.
[glibc/history.git] / string / memset.c
blob592b11e4351ed2c8a2f2417bd8df07574333dda3
1 /* Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
19 #include <string.h>
20 #include <memcopy.h>
22 #undef memset
24 void *
25 memset (dstpp, c, len)
26 void *dstpp;
27 int c;
28 size_t len;
30 long int dstp = (long int) dstpp;
32 if (len >= 8)
34 size_t xlen;
35 op_t cccc;
37 cccc = (unsigned char) c;
38 cccc |= cccc << 8;
39 cccc |= cccc << 16;
40 if (OPSIZ > 4)
41 /* Do the shift in two steps to avoid warning if long has 32 bits. */
42 cccc |= (cccc << 16) << 16;
44 /* There are at least some bytes to set.
45 No need to test for LEN == 0 in this alignment loop. */
46 while (dstp % OPSIZ != 0)
48 ((byte *) dstp)[0] = c;
49 dstp += 1;
50 len -= 1;
53 /* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */
54 xlen = len / (OPSIZ * 8);
55 while (xlen > 0)
57 ((op_t *) dstp)[0] = cccc;
58 ((op_t *) dstp)[1] = cccc;
59 ((op_t *) dstp)[2] = cccc;
60 ((op_t *) dstp)[3] = cccc;
61 ((op_t *) dstp)[4] = cccc;
62 ((op_t *) dstp)[5] = cccc;
63 ((op_t *) dstp)[6] = cccc;
64 ((op_t *) dstp)[7] = cccc;
65 dstp += 8 * OPSIZ;
66 xlen -= 1;
68 len %= OPSIZ * 8;
70 /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */
71 xlen = len / OPSIZ;
72 while (xlen > 0)
74 ((op_t *) dstp)[0] = cccc;
75 dstp += OPSIZ;
76 xlen -= 1;
78 len %= OPSIZ;
81 /* Write the last few bytes. */
82 while (len > 0)
84 ((byte *) dstp)[0] = c;
85 dstp += 1;
86 len -= 1;
89 return dstpp;
91 libc_hidden_builtin_def (memset)