opnsense-src/lib/libc/string/memset.c
Warner Losh dc36d6f9bb lib: Remove ancient SCCS tags.
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by:		Netflix
2023-11-26 22:23:28 -07:00

127 lines
3.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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.
*/
#include <sys/types.h>
#include <limits.h>
#define wsize sizeof(u_long)
#define wmask (wsize - 1)
#ifdef BZERO
#include <strings.h>
#define RETURN return
#define VAL 0
#define WIDEVAL 0
void
bzero(void *dst0, size_t length)
#else
#include <string.h>
#define RETURN return (dst0)
#define VAL c0
#define WIDEVAL c
void *
memset(void *dst0, int c0, size_t length)
#endif
{
size_t t;
#ifndef BZERO
u_long c;
#endif
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.
*
* TODO: This threshold might not be sensible for 64-bit u_long.
* We should benchmark and revisit this decision.
*/
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_long is 16 bits. */
#if ULONG_MAX > 0xffff
c = (c << 16) | c; /* u_long is 32 bits. */
#endif
#if ULONG_MAX > 0xffffffff
c = (c << 32) | c; /* u_long is 64 bits. */
#endif
}
#endif
/* Align destination by filling in bytes. */
if ((t = (long)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_long *)(void *)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;
}