gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-15.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-optimized" } */
   3
   4 /* Check that the initial values are honored when necessary.  */
   5
   6 void link_error (void);
   7
   8 /* The call to link_error cannot be eliminated in this case.  */
   9
  10 void test1 (int param1, int param2, int x)
  11 {
  12   if (param1)
  13     x = 3;
  14
  15   if (param2)
  16     if (x != 3)
  17       link_error ();
  18 }
  19
  20 /* The call to link_error cannot be eliminated in this case.  */
  21
  22 int global;
  23 void test2 (int param1, int param2)
  24 {
  25   if (param1)
  26     global = 3;
  27
  28   if (param2)
  29     if (global != 3)
  30       link_error ();
  31 }
  32
  33 /* In this case, we can eliminate the call, as unless "local" is set
  34    to 3, its value is undefined.  */
  35
  36 void test3 (int param1, int param2)
  37 {
  38   int local;
  39
  40   if (param1)
  41     local = 3;
  42
  43   if (param2)
  44     if (local != 3)
  45       link_error ();
  46 }
  47
  48 /* { dg-final { scan-tree-dump-times "link_error" 2 "optimized" } } */