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 <private/bionic_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 #if defined(MEMCOPY) 42 ENTRY(memcpy) 43 #elif defined(MEMMOVE) 44 ENTRY(memmove) 45 #else 46 ENTRY(bcopy) 47 #endif 48 pushl %esi 49 pushl %edi 50 #if defined(MEMCOPY) || defined(MEMMOVE) 51 movl 12(%esp),%edi 52 movl 16(%esp),%esi 53 movl %edi, %eax 54 #else 55 movl 12(%esp),%esi 56 movl 16(%esp),%edi 57 #endif 58 movl 20(%esp),%ecx 59 movl %ecx,%edx 60 cmpl %esi,%edi /* potentially overlapping? */ 61 jnb 1f 62 cld /* nope, copy forwards. */ 63 shrl $2,%ecx /* copy by words */ 64 rep 65 movsl 66 movl %edx,%ecx 67 andl $3,%ecx /* any bytes left? */ 68 rep 69 movsb 70 popl %edi 71 popl %esi 72 ret 73 1: 74 addl %ecx,%edi /* copy backwards. */ 75 addl %ecx,%esi 76 std 77 andl $3,%ecx /* any fractional bytes? */ 78 decl %edi 79 decl %esi 80 rep 81 movsb 82 movl %edx,%ecx 83 shrl $2,%ecx 84 subl $3,%esi 85 subl $3,%edi 86 rep 87 movsl 88 popl %edi 89 popl %esi 90 cld 91 ret 92 #if defined(MEMCOPY) 93 END(memcpy) 94 #elif defined(MEMMOVE) 95 END(memmove) 96 #else 97 END(bcopy) 98 #endif 99
