strcmp.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/strcmp.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 * strcmp(s1, s2) 401849Swollman * return an integer greater than, equal to, or less than 0, 411849Swollman * according as string s1 is greater than, equal to, or less 421849Swollman * than the string s2. 431849Swollman * 441849Swollman * %eax - pointer to s1 451849Swollman * %edx - pointer to s2 461849Swollman * 471849Swollman * Written by: 481849Swollman * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 491849Swollman */ 501849Swollman 511849Swollman/* 521849Swollman * I've unrolled the loop eight times: large enough to make a 531849Swollman * significant difference, and small enough not to totally trash the 541849Swollman * cashe. 551849Swollman */ 561849Swollman 571849SwollmanENTRY(strcmp) 581849Swollman movl 0x04(%esp),%eax 591849Swollman movl 0x08(%esp),%edx 601849Swollman jmp L2 /* Jump into the loop! */ 611849Swollman 621849Swollman .align 2,0x90 631849SwollmanL1: incl %eax 641849Swollman incl %edx 651849SwollmanL2: movb (%eax),%cl 661849Swollman testb %cl,%cl 671849Swollman je L3 681849Swollman cmpb %cl,(%edx) 691849Swollman jne L3 701849Swollman incl %eax 711849Swollman incl %edx 721849Swollman movb (%eax),%cl 731849Swollman testb %cl,%cl 741849Swollman je L3 751849Swollman cmpb %cl,(%edx) 761849Swollman jne L3 771849Swollman incl %eax 781849Swollman incl %edx 791849Swollman movb (%eax),%cl 801849Swollman testb %cl,%cl 811849Swollman je L3 821849Swollman cmpb %cl,(%edx) 831849Swollman jne L3 841849Swollman incl %eax 851849Swollman incl %edx 861849Swollman movb (%eax),%cl 871849Swollman testb %cl,%cl 881849Swollman je L3 891849Swollman cmpb %cl,(%edx) 901849Swollman jne L3 911849Swollman incl %eax 921849Swollman incl %edx 931849Swollman movb (%eax),%cl 941849Swollman testb %cl,%cl 951849Swollman je L3 961849Swollman cmpb %cl,(%edx) 971849Swollman jne L3 981849Swollman incl %eax 991849Swollman incl %edx 1001849Swollman movb (%eax),%cl 1011849Swollman testb %cl,%cl 1021849Swollman je L3 1031849Swollman cmpb %cl,(%edx) 1041849Swollman jne L3 1051849Swollman incl %eax 1061849Swollman incl %edx 1071849Swollman movb (%eax),%cl 1081849Swollman testb %cl,%cl 1091849Swollman je L3 1101849Swollman cmpb %cl,(%edx) 1111849Swollman jne L3 1121849Swollman incl %eax 1131849Swollman incl %edx 1141849Swollman movb (%eax),%cl 1151849Swollman testb %cl,%cl 1161849Swollman je L3 1171849Swollman cmpb %cl,(%edx) 1181849Swollman je L1 1191849Swollman .align 2, 0x90 1201849SwollmanL3: movzbl (%eax),%eax /* unsigned comparison */ 1211849Swollman movzbl (%edx),%edx 1221849Swollman subl %edx,%eax 1231849Swollman ret 124