re PR tree-optimization/58955 (wrong code at -O3 on x86_64-linux-gnu)

2013-11-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58955
	* tree-loop-distribution.c (pg_add_dependence_edges): Fix
	edge direction.

	* gcc.dg/torture/pr58955-1.c: New testcase.
	* gcc.dg/torture/pr58955-2.c: Likewise.

From-SVN: r204398

gcc/ChangeLog

+2013-11-05  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58955
+	* tree-loop-distribution.c (pg_add_dependence_edges): Fix
+	edge direction.
+
 2013-11-05  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* config/rs6000/vector.md (vec_pack_sfix_trunc_v2df): Adjust for

gcc/testsuite/ChangeLog

+2013-11-05  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58955
+	* gcc.dg/torture/pr58955-1.c: New testcase.
+	* gcc.dg/torture/pr58955-2.c: Likewise.
+
 2013-11-05  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR middle-end/58981

gcc/testsuite/gcc.dg/torture/pr58955-1.c

+/* { dg-do run } */
+
+extern void abort (void);
+
+int a, b, c, d[4] = { 0, 0, 0, 1 };
+
+int
+main ()
+{
+  for (; a < 4; a++)
+    {
+      int e = d[a];
+      for (c = 1; c < 1; c++);
+      b = e;
+      d[a] = 0;
+    }
+  if (b != 1)
+    abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/pr58955-2.c

+/* { dg-do run } */
+
+extern void abort (void);
+
+int a, b[10];
+
+int
+main ()
+{
+  for (; a < 2; a++)
+    {
+      b[a] = 1;
+      b[a + 1] = 0;
+    }
+  if (b[1] != 1)
+    abort ();
+  return 0;
+}

gcc/tree-loop-distribution.c

@@ -1324,7 +1324,7 @@ pg_add_dependence_edges (struct graph *rdg, vec<loop_p> loops, int dir,
   for (int ii = 0; drs1.iterate (ii, &dr1); ++ii)
     for (int jj = 0; drs2.iterate (jj, &dr2); ++jj)
       {
-	int this_dir = 1;
+	int this_dir = -1;
 	ddr_p ddr;
 	/* Re-shuffle data-refs to be in dominator order.  */
 	if (rdg_vertex_for_stmt (rdg, DR_STMT (dr1))