memcpy.S revision 1.2.2.2
1 1.2.2.2 matt /* $NetBSD: memcpy.S,v 1.2.2.2 2008/03/23 00:12:43 matt Exp $ */ 2 1.2.2.2 matt 3 1.2.2.2 matt /* stropt/memcpy_440.S, pl_string_common, pl_linux 10/11/04 11:45:36 4 1.2.2.2 matt * ========================================================================== 5 1.2.2.2 matt * Optimized memcpy implementation for IBM PowerPC 440. 6 1.2.2.2 matt * 7 1.2.2.2 matt * Copyright (c) 2003, IBM Corporation 8 1.2.2.2 matt * All rights reserved. 9 1.2.2.2 matt * 10 1.2.2.2 matt * Redistribution and use in source and binary forms, with or 11 1.2.2.2 matt * without modification, are permitted provided that the following 12 1.2.2.2 matt * conditions are met: 13 1.2.2.2 matt * 14 1.2.2.2 matt * * Redistributions of source code must retain the above 15 1.2.2.2 matt * copyright notice, this list of conditions and the following 16 1.2.2.2 matt * disclaimer. 17 1.2.2.2 matt * * Redistributions in binary form must reproduce the above 18 1.2.2.2 matt * copyright notice, this list of conditions and the following 19 1.2.2.2 matt * disclaimer in the documentation and/or other materials 20 1.2.2.2 matt * provided with the distribution. 21 1.2.2.2 matt * * Neither the name of IBM nor the names of its contributors 22 1.2.2.2 matt * may be used to endorse or promote products derived from this 23 1.2.2.2 matt * software without specific prior written permission. 24 1.2.2.2 matt * 25 1.2.2.2 matt * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 26 1.2.2.2 matt * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 27 1.2.2.2 matt * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 28 1.2.2.2 matt * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 29 1.2.2.2 matt * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 30 1.2.2.2 matt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 1.2.2.2 matt * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 32 1.2.2.2 matt * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 33 1.2.2.2 matt * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 34 1.2.2.2 matt * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 1.2.2.2 matt * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 36 1.2.2.2 matt * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 1.2.2.2 matt * 38 1.2.2.2 matt * ========================================================================== 39 1.2.2.2 matt * 40 1.2.2.2 matt * Function: Copy n bytes of the source to the destination. Behavior is 41 1.2.2.2 matt * undefined for objects that overlap. 42 1.2.2.2 matt * 43 1.2.2.2 matt * 44 1.2.2.2 matt * void *memcpy(void * dest, const void * src, int n) 45 1.2.2.2 matt * 46 1.2.2.2 matt * Input: r3 - destination address 47 1.2.2.2 matt * r4 - source address 48 1.2.2.2 matt * r5 - byte count 49 1.2.2.2 matt * Output: r3 - destination address 50 1.2.2.2 matt * 51 1.2.2.2 matt * ========================================================================== 52 1.2.2.2 matt */ 53 1.2.2.2 matt 54 1.2.2.2 matt #define _NOREGNAMES 55 1.2.2.2 matt #include <machine/asm.h> 56 1.2.2.2 matt 57 1.2.2.2 matt .text 58 1.2.2.2 matt .align 4 59 1.2.2.2 matt /* LINTSTUB: Func: void *memcpy(void *, const void *, size_t) */ 60 1.2.2.2 matt ENTRY(memcpy) 61 1.2.2.2 matt /* 62 1.2.2.2 matt * Check count passed in R5. If zero, return; otherwise continue. 63 1.2.2.2 matt */ 64 1.2.2.2 matt cmpwi %r5,0 65 1.2.2.2 matt beqlr- 66 1.2.2.2 matt 67 1.2.2.2 matt mr %r8, %r3 /* Copy dst (return value) */ 68 1.2.2.2 matt 69 1.2.2.2 matt addi %r4, %r4, -4 /* Prepare for main loop's auto */ 70 1.2.2.2 matt addi %r8, %r8, -4 /* update */ 71 1.2.2.2 matt 72 1.2.2.2 matt srwi. %r9,%r5,2 /* Word count -> r9 */ 73 1.2.2.2 matt beq- last1 /* Partial copy if <4 bytes */ 74 1.2.2.2 matt 75 1.2.2.2 matt mtctr %r9 /* Word cnt in CTR for loop */ 76 1.2.2.2 matt lwzu %r7, 4(%r4) /* Preload for main loop */ 77 1.2.2.2 matt 78 1.2.2.2 matt b g1 79 1.2.2.2 matt 80 1.2.2.2 matt g0: /* Main loop */ 81 1.2.2.2 matt 82 1.2.2.2 matt lwzu %r7, 4(%r4) /* Load a new word */ 83 1.2.2.2 matt stwu %r6, 4(%r8) /* Store previous word */ 84 1.2.2.2 matt 85 1.2.2.2 matt g1: 86 1.2.2.2 matt 87 1.2.2.2 matt bdz- last /* Dec ctr and exit loop if no */ 88 1.2.2.2 matt /* more words */ 89 1.2.2.2 matt lwzu %r6, 4(%r4) /* Load another word */ 90 1.2.2.2 matt stwu %r7, 4(%r8) /* Store previous word */ 91 1.2.2.2 matt bdnz+ g0 /* Dec ctr and continue loop if */ 92 1.2.2.2 matt /* more words */ 93 1.2.2.2 matt 94 1.2.2.2 matt mr %r7, %r6 95 1.2.2.2 matt 96 1.2.2.2 matt last: 97 1.2.2.2 matt 98 1.2.2.2 matt stwu %r7, 4(%r8) /* Store last word */ 99 1.2.2.2 matt 100 1.2.2.2 matt last1: /* Byte-by-byte copy */ 101 1.2.2.2 matt 102 1.2.2.2 matt clrlwi. %r5,%r5,30 103 1.2.2.2 matt beqlr 104 1.2.2.2 matt 105 1.2.2.2 matt mtctr %r5 106 1.2.2.2 matt 107 1.2.2.2 matt lbzu %r6, 4(%r4) /* 1st byte: update by word */ 108 1.2.2.2 matt stbu %r6, 4(%r8) 109 1.2.2.2 matt bdzlr- 110 1.2.2.2 matt 111 1.2.2.2 matt last2: 112 1.2.2.2 matt 113 1.2.2.2 matt lbzu %r6, 1(%r4) /* Handle the rest */ 114 1.2.2.2 matt stbu %r6, 1(%r8) 115 1.2.2.2 matt bdnz+ last2 116 1.2.2.2 matt 117 1.2.2.2 matt blr 118 1.2.2.2 matt 119
Indexes created Tue Sep 23 02:09:52 GMT 2025