1/* $NetBSD: memmove.S,v 1.1 2014/09/03 19:34:25 matt Exp $ */ 2 3/* stropt/memmove.S, pl_string_common, pl_linux 10/11/04 11:45:37 4 * ========================================================================== 5 * Optimized memmove implementation for IBM PowerPC 405/440. 6 * 7 * Copyright (c) 2003, IBM Corporation 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or 11 * without modification, are permitted provided that the following 12 * conditions are met: 13 * 14 * * Redistributions of source code must retain the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer. 17 * * Redistributions in binary form must reproduce the above 18 * copyright notice, this list of conditions and the following 19 * disclaimer in the documentation and/or other materials 20 * provided with the distribution. 21 * * Neither the name of IBM nor the names of its contributors 22 * may be used to endorse or promote products derived from this 23 * software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 26 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 27 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 28 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 29 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 34 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 36 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 * 38 * ========================================================================== 39 * 40 * Function: Move memory area (handles overlapping regions) 41 * 42 * void *memmove(void * dest, const void * src, int n) 43 * 44 * Input: r3 - destination address 45 * r4 - source address 46 * r5 - byte count 47 * Output: r11 - destination address 48 * 49 * ========================================================================== 50 */ 51 52#include <machine/asm.h> 53 54#ifdef _BCOPY 55/* bcopy = memcpy/memmove with arguments reversed. */ 56/* LINTSTUB: Func: void bcopy(void *, void *, size_t) */ 57ENTRY(bcopy) 58 l.or r6, r3, r0 /* swap src/dst */ 59 l.or r3, r4, r0 60 l.or r4, r6, r0 61#else 62/* LINTSTUB: Func: void *memmove(void *, const void *, size_t) */ 63ENTRY(memmove) 64#endif 65 66 l.or r11, r3, r0 /* Save dst (return value) */ 67 68 l.sfges r4, r3 /* Branch to reverse if */ 69 l.bnf .Lreverse /* src < dest. Don't want to */ 70 /* overwrite end of src with */ 71 /* start of dest */ 72 73 l.addi r4, r4, -4 /* Back up src and dst pointers */ 74 l.addi r3, r3, -4 /* due to auto-update of 'load' */ 75 76 l.srli r13, r5, 2 /* How many words in total cnt */ 77 l.sfeqi r13, 0 78 l.bf .Llast1 /* Handle byte by byte if < 4 */ 79 /* bytes total */ 80 l.lwz r7, 4(r4) /* Preload first word */ 81 l.addi r4, r4, 4 82 83 l.j .Lg1 84 l.nop 85 86.Lg0: /* Main loop */ 87 88 l.lwz r7, 4(r4) /* Load a new word */ 89 l.sw 4(r3), r6 /* Store previous word */ 90 l.addi r4, r4, 4 /* advance */ 91 l.addi r3, r3, 4 /* advance */ 92 93.Lg1: 94 95 l.addi r13, r13, -1 96 l.sfeqi r13, 0 97 l.bf .Llast /* Dec cnt, and branch if just */ 98 l.nop 99 /* one word to store */ 100 l.lwz r6, 4(r4) /* Load another word */ 101 l.sw 4(r3), r7 /* Store previous word */ 102 l.addi r4, r4, 4 /* advance to next word */ 103 l.addi r3, r3, 4 /* advance to next word */ 104 l.addi r13, r13, -1 /* Decrement count */ 105 l.sfeqi r13, 0 /* last word? */ 106 l.bnf .Lg0 /* no, loop, more words */ 107 l.nop 108 109 l.or r7, r6, r0 /* If word count -> 0, then... */ 110 111.Llast: 112 113 l.sw 4(r3), r7 /* ... store last word */ 114 l.addi r3, r3, 4 115 116.Llast1: /* Byte-by-byte copy */ 117 118 l.andi r5, r5, 3 /* get remaining byte count */ 119 l.sfeqi r5, 0 /* is it 0? */ 120 l.bf .Ldone /* yes, we're done */ 121 l.nop /* -- delay slot -- */ 122 123 l.lbz r6, 4(r4) /* 1st byte: update addr by 4 */ 124 l.sb 4(r3), r6 /* since we pre-adjusted by 4 */ 125 l.addi r4, r4, 4 /* advance to next word */ 126 l.addi r3, r3, 4 /* advance to next word */ 127 l.addi r5, r5, -1 /* decrement count */ 128 l.sfeqi r5, 0 /* is it 0? */ 129 l.bf .Ldone /* yes, we're done */ 130 l.nop /* -- delay slot -- */ 131 132.Llast2: 133 134 l.lbz r6, 1(r4) /* But handle the rest by */ 135 l.sb 1(r3), r6 /* updating addr by 1 */ 136 l.addi r4, r4, 1 /* advance to next word */ 137 l.addi r3, r3, 1 /* advance to next word */ 138 l.addi r5, r5, -1 /* decrement count */ 139 l.sfeqi r5, 0 /* is it 0? */ 140 l.bnf .Llast2 /* yes, we're done */ 141 l.nop /* -- delay slot -- */ 142.Ldone: 143 l.jr lr /* return */ 144 l.nop /* -- delay slot -- */ 145 146 /* We're here since src < dest. Don't want to overwrite end of */ 147 /* src with start of dest */ 148 149.Lreverse: 150 151 l.add r4, r4, r5 /* Work from end to beginning */ 152 l.add r3, r3, r5 /* so add count to string ptrs */ 153 l.srli r13, r5, 2 /* Words in total count */ 154 l.sfeqi r13, 0 155 l.bf .Lrlast1 /* Handle byte by byte if < 4 */ 156 /* bytes total */ 157 l.nop 158 159 l.lwz r7, -4(r4) /* Preload first word */ 160 l.addi r4, r4, -4 /* update pointer */ 161 162 l.j .Lrg1 163 164.Lrg0: /* Main loop */ 165 166 l.lwz r7, -4(r4) /* Load a new word */ 167 l.sw -4(r3), r6 /* Store previous word */ 168 l.addi r4, r4, -4 169 l.addi r3, r3, -4 170 171.Lrg1: 172 173 l.addi r13, r13, -1 /* decrement count */ 174 l.sfeqi r13, 0 /* just one pending word left? */ 175 l.bf .Lrlast /* yes, deal with it */ 176 177 l.lwz r6, -4(r4) /* Load another word */ 178 l.sw -4(r3), r7 /* Store previous word */ 179 l.addi r4, r4, -4 180 l.addi r3, r3, -4 181 182 l.addi r13, r13, -1 /* decrement count */ 183 l.sfeqi r13, 0 /* just one pending word left? */ 184 l.bnf .Lrg0 /* no, loop again more words */ 185 l.nop 186 187 l.or r7, r6, r0 /* If word count -> 0, then... */ 188 189.Lrlast: 190 191 l.sw -4(r3), r7 /* ... store last word */ 192 l.addi r3, r3, -4 /* update pointer */ 193 194.Lrlast1: /* Byte-by-byte copy */ 195 196 l.andi r5, r5, 3 197 l.sfeqi r5, 0 198 l.bf .Lrdone 199 200.Lrlast2: 201 202 l.lbz r6, -1(r4) /* Handle the rest, byte by */ 203 l.sb -1(r3), r6 /* byte */ 204 l.addi r4, r4, -1 205 l.addi r3, r3, -1 206 l.addi r5, r5, -1 /* decrement count */ 207 l.sfeqi r5, 0 /* is it 0? */ 208 l.bnf .Lrlast2 /* no, loop again */ 209 l.nop 210.Lrdone: 211 l.jr lr 212 l.nop 213 214#ifdef _BCOPY 215END(bcopy) 216#else 217END(memmove) 218#endif 219