1// Copyright 2016 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#include "textflag.h" 6 7// See memmove Go doc for important implementation constraints. 8 9// func memmove(to, from unsafe.Pointer, n uintptr) 10TEXT runtime·memmove(SB),NOSPLIT|NOFRAME,$0-24 11 MOVD to+0(FP), R6 12 MOVD from+8(FP), R4 13 MOVD n+16(FP), R5 14 15 CMPBEQ R6, R4, done 16 17start: 18 CMPBLE R5, $3, move0to3 19 CMPBLE R5, $7, move4to7 20 CMPBLE R5, $11, move8to11 21 CMPBLE R5, $15, move12to15 22 CMPBNE R5, $16, movemt16 23 MOVD 0(R4), R7 24 MOVD 8(R4), R8 25 MOVD R7, 0(R6) 26 MOVD R8, 8(R6) 27 RET 28 29movemt16: 30 CMPBGT R4, R6, forwards 31 ADD R5, R4, R7 32 CMPBLE R7, R6, forwards 33 ADD R5, R6, R8 34backwards: 35 MOVD -8(R7), R3 36 MOVD R3, -8(R8) 37 MOVD -16(R7), R3 38 MOVD R3, -16(R8) 39 ADD $-16, R5 40 ADD $-16, R7 41 ADD $-16, R8 42 CMP R5, $16 43 BGE backwards 44 BR start 45 46forwards: 47 CMPBGT R5, $64, forwards_fast 48 MOVD 0(R4), R3 49 MOVD R3, 0(R6) 50 MOVD 8(R4), R3 51 MOVD R3, 8(R6) 52 ADD $16, R4 53 ADD $16, R6 54 ADD $-16, R5 55 CMP R5, $16 56 BGE forwards 57 BR start 58 59forwards_fast: 60 CMP R5, $256 61 BLE forwards_small 62 MVC $256, 0(R4), 0(R6) 63 ADD $256, R4 64 ADD $256, R6 65 ADD $-256, R5 66 BR forwards_fast 67 68forwards_small: 69 CMPBEQ R5, $0, done 70 ADD $-1, R5 71 EXRL $memmove_exrl_mvc<>(SB), R5 72 RET 73 74move0to3: 75 CMPBEQ R5, $0, done 76move1: 77 CMPBNE R5, $1, move2 78 MOVB 0(R4), R3 79 MOVB R3, 0(R6) 80 RET 81move2: 82 CMPBNE R5, $2, move3 83 MOVH 0(R4), R3 84 MOVH R3, 0(R6) 85 RET 86move3: 87 MOVH 0(R4), R3 88 MOVB 2(R4), R7 89 MOVH R3, 0(R6) 90 MOVB R7, 2(R6) 91 RET 92 93move4to7: 94 CMPBNE R5, $4, move5 95 MOVW 0(R4), R3 96 MOVW R3, 0(R6) 97 RET 98move5: 99 CMPBNE R5, $5, move6 100 MOVW 0(R4), R3 101 MOVB 4(R4), R7 102 MOVW R3, 0(R6) 103 MOVB R7, 4(R6) 104 RET 105move6: 106 CMPBNE R5, $6, move7 107 MOVW 0(R4), R3 108 MOVH 4(R4), R7 109 MOVW R3, 0(R6) 110 MOVH R7, 4(R6) 111 RET 112move7: 113 MOVW 0(R4), R3 114 MOVH 4(R4), R7 115 MOVB 6(R4), R8 116 MOVW R3, 0(R6) 117 MOVH R7, 4(R6) 118 MOVB R8, 6(R6) 119 RET 120 121move8to11: 122 CMPBNE R5, $8, move9 123 MOVD 0(R4), R3 124 MOVD R3, 0(R6) 125 RET 126move9: 127 CMPBNE R5, $9, move10 128 MOVD 0(R4), R3 129 MOVB 8(R4), R7 130 MOVD R3, 0(R6) 131 MOVB R7, 8(R6) 132 RET 133move10: 134 CMPBNE R5, $10, move11 135 MOVD 0(R4), R3 136 MOVH 8(R4), R7 137 MOVD R3, 0(R6) 138 MOVH R7, 8(R6) 139 RET 140move11: 141 MOVD 0(R4), R3 142 MOVH 8(R4), R7 143 MOVB 10(R4), R8 144 MOVD R3, 0(R6) 145 MOVH R7, 8(R6) 146 MOVB R8, 10(R6) 147 RET 148 149move12to15: 150 CMPBNE R5, $12, move13 151 MOVD 0(R4), R3 152 MOVW 8(R4), R7 153 MOVD R3, 0(R6) 154 MOVW R7, 8(R6) 155 RET 156move13: 157 CMPBNE R5, $13, move14 158 MOVD 0(R4), R3 159 MOVW 8(R4), R7 160 MOVB 12(R4), R8 161 MOVD R3, 0(R6) 162 MOVW R7, 8(R6) 163 MOVB R8, 12(R6) 164 RET 165move14: 166 CMPBNE R5, $14, move15 167 MOVD 0(R4), R3 168 MOVW 8(R4), R7 169 MOVH 12(R4), R8 170 MOVD R3, 0(R6) 171 MOVW R7, 8(R6) 172 MOVH R8, 12(R6) 173 RET 174move15: 175 MOVD 0(R4), R3 176 MOVW 8(R4), R7 177 MOVH 12(R4), R8 178 MOVB 14(R4), R10 179 MOVD R3, 0(R6) 180 MOVW R7, 8(R6) 181 MOVH R8, 12(R6) 182 MOVB R10, 14(R6) 183done: 184 RET 185 186// DO NOT CALL - target for exrl (execute relative long) instruction. 187TEXT memmove_exrl_mvc<>(SB),NOSPLIT|NOFRAME,$0-0 188 MVC $1, 0(R4), 0(R6) 189 MOVD R0, 0(R0) 190 RET 191 192