2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * Mike Hibler and Chris Torek.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)memset.c 8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <sys/types.h>
45 #define wsize sizeof(u_int)
46 #define wmask (wsize - 1)
56 bzero(void *dst0, size_t length)
60 #define RETURN return (dst0)
65 memset(void *dst0, int c0, size_t length)
76 * If not enough words, just fill bytes. A length >= 2 words
77 * guarantees that at least one of them is `complete' after
78 * any necessary alignment. For instance:
80 * |-----------|-----------|-----------|
81 * |00|01|02|03|04|05|06|07|08|09|0A|00|
82 * ^---------------------^
85 * but we use a minimum of 3 here since the overhead of the code
86 * to do word writes is substantial.
88 if (length < 3 * wsize) {
97 if ((c = (u_char)c0) != 0) { /* Fill the word. */
98 c = (c << 8) | c; /* u_int is 16 bits. */
100 c = (c << 16) | c; /* u_int is 32 bits. */
102 #if UINT_MAX > 0xffffffff
103 c = (c << 32) | c; /* u_int is 64 bits. */
107 /* Align destination by filling in bytes. */
108 if ((t = (long)dst & wmask) != 0) {
116 /* Fill words. Length was >= 2*words so we know t >= 1 here. */
119 *(u_int *)dst = WIDEVAL;
123 /* Mop up trailing bytes, if any. */