strcat.S revision 85437
11849Swollman/* 21849Swollman * Copyright (c) 1993 Winning Strategies, Inc. 31849Swollman * All rights reserved. 41849Swollman * 51849Swollman * Redistribution and use in source and binary forms, with or without 61849Swollman * modification, are permitted provided that the following conditions 71849Swollman * are met: 81849Swollman * 1. Redistributions of source code must retain the above copyright 91849Swollman * notice, this list of conditions and the following disclaimer. 101849Swollman * 2. Redistributions in binary form must reproduce the above copyright 111849Swollman * notice, this list of conditions and the following disclaimer in the 121849Swollman * documentation and/or other materials provided with the distribution. 131849Swollman * 3. All advertising materials mentioning features or use of this software 141849Swollman * must display the following acknowledgement: 151849Swollman * This product includes software developed by Winning Strategies, Inc. 161849Swollman * 4. The name of the author may not be used to endorse or promote products 171849Swollman * derived from this software withough specific prior written permission 181849Swollman * 191849Swollman * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 201849Swollman * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 211849Swollman * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 221849Swollman * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 231849Swollman * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 241849Swollman * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 251849Swollman * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 261849Swollman * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 271849Swollman * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 281849Swollman * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 291849Swollman */ 301849Swollman 311849Swollman#if defined(LIBC_RCS) && !defined(lint) 325790Sdg .text 3350476Speter .asciz "$FreeBSD: head/lib/libc/i386/string/strcat.S 85437 2001-10-24 20:29:14Z peter $" 341849Swollman#endif /* LIBC_RCS and not lint */ 351849Swollman 3685437Speter#include <machine/asm.h> 371849Swollman 381849Swollman/* 391849Swollman * strcat(s, append) 401849Swollman * append a copy of the null-terminated string "append" to the end 411849Swollman * of the null-terminated string s, then add a terminating `\0'. 421849Swollman * 431849Swollman * Written by: 441849Swollman * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 451849Swollman */ 461849Swollman 471849Swollman/* 481849Swollman * I've unrolled the loop eight times: large enough to make a 491849Swollman * significant difference, and small enough not to totally trash the 501849Swollman * cashe. 511849Swollman */ 521849Swollman 531849SwollmanENTRY(strcat) 541849Swollman pushl %edi /* save edi */ 551849Swollman movl 8(%esp),%edi /* dst address */ 561849Swollman movl 12(%esp),%edx /* src address */ 571849Swollman pushl %edi /* push destination address */ 581849Swollman 591849Swollman cld /* set search forward */ 601849Swollman xorl %eax,%eax /* set search for null terminator */ 611849Swollman movl $-1,%ecx /* set search for lots of characters */ 621849Swollman repne /* search! */ 631849Swollman scasb 641849Swollman 651849Swollman leal -1(%edi),%ecx /* correct dst address */ 661849Swollman 671849Swollman .align 2,0x90 681849SwollmanL1: movb (%edx),%al /* unroll loop, but not too much */ 691849Swollman movb %al,(%ecx) 701849Swollman testb %al,%al 711849Swollman je L2 721849Swollman movb 1(%edx),%al 731849Swollman movb %al,1(%ecx) 741849Swollman testb %al,%al 751849Swollman je L2 761849Swollman movb 2(%edx),%al 771849Swollman movb %al,2(%ecx) 781849Swollman testb %al,%al 791849Swollman je L2 801849Swollman movb 3(%edx),%al 811849Swollman movb %al,3(%ecx) 821849Swollman testb %al,%al 831849Swollman je L2 841849Swollman movb 4(%edx),%al 851849Swollman movb %al,4(%ecx) 861849Swollman testb %al,%al 871849Swollman je L2 881849Swollman movb 5(%edx),%al 891849Swollman movb %al,5(%ecx) 901849Swollman testb %al,%al 911849Swollman je L2 921849Swollman movb 6(%edx),%al 931849Swollman movb %al,6(%ecx) 941849Swollman testb %al,%al 951849Swollman je L2 961849Swollman movb 7(%edx),%al 971849Swollman movb %al,7(%ecx) 981849Swollman addl $8,%edx 991849Swollman addl $8,%ecx 1001849Swollman testb %al,%al 1011849Swollman jne L1 1021849SwollmanL2: popl %eax /* pop destination address */ 1031849Swollman popl %edi /* restore edi */ 1041849Swollman ret 105