xref: /onnv-gate/usr/src/lib/libc/i386/gen/memccpy.s (revision 7298:b69e27387f74)
10Sstevel@tonic-gate/*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*7298SMark.J.Nelson@Sun.COM * Common Development and Distribution License (the "License").
6*7298SMark.J.Nelson@Sun.COM * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate *
80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate * See the License for the specific language governing permissions
110Sstevel@tonic-gate * and limitations under the License.
120Sstevel@tonic-gate *
130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate *
190Sstevel@tonic-gate * CDDL HEADER END
200Sstevel@tonic-gate */
210Sstevel@tonic-gate/*
220Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
230Sstevel@tonic-gate * Use is subject to license terms.
240Sstevel@tonic-gate */
250Sstevel@tonic-gate
26*7298SMark.J.Nelson@Sun.COM	.file	"memccpy.s"
270Sstevel@tonic-gate
280Sstevel@tonic-gate#include <sys/asm_linkage.h>
290Sstevel@tonic-gate
300Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(memccpy,function)
310Sstevel@tonic-gate
320Sstevel@tonic-gate#include "SYS.h"
330Sstevel@tonic-gate
340Sstevel@tonic-gate	ENTRY(memccpy)
350Sstevel@tonic-gate	pushl	%esi		/ save register variable
360Sstevel@tonic-gate	movl	8(%esp),%eax	/ %eax = address of dest string
370Sstevel@tonic-gate	movl	12(%esp),%esi	/ %esi = address of source string
380Sstevel@tonic-gate	movb	16(%esp),%dh	/ %dh = character to search for
390Sstevel@tonic-gate	movl	20(%esp),%ecx	/ %ecx = length to go still
400Sstevel@tonic-gate.loop:
410Sstevel@tonic-gate	decl	%ecx		/ decrement bytes to go
420Sstevel@tonic-gate	jl	.notfound
430Sstevel@tonic-gate	movb	(%esi),%dl
440Sstevel@tonic-gate	movb	%dl,(%eax)	/ move byte
450Sstevel@tonic-gate	cmpb	%dh,%dl		/ is it the byte sought?
460Sstevel@tonic-gate	je	.found		/ yes
470Sstevel@tonic-gate
480Sstevel@tonic-gate	decl	%ecx		/ decrement bytes to go
490Sstevel@tonic-gate	jl	.notfound
500Sstevel@tonic-gate	movb	1(%esi),%dl
510Sstevel@tonic-gate	movb	%dl,1(%eax)	/ move byte
520Sstevel@tonic-gate	cmpb	%dh,%dl		/ is it the byte sought?
530Sstevel@tonic-gate	je	.found1		/ yes
540Sstevel@tonic-gate
550Sstevel@tonic-gate	decl	%ecx		/ decrement bytes to go
560Sstevel@tonic-gate	jl	.notfound
570Sstevel@tonic-gate	movb	2(%esi),%dl
580Sstevel@tonic-gate	movb	%dl,2(%eax)	/ move byte
590Sstevel@tonic-gate	cmpb	%dh,%dl		/ is it the byte sought?
600Sstevel@tonic-gate	je	.found2		/ yes
610Sstevel@tonic-gate
620Sstevel@tonic-gate	decl	%ecx		/ decrement bytes to go
630Sstevel@tonic-gate	jl	.notfound
640Sstevel@tonic-gate	movb	3(%esi),%dl
650Sstevel@tonic-gate	movb	%dl,3(%eax)	/ move byte
660Sstevel@tonic-gate	addl	$4,%esi
670Sstevel@tonic-gate	addl	$4,%eax
680Sstevel@tonic-gate	cmpb	%dh,%dl		/ is it the byte sought?
690Sstevel@tonic-gate	jne	.loop		/ no
700Sstevel@tonic-gate	decl	%eax
710Sstevel@tonic-gate
720Sstevel@tonic-gate.found:
730Sstevel@tonic-gate	popl	%esi		/ restore register variable
740Sstevel@tonic-gate	incl	%eax		/ return pointer to next byte in dest
750Sstevel@tonic-gate	ret
760Sstevel@tonic-gate
770Sstevel@tonic-gate	.align	4
780Sstevel@tonic-gate.found2:
790Sstevel@tonic-gate	incl	%eax
800Sstevel@tonic-gate.found1:
810Sstevel@tonic-gate	popl	%esi		/ restore register variable
820Sstevel@tonic-gate	addl	$2,%eax		/ return pointer to next byte in dest
830Sstevel@tonic-gate	ret
840Sstevel@tonic-gate
850Sstevel@tonic-gate	.align	4
860Sstevel@tonic-gate.notfound:
870Sstevel@tonic-gate	popl	%esi		/ restore register variable
880Sstevel@tonic-gate	xorl	%eax,%eax	/ search fails
890Sstevel@tonic-gate	ret
900Sstevel@tonic-gate	SET_SIZE(memccpy)
91