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Diffstat (limited to 'src/runtime/memmove_loong64.s')
| -rw-r--r-- | src/runtime/memmove_loong64.s | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/runtime/memmove_loong64.s b/src/runtime/memmove_loong64.s new file mode 100644 index 0000000..5b7aeba --- /dev/null +++ b/src/runtime/memmove_loong64.s @@ -0,0 +1,109 @@ +// Copyright 2022 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 "textflag.h" + +// See memmove Go doc for important implementation constraints. + +// func memmove(to, from unsafe.Pointer, n uintptr) +TEXT runtime·memmove<ABIInternal>(SB), NOSPLIT|NOFRAME, $0-24 +#ifndef GOEXPERIMENT_regabiargs + MOVV to+0(FP), R4 + MOVV from+8(FP), R5 + MOVV n+16(FP), R6 +#endif + BNE R6, check + RET + +check: + SGTU R4, R5, R7 + BNE R7, backward + + ADDV R4, R6, R9 // end pointer + + // if the two pointers are not of same alignments, do byte copying + SUBVU R5, R4, R7 + AND $7, R7 + BNE R7, out + + // if less than 8 bytes, do byte copying + SGTU $8, R6, R7 + BNE R7, out + + // do one byte at a time until 8-aligned + AND $7, R4, R8 + BEQ R8, words + MOVB (R5), R7 + ADDV $1, R5 + MOVB R7, (R4) + ADDV $1, R4 + JMP -6(PC) + +words: + // do 8 bytes at a time if there is room + ADDV $-7, R9, R6 // R6 is end pointer-7 + + PCALIGN $16 + SGTU R6, R4, R8 + BEQ R8, out + MOVV (R5), R7 + ADDV $8, R5 + MOVV R7, (R4) + ADDV $8, R4 + JMP -6(PC) + +out: + BEQ R4, R9, done + MOVB (R5), R7 + ADDV $1, R5 + MOVB R7, (R4) + ADDV $1, R4 + JMP -5(PC) +done: + RET + +backward: + ADDV R6, R5 // from-end pointer + ADDV R4, R6, R9 // to-end pointer + + // if the two pointers are not of same alignments, do byte copying + SUBVU R9, R5, R7 + AND $7, R7 + BNE R7, out1 + + // if less than 8 bytes, do byte copying + SGTU $8, R6, R7 + BNE R7, out1 + + // do one byte at a time until 8-aligned + AND $7, R9, R8 + BEQ R8, words1 + ADDV $-1, R5 + MOVB (R5), R7 + ADDV $-1, R9 + MOVB R7, (R9) + JMP -6(PC) + +words1: + // do 8 bytes at a time if there is room + ADDV $7, R4, R6 // R6 is start pointer+7 + + PCALIGN $16 + SGTU R9, R6, R8 + BEQ R8, out1 + ADDV $-8, R5 + MOVV (R5), R7 + ADDV $-8, R9 + MOVV R7, (R9) + JMP -6(PC) + +out1: + BEQ R4, R9, done1 + ADDV $-1, R5 + MOVB (R5), R7 + ADDV $-1, R9 + MOVB R7, (R9) + JMP -5(PC) +done1: + RET |