/*

 * 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.

 */

/*

 * char *memset(sp, c, n)

 *

 * Set an array of n chars starting at sp to the character c.

 * Return sp.

 *

 * Fast assembler language version of the following C-program for memset

 * which represents the `standard' for the C-library.

 *

 *	void *

 *	memset(void *sp1, int c, size_t n)

 *	{

 *	    if (n != 0) {

 *		char *sp = sp1;

 *		do {

 *		    *sp++ = (char)c;

 *		} while (--n != 0);

 *	    }

 *	    return (sp1);

 *	}

 */

#include <sys/asm_linkage.h>

	ANSI_PRAGMA_WEAK(memset,function)

	ENTRY(memset)

	mov	%o0, %o5		! copy sp before using it

	cmp	%o2, 7			! if small counts, just write bytes

	blu	.wrchar

	.empty				! following lable is ok in delay slot

.walign:btst	3, %o5			! if bigger, align to 4 bytes

	bz	.wrword

	andn	%o2, 3, %o3		! create word sized count in %o3

	dec	%o2			! decrement count

	stb	%o1, [%o5]		! clear a byte

	b	.walign

	inc	%o5			! next byte

.wrword:and	%o1, 0xff, %o1		! generate a word filled with c

	sll	%o1, 8, %o4

	or 	%o1, %o4, %o1

	sll	%o1, 16, %o4

	or	%o1, %o4, %o1

1:	st	%o1, [%o5]		! word writing loop

	subcc	%o3, 4, %o3

	bnz	1b

	inc	4, %o5

	and	%o2, 3, %o2		! leftover count, if any

.wrchar:deccc	%o2			! byte clearing loop

	inc	%o5

	bgeu,a	.wrchar

	stb	%o1, [%o5 + -1]		! we've already incremented the address

	retl

	nop

	SET_SIZE(memset)