69 lines
1.2 KiB
ArmAsm
69 lines
1.2 KiB
ArmAsm
|
// Copied from S2 implementation.
|
||
|
|
|
||
|
|
//go:build !appengine && !noasm && gc && !noasm
|
||
|
|
|
||
|
|
#include "textflag.h"
|
||
|
|
|
||
|
|
// func matchLen(a []byte, b []byte) int
|
||
|
|
// Requires: BMI
|
||
|
|
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
|
||
|
|
TESTQ BX, BX
|
||
|
|
JZ matchlen_loop_standalone
|
||
|
|
|
||
|
|
#ifdef GOAMD64_v3
|
||
|
|
TZCNTQ BX, BX
|
||
|
|
#else
|
||
|
|
BSFQ BX, BX
|
||
|
|
#endif
|
||
|
|
SARQ $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
|