strncmp.S revision 1.3
1 1.1 cgd /* 2 1.1 cgd * Copyright (c) 1993 Winning Strategies, Inc. 3 1.1 cgd * All rights reserved. 4 1.1 cgd * 5 1.1 cgd * Redistribution and use in source and binary forms, with or without 6 1.1 cgd * modification, are permitted provided that the following conditions 7 1.1 cgd * are met: 8 1.1 cgd * 1. Redistributions of source code must retain the above copyright 9 1.1 cgd * notice, this list of conditions and the following disclaimer. 10 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright 11 1.1 cgd * notice, this list of conditions and the following disclaimer in the 12 1.1 cgd * documentation and/or other materials provided with the distribution. 13 1.1 cgd * 3. All advertising materials mentioning features or use of this software 14 1.1 cgd * must display the following acknowledgement: 15 1.1 cgd * This product includes software developed by Winning Strategies, Inc. 16 1.1 cgd * 4. The name of the author may not be used to endorse or promote products 17 1.1 cgd * derived from this software withough specific prior written permission 18 1.1 cgd * 19 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 1.1 cgd * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 1.1 cgd * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 1.1 cgd * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 1.1 cgd * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 1.1 cgd * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 1.1 cgd * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 1.1 cgd * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 1.1 cgd * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 1.1 cgd * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 1.1 cgd * 30 1.3 jtc * $Id: strncmp.S,v 1.3 1993/10/21 01:40:42 jtc Exp $ 31 1.1 cgd */ 32 1.1 cgd 33 1.3 jtc #if defined(LIBC_SCCS) 34 1.1 cgd .text 35 1.3 jtc .asciz "$Id: strncmp.S,v 1.3 1993/10/21 01:40:42 jtc Exp $" 36 1.3 jtc #endif 37 1.1 cgd 38 1.1 cgd #include "DEFS.h" 39 1.1 cgd 40 1.1 cgd /* 41 1.1 cgd * strncmp(s1, s2, n) 42 1.1 cgd * return an integer greater than, equal to, or less than 0, 43 1.1 cgd * according as the first n characters of string s1 is greater 44 1.1 cgd * than, equal to, or less than the string s2. 45 1.1 cgd * 46 1.1 cgd * %eax - pointer to s1 47 1.1 cgd * %ecx - pointer to s2 48 1.1 cgd * %edx - length 49 1.1 cgd * 50 1.1 cgd * Written by: 51 1.1 cgd * J.T. Conklin (jtc (at) wimsey.com), Winning Strategies, Inc. 52 1.1 cgd */ 53 1.1 cgd 54 1.1 cgd /* 55 1.1 cgd * I've unrolled the loop eight times: large enough to make a 56 1.1 cgd * significant difference, and small enough not to totally trash the 57 1.1 cgd * cashe. 58 1.1 cgd */ 59 1.1 cgd 60 1.1 cgd ENTRY(strncmp) 61 1.1 cgd pushl %ebx 62 1.1 cgd movl 8(%esp),%eax 63 1.1 cgd movl 12(%esp),%ecx 64 1.1 cgd movl 16(%esp),%edx 65 1.1 cgd jmp L2 /* Jump into the loop! */ 66 1.1 cgd 67 1.1 cgd .align 2,0x90 68 1.1 cgd L1: incl %eax 69 1.1 cgd incl %ecx 70 1.1 cgd decl %edx 71 1.1 cgd L2: testl %edx,%edx /* Have we compared n chars yet? */ 72 1.1 cgd jle L4 /* Yes, strings are equal */ 73 1.1 cgd movb (%eax),%bl 74 1.2 jtc testb %bl,%bl 75 1.1 cgd je L3 76 1.1 cgd cmpb %bl,(%ecx) 77 1.1 cgd jne L3 78 1.1 cgd incl %eax 79 1.1 cgd incl %ecx 80 1.1 cgd decl %edx 81 1.1 cgd testl %edx,%edx 82 1.1 cgd jle L4 83 1.1 cgd movb (%eax),%bl 84 1.2 jtc testb %bl,%bl 85 1.1 cgd je L3 86 1.1 cgd cmpb %bl,(%ecx) 87 1.1 cgd jne L3 88 1.1 cgd incl %eax 89 1.1 cgd incl %ecx 90 1.1 cgd decl %edx 91 1.1 cgd testl %edx,%edx 92 1.1 cgd jle L4 93 1.1 cgd movb (%eax),%bl 94 1.2 jtc testb %bl,%bl 95 1.1 cgd je L3 96 1.1 cgd cmpb %bl,(%ecx) 97 1.1 cgd jne L3 98 1.1 cgd incl %eax 99 1.1 cgd incl %ecx 100 1.1 cgd decl %edx 101 1.1 cgd testl %edx,%edx 102 1.1 cgd jle L4 103 1.1 cgd movb (%eax),%bl 104 1.2 jtc testb %bl,%bl 105 1.1 cgd je L3 106 1.1 cgd cmpb %bl,(%ecx) 107 1.1 cgd jne L3 108 1.1 cgd incl %eax 109 1.1 cgd incl %ecx 110 1.1 cgd decl %edx 111 1.1 cgd testl %edx,%edx 112 1.1 cgd jle L4 113 1.1 cgd movb (%eax),%bl 114 1.2 jtc testb %bl,%bl 115 1.1 cgd je L3 116 1.1 cgd cmpb %bl,(%ecx) 117 1.1 cgd jne L3 118 1.1 cgd incl %eax 119 1.1 cgd incl %ecx 120 1.1 cgd decl %edx 121 1.1 cgd testl %edx,%edx 122 1.1 cgd jle L4 123 1.1 cgd movb (%eax),%bl 124 1.2 jtc testb %bl,%bl 125 1.1 cgd je L3 126 1.1 cgd cmpb %bl,(%ecx) 127 1.1 cgd jne L3 128 1.1 cgd incl %eax 129 1.1 cgd incl %ecx 130 1.1 cgd decl %edx 131 1.1 cgd testl %edx,%edx 132 1.1 cgd jle L4 133 1.1 cgd movb (%eax),%bl 134 1.2 jtc testb %bl,%bl 135 1.1 cgd je L3 136 1.1 cgd cmpb %bl,(%ecx) 137 1.1 cgd jne L3 138 1.1 cgd incl %eax 139 1.1 cgd incl %ecx 140 1.1 cgd decl %edx 141 1.1 cgd testl %edx,%edx 142 1.1 cgd jle L4 143 1.1 cgd movb (%eax),%bl 144 1.2 jtc testb %bl,%bl 145 1.1 cgd je L3 146 1.1 cgd cmpb %bl,(%ecx) 147 1.1 cgd je L1 148 1.1 cgd .align 2,0x90 149 1.1 cgd L3: movsbl (%eax),%eax /* unsigned comparision */ 150 1.1 cgd movsbl (%ecx),%ecx 151 1.1 cgd subl %ecx,%eax 152 1.1 cgd popl %ebx 153 1.1 cgd ret 154 1.1 cgd .align 2,0x90 155 1.1 cgd L4: xorl %eax,%eax 156 1.1 cgd popl %ebx 157 1.1 cgd ret 158
Indexes created Sun Sep 21 20:09:37 GMT 2025