github.com/comwrg/go/src@v0.0.0-20220319063731-c238d0440370/runtime/memmove_mips64x.s (about) 1 // Copyright 2015 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 //go:build mips64 || mips64le 6 // +build mips64 mips64le 7 8 #include "textflag.h" 9 10 // See memmove Go doc for important implementation constraints. 11 12 // func memmove(to, from unsafe.Pointer, n uintptr) 13 TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24 14 MOVV to+0(FP), R1 15 MOVV from+8(FP), R2 16 MOVV n+16(FP), R3 17 BNE R3, check 18 RET 19 20 check: 21 SGTU R1, R2, R4 22 BNE R4, backward 23 24 ADDV R1, R3, R6 // end pointer 25 26 // if the two pointers are not of same alignments, do byte copying 27 SUBVU R2, R1, R4 28 AND $7, R4 29 BNE R4, out 30 31 // if less than 8 bytes, do byte copying 32 SGTU $8, R3, R4 33 BNE R4, out 34 35 // do one byte at a time until 8-aligned 36 AND $7, R1, R5 37 BEQ R5, words 38 MOVB (R2), R4 39 ADDV $1, R2 40 MOVB R4, (R1) 41 ADDV $1, R1 42 JMP -6(PC) 43 44 words: 45 // do 8 bytes at a time if there is room 46 ADDV $-7, R6, R3 // R3 is end pointer-7 47 48 SGTU R3, R1, R5 49 BEQ R5, out 50 MOVV (R2), R4 51 ADDV $8, R2 52 MOVV R4, (R1) 53 ADDV $8, R1 54 JMP -6(PC) 55 56 out: 57 BEQ R1, R6, done 58 MOVB (R2), R4 59 ADDV $1, R2 60 MOVB R4, (R1) 61 ADDV $1, R1 62 JMP -5(PC) 63 done: 64 RET 65 66 backward: 67 ADDV R3, R2 // from-end pointer 68 ADDV R1, R3, R6 // to-end pointer 69 70 // if the two pointers are not of same alignments, do byte copying 71 SUBVU R6, R2, R4 72 AND $7, R4 73 BNE R4, out1 74 75 // if less than 8 bytes, do byte copying 76 SGTU $8, R3, R4 77 BNE R4, out1 78 79 // do one byte at a time until 8-aligned 80 AND $7, R6, R5 81 BEQ R5, words1 82 ADDV $-1, R2 83 MOVB (R2), R4 84 ADDV $-1, R6 85 MOVB R4, (R6) 86 JMP -6(PC) 87 88 words1: 89 // do 8 bytes at a time if there is room 90 ADDV $7, R1, R3 // R3 is start pointer+7 91 92 SGTU R6, R3, R5 93 BEQ R5, out1 94 ADDV $-8, R2 95 MOVV (R2), R4 96 ADDV $-8, R6 97 MOVV R4, (R6) 98 JMP -6(PC) 99 100 out1: 101 BEQ R1, R6, done1 102 ADDV $-1, R2 103 MOVB (R2), R4 104 ADDV $-1, R6 105 MOVB R4, (R6) 106 JMP -5(PC) 107 done1: 108 RET