diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/alpha/lib/ev6-memchr.S')
| -rw-r--r-- | ANDROID_3.4.5/arch/alpha/lib/ev6-memchr.S | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/ANDROID_3.4.5/arch/alpha/lib/ev6-memchr.S b/ANDROID_3.4.5/arch/alpha/lib/ev6-memchr.S deleted file mode 100644 index 1a5f71b9..00000000 --- a/ANDROID_3.4.5/arch/alpha/lib/ev6-memchr.S +++ /dev/null @@ -1,191 +0,0 @@ -/* - * arch/alpha/lib/ev6-memchr.S - * - * 21264 version contributed by Rick Gorton <rick.gorton@alpha-processor.com> - * - * Finds characters in a memory area. Optimized for the Alpha: - * - * - memory accessed as aligned quadwords only - * - uses cmpbge to compare 8 bytes in parallel - * - does binary search to find 0 byte in last - * quadword (HAKMEM needed 12 instructions to - * do this instead of the 9 instructions that - * binary search needs). - * - * For correctness consider that: - * - * - only minimum number of quadwords may be accessed - * - the third argument is an unsigned long - * - * Much of the information about 21264 scheduling/coding comes from: - * Compiler Writer's Guide for the Alpha 21264 - * abbreviated as 'CWG' in other comments here - * ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html - * Scheduling notation: - * E - either cluster - * U - upper subcluster; U0 - subcluster U0; U1 - subcluster U1 - * L - lower subcluster; L0 - subcluster L0; L1 - subcluster L1 - * Try not to change the actual algorithm if possible for consistency. - */ - - .set noreorder - .set noat - - .align 4 - .globl memchr - .ent memchr -memchr: - .frame $30,0,$26,0 - .prologue 0 - - # Hack -- if someone passes in (size_t)-1, hoping to just - # search til the end of the address space, we will overflow - # below when we find the address of the last byte. Given - # that we will never have a 56-bit address space, cropping - # the length is the easiest way to avoid trouble. - zap $18, 0x80, $5 # U : Bound length - beq $18, $not_found # U : - ldq_u $1, 0($16) # L : load first quadword Latency=3 - and $17, 0xff, $17 # E : L L U U : 00000000000000ch - - insbl $17, 1, $2 # U : 000000000000ch00 - cmpult $18, 9, $4 # E : small (< 1 quad) string? - or $2, $17, $17 # E : 000000000000chch - lda $3, -1($31) # E : U L L U - - sll $17, 16, $2 # U : 00000000chch0000 - addq $16, $5, $5 # E : Max search address - or $2, $17, $17 # E : 00000000chchchch - sll $17, 32, $2 # U : U L L U : chchchch00000000 - - or $2, $17, $17 # E : chchchchchchchch - extql $1, $16, $7 # U : $7 is upper bits - beq $4, $first_quad # U : - ldq_u $6, -1($5) # L : L U U L : eight or less bytes to search Latency=3 - - extqh $6, $16, $6 # U : 2 cycle stall for $6 - mov $16, $0 # E : - nop # E : - or $7, $6, $1 # E : L U L U $1 = quadword starting at $16 - - # Deal with the case where at most 8 bytes remain to be searched - # in $1. E.g.: - # $18 = 6 - # $1 = ????c6c5c4c3c2c1 -$last_quad: - negq $18, $6 # E : - xor $17, $1, $1 # E : - srl $3, $6, $6 # U : $6 = mask of $18 bits set - cmpbge $31, $1, $2 # E : L U L U - - nop - nop - and $2, $6, $2 # E : - beq $2, $not_found # U : U L U L - -$found_it: -#ifdef CONFIG_ALPHA_EV67 - /* - * Since we are guaranteed to have set one of the bits, we don't - * have to worry about coming back with a 0x40 out of cttz... - */ - cttz $2, $3 # U0 : - addq $0, $3, $0 # E : All done - nop # E : - ret # L0 : L U L U -#else - /* - * Slow and clunky. It can probably be improved. - * An exercise left for others. - */ - negq $2, $3 # E : - and $2, $3, $2 # E : - and $2, 0x0f, $1 # E : - addq $0, 4, $3 # E : - - cmoveq $1, $3, $0 # E : Latency 2, extra map cycle - nop # E : keep with cmov - and $2, 0x33, $1 # E : - addq $0, 2, $3 # E : U L U L : 2 cycle stall on $0 - - cmoveq $1, $3, $0 # E : Latency 2, extra map cycle - nop # E : keep with cmov - and $2, 0x55, $1 # E : - addq $0, 1, $3 # E : U L U L : 2 cycle stall on $0 - - cmoveq $1, $3, $0 # E : Latency 2, extra map cycle - nop - nop - ret # L0 : L U L U -#endif - - # Deal with the case where $18 > 8 bytes remain to be - # searched. $16 may not be aligned. - .align 4 -$first_quad: - andnot $16, 0x7, $0 # E : - insqh $3, $16, $2 # U : $2 = 0000ffffffffffff ($16<0:2> ff) - xor $1, $17, $1 # E : - or $1, $2, $1 # E : U L U L $1 = ====ffffffffffff - - cmpbge $31, $1, $2 # E : - bne $2, $found_it # U : - # At least one byte left to process. - ldq $1, 8($0) # L : - subq $5, 1, $18 # E : U L U L - - addq $0, 8, $0 # E : - # Make $18 point to last quad to be accessed (the - # last quad may or may not be partial). - andnot $18, 0x7, $18 # E : - cmpult $0, $18, $2 # E : - beq $2, $final # U : U L U L - - # At least two quads remain to be accessed. - - subq $18, $0, $4 # E : $4 <- nr quads to be processed - and $4, 8, $4 # E : odd number of quads? - bne $4, $odd_quad_count # U : - # At least three quads remain to be accessed - mov $1, $4 # E : L U L U : move prefetched value to correct reg - - .align 4 -$unrolled_loop: - ldq $1, 8($0) # L : prefetch $1 - xor $17, $4, $2 # E : - cmpbge $31, $2, $2 # E : - bne $2, $found_it # U : U L U L - - addq $0, 8, $0 # E : - nop # E : - nop # E : - nop # E : - -$odd_quad_count: - xor $17, $1, $2 # E : - ldq $4, 8($0) # L : prefetch $4 - cmpbge $31, $2, $2 # E : - addq $0, 8, $6 # E : - - bne $2, $found_it # U : - cmpult $6, $18, $6 # E : - addq $0, 8, $0 # E : - nop # E : - - bne $6, $unrolled_loop # U : - mov $4, $1 # E : move prefetched value into $1 - nop # E : - nop # E : - -$final: subq $5, $0, $18 # E : $18 <- number of bytes left to do - nop # E : - nop # E : - bne $18, $last_quad # U : - -$not_found: - mov $31, $0 # E : - nop # E : - nop # E : - ret # L0 : - - .end memchr |