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Diffstat (limited to 'src/runtime/memmove_mips64x.s')
| -rw-r--r-- | src/runtime/memmove_mips64x.s | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/runtime/memmove_mips64x.s b/src/runtime/memmove_mips64x.s new file mode 100644 index 0000000..b69178c --- /dev/null +++ b/src/runtime/memmove_mips64x.s @@ -0,0 +1,107 @@ +// 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 |