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)
   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 }