diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/matchlen_amd64.s')
| -rw-r--r-- | vendor/github.com/klauspost/compress/zstd/matchlen_amd64.s | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/matchlen_amd64.s b/vendor/github.com/klauspost/compress/zstd/matchlen_amd64.s new file mode 100644 index 000000000..0782b86e3 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/matchlen_amd64.s @@ -0,0 +1,66 @@ +// Copied from S2 implementation. + +//go:build !appengine && !noasm && gc && !noasm + +#include "textflag.h" + +// func matchLen(a []byte, b []byte) int +TEXT ·matchLen(SB), NOSPLIT, $0-56 + MOVQ a_base+0(FP), AX + MOVQ b_base+24(FP), CX + MOVQ a_len+8(FP), DX + + // matchLen + XORL SI, SI + CMPL DX, $0x08 + JB matchlen_match4_standalone + +matchlen_loopback_standalone: + MOVQ (AX)(SI*1), BX + XORQ (CX)(SI*1), BX + JZ matchlen_loop_standalone + +#ifdef GOAMD64_v3 + TZCNTQ BX, BX +#else + BSFQ BX, BX +#endif + SHRL $0x03, BX + LEAL (SI)(BX*1), SI + JMP gen_match_len_end + +matchlen_loop_standalone: + LEAL -8(DX), DX + LEAL 8(SI), SI + CMPL DX, $0x08 + JAE matchlen_loopback_standalone + +matchlen_match4_standalone: + CMPL DX, $0x04 + JB matchlen_match2_standalone + MOVL (AX)(SI*1), BX + CMPL (CX)(SI*1), BX + JNE matchlen_match2_standalone + LEAL -4(DX), DX + LEAL 4(SI), SI + +matchlen_match2_standalone: + CMPL DX, $0x02 + JB matchlen_match1_standalone + MOVW (AX)(SI*1), BX + CMPW (CX)(SI*1), BX + JNE matchlen_match1_standalone + LEAL -2(DX), DX + LEAL 2(SI), SI + +matchlen_match1_standalone: + CMPL DX, $0x01 + JB gen_match_len_end + MOVB (AX)(SI*1), BL + CMPB (CX)(SI*1), BL + JNE gen_match_len_end + INCL SI + +gen_match_len_end: + MOVQ SI, ret+48(FP) + RET |