gcc/testsuite/gcc.dg/pr91720.c

   1 /* PR rtl-optimization/91720 */
   2 /* { dg-do run } */
   3 /* { dg-options "-Og -fno-forward-propagate -frerun-cse-after-loop -fno-tree-fre" } */
   4
   5 unsigned a, b;
   6
   7 int
   8 main ()
   9 {
  10 #if __CHAR_BIT__ == 8
  11   unsigned c = 1;
  12   unsigned long long d = 0;
  13   unsigned char e = 0;
  14   e = __builtin_sub_overflow (d, e, &a) ? 0 : 0x80;
  15   e = e << 7 | e >> c;
  16   __builtin_memmove (&d, &a, 2);
  17   b = e;
  18   if (b != 0x40)
  19     __builtin_abort ();
  20 #endif
  21   return 0;
  22 }