1/* 2 * Copyright (c) 1993 Winning Strategies, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Winning Strategies, Inc. 16 * 4. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <machine/asm.h> 32__FBSDID("$FreeBSD$"); 33 34/* 35 * memset(void *b, int c, size_t len) 36 * write len bytes of value c (converted to an unsigned char) to 37 * the string b. 38 * 39 * Written by: 40 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 41 */ 42 43ENTRY(memset) 44 pushl %edi 45 pushl %ebx 46 movl 12(%esp),%edi 47 movzbl 16(%esp),%eax /* unsigned char, zero extend */ 48 movl 20(%esp),%ecx 49 pushl %edi /* push address of buffer */ 50 51 cld /* set fill direction forward */ 52 53 /* 54 * if the string is too short, it's really not worth the overhead 55 * of aligning to word boundries, etc. So we jump to a plain 56 * unaligned set. 57 */ 58 cmpl $0x0f,%ecx 59 jle L1 60 61 movb %al,%ah /* copy char to all bytes in word */ 62 movl %eax,%edx 63 sall $16,%eax 64 orl %edx,%eax 65 66 movl %edi,%edx /* compute misalignment */ 67 negl %edx 68 andl $3,%edx 69 movl %ecx,%ebx 70 subl %edx,%ebx 71 72 movl %edx,%ecx /* set until word aligned */ 73 rep 74 stosb 75 76 movl %ebx,%ecx 77 shrl $2,%ecx /* set by words */ 78 rep 79 stosl 80 81 movl %ebx,%ecx /* set remainder by bytes */ 82 andl $3,%ecx 83L1: rep 84 stosb 85 86 popl %eax /* pop address of buffer */ 87 popl %ebx 88 popl %edi 89 ret 90END(memset) 91 92 .section .note.GNU-stack,"",%progbits 93