Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/v850/lib/memset.c -- Memory initialization |
| 3 | * |
| 4 | * Copyright (C) 2001,02,04 NEC Corporation |
| 5 | * Copyright (C) 2001,02,04 Miles Bader <miles@gnu.org> |
| 6 | * |
| 7 | * This file is subject to the terms and conditions of the GNU General |
| 8 | * Public License. See the file COPYING in the main directory of this |
| 9 | * archive for more details. |
| 10 | * |
| 11 | * Written by Miles Bader <miles@gnu.org> |
| 12 | */ |
| 13 | |
| 14 | #include <linux/types.h> |
| 15 | |
| 16 | void *memset (void *dst, int val, __kernel_size_t count) |
| 17 | { |
| 18 | if (count) { |
| 19 | register unsigned loop; |
| 20 | register void *ptr asm ("ep") = dst; |
| 21 | |
| 22 | /* replicate VAL into a long. */ |
| 23 | val &= 0xff; |
| 24 | val |= val << 8; |
| 25 | val |= val << 16; |
| 26 | |
| 27 | /* copy initial unaligned bytes. */ |
| 28 | if ((long)ptr & 1) { |
| 29 | *(char *)ptr = val; |
| 30 | ptr = (void *)((char *)ptr + 1); |
| 31 | count--; |
| 32 | } |
| 33 | if (count > 2 && ((long)ptr & 2)) { |
| 34 | *(short *)ptr = val; |
| 35 | ptr = (void *)((short *)ptr + 1); |
| 36 | count -= 2; |
| 37 | } |
| 38 | |
| 39 | /* 32-byte copying loop. */ |
| 40 | for (loop = count / 32; loop; loop--) { |
| 41 | asm ("sst.w %0, 0[ep]; sst.w %0, 4[ep];" |
| 42 | "sst.w %0, 8[ep]; sst.w %0, 12[ep];" |
| 43 | "sst.w %0, 16[ep]; sst.w %0, 20[ep];" |
| 44 | "sst.w %0, 24[ep]; sst.w %0, 28[ep]" |
| 45 | :: "r" (val) : "memory"); |
| 46 | ptr += 32; |
| 47 | } |
| 48 | count %= 32; |
| 49 | |
| 50 | /* long copying loop. */ |
| 51 | for (loop = count / 4; loop; loop--) { |
| 52 | *(long *)ptr = val; |
| 53 | ptr = (void *)((long *)ptr + 1); |
| 54 | } |
| 55 | count %= 4; |
| 56 | |
| 57 | /* finish up with any trailing bytes. */ |
| 58 | if (count & 2) { |
| 59 | *(short *)ptr = val; |
| 60 | ptr = (void *)((short *)ptr + 1); |
| 61 | } |
| 62 | if (count & 1) { |
| 63 | *(char *)ptr = val; |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | return dst; |
| 68 | } |