memcpy.S revision 1.2.4.2
1 1.2.4.2 keiichi /* $NetBSD: memcpy.S,v 1.2.4.2 2008/03/24 07:14:29 keiichi Exp $ */ 2 1.2.4.2 keiichi 3 1.2.4.2 keiichi /* stropt/memcpy_440.S, pl_string_common, pl_linux 10/11/04 11:45:36 4 1.2.4.2 keiichi * ========================================================================== 5 1.2.4.2 keiichi * Optimized memcpy implementation for IBM PowerPC 440. 6 1.2.4.2 keiichi * 7 1.2.4.2 keiichi * Copyright (c) 2003, IBM Corporation 8 1.2.4.2 keiichi * All rights reserved. 9 1.2.4.2 keiichi * 10 1.2.4.2 keiichi * Redistribution and use in source and binary forms, with or 11 1.2.4.2 keiichi * without modification, are permitted provided that the following 12 1.2.4.2 keiichi * conditions are met: 13 1.2.4.2 keiichi * 14 1.2.4.2 keiichi * * Redistributions of source code must retain the above 15 1.2.4.2 keiichi * copyright notice, this list of conditions and the following 16 1.2.4.2 keiichi * disclaimer. 17 1.2.4.2 keiichi * * Redistributions in binary form must reproduce the above 18 1.2.4.2 keiichi * copyright notice, this list of conditions and the following 19 1.2.4.2 keiichi * disclaimer in the documentation and/or other materials 20 1.2.4.2 keiichi * provided with the distribution. 21 1.2.4.2 keiichi * * Neither the name of IBM nor the names of its contributors 22 1.2.4.2 keiichi * may be used to endorse or promote products derived from this 23 1.2.4.2 keiichi * software without specific prior written permission. 24 1.2.4.2 keiichi * 25 1.2.4.2 keiichi * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 26 1.2.4.2 keiichi * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 27 1.2.4.2 keiichi * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 28 1.2.4.2 keiichi * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 29 1.2.4.2 keiichi * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 30 1.2.4.2 keiichi * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 1.2.4.2 keiichi * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 32 1.2.4.2 keiichi * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 33 1.2.4.2 keiichi * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 34 1.2.4.2 keiichi * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 1.2.4.2 keiichi * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 36 1.2.4.2 keiichi * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 1.2.4.2 keiichi * 38 1.2.4.2 keiichi * ========================================================================== 39 1.2.4.2 keiichi * 40 1.2.4.2 keiichi * Function: Copy n bytes of the source to the destination. Behavior is 41 1.2.4.2 keiichi * undefined for objects that overlap. 42 1.2.4.2 keiichi * 43 1.2.4.2 keiichi * 44 1.2.4.2 keiichi * void *memcpy(void * dest, const void * src, int n) 45 1.2.4.2 keiichi * 46 1.2.4.2 keiichi * Input: r3 - destination address 47 1.2.4.2 keiichi * r4 - source address 48 1.2.4.2 keiichi * r5 - byte count 49 1.2.4.2 keiichi * Output: r3 - destination address 50 1.2.4.2 keiichi * 51 1.2.4.2 keiichi * ========================================================================== 52 1.2.4.2 keiichi */ 53 1.2.4.2 keiichi 54 1.2.4.2 keiichi #define _NOREGNAMES 55 1.2.4.2 keiichi #include <machine/asm.h> 56 1.2.4.2 keiichi 57 1.2.4.2 keiichi .text 58 1.2.4.2 keiichi .align 4 59 1.2.4.2 keiichi /* LINTSTUB: Func: void *memcpy(void *, const void *, size_t) */ 60 1.2.4.2 keiichi ENTRY(memcpy) 61 1.2.4.2 keiichi /* 62 1.2.4.2 keiichi * Check count passed in R5. If zero, return; otherwise continue. 63 1.2.4.2 keiichi */ 64 1.2.4.2 keiichi cmpwi %r5,0 65 1.2.4.2 keiichi beqlr- 66 1.2.4.2 keiichi 67 1.2.4.2 keiichi mr %r8, %r3 /* Copy dst (return value) */ 68 1.2.4.2 keiichi 69 1.2.4.2 keiichi addi %r4, %r4, -4 /* Prepare for main loop's auto */ 70 1.2.4.2 keiichi addi %r8, %r8, -4 /* update */ 71 1.2.4.2 keiichi 72 1.2.4.2 keiichi srwi. %r9,%r5,2 /* Word count -> r9 */ 73 1.2.4.2 keiichi beq- last1 /* Partial copy if <4 bytes */ 74 1.2.4.2 keiichi 75 1.2.4.2 keiichi mtctr %r9 /* Word cnt in CTR for loop */ 76 1.2.4.2 keiichi lwzu %r7, 4(%r4) /* Preload for main loop */ 77 1.2.4.2 keiichi 78 1.2.4.2 keiichi b g1 79 1.2.4.2 keiichi 80 1.2.4.2 keiichi g0: /* Main loop */ 81 1.2.4.2 keiichi 82 1.2.4.2 keiichi lwzu %r7, 4(%r4) /* Load a new word */ 83 1.2.4.2 keiichi stwu %r6, 4(%r8) /* Store previous word */ 84 1.2.4.2 keiichi 85 1.2.4.2 keiichi g1: 86 1.2.4.2 keiichi 87 1.2.4.2 keiichi bdz- last /* Dec ctr and exit loop if no */ 88 1.2.4.2 keiichi /* more words */ 89 1.2.4.2 keiichi lwzu %r6, 4(%r4) /* Load another word */ 90 1.2.4.2 keiichi stwu %r7, 4(%r8) /* Store previous word */ 91 1.2.4.2 keiichi bdnz+ g0 /* Dec ctr and continue loop if */ 92 1.2.4.2 keiichi /* more words */ 93 1.2.4.2 keiichi 94 1.2.4.2 keiichi mr %r7, %r6 95 1.2.4.2 keiichi 96 1.2.4.2 keiichi last: 97 1.2.4.2 keiichi 98 1.2.4.2 keiichi stwu %r7, 4(%r8) /* Store last word */ 99 1.2.4.2 keiichi 100 1.2.4.2 keiichi last1: /* Byte-by-byte copy */ 101 1.2.4.2 keiichi 102 1.2.4.2 keiichi clrlwi. %r5,%r5,30 103 1.2.4.2 keiichi beqlr 104 1.2.4.2 keiichi 105 1.2.4.2 keiichi mtctr %r5 106 1.2.4.2 keiichi 107 1.2.4.2 keiichi lbzu %r6, 4(%r4) /* 1st byte: update by word */ 108 1.2.4.2 keiichi stbu %r6, 4(%r8) 109 1.2.4.2 keiichi bdzlr- 110 1.2.4.2 keiichi 111 1.2.4.2 keiichi last2: 112 1.2.4.2 keiichi 113 1.2.4.2 keiichi lbzu %r6, 1(%r4) /* Handle the rest */ 114 1.2.4.2 keiichi stbu %r6, 1(%r8) 115 1.2.4.2 keiichi bdnz+ last2 116 1.2.4.2 keiichi 117 1.2.4.2 keiichi blr 118 1.2.4.2 keiichi 119
Indexes created Tue Sep 23 07:09:52 GMT 2025