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glibc  2.9
Functions
memset_chk.c File Reference
#include <string.h>
#include <memcopy.h>

Go to the source code of this file.

Functions

void * __memset_chk (void *dstpp, int c, size_t len, size_t dstlen)

Function Documentation

void* __memset_chk ( void *  dstpp,
int  c,
size_t  len,
size_t  dstlen 
)

Definition at line 23 of file memset_chk.c.

{
  if (__builtin_expect (dstlen < len, 0))
    __chk_fail ();

  long int dstp = (long int) dstpp;

  if (len >= 8)
    {
      size_t xlen;
      op_t cccc;

      cccc = (unsigned char) c;
      cccc |= cccc << 8;
      cccc |= cccc << 16;
      if (OPSIZ > 4)
       /* Do the shift in two steps to avoid warning if long has 32 bits.  */
       cccc |= (cccc << 16) << 16;

      /* There are at least some bytes to set.
        No need to test for LEN == 0 in this alignment loop.  */
      while (dstp % OPSIZ != 0)
       {
         ((byte *) dstp)[0] = c;
         dstp += 1;
         len -= 1;
       }

      /* Write 8 `op_t' per iteration until less than 8 `op_t' remain.  */
      xlen = len / (OPSIZ * 8);
      while (xlen > 0)
       {
         ((op_t *) dstp)[0] = cccc;
         ((op_t *) dstp)[1] = cccc;
         ((op_t *) dstp)[2] = cccc;
         ((op_t *) dstp)[3] = cccc;
         ((op_t *) dstp)[4] = cccc;
         ((op_t *) dstp)[5] = cccc;
         ((op_t *) dstp)[6] = cccc;
         ((op_t *) dstp)[7] = cccc;
         dstp += 8 * OPSIZ;
         xlen -= 1;
       }
      len %= OPSIZ * 8;

      /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain.  */
      xlen = len / OPSIZ;
      while (xlen > 0)
       {
         ((op_t *) dstp)[0] = cccc;
         dstp += OPSIZ;
         xlen -= 1;
       }
      len %= OPSIZ;
    }

  /* Write the last few bytes.  */
  while (len > 0)
    {
      ((byte *) dstp)[0] = c;
      dstp += 1;
      len -= 1;
    }

  return dstpp;
}

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