gnu/dist/gcc4/gcc/testsuite/gcc.dg/tree-ssa/pr20256.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -ftree-loop-linear -fdump-tree-ltrans-all" } */
   3
   4 int foo()
   5 {
   6   int x[2][2], y[2];
   7   int i, n, s;
   8
   9   /* This is a reduction: there is a scalar dependence that cannot be
  10      removed by rewriting IVs.  This code cannot and should not be
  11      transformed into a perfect loop.  */
  12   for (n = 0; n < 2; n++)
  13     {
  14       s = 0;
  15       for (i = 0; i < 2; i++)
  16         s += x[n][i]*y[i];
  17       s += 1;
  18     }
  19
  20   return s;
  21 }
  22
  23 /* { dg-final { scan-tree-dump-times "converted loop nest to perfect loop nest" 0 "ltrans"} } */
  24 /* { dg-final { cleanup-tree-dump "ltrans" } } */