glibc/string/memset.c

92 lines
2.2 KiB
C

/* Copyright (C) 1991-2013 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, see
<http://www.gnu.org/licenses/>. */
#include <string.h>
#include <memcopy.h>
#undef memset
void *
inhibit_loop_to_libcall
memset (dstpp, c, len)
void *dstpp;
int c;
size_t len;
{
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)
{
((byte *) 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)
{
((byte *) dstp)[0] = c;
dstp += 1;
len -= 1;
}
return dstpp;
}
libc_hidden_builtin_def (memset)