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

   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)
   6typedef unsigned long op_t;
   7
   8void *
   9memset (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