1/* $NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $ */ 2 3/*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from locore.s. 8 * Optimised by David Laight 2003 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <machine/asm.h> 36 37#if defined(LIBC_SCCS) 38 RCSID("$NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $") 39#endif 40 41 /* 42 * (ov)bcopy (src,dst,cnt) 43 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 44 */ 45 46#ifdef BCOPY 47ENTRY(bcopy) 48#else 49#ifdef MEMMOVE 50ENTRY(memmove) 51#else 52#define MEMCPY 53#define NO_OVERLAP 54ENTRY(memcpy) 55#endif 56#endif 57 push %esi 58 mov %edi,%edx 59#if defined(MEMCPY) || defined(MEMMOVE) 60 movl 8(%esp),%edi 61 movl 12(%esp),%esi 62#else 63 movl 8(%esp),%esi 64 movl 12(%esp),%edi 65#endif 66 movl 16(%esp),%ecx 67#if defined(NO_OVERLAP) 68 movl %ecx,%eax 69#else 70 movl %edi,%eax 71 subl %esi,%eax 72 cmpl %ecx,%eax /* overlapping? */ 73 movl %ecx,%eax 74 jb .Lbackwards 75#endif 76 /* nope, copy forwards. */ 77 shrl $2,%ecx /* copy by words */ 78 rep 79 movsl 80 and $3,%eax /* any bytes left? */ 81 jnz .Ltrailing 82.Ldone: 83#if defined(MEMCPY) || defined(MEMMOVE) 84 movl 8(%esp),%eax 85#endif 86 mov %edx,%edi 87 pop %esi 88 ret 89 90.Ltrailing: 91 cmp $2,%eax 92 jb 1f 93 movw (%esi),%ax 94 movw %ax,(%edi) 95 je .Ldone 96 movb 2(%esi),%al 97 movb %al,2(%edi) 98 jmp .Ldone 991: movb (%esi),%al 100 movb %al,(%edi) 101 jmp .Ldone 102 103#if !defined(NO_OVERLAP) 104.Lbackwards: 105 addl %ecx,%edi /* copy backwards. */ 106 addl %ecx,%esi 107 and $3,%eax /* any fractional bytes? */ 108 jnz .Lback_align 109.Lback_aligned: 110 shrl $2,%ecx 111 subl $4,%esi 112 subl $4,%edi 113 std 114 rep 115 movsl 116 cld 117 jmp .Ldone 118 119.Lback_align: 120 sub %eax,%esi 121 sub %eax,%edi 122 cmp $2,%eax 123 jb 1f 124 je 2f 125 movb 2(%esi),%al 126 movb %al,2(%edi) 1272: movw (%esi),%ax 128 movw %ax,(%edi) 129 jmp .Lback_aligned 1301: movb (%esi),%al 131 movb %al,(%edi) 132 jmp .Lback_aligned 133#endif 134 135#ifdef BCOPY 136END(bcopy) 137#else 138#ifdef MEMMOVE 139END(memmove) 140#else 141END(memcpy) 142#endif 143#endif 144