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// Copyright 2018 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 "go_asm.h"
#include "textflag.h"
// memequal(a, b unsafe.Pointer, size uintptr) bool
TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-25
MOVD a+0(FP), R3
MOVD b+8(FP), R5
MOVD size+16(FP), R6
LA ret+24(FP), R7
BR memeqbody<>(SB)
// memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen(SB),NOSPLIT|NOFRAME,$0-17
MOVD a+0(FP), R3
MOVD b+8(FP), R5
MOVD 8(R12), R6 // compiler stores size at offset 8 in the closure
LA ret+16(FP), R7
BR memeqbody<>(SB)
// input:
// R3 = a
// R5 = b
// R6 = len
// R7 = address of output byte (stores 0 or 1 here)
// a and b have the same length
TEXT memeqbody<>(SB),NOSPLIT|NOFRAME,$0-0
CMPBEQ R3, R5, equal
loop:
CMPBEQ R6, $0, equal
CMPBLT R6, $32, tiny
CMP R6, $256
BLT tail
CLC $256, 0(R3), 0(R5)
BNE notequal
SUB $256, R6
LA 256(R3), R3
LA 256(R5), R5
BR loop
tail:
SUB $1, R6, R8
EXRL $memeqbodyclc<>(SB), R8
BEQ equal
notequal:
MOVB $0, 0(R7)
RET
equal:
MOVB $1, 0(R7)
RET
tiny:
MOVD $0, R2
CMPBLT R6, $16, lt16
MOVD 0(R3), R8
MOVD 0(R5), R9
CMPBNE R8, R9, notequal
MOVD 8(R3), R8
MOVD 8(R5), R9
CMPBNE R8, R9, notequal
LA 16(R2), R2
SUB $16, R6
lt16:
CMPBLT R6, $8, lt8
MOVD 0(R3)(R2*1), R8
MOVD 0(R5)(R2*1), R9
CMPBNE R8, R9, notequal
LA 8(R2), R2
SUB $8, R6
lt8:
CMPBLT R6, $4, lt4
MOVWZ 0(R3)(R2*1), R8
MOVWZ 0(R5)(R2*1), R9
CMPBNE R8, R9, notequal
LA 4(R2), R2
SUB $4, R6
lt4:
#define CHECK(n) \
CMPBEQ R6, $n, equal \
MOVB n(R3)(R2*1), R8 \
MOVB n(R5)(R2*1), R9 \
CMPBNE R8, R9, notequal
CHECK(0)
CHECK(1)
CHECK(2)
CHECK(3)
BR equal
TEXT memeqbodyclc<>(SB),NOSPLIT|NOFRAME,$0-0
CLC $1, 0(R3), 0(R5)
RET
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