gcc/testsuite/gcc.dg/ext-elim-1.c

   1 /* PR rtl-optimization/51924 */
   2 /* Testcase by Zdenek Sojka <zsojka@seznam.cz> */
   3
   4 /* { dg-do run } */
   5 /* { dg-options "-O -free -fno-rename-registers -ftree-vectorize -funroll-loops" } */
   6
   7 typedef __UINT64_TYPE__ uint64_t;
   8
   9 uint64_t __attribute__ ((noinline, noclone))
  10 bn_sub_words (uint64_t * r, const uint64_t * a, const uint64_t * b, int n)
  11 {
  12   uint64_t t1, t2;
  13   unsigned c = 0;
  14
  15   while (n)
  16     {
  17       t1 = a[0];
  18       t2 = b[0];
  19       r[0] = (t1 - t2 - c);
  20       if (t1 != t2)
  21         c = (t1 < t2);
  22       a++;
  23       b++;
  24       r++;
  25       n--;
  26     }
  27   return (c);
  28 }
  29
  30 int
  31 main (void)
  32 {
  33   uint64_t r[2];
  34   uint64_t a[2] = { -1, -1 };
  35   uint64_t b[2] = { 0, 0 };
  36   if (bn_sub_words (r, a, b, 2) != 0)
  37     __builtin_abort ();
  38   return 0;
  39 }