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 * strcmp(s1, s2) 36 * return an integer greater than, equal to, or less than 0, 37 * according as string s1 is greater than, equal to, or less 38 * than the string s2. 39 * 40 * %eax - pointer to s1 41 * %edx - pointer to s2 42 * 43 * Written by: 44 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 45 */ 46 47/* 48 * I've unrolled the loop eight times: large enough to make a 49 * significant difference, and small enough not to totally trash the 50 * cache. 51 */ 52 53ENTRY(strcmp) 54 movl 0x04(%esp),%eax 55 movl 0x08(%esp),%edx 56 jmp L2 /* Jump into the loop! */ 57 58 .align 2,0x90 59L1: incl %eax 60 incl %edx 61L2: movb (%eax),%cl 62 testb %cl,%cl 63 je L3 64 cmpb %cl,(%edx) 65 jne L3 66 incl %eax 67 incl %edx 68 movb (%eax),%cl 69 testb %cl,%cl 70 je L3 71 cmpb %cl,(%edx) 72 jne L3 73 incl %eax 74 incl %edx 75 movb (%eax),%cl 76 testb %cl,%cl 77 je L3 78 cmpb %cl,(%edx) 79 jne L3 80 incl %eax 81 incl %edx 82 movb (%eax),%cl 83 testb %cl,%cl 84 je L3 85 cmpb %cl,(%edx) 86 jne L3 87 incl %eax 88 incl %edx 89 movb (%eax),%cl 90 testb %cl,%cl 91 je L3 92 cmpb %cl,(%edx) 93 jne L3 94 incl %eax 95 incl %edx 96 movb (%eax),%cl 97 testb %cl,%cl 98 je L3 99 cmpb %cl,(%edx) 100 jne L3 101 incl %eax 102 incl %edx 103 movb (%eax),%cl 104 testb %cl,%cl 105 je L3 106 cmpb %cl,(%edx) 107 jne L3 108 incl %eax 109 incl %edx 110 movb (%eax),%cl 111 testb %cl,%cl 112 je L3 113 cmpb %cl,(%edx) 114 je L1 115 .align 2, 0x90 116L3: movzbl (%eax),%eax /* unsigned comparison */ 117 movzbl (%edx),%edx 118 subl %edx,%eax 119 ret 120