re PR tree-optimization/53163 (crash due to null ptr deref)

	PR tree-optimization/53163
	* tree-ssa-phiopt.c (cond_if_else_store_replacement): Don't ignore
	return value from compute_all_dependences.

	* gcc.c-torture/compile/pr53163.c: New test.

From-SVN: r187038

gcc/ChangeLog

 2012-05-02  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/53163
+	* tree-ssa-phiopt.c (cond_if_else_store_replacement): Don't ignore
+	return value from compute_all_dependences.
+
 	PR rtl-optimization/53160
 	* ree.c (combine_reaching_defs): Handle the case where cand->insn
 	has been modified by ree pass already.

gcc/testsuite/ChangeLog

 2012-05-02  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/53163
+	* gcc.c-torture/compile/pr53163.c: New test.
+
 	PR rtl-optimization/53160
 	* gcc.c-torture/execute/pr53160.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr53163.c

+/* PR tree-optimization/53163 */
+
+struct S { int s; } b, f;
+int a, c;
+
+void
+foo (void)
+{
+  int d, e;
+  for (d = 4; d < 19; ++d)
+    for (e = 2; e >= 0; e--)
+      {
+	a = 0;
+	a = 1;
+      }
+}
+
+void
+bar (void)
+{
+  int g, h, i;
+  for (i = 1; i >= 0; i--)
+    {
+      b = f;
+      for (g = 0; g <= 1; g++)
+	{
+	  if (c)
+	    break;
+	  for (h = 0; h <= 1; h++)
+	    foo ();
+	  foo ();
+	}
+    }
+}

gcc/tree-ssa-phiopt.c

@@ -1624,8 +1624,17 @@ cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb,
   /* Compute and check data dependencies in both basic blocks.  */
   then_ddrs = VEC_alloc (ddr_p, heap, 1);
   else_ddrs = VEC_alloc (ddr_p, heap, 1);
-  compute_all_dependences (then_datarefs, &then_ddrs, NULL, false);
-  compute_all_dependences (else_datarefs, &else_ddrs, NULL, false);
+  if (!compute_all_dependences (then_datarefs, &then_ddrs, NULL, false)
+      || !compute_all_dependences (else_datarefs, &else_ddrs, NULL, false))
+    {
+      free_dependence_relations (then_ddrs);
+      free_dependence_relations (else_ddrs);
+      free_data_refs (then_datarefs);
+      free_data_refs (else_datarefs);
+      VEC_free (gimple, heap, then_stores);
+      VEC_free (gimple, heap, else_stores);
+      return false;
+    }
   blocks[0] = then_bb;
   blocks[1] = else_bb;
   blocks[2] = join_bb;