LXR linux/arch/v850/lib/memset.c

   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
  16void *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}
  69