2N/A/*
2N/A * CDDL HEADER START
2N/A *
2N/A * The contents of this file are subject to the terms of the
2N/A * Common Development and Distribution License (the "License").
2N/A * You may not use this file except in compliance with the License.
2N/A *
2N/A * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
2N/A * or http://www.opensolaris.org/os/licensing.
2N/A * See the License for the specific language governing permissions
2N/A * and limitations under the License.
2N/A *
2N/A * When distributing Covered Code, include this CDDL HEADER in each
2N/A * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
2N/A * If applicable, add the following below this CDDL HEADER, with the
2N/A * fields enclosed by brackets "[]" replaced with your own identifying
2N/A * information: Portions Copyright [yyyy] [name of copyright owner]
2N/A *
2N/A * CDDL HEADER END
2N/A */
2N/A/*
2N/A * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
2N/A * Use is subject to license terms.
2N/A */
2N/A
2N/A .file "strncmp.s"
2N/A
2N/A#include "SYS.h"
2N/A
2N/A ENTRY(strncmp)
2N/A pushl %esi / save register variables
2N/A movl 8(%esp),%esi / %esi = first string
2N/A movl %edi,%edx
2N/A movl 12(%esp),%edi / %edi = second string
2N/A cmpl %esi,%edi / same string?
2N/A je .equal
2N/A movl 16(%esp),%ecx / %ecx = length
2N/A incl %ecx / will later predecrement this uint
2N/A.loop:
2N/A decl %ecx
2N/A je .equal / Used all n chars?
2N/A movb (%esi),%al / slodb ; scab
2N/A cmpb (%edi),%al
2N/A jne .notequal_0 / Are the bytes equal?
2N/A testb %al,%al
2N/A je .equal / End of string?
2N/A
2N/A decl %ecx
2N/A je .equal / Used all n chars?
2N/A movb 1(%esi),%al / slodb ; scab
2N/A cmpb 1(%edi),%al
2N/A jne .notequal_1 / Are the bytes equal?
2N/A testb %al,%al
2N/A je .equal / End of string?
2N/A
2N/A decl %ecx
2N/A je .equal / Used all n chars?
2N/A movb 2(%esi),%al / slodb ; scab
2N/A cmpb 2(%edi),%al
2N/A jne .notequal_2 / Are the bytes equal?
2N/A testb %al,%al
2N/A je .equal / End of string?
2N/A
2N/A decl %ecx
2N/A je .equal / Used all n chars?
2N/A movb 3(%esi),%al / slodb ; scab
2N/A cmpb 3(%edi),%al
2N/A jne .notequal_3 / Are the bytes equal?
2N/A addl $4,%esi
2N/A addl $4,%edi
2N/A testb %al,%al
2N/A jne .loop / End of string?
2N/A
2N/A.equal:
2N/A popl %esi / restore registers
2N/A xorl %eax,%eax / return 0
2N/A movl %edx,%edi
2N/A ret
2N/A
2N/A .align 4
2N/A.notequal_3:
2N/A incl %edi
2N/A.notequal_2:
2N/A incl %edi
2N/A.notequal_1:
2N/A incl %edi
2N/A.notequal_0:
2N/A popl %esi / restore registers
2N/A clc / clear carry bit
2N/A subb (%edi),%al
2N/A movl %edx,%edi
2N/A movl $-1, %eax / possibly wasted instr
2N/A jc .neg / did we overflow in the sub
2N/A movl $1, %eax / if not a > b
2N/A.neg:
2N/A ret
2N/A SET_SIZE(strncmp)