graphite-sese-to-poly.c (reduction_phi_p): Call remove_invariant_phi when the loop stride is zero.

2009-10-07  Sebastian Pop  <sebastian.pop@amd.com>

	* graphite-sese-to-poly.c (reduction_phi_p): Call remove_invariant_phi
	when the loop stride is zero.

	* gcc.dg/graphite/id-16.c: New.

From-SVN: r154565

gcc/ChangeLog.graphite

+2009-10-07  Sebastian Pop  <sebastian.pop@amd.com>
+
+	* graphite-sese-to-poly.c (reduction_phi_p): Call remove_invariant_phi
+	when the loop stride is zero.
+
+	* gcc.dg/graphite/id-16.c: New.
+
 2009-10-06  Sebastian Pop  <sebastian.pop@amd.com>
 
 	* graphite-dependences.c (reduction_dr_1): New.

gcc/graphite-sese-to-poly.c

@@ -193,7 +193,11 @@ reduction_phi_p (sese region, gimple_stmt_iterator *psi)
      reductions.  */
   if (simple_iv (loop, loop, res, &iv, true))
     {
-      gsi_next (psi);
+      if (integer_zerop (iv.step))
+	remove_invariant_phi (region, psi);
+      else
+	gsi_next (psi);
+
       return false;
     }