gcc/testsuite/gcc.dg/tree-ssa/pr23234.c

   1 /* The problem in this PR was mostly finding a suitable place to insert
   2    the reciprocals of the function arguments.  This test case tries to
   3    test three possible ways of how this may go wrong.  */
   4 /* { dg-options "-O2 -ffast-math" } */
   5 /* { dg-do compile } */
   6
   7 /* The original test case.  */
   8 double
   9 f1 (double a, double b, double c)
  10 {
  11   double y0;
  12   double y1;
  13
  14   if (a == 0.0)
  15     {
  16       y0 = -c / b;
  17       return y0;
  18     }
  19   y0 = c / b;
  20   y1 = a / b;
  21   return y0 * y1;
  22 }
  23
  24 /* Labels may end up in the middle of a block.  Also bad.  */
  25 double
  26 f2 (double a, double b, double c)
  27 {
  28   double y0;
  29   double y1;
  30
  31 a_label:
  32 another_label:
  33   if (a == 0.0)
  34     {
  35       y0 = -c / b;
  36       return y0;
  37     }
  38   y0 = c / b;
  39   y1 = a / b;
  40   return y0 * y1;
  41 }
  42
  43 /* Uses must still be dominated by their defs.  */
  44 double
  45 f3 (double a, double b, double c)
  46 {
  47   double y0;
  48   double y1;
  49
  50   y0 = -c / b;
  51   if (a == 0.0)
  52     {
  53       return y0;
  54     }
  55   y0 = c / b;
  56   y1 = a / b;
  57   return y0 * y1;
  58 }