/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

        .file   "memccpy.s"

#include <sys/asm_linkage.h>

        ANSI_PRAGMA_WEAK(memccpy,function)

#include "SYS.h"

        ENTRY(memccpy)
        pushl   %esi            / save register variable
        movl    8(%esp),%eax    / %eax = address of dest string
        movl    12(%esp),%esi   / %esi = address of source string
        movb    16(%esp),%dh    / %dh = character to search for
        movl    20(%esp),%ecx   / %ecx = length to go still
.loop:
        decl    %ecx            / decrement bytes to go
        jl      .notfound
        movb    (%esi),%dl
        movb    %dl,(%eax)      / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found          / yes

        decl    %ecx            / decrement bytes to go
        jl      .notfound
        movb    1(%esi),%dl
        movb    %dl,1(%eax)     / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found1         / yes

        decl    %ecx            / decrement bytes to go
        jl      .notfound
        movb    2(%esi),%dl
        movb    %dl,2(%eax)     / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found2         / yes

        decl    %ecx            / decrement bytes to go
        jl      .notfound
        movb    3(%esi),%dl
        movb    %dl,3(%eax)     / move byte
        addl    $4,%esi
        addl    $4,%eax
        cmpb    %dh,%dl         / is it the byte sought?
        jne     .loop           / no
        decl    %eax

.found:
        popl    %esi            / restore register variable
        incl    %eax            / return pointer to next byte in dest
        ret

        .align  4
.found2:
        incl    %eax
.found1:
        popl    %esi            / restore register variable
        addl    $2,%eax         / return pointer to next byte in dest
        ret

        .align  4
.notfound:
        popl    %esi            / restore register variable
        xorl    %eax,%eax       / search fails
        ret
        SET_SIZE(memccpy)