gnu/dist/gcc4/gcc/testsuite/gcc.c-torture/execute/bitfld-4.c

   1 /* When comparisons of bit-fields to unsigned constants got shortened,
   2    the shortened signed constant was wrongly marked as overflowing,
   3    leading to a later integer_zerop failure and misoptimization.
   4
   5    Related to bug tree-optimization/16437 but shows the problem on
   6    32-bit systems.  */
   7 /* Origin: Joseph Myers <jsm@polyomino.org.uk> */
   8
   9 extern void abort (void);
  10
  11 struct s { int a:12, b:20; };
  12
  13 struct s x = { -123, -456 };
  14
  15 int
  16 main (void)
  17 {
  18   if (x.a != -123U || x.b != -456U)
  19     abort ();
  20   return 0;
  21 }