diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/xtensa/lib/strnlen_user.S')
| -rw-r--r-- | ANDROID_3.4.5/arch/xtensa/lib/strnlen_user.S | 148 |
1 files changed, 0 insertions, 148 deletions
diff --git a/ANDROID_3.4.5/arch/xtensa/lib/strnlen_user.S b/ANDROID_3.4.5/arch/xtensa/lib/strnlen_user.S deleted file mode 100644 index 23f2a898..00000000 --- a/ANDROID_3.4.5/arch/xtensa/lib/strnlen_user.S +++ /dev/null @@ -1,148 +0,0 @@ -/* - * arch/xtensa/lib/strnlen_user.S - * - * This file is subject to the terms and conditions of the GNU General - * Public License. See the file "COPYING" in the main directory of - * this archive for more details. - * - * Returns strnlen, including trailing zero terminator. - * Zero indicates error. - * - * Copyright (C) 2002 Tensilica Inc. - */ - -#include <variant/core.h> - -/* Load or store instructions that may cause exceptions use the EX macro. */ - -#define EX(insn,reg1,reg2,offset,handler) \ -9: insn reg1, reg2, offset; \ - .section __ex_table, "a"; \ - .word 9b, handler; \ - .previous - -/* - * size_t __strnlen_user(const char *s, size_t len) - */ - -#ifdef __XTENSA_EB__ -# define MASK0 0xff000000 -# define MASK1 0x00ff0000 -# define MASK2 0x0000ff00 -# define MASK3 0x000000ff -#else -# define MASK0 0x000000ff -# define MASK1 0x0000ff00 -# define MASK2 0x00ff0000 -# define MASK3 0xff000000 -#endif - -# Register use: -# a2/ src -# a3/ len -# a4/ tmp -# a5/ mask0 -# a6/ mask1 -# a7/ mask2 -# a8/ mask3 -# a9/ tmp -# a10/ tmp - -.text -.align 4 -.global __strnlen_user -.type __strnlen_user,@function -__strnlen_user: - entry sp, 16 # minimal stack frame - # a2/ s, a3/ len - addi a4, a2, -4 # because we overincrement at the end; - # we compensate with load offsets of 4 - movi a5, MASK0 # mask for byte 0 - movi a6, MASK1 # mask for byte 1 - movi a7, MASK2 # mask for byte 2 - movi a8, MASK3 # mask for byte 3 - bbsi.l a2, 0, .L1mod2 # if only 8-bit aligned - bbsi.l a2, 1, .L2mod4 # if only 16-bit aligned - -/* - * String is word-aligned. - */ -.Laligned: - srli a10, a3, 2 # number of loop iterations with 4B per loop -#if XCHAL_HAVE_LOOPS - loopnez a10, .Ldone -#else - beqz a10, .Ldone - slli a10, a10, 2 - add a10, a10, a4 # a10 = end of last 4B chunk -#endif /* XCHAL_HAVE_LOOPS */ -.Loop: - EX(l32i, a9, a4, 4, lenfixup) # get next word of string - addi a4, a4, 4 # advance string pointer - bnone a9, a5, .Lz0 # if byte 0 is zero - bnone a9, a6, .Lz1 # if byte 1 is zero - bnone a9, a7, .Lz2 # if byte 2 is zero - bnone a9, a8, .Lz3 # if byte 3 is zero -#if !XCHAL_HAVE_LOOPS - blt a4, a10, .Loop -#endif - -.Ldone: - EX(l32i, a9, a4, 4, lenfixup) # load 4 bytes for remaining checks - - bbci.l a3, 1, .L100 - # check two more bytes (bytes 0, 1 of word) - addi a4, a4, 2 # advance string pointer - bnone a9, a5, .Lz0 # if byte 0 is zero - bnone a9, a6, .Lz1 # if byte 1 is zero -.L100: - bbci.l a3, 0, .L101 - # check one more byte (byte 2 of word) - # Actually, we don't need to check. Zero or nonzero, we'll add one. - # Do not add an extra one for the NULL terminator since we have - # exhausted the original len parameter. - addi a4, a4, 1 # advance string pointer -.L101: - sub a2, a4, a2 # compute length - retw - -# NOTE that in several places below, we point to the byte just after -# the zero byte in order to include the NULL terminator in the count. - -.Lz3: # byte 3 is zero - addi a4, a4, 3 # point to zero byte -.Lz0: # byte 0 is zero - addi a4, a4, 1 # point just beyond zero byte - sub a2, a4, a2 # subtract to get length - retw -.Lz1: # byte 1 is zero - addi a4, a4, 1+1 # point just beyond zero byte - sub a2, a4, a2 # subtract to get length - retw -.Lz2: # byte 2 is zero - addi a4, a4, 2+1 # point just beyond zero byte - sub a2, a4, a2 # subtract to get length - retw - -.L1mod2: # address is odd - EX(l8ui, a9, a4, 4, lenfixup) # get byte 0 - addi a4, a4, 1 # advance string pointer - beqz a9, .Lz3 # if byte 0 is zero - bbci.l a4, 1, .Laligned # if string pointer is now word-aligned - -.L2mod4: # address is 2 mod 4 - addi a4, a4, 2 # advance ptr for aligned access - EX(l32i, a9, a4, 0, lenfixup) # get word with first two bytes of string - bnone a9, a7, .Lz2 # if byte 2 (of word, not string) is zero - bany a9, a8, .Laligned # if byte 3 (of word, not string) is nonzero - # byte 3 is zero - addi a4, a4, 3+1 # point just beyond zero byte - sub a2, a4, a2 # subtract to get length - retw - - .section .fixup, "ax" - .align 4 -lenfixup: - movi a2, 0 - retw - |