memmove.S (2658B)
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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <asm.h> 37 38 /* 39 * (ov)bcopy (src,dst,cnt) 40 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 41 */ 42 43 ENTRY(memmove) 44 pushl %esi 45 pushl %edi 46 movl 12(%esp),%edi 47 movl 16(%esp),%esi 48 movl %edi,%eax 49 movl 20(%esp),%ecx 50 movl %edi,%edx 51 subl %esi,%edx 52 cmpl %ecx,%edx /* overlapping? */ 53 jb 1f 54 cld /* nope, copy forwards. */ 55 movl %ecx,%edx 56 shrl $2,%ecx /* copy by words */ 57 rep 58 movsl 59 movl %edx,%ecx 60 andl $3,%ecx /* any bytes left? */ 61 rep 62 movsb 63 popl %edi 64 popl %esi 65 ret 66 1: 67 addl %ecx,%edi /* copy backwards. */ 68 addl %ecx,%esi 69 std 70 movl %ecx,%edx 71 andl $3,%ecx /* any fractional bytes? */ 72 decl %edi 73 decl %esi 74 rep 75 movsb 76 movl %edx,%ecx /* copy remainder by words */ 77 shrl $2,%ecx 78 subl $3,%esi 79 subl $3,%edi 80 rep 81 movsl 82 popl %edi 83 popl %esi 84 cld 85 ret 86