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optimization: faster crc-16 calculation

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This commit is contained in:
Josh Coalson
2007-03-22 07:23:14 +00:00
parent 645620c24b
commit 6942044be1
1 changed files with 39 additions and 39 deletions
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78
src/libFLAC/ia32/bitreader_asm.nasm
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@@ -151,26 +151,26 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap
jnz .c0b4 ; [br->crc16_align is 0 the vast majority of the time so we optimize the common case]
.c0b0: xor dl, ah ; dl <- (crc>>8)^(word>>24)
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
.c0b1: xor dh, ah ; dh <- (crc>>8)^((word>>16)&0xff))
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shr edx, 16
.c0b2: xor dl, ah ; dl <- (crc>>8)^((word>>8)&0xff))
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
.c0b3: xor dh, ah ; dh <- (crc>>8)^(word&0xff)
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], eax ; br->read_crc <- crc
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], ax ; br->read_crc <- crc
pop ecx
pop edi
@@ -225,26 +225,26 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap
jnz .c1b4 ; [br->crc16_align is 0 the vast majority of the time so we optimize the common case]
.c1b0: xor dl, ah ; dl <- (crc>>8)^(word>>24)
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
.c1b1: xor dh, ah ; dh <- (crc>>8)^((word>>16)&0xff))
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shr edx, 16
.c1b2: xor dl, ah ; dl <- (crc>>8)^((word>>8)&0xff))
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
.c1b3: xor dh, ah ; dh <- (crc>>8)^(word&0xff)
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], eax ; br->read_crc <- crc
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], ax ; br->read_crc <- crc
pop ecx
pop edi
@@ -436,26 +436,26 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap
jnz .c2b4 ; [br->crc16_align is 0 the vast majority of the time so we optimize the common case]
.c2b0: xor dl, ah ; dl <- (crc>>8)^(word>>24)
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word>>24)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word>>24)]
.c2b1: xor dh, ah ; dh <- (crc>>8)^((word>>16)&0xff))
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>16)&0xff))]
shr edx, 16
.c2b2: xor dl, ah ; dl <- (crc>>8)^((word>>8)&0xff))
movzx ebx, dl
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^((word>>8)&0xff))]
.c2b3: xor dh, ah ; dh <- (crc>>8)^(word&0xff)
movzx ebx, dh
mov cx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl ax, 8 ; ax <- (crc<<8)
xor ax, cx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], eax ; br->read_crc <- crc
mov ecx, [ebx*4 + edi] ; cx <- FLAC__crc16_table[(crc>>8)^(word&0xff)]
shl eax, 8 ; ax <- (crc<<8)
xor eax, ecx ; crc <- ax <- (crc<<8) ^ FLAC__crc16_table[(crc>>8)^(word&0xff)]
mov [ebp + 24], ax ; br->read_crc <- crc
pop eax
pop ecx
pop ebx