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// Copyright 2019 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"
#define CTXT S10
// func memequal(a, b unsafe.Pointer, size uintptr) bool
TEXT runtime·memequal<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-25
// X10 = a_base
// X11 = b_base
// X12 = size
JMP memequal<>(SB)
// func memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-17
MOV 8(CTXT), X12 // compiler stores size at offset 8 in the closure
// X10 = a_base
// X11 = b_base
JMP memequal<>(SB)
// On entry X10 and X11 contain pointers, X12 contains length.
// For non-regabi X13 contains address for return value.
// For regabi return value in X10.
TEXT memequal<>(SB),NOSPLIT|NOFRAME,$0
BEQ X10, X11, eq
MOV $32, X23
BLT X12, X23, loop4_check
// Check alignment - if alignment differs we have to do one byte at a time.
AND $7, X10, X9
AND $7, X11, X19
BNE X9, X19, loop4_check
BEQZ X9, loop32_check
// Check one byte at a time until we reach 8 byte alignment.
SUB X9, X0, X9
ADD $8, X9, X9
SUB X9, X12, X12
align:
ADD $-1, X9
MOVBU 0(X10), X19
MOVBU 0(X11), X20
BNE X19, X20, not_eq
ADD $1, X10
ADD $1, X11
BNEZ X9, align
loop32_check:
MOV $32, X9
BLT X12, X9, loop16_check
loop32:
MOV 0(X10), X19
MOV 0(X11), X20
MOV 8(X10), X21
MOV 8(X11), X22
BNE X19, X20, not_eq
BNE X21, X22, not_eq
MOV 16(X10), X14
MOV 16(X11), X15
MOV 24(X10), X16
MOV 24(X11), X17
BNE X14, X15, not_eq
BNE X16, X17, not_eq
ADD $32, X10
ADD $32, X11
ADD $-32, X12
BGE X12, X9, loop32
BEQZ X12, eq
loop16_check:
MOV $16, X23
BLT X12, X23, loop4_check
loop16:
MOV 0(X10), X19
MOV 0(X11), X20
MOV 8(X10), X21
MOV 8(X11), X22
BNE X19, X20, not_eq
BNE X21, X22, not_eq
ADD $16, X10
ADD $16, X11
ADD $-16, X12
BGE X12, X23, loop16
BEQZ X12, eq
loop4_check:
MOV $4, X23
BLT X12, X23, loop1
loop4:
MOVBU 0(X10), X19
MOVBU 0(X11), X20
MOVBU 1(X10), X21
MOVBU 1(X11), X22
BNE X19, X20, not_eq
BNE X21, X22, not_eq
MOVBU 2(X10), X14
MOVBU 2(X11), X15
MOVBU 3(X10), X16
MOVBU 3(X11), X17
BNE X14, X15, not_eq
BNE X16, X17, not_eq
ADD $4, X10
ADD $4, X11
ADD $-4, X12
BGE X12, X23, loop4
loop1:
BEQZ X12, eq
MOVBU 0(X10), X19
MOVBU 0(X11), X20
BNE X19, X20, not_eq
ADD $1, X10
ADD $1, X11
ADD $-1, X12
JMP loop1
not_eq:
MOVB ZERO, X10
RET
eq:
MOV $1, X10
RET
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