type Vcd_Value_Kind is (Vcd_Effective, Vcd_Driving);
 
    type Verilog_Wire_Info is record
+      --  Signal address
       Addr : Address;
+
       Irange : Ghdl_Range_Ptr;
       Kind : Vcd_Var_Kind;
       Val : Vcd_Value_Kind;