gcc/testsuite/gcc.target/i386/pr52171.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2" } */
   3 /* { dg-final { scan-assembler-not "memcmp" } } */
   4 /* { dg-final { scan-assembler "1752394086" } } */
   5
   6 /* This should turn into four compare/jump pairs with -m32, within the
   7    limit of what the tuning considers acceptable for -O2.  */
   8 int cmp (char *p, char *q)
   9 {
  10   char *pa = __builtin_assume_aligned (p, 4);
  11   char *qa = __builtin_assume_aligned (q, 4);
  12   if (__builtin_memcmp (pa, qa, 16) != 0)
  13     return 1;
  14   return 0;
  15 }
  16 /* Since we have fast unaligned access, we should make a single
  17    constant comparison.  The constant becomes 1752394086.  */
  18 int cmp2 (char *p)
  19 {
  20   if (__builtin_memcmp (p, "fish", 4) != 0)
  21     return 1;
  22   return 0;
  23 }