1*5d9d9091SRichard Lowe/* 2*5d9d9091SRichard Lowe * CDDL HEADER START 3*5d9d9091SRichard Lowe * 4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the 5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License"). 6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License. 7*5d9d9091SRichard Lowe * 8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing. 10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions 11*5d9d9091SRichard Lowe * and limitations under the License. 12*5d9d9091SRichard Lowe * 13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each 14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the 16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying 17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner] 18*5d9d9091SRichard Lowe * 19*5d9d9091SRichard Lowe * CDDL HEADER END 20*5d9d9091SRichard Lowe */ 21*5d9d9091SRichard Lowe/* 22*5d9d9091SRichard Lowe * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 23*5d9d9091SRichard Lowe * Use is subject to license terms. 24*5d9d9091SRichard Lowe */ 25*5d9d9091SRichard Lowe 26*5d9d9091SRichard Lowe .file "strncmp.s" 27*5d9d9091SRichard Lowe 28*5d9d9091SRichard Lowe#include "SYS.h" 29*5d9d9091SRichard Lowe 30*5d9d9091SRichard Lowe ENTRY(strncmp) 31*5d9d9091SRichard Lowe pushl %esi / save register variables 32*5d9d9091SRichard Lowe movl 8(%esp),%esi / %esi = first string 33*5d9d9091SRichard Lowe movl %edi,%edx 34*5d9d9091SRichard Lowe movl 12(%esp),%edi / %edi = second string 35*5d9d9091SRichard Lowe cmpl %esi,%edi / same string? 36*5d9d9091SRichard Lowe je .equal 37*5d9d9091SRichard Lowe movl 16(%esp),%ecx / %ecx = length 38*5d9d9091SRichard Lowe incl %ecx / will later predecrement this uint 39*5d9d9091SRichard Lowe.loop: 40*5d9d9091SRichard Lowe decl %ecx 41*5d9d9091SRichard Lowe je .equal / Used all n chars? 42*5d9d9091SRichard Lowe movb (%esi),%al / slodb ; scab 43*5d9d9091SRichard Lowe cmpb (%edi),%al 44*5d9d9091SRichard Lowe jne .notequal_0 / Are the bytes equal? 45*5d9d9091SRichard Lowe testb %al,%al 46*5d9d9091SRichard Lowe je .equal / End of string? 47*5d9d9091SRichard Lowe 48*5d9d9091SRichard Lowe decl %ecx 49*5d9d9091SRichard Lowe je .equal / Used all n chars? 50*5d9d9091SRichard Lowe movb 1(%esi),%al / slodb ; scab 51*5d9d9091SRichard Lowe cmpb 1(%edi),%al 52*5d9d9091SRichard Lowe jne .notequal_1 / Are the bytes equal? 53*5d9d9091SRichard Lowe testb %al,%al 54*5d9d9091SRichard Lowe je .equal / End of string? 55*5d9d9091SRichard Lowe 56*5d9d9091SRichard Lowe decl %ecx 57*5d9d9091SRichard Lowe je .equal / Used all n chars? 58*5d9d9091SRichard Lowe movb 2(%esi),%al / slodb ; scab 59*5d9d9091SRichard Lowe cmpb 2(%edi),%al 60*5d9d9091SRichard Lowe jne .notequal_2 / Are the bytes equal? 61*5d9d9091SRichard Lowe testb %al,%al 62*5d9d9091SRichard Lowe je .equal / End of string? 63*5d9d9091SRichard Lowe 64*5d9d9091SRichard Lowe decl %ecx 65*5d9d9091SRichard Lowe je .equal / Used all n chars? 66*5d9d9091SRichard Lowe movb 3(%esi),%al / slodb ; scab 67*5d9d9091SRichard Lowe cmpb 3(%edi),%al 68*5d9d9091SRichard Lowe jne .notequal_3 / Are the bytes equal? 69*5d9d9091SRichard Lowe addl $4,%esi 70*5d9d9091SRichard Lowe addl $4,%edi 71*5d9d9091SRichard Lowe testb %al,%al 72*5d9d9091SRichard Lowe jne .loop / End of string? 73*5d9d9091SRichard Lowe 74*5d9d9091SRichard Lowe.equal: 75*5d9d9091SRichard Lowe popl %esi / restore registers 76*5d9d9091SRichard Lowe xorl %eax,%eax / return 0 77*5d9d9091SRichard Lowe movl %edx,%edi 78*5d9d9091SRichard Lowe ret 79*5d9d9091SRichard Lowe 80*5d9d9091SRichard Lowe .align 4 81*5d9d9091SRichard Lowe.notequal_3: 82*5d9d9091SRichard Lowe incl %edi 83*5d9d9091SRichard Lowe.notequal_2: 84*5d9d9091SRichard Lowe incl %edi 85*5d9d9091SRichard Lowe.notequal_1: 86*5d9d9091SRichard Lowe incl %edi 87*5d9d9091SRichard Lowe.notequal_0: 88*5d9d9091SRichard Lowe popl %esi / restore registers 89*5d9d9091SRichard Lowe clc / clear carry bit 90*5d9d9091SRichard Lowe subb (%edi),%al 91*5d9d9091SRichard Lowe movl %edx,%edi 92*5d9d9091SRichard Lowe movl $-1, %eax / possibly wasted instr 93*5d9d9091SRichard Lowe jc .neg / did we overflow in the sub 94*5d9d9091SRichard Lowe movl $1, %eax / if not a > b 95*5d9d9091SRichard Lowe.neg: 96*5d9d9091SRichard Lowe ret 97*5d9d9091SRichard Lowe SET_SIZE(strncmp) 98