gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-32.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O" } */
   3
   4 extern void link_error (void);
   5 unsigned int __attribute__((noinline,noclone))
   6 test0 (unsigned int a)
   7 {
   8   a = a & 1;
   9   a = a << 1 | a >> (sizeof (unsigned int) * 8 - 1);
  10   if (a & 1)
  11     {
  12       a = a | 4;
  13       link_error ();
  14     }
  15   if (a & 4)
  16     link_error ();
  17   return a;
  18 }
  19 int __attribute__((noinline,noclone))
  20 test1 (int a)
  21 {
  22   a |= 1;
  23   a = a << (sizeof (int) * 8 - 1);
  24   if (a >= 0)
  25     link_error ();
  26   a = a * 4;
  27   if (a & ~3)
  28     link_error ();
  29   if (a == -1)
  30     link_error ();
  31   return a;
  32 }
  33 int __attribute__((noinline,noclone))
  34 test2 (int a)
  35 {
  36   a = a | 0xff;
  37   a = a + 1;
  38   if (a & 0xff)
  39     link_error ();
  40   a = -a;
  41   if (a & 0xff)
  42     link_error ();
  43   a = a - 1;
  44   if ((a & 0xff) != 0xff)
  45     link_error ();
  46   return a;
  47 }
  48 extern void abort (void);
  49 int main()
  50 {
  51   if (test0 (1) != 2)
  52     abort ();
  53   if (test1 (0) != 0)
  54     abort ();
  55   if (test2 (-1) != -1)
  56     abort ();
  57   return 0;
  58 }