bcopy.S revision 1.14
1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from locore.s. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <machine/asm.h> 33 34 #if defined(LIBC_SCCS) 35 RCSID("$NetBSD: bcopy.S,v 1.14 2005/02/07 05:22:51 christos Exp $") 36 #endif 37 38 /* 39 * (ov)bcopy (src,dst,cnt) 40 * ws (at) tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 41 */ 42 43 #ifdef MEMCOPY 44 ENTRY(memcpy) 45 #else 46 #ifdef MEMMOVE 47 ENTRY(memmove) 48 #else 49 ENTRY(bcopy) 50 #endif 51 #endif 52 pushl %esi 53 pushl %edi 54 #if defined(MEMCOPY) || defined(MEMMOVE) 55 movl 12(%esp),%edi 56 movl 16(%esp),%esi 57 movl %edi,%eax /* return value */ 58 #else 59 movl 12(%esp),%esi 60 movl 16(%esp),%edi 61 #endif 62 movl 20(%esp),%ecx 63 #if defined(MEMCOPY) 64 movl %ecx,%edx 65 #else 66 movl %edi,%edx 67 subl %esi,%edx 68 cmpl %ecx,%edx /* overlapping? */ 69 movl %ecx,%edx 70 jb 1f 71 #endif 72 cld /* nope, copy forwards. */ 73 shrl $2,%ecx /* copy by words */ 74 rep 75 movsl 76 movl %edx,%ecx 77 andl $3,%ecx /* any bytes left? */ 78 rep 79 movsb 80 popl %edi 81 popl %esi 82 ret 83 1: 84 addl %ecx,%edi /* copy backwards. */ 85 addl %ecx,%esi 86 std 87 andl $3,%ecx /* any fractional bytes? */ 88 decl %edi 89 decl %esi 90 rep 91 movsb 92 movl %edx,%ecx /* copy remainder by words */ 93 shrl $2,%ecx 94 subl $3,%esi 95 subl $3,%edi 96 rep 97 movsl 98 popl %edi 99 popl %esi 100 cld 101 ret 102
Indexes created Sun Sep 28 12:09:53 GMT 2025