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 * strcat(s, append) 36 * append a copy of the null-terminated string "append" to the end 37 * of the null-terminated string s, then add a terminating `\0'. 38 * 39 * Written by: 40 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 41 */ 42 43/* 44 * I've unrolled the loop eight times: large enough to make a 45 * significant difference, and small enough not to totally trash the 46 * cache. 47 */ 48 49ENTRY(strcat) 50 pushl %edi /* save edi */ 51 movl 8(%esp),%edi /* dst address */ 52 movl 12(%esp),%edx /* src address */ 53 pushl %edi /* push destination address */ 54 55 cld /* set search forward */ 56 xorl %eax,%eax /* set search for null terminator */ 57 movl $-1,%ecx /* set search for lots of characters */ 58 repne /* search! */ 59 scasb 60 61 leal -1(%edi),%ecx /* correct dst address */ 62 63 .align 2,0x90 64L1: movb (%edx),%al /* unroll loop, but not too much */ 65 movb %al,(%ecx) 66 testb %al,%al 67 je L2 68 movb 1(%edx),%al 69 movb %al,1(%ecx) 70 testb %al,%al 71 je L2 72 movb 2(%edx),%al 73 movb %al,2(%ecx) 74 testb %al,%al 75 je L2 76 movb 3(%edx),%al 77 movb %al,3(%ecx) 78 testb %al,%al 79 je L2 80 movb 4(%edx),%al 81 movb %al,4(%ecx) 82 testb %al,%al 83 je L2 84 movb 5(%edx),%al 85 movb %al,5(%ecx) 86 testb %al,%al 87 je L2 88 movb 6(%edx),%al 89 movb %al,6(%ecx) 90 testb %al,%al 91 je L2 92 movb 7(%edx),%al 93 movb %al,7(%ecx) 94 addl $8,%edx 95 addl $8,%ecx 96 testb %al,%al 97 jne L1 98L2: popl %eax /* pop destination address */ 99 popl %edi /* restore edi */ 100 ret 101END(strcat) 102 103 .section .note.GNU-stack,"",%progbits 104