diff options
Diffstat (limited to 'src/hash/crc32/crc32_amd64.s')
| -rw-r--r-- | src/hash/crc32/crc32_amd64.s | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/hash/crc32/crc32_amd64.s b/src/hash/crc32/crc32_amd64.s new file mode 100644 index 000000000..30b0d0691 --- /dev/null +++ b/src/hash/crc32/crc32_amd64.s @@ -0,0 +1,64 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" + +// func castagnoliSSE42(crc uint32, p []byte) uint32 +TEXT ·castagnoliSSE42(SB),NOSPLIT,$0 + MOVL crc+0(FP), AX // CRC value + MOVQ p+8(FP), SI // data pointer + MOVQ p_len+16(FP), CX // len(p) + + NOTL AX + + /* If there's less than 8 bytes to process, we do it byte-by-byte. */ + CMPQ CX, $8 + JL cleanup + + /* Process individual bytes until the input is 8-byte aligned. */ +startup: + MOVQ SI, BX + ANDQ $7, BX + JZ aligned + + CRC32B (SI), AX + DECQ CX + INCQ SI + JMP startup + +aligned: + /* The input is now 8-byte aligned and we can process 8-byte chunks. */ + CMPQ CX, $8 + JL cleanup + + CRC32Q (SI), AX + ADDQ $8, SI + SUBQ $8, CX + JMP aligned + +cleanup: + /* We may have some bytes left over that we process one at a time. */ + CMPQ CX, $0 + JE done + + CRC32B (SI), AX + INCQ SI + DECQ CX + JMP cleanup + +done: + NOTL AX + MOVL AX, ret+32(FP) + RET + +// func haveSSE42() bool +TEXT ·haveSSE42(SB),NOSPLIT,$0 + XORQ AX, AX + INCL AX + CPUID + SHRQ $20, CX + ANDQ $1, CX + MOVB CX, ret+0(FP) + RET + |