1/* $NetBSD: memcpy.S,v 1.6 2014/03/04 17:05:14 macallan Exp $ */ 2 3/* stropt/memcpy_440.S, pl_string_common, pl_linux 10/11/04 11:45:36 4 * ========================================================================== 5 * Optimized memcpy implementation for IBM PowerPC 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: Copy n bytes of the source to the destination. Behavior is 41 * undefined for objects that overlap. 42 * 43 * 44 * void *memcpy(void * dest, const void * src, int n) 45 * 46 * Input: r3 - destination address 47 * r4 - source address 48 * r5 - byte count 49 * Output: r3 - destination address 50 * 51 * ========================================================================== 52 */ 53 54#include <machine/asm.h> 55#ifdef _KERNEL_OPT 56#include "opt_ppcarch.h" 57#endif 58 59 .text 60 .align 4 61/* LINTSTUB: Func: void *memcpy(void *, const void *, size_t) */ 62ENTRY(memcpy) 63 /* 64 * Check count passed in R5. If zero, return; otherwise continue. 65 */ 66 cmpwi %r5,0 67 beqlr- 68 69#if defined(_KERNEL) && defined(PPC_OEA601) 70 /* 71 * 601 will generate alignment exceptions if operand crosses 72 * 4k page boundary, so do byte copy when exception handler 73 * not available. Maybe want to have a different memcpy for 601 74 * that checks for page boundaries/word alignment... 75 */ 76 mfspr %r6, 287 /* mfpvbr %r6 PVR = 287 */ 77 srwi %r6, %r6, 0x10 /* get version field from PVR */ 78 cmpwi %r6, 0x1 /* 601 CPU = 0x0001 */ 79 bne bnorm /* skip byte-only unless 601 */ 80 81 or %r6, %r3, %r4 /* see if both source and dest */ 82 andi. %r6, %r6, 3 /* are 32bit aligned */ 83 beq bnorm /* skip byte-only if they are */ 84bcpy: 85 mtctr %r5 /* byte copy everything */ 86 li %r6, 0 87bloop: 88 lbzx %r7, %r4, %r6 89 stbx %r7, %r3, %r6 90 addi %r6, %r6, 1 91 bdnz bloop 92 blr 93 94bnorm: 95 96#endif 97 98 mr %r8, %r3 /* Copy dst (return value) */ 99 100 addi %r4, %r4, -4 /* Prepare for main loop's auto */ 101 addi %r8, %r8, -4 /* update */ 102 103 srwi. %r9,%r5,2 /* Word count -> r9 */ 104 beq- last1 /* Partial copy if <4 bytes */ 105 106 mtctr %r9 /* Word cnt in CTR for loop */ 107 lwzu %r7, 4(%r4) /* Preload for main loop */ 108 109 b g1 110 111g0: /* Main loop */ 112 113 lwzu %r7, 4(%r4) /* Load a new word */ 114 stwu %r6, 4(%r8) /* Store previous word */ 115 116g1: 117 118 bdz- last /* Dec ctr and exit loop if no */ 119 /* more words */ 120 lwzu %r6, 4(%r4) /* Load another word */ 121 stwu %r7, 4(%r8) /* Store previous word */ 122 bdnz+ g0 /* Dec ctr and continue loop if */ 123 /* more words */ 124 125 mr %r7, %r6 126 127last: 128 129 stwu %r7, 4(%r8) /* Store last word */ 130 131last1: /* Byte-by-byte copy */ 132 133 clrlwi. %r5,%r5,30 134 beqlr 135 136 mtctr %r5 137 138 lbzu %r6, 4(%r4) /* 1st byte: update by word */ 139 stbu %r6, 4(%r8) 140 bdzlr- 141 142last2: 143 144 lbzu %r6, 1(%r4) /* Handle the rest */ 145 stbu %r6, 1(%r8) 146 bdnz+ last2 147 148 blr 149END(memcpy) 150