| 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
|---|---|
| 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 |