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// Copyright 2015 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.
//go:build mips64 || mips64le
#include "textflag.h"
// See memmove Go doc for important implementation constraints.
// func memmove(to, from unsafe.Pointer, n uintptr)
TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24
MOVV to+0(FP), R1
MOVV from+8(FP), R2
MOVV n+16(FP), R3
BNE R3, check
RET
check:
SGTU R1, R2, R4
BNE R4, backward
ADDV R1, R3, R6 // end pointer
// if the two pointers are not of same alignments, do byte copying
SUBVU R2, R1, R4
AND $7, R4
BNE R4, out
// if less than 8 bytes, do byte copying
SGTU $8, R3, R4
BNE R4, out
// do one byte at a time until 8-aligned
AND $7, R1, R5
BEQ R5, words
MOVB (R2), R4
ADDV $1, R2
MOVB R4, (R1)
ADDV $1, R1
JMP -6(PC)
words:
// do 8 bytes at a time if there is room
ADDV $-7, R6, R3 // R3 is end pointer-7
SGTU R3, R1, R5
BEQ R5, out
MOVV (R2), R4
ADDV $8, R2
MOVV R4, (R1)
ADDV $8, R1
JMP -6(PC)
out:
BEQ R1, R6, done
MOVB (R2), R4
ADDV $1, R2
MOVB R4, (R1)
ADDV $1, R1
JMP -5(PC)
done:
RET
backward:
ADDV R3, R2 // from-end pointer
ADDV R1, R3, R6 // to-end pointer
// if the two pointers are not of same alignments, do byte copying
SUBVU R6, R2, R4
AND $7, R4
BNE R4, out1
// if less than 8 bytes, do byte copying
SGTU $8, R3, R4
BNE R4, out1
// do one byte at a time until 8-aligned
AND $7, R6, R5
BEQ R5, words1
ADDV $-1, R2
MOVB (R2), R4
ADDV $-1, R6
MOVB R4, (R6)
JMP -6(PC)
words1:
// do 8 bytes at a time if there is room
ADDV $7, R1, R3 // R3 is start pointer+7
SGTU R6, R3, R5
BEQ R5, out1
ADDV $-8, R2
MOVV (R2), R4
ADDV $-8, R6
MOVV R4, (R6)
JMP -6(PC)
out1:
BEQ R1, R6, done1
ADDV $-1, R2
MOVB (R2), R4
ADDV $-1, R6
MOVB R4, (R6)
JMP -5(PC)
done1:
RET