1 /* Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18 #include <string.h>
19 #include "memcopy.h"
20
memset(void * dstpp,int c,size_t len)21 void *memset (void *dstpp, int c, size_t len)
22 {
23 long int dstp = (long int) dstpp;
24
25 if (len >= 8)
26 {
27 size_t xlen;
28 op_t cccc;
29
30 cccc = (unsigned char) c;
31 cccc |= cccc << 8;
32 cccc |= cccc << 16;
33 if (OPSIZ > 4)
34 /* Do the shift in two steps to avoid warning if long has 32 bits. */
35 cccc |= (cccc << 16) << 16;
36
37 /* There are at least some bytes to set.
38 No need to test for LEN == 0 in this alignment loop. */
39 while (dstp % OPSIZ != 0)
40 {
41 ((byte *) dstp)[0] = c;
42 dstp += 1;
43 len -= 1;
44 }
45
46 /* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */
47 xlen = len / (OPSIZ * 8);
48 while (xlen > 0)
49 {
50 ((op_t *) dstp)[0] = cccc;
51 ((op_t *) dstp)[1] = cccc;
52 ((op_t *) dstp)[2] = cccc;
53 ((op_t *) dstp)[3] = cccc;
54 ((op_t *) dstp)[4] = cccc;
55 ((op_t *) dstp)[5] = cccc;
56 ((op_t *) dstp)[6] = cccc;
57 ((op_t *) dstp)[7] = cccc;
58 dstp += 8 * OPSIZ;
59 xlen -= 1;
60 }
61 len %= OPSIZ * 8;
62
63 /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */
64 xlen = len / OPSIZ;
65 while (xlen > 0)
66 {
67 ((op_t *) dstp)[0] = cccc;
68 dstp += OPSIZ;
69 xlen -= 1;
70 }
71 len %= OPSIZ;
72 }
73
74 /* Write the last few bytes. */
75 while (len > 0)
76 {
77 ((byte *) dstp)[0] = c;
78 dstp += 1;
79 len -= 1;
80 }
81
82 return dstpp;
83 }
84 libc_hidden_weak(memset)
85