1 /* $OpenBSD: bcopy.S,v 1.5 2005/08/07 11:30:38 espie 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 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <machine/asm.h> 35 36 /* 37 * (ov)bcopy (src,dst,cnt) 38 * ws (at) tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 39 */ 40 41 #ifdef MEMCOPY 42 ENTRY(memcpy) 43 #else 44 #ifdef MEMMOVE 45 ENTRY(memmove) 46 #else 47 ENTRY(bcopy) 48 #endif 49 #endif 50 pushl %esi 51 pushl %edi 52 #if defined(MEMCOPY) || defined(MEMMOVE) 53 movl 12(%esp),%edi 54 movl 16(%esp),%esi 55 movl %edi, %eax 56 #else 57 movl 12(%esp),%esi 58 movl 16(%esp),%edi 59 #endif 60 movl 20(%esp),%ecx 61 movl %ecx,%edx 62 cmpl %esi,%edi /* potentially overlapping? */ 63 jnb 1f 64 cld /* nope, copy forwards. */ 65 shrl $2,%ecx /* copy by words */ 66 rep 67 movsl 68 movl %edx,%ecx 69 andl $3,%ecx /* any bytes left? */ 70 rep 71 movsb 72 popl %edi 73 popl %esi 74 ret 75 1: 76 addl %ecx,%edi /* copy backwards. */ 77 addl %ecx,%esi 78 std 79 andl $3,%ecx /* any fractional bytes? */ 80 decl %edi 81 decl %esi 82 rep 83 movsb 84 movl %edx,%ecx 85 shrl $2,%ecx 86 subl $3,%esi 87 subl $3,%edi 88 rep 89 movsl 90 popl %edi 91 popl %esi 92 cld 93 ret 94
