memset.c
2.38 KB
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/* Copyright (C) 1991, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* Slight modifications for pa-risc linux - Paul Bame <bame@debian.org> */
#include <linux/types.h>
#include <asm/string.h>
#define OPSIZ (BITS_PER_LONG/8)
typedef unsigned long op_t;
void *
memset (void *dstpp, int sc, size_t len)
{
unsigned int c = sc;
long int dstp = (long int) dstpp;
if (len >= 8)
{
size_t xlen;
op_t cccc;
cccc = (unsigned char) c;
cccc |= cccc << 8;
cccc |= cccc << 16;
if (OPSIZ > 4)
/* Do the shift in two steps to avoid warning if long has 32 bits. */
cccc |= (cccc << 16) << 16;
/* There are at least some bytes to set.
No need to test for LEN == 0 in this alignment loop. */
while (dstp % OPSIZ != 0)
{
((unsigned char *) dstp)[0] = c;
dstp += 1;
len -= 1;
}
/* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */
xlen = len / (OPSIZ * 8);
while (xlen > 0)
{
((op_t *) dstp)[0] = cccc;
((op_t *) dstp)[1] = cccc;
((op_t *) dstp)[2] = cccc;
((op_t *) dstp)[3] = cccc;
((op_t *) dstp)[4] = cccc;
((op_t *) dstp)[5] = cccc;
((op_t *) dstp)[6] = cccc;
((op_t *) dstp)[7] = cccc;
dstp += 8 * OPSIZ;
xlen -= 1;
}
len %= OPSIZ * 8;
/* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */
xlen = len / OPSIZ;
while (xlen > 0)
{
((op_t *) dstp)[0] = cccc;
dstp += OPSIZ;
xlen -= 1;
}
len %= OPSIZ;
}
/* Write the last few bytes. */
while (len > 0)
{
((unsigned char *) dstp)[0] = c;
dstp += 1;
len -= 1;
}
return dstpp;
}