/*
 * 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 2008 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)

        ENTRY(memccpy)  /* (void *dst, void *src, uchar_t c, size_t) */
.loop:
        decq    %rcx            / decrement bytes to go
        jl      .notfound
        movb    (%rsi),%dh
        movb    %dh,(%rdi)      / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found          / yes

        decq    %rcx            / decrement bytes to go
        jl      .notfound
        movb    1(%rsi),%dh
        movb    %dh,1(%rdi)     / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found1         / yes

        decq    %rcx            / decrement bytes to go
        jl      .notfound
        movb    2(%rsi),%dh
        movb    %dh,2(%rdi)     / move byte
        cmpb    %dh,%dl         / is it the byte sought?
        je      .found2         / yes

        decq    %rcx            / decrement bytes to go
        jl      .notfound
        movb    3(%rsi),%dh
        movb    %dh,3(%rdi)     / move byte
        addq    $4,%rsi
        addq    $4,%rdi
        cmpb    %dh,%dl         / is it the byte sought?
        jne     .loop           / no
        decq    %rdi

.found:
        incq    %rdi            / return pointer to next byte in dest
        movq    %rdi,%rax
        ret

        .align  4
.found2:
        incq    %rdi
.found1:
        addq    $2,%rdi         / return pointer to next byte in dest
        movq    %rdi,%rax
        ret

        .align  4
.notfound:
        xorl    %eax,%eax       / search fails
        ret
        SET_SIZE(memccpy)