1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
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2 | #include <linux/types.h> |
3 | #include <asm/string.h> |
4 | |
5 | #define OPSIZ (BITS_PER_LONG/8) |
6 | typedef unsigned long op_t; |
7 | |
8 | void * |
9 | memset (void *dstpp, int sc, size_t len) |
10 | { |
11 | unsigned int c = sc; |
12 | long int dstp = (long int) dstpp; |
13 | |
14 | if (len >= 8) |
15 | { |
16 | size_t xlen; |
17 | op_t cccc; |
18 | |
19 | cccc = (unsigned char) c; |
20 | cccc |= cccc << 8; |
21 | cccc |= cccc << 16; |
22 | if (OPSIZ > 4) |
23 | /* Do the shift in two steps to avoid warning if long has 32 bits. */ |
24 | cccc |= (cccc << 16) << 16; |
25 | |
26 | /* There are at least some bytes to set. |
27 | No need to test for LEN == 0 in this alignment loop. */ |
28 | while (dstp % OPSIZ != 0) |
29 | { |
30 | ((unsigned char *) dstp)[0] = c; |
31 | dstp += 1; |
32 | len -= 1; |
33 | } |
34 | |
35 | /* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */ |
36 | xlen = len / (OPSIZ * 8); |
37 | while (xlen > 0) |
38 | { |
39 | ((op_t *) dstp)[0] = cccc; |
40 | ((op_t *) dstp)[1] = cccc; |
41 | ((op_t *) dstp)[2] = cccc; |
42 | ((op_t *) dstp)[3] = cccc; |
43 | ((op_t *) dstp)[4] = cccc; |
44 | ((op_t *) dstp)[5] = cccc; |
45 | ((op_t *) dstp)[6] = cccc; |
46 | ((op_t *) dstp)[7] = cccc; |
47 | dstp += 8 * OPSIZ; |
48 | xlen -= 1; |
49 | } |
50 | len %= OPSIZ * 8; |
51 | |
52 | /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */ |
53 | xlen = len / OPSIZ; |
54 | while (xlen > 0) |
55 | { |
56 | ((op_t *) dstp)[0] = cccc; |
57 | dstp += OPSIZ; |
58 | xlen -= 1; |
59 | } |
60 | len %= OPSIZ; |
61 | } |
62 | |
63 | /* Write the last few bytes. */ |
64 | while (len > 0) |
65 | { |
66 | ((unsigned char *) dstp)[0] = c; |
67 | dstp += 1; |
68 | len -= 1; |
69 | } |
70 | |
71 | return dstpp; |
72 | } |
73 |