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| author | Josh Coalson <jcoalson@users.sourceforce.net> | 2007-03-23 04:48:52 +0000 |
|---|---|---|
| committer | Josh Coalson <jcoalson@users.sourceforce.net> | 2007-03-23 04:48:52 +0000 |
| commit | 0bddabc5df255e6f1b194667c05988099440dd0c (patch) | |
| tree | 6a53f8fef286745797caf4178d3f26222ef5272c /src/libFLAC/ia32 | |
| parent | 49cb34a543157d3723498ab1560deb3f33d37ca7 (diff) | |
| download | flac-0bddabc5df255e6f1b194667c05988099440dd0c.tar.gz | |
minor optimizations
Diffstat (limited to 'src/libFLAC/ia32')
| -rw-r--r-- | src/libFLAC/ia32/bitreader_asm.nasm | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/src/libFLAC/ia32/bitreader_asm.nasm b/src/libFLAC/ia32/bitreader_asm.nasm index 5b923aa1..da630717 100644 --- a/src/libFLAC/ia32/bitreader_asm.nasm +++ b/src/libFLAC/ia32/bitreader_asm.nasm @@ -134,11 +134,9 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap jz near .break1 ; if(cbits >= FLAC__BITS_PER_WORD) { /* faster way of testing if(cbits == FLAC__BITS_PER_WORD) */ ; crc16_update_word_(br, br->buffer[cwords]); push edi ; [need more registers] - push ecx ; [need more registers] bswap edx ; edx = br->buffer[cwords] swapped; now we can CRC the bytes from LSByte to MSByte which makes things much easier mov ecx, [ebp + 28] ; ecx <- br->crc16_align mov eax, [ebp + 24] ; ax <- br->read_crc (a.k.a. crc) - xor ebx, ebx ; [code from here down assumes and requires that the top 24 bits of ebx stay zero] mov edi, FLAC__crc16_table ;; eax (ax) crc a.k.a. br->read_crc ;; ebx (bl) intermediate result index into FLAC__crc16_table[] @@ -170,8 +168,8 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap 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 + movzx eax, ax + mov [ebp + 24], eax ; br->read_crc <- crc pop edi add esi, 1 ; cwords++; @@ -208,11 +206,9 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap sub edi, ecx ; uval += FLAC__BITS_PER_WORD - cbits; ; crc16_update_word_(br, br->buffer[cwords]); push edi ; [need more registers] - push ecx ; [need more registers] bswap edx ; edx = br->buffer[cwords] swapped; now we can CRC the bytes from LSByte to MSByte which makes things much easier mov ecx, [ebp + 28] ; ecx <- br->crc16_align mov eax, [ebp + 24] ; ax <- br->read_crc (a.k.a. crc) - xor ebx, ebx ; [code from here down assumes and requires that the top 24 bits of ebx stay zero] mov edi, FLAC__crc16_table ;; eax (ax) crc a.k.a. br->read_crc ;; ebx (bl) intermediate result index into FLAC__crc16_table[] @@ -244,8 +240,8 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap 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 + movzx eax, ax + mov [ebp + 24], eax ; br->read_crc <- crc pop edi add esi, 1 ; cwords++; @@ -418,12 +414,10 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap ; crc16_update_word_(br, br->buffer[cwords]); push edi ; [need more registers] push ebx ; [need more registers] - push ecx ; [need more registers] push eax ; [need more registers] bswap edx ; edx = br->buffer[cwords] swapped; now we can CRC the bytes from LSByte to MSByte which makes things much easier mov ecx, [ebp + 28] ; ecx <- br->crc16_align mov eax, [ebp + 24] ; ax <- br->read_crc (a.k.a. crc) - xor ebx, ebx ; [code from here down assumes and requires that the top 24 bits of ebx stay zero] mov edi, FLAC__crc16_table ;; eax (ax) crc a.k.a. br->read_crc ;; ebx (bl) intermediate result index into FLAC__crc16_table[] @@ -455,9 +449,9 @@ cident FLAC__bitreader_read_rice_signed_block_asm_ia32_bswap 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 + movzx eax, ax + mov [ebp + 24], eax ; br->read_crc <- crc pop eax - pop ecx pop ebx pop edi add esi, 1 ; cwords++; |