gcc/testsuite/gcc.dg/tree-ssa/bittest.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-optimized" } */
   3
   4
   5 void bar (void);
   6
   7 void
   8 foo(unsigned int abc123)
   9 {
  10   unsigned int xyzpdq = (1 << abc123);
  11   if ((xyzpdq & 0x800) != 0)
  12     bar();
  13 }
  14
  15 void
  16 baz(unsigned int abc123)
  17 {
  18   unsigned int xyzpdq = (1 << abc123);
  19   if ((xyzpdq & 0x800) == 0)
  20     bar();
  21 }
  22
  23 /* What we want to verify is that the bit test against xyzpdq is
  24    replaced with a test against abc123 which avoids the shifting
  25    and bit ops.  */
  26 /* { dg-final { scan-tree-dump-not "xyzpdq" "optimized"} } */
  27 /* { dg-final { scan-tree-dump-times "if .abc123" 2 "optimized"} } */