[apple/libc.git] / string / memset.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Hibler and Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)memset.c	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>

#include <limits.h>
#include <string.h>

#define	wsize	sizeof(u_int)
#define	wmask	(wsize - 1)

#ifndef __ppc__ 

#ifdef BZERO
#define	RETURN	return
#define	VAL	0
#define	WIDEVAL	0

void
bzero(dst0, length)
	void *dst0;
	register size_t length;
#else
#define	RETURN	return (dst0)
#define	VAL	c0
#define	WIDEVAL	c

void *
memset(dst0, c0, length)
	void *dst0;
	register int c0;
	register size_t length;
#endif
{
	register size_t t;
	register u_int c;
	register u_char *dst;

	dst = dst0;
	/*
	 * If not enough words, just fill bytes.  A length >= 2 words
	 * guarantees that at least one of them is `complete' after
	 * any necessary alignment.  For instance:
	 *
	 *	|-----------|-----------|-----------|
	 *	|00|01|02|03|04|05|06|07|08|09|0A|00|
	 *	          ^---------------------^
	 *		 dst		 dst+length-1
	 *
	 * but we use a minimum of 3 here since the overhead of the code
	 * to do word writes is substantial.
	 */ 
	if (length < 3 * wsize) {
		while (length != 0) {
			*dst++ = VAL;
			--length;
		}
		RETURN;
	}

#ifndef BZERO
	if ((c = (u_char)c0) != 0) {	/* Fill the word. */
		c = (c << 8) | c;	/* u_int is 16 bits. */
#if UINT_MAX > 0xffff
		c = (c << 16) | c;	/* u_int is 32 bits. */
#endif
#if UINT_MAX > 0xffffffff
		c = (c << 32) | c;	/* u_int is 64 bits. */
#endif
	}
#endif
	/* Align destination by filling in bytes. */
	if ((t = (int)dst & wmask) != 0) {
		t = wsize - t;
		length -= t;
		do {
			*dst++ = VAL;
		} while (--t != 0);
	}

	/* Fill words.  Length was >= 2*words so we know t >= 1 here. */
	t = length / wsize;
	do {
		*(u_int *)dst = WIDEVAL;
		dst += wsize;
	} while (--t != 0);

	/* Mop up trailing bytes, if any. */
	t = length & wmask;
	if (t != 0)
		do {
			*dst++ = VAL;
		} while (--t != 0);
	RETURN;
}
#endif /* __ppc__ */
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
734aad71	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
e9ce8d39	7	*
734aad71 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
e9ce8d39 A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
e9ce8d39 A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
734aad71 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
e9ce8d39 A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1990, 1993
	27	* The Regents of the University of California. All rights reserved.
	28	*
	29	* This code is derived from software contributed to Berkeley by
	30	* Mike Hibler and Chris Torek.
	31	*
	32	* Redistribution and use in source and binary forms, with or without
	33	* modification, are permitted provided that the following conditions
	34	* are met:
	35	* 1. Redistributions of source code must retain the above copyright
	36	* notice, this list of conditions and the following disclaimer.
	37	* 2. Redistributions in binary form must reproduce the above copyright
	38	* notice, this list of conditions and the following disclaimer in the
	39	* documentation and/or other materials provided with the distribution.
	40	* 3. All advertising materials mentioning features or use of this software
	41	* must display the following acknowledgement:
	42	* This product includes software developed by the University of
	43	* California, Berkeley and its contributors.
	44	* 4. Neither the name of the University nor the names of its contributors
	45	* may be used to endorse or promote products derived from this software
	46	* without specific prior written permission.
	47	*
	48	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	49	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	50	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	51	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	52	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	53	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	54	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	55	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	56	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	57	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	58	* SUCH DAMAGE.
	59	*/
	60
	61	#if defined(LIBC_SCCS) && !defined(lint)
	62	static char sccsid[] = "@(#)memset.c 8.1 (Berkeley) 6/4/93";
	63	#endif /* LIBC_SCCS and not lint */
	64
	65	#include <sys/types.h>
	66
	67	#include <limits.h>
	68	#include <string.h>
	69
	70	#define wsize sizeof(u_int)
	71	#define wmask (wsize - 1)
	72
5b2abdfb A	73	#ifndef __ppc__
5b2abdfb A	74
e9ce8d39 A	75	#ifdef BZERO
	76	#define RETURN return
	77	#define VAL 0
	78	#define WIDEVAL 0
	79
	80	void
	81	bzero(dst0, length)
	82	void *dst0;
	83	register size_t length;
	84	#else
	85	#define RETURN return (dst0)
	86	#define VAL c0
	87	#define WIDEVAL c
	88
	89	void *
	90	memset(dst0, c0, length)
	91	void *dst0;
	92	register int c0;
	93	register size_t length;
	94	#endif
	95	{
	96	register size_t t;
	97	register u_int c;
	98	register u_char *dst;
	99
	100	dst = dst0;
	101	/*
	102	* If not enough words, just fill bytes. A length >= 2 words
	103	* guarantees that at least one of them is `complete' after
	104	* any necessary alignment. For instance:
	105	*
	106	* \|-----------\|-----------\|-----------\|
	107	* \|00\|01\|02\|03\|04\|05\|06\|07\|08\|09\|0A\|00\|
	108	* ^---------------------^
	109	* dst dst+length-1
	110	*
	111	* but we use a minimum of 3 here since the overhead of the code
	112	* to do word writes is substantial.
	113	*/
	114	if (length < 3 * wsize) {
	115	while (length != 0) {
	116	*dst++ = VAL;
	117	--length;
	118	}
	119	RETURN;
	120	}
	121
	122	#ifndef BZERO
	123	if ((c = (u_char)c0) != 0) { /* Fill the word. */
	124	c = (c << 8) \| c; /* u_int is 16 bits. */
	125	#if UINT_MAX > 0xffff
	126	c = (c << 16) \| c; /* u_int is 32 bits. */
	127	#endif
	128	#if UINT_MAX > 0xffffffff
	129	c = (c << 32) \| c; /* u_int is 64 bits. */
	130	#endif
	131	}
	132	#endif
	133	/* Align destination by filling in bytes. */
	134	if ((t = (int)dst & wmask) != 0) {
	135	t = wsize - t;
	136	length -= t;
	137	do {
	138	*dst++ = VAL;
139	} while (--t != 0);
140	}
141
142	/* Fill words. Length was >= 2words so we know t >= 1 here. /
143	t = length / wsize;
144	do {
145	(u_int )dst = WIDEVAL;
146	dst += wsize;
147	} while (--t != 0);
148
149	/* Mop up trailing bytes, if any. */
150	t = length & wmask;
151	if (t != 0)
152	do {
153	*dst++ = VAL;
154	} while (--t != 0);
155	RETURN;
156	}
5b2abdfb	157	#endif /* __ppc__ */