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 withough 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#if defined(LIBC_RCS) && !defined(lint) 32 .text 33 .asciz "$FreeBSD$" 34#endif /* LIBC_RCS and not lint */ 35 36#include <machine/asm.h> 37 38/* 39 * strcmp(s1, s2) 40 * return an integer greater than, equal to, or less than 0, 41 * according as string s1 is greater than, equal to, or less 42 * than the string s2. 43 * 44 * %eax - pointer to s1 45 * %edx - pointer to s2 46 * 47 * Written by: 48 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. 49 */ 50 51/* 52 * I've unrolled the loop eight times: large enough to make a 53 * significant difference, and small enough not to totally trash the 54 * cashe. 55 */ 56 57ENTRY(strcmp) 58 movl 0x04(%esp),%eax 59 movl 0x08(%esp),%edx 60 jmp L2 /* Jump into the loop! */ 61 62 .align 2,0x90 63L1: incl %eax 64 incl %edx 65L2: movb (%eax),%cl 66 testb %cl,%cl 67 je L3 68 cmpb %cl,(%edx) 69 jne L3 70 incl %eax 71 incl %edx 72 movb (%eax),%cl 73 testb %cl,%cl 74 je L3 75 cmpb %cl,(%edx) 76 jne L3 77 incl %eax 78 incl %edx 79 movb (%eax),%cl 80 testb %cl,%cl 81 je L3 82 cmpb %cl,(%edx) 83 jne L3 84 incl %eax 85 incl %edx 86 movb (%eax),%cl 87 testb %cl,%cl 88 je L3 89 cmpb %cl,(%edx) 90 jne L3 91 incl %eax 92 incl %edx 93 movb (%eax),%cl 94 testb %cl,%cl 95 je L3 96 cmpb %cl,(%edx) 97 jne L3 98 incl %eax 99 incl %edx 100 movb (%eax),%cl 101 testb %cl,%cl 102 je L3 103 cmpb %cl,(%edx) 104 jne L3 105 incl %eax 106 incl %edx 107 movb (%eax),%cl 108 testb %cl,%cl 109 je L3 110 cmpb %cl,(%edx) 111 jne L3 112 incl %eax 113 incl %edx 114 movb (%eax),%cl 115 testb %cl,%cl 116 je L3 117 cmpb %cl,(%edx) 118 je L1 119 .align 2, 0x90 120L3: movzbl (%eax),%eax /* unsigned comparison */ 121 movzbl (%edx),%edx 122 subl %edx,%eax 123 ret 124