re PR tree-optimization/63941 (ICE on valid code at -O3 and above on x86_64-linux-gnu)

gcc/

	PR tree-optimization/63941
	* tree-if-conv.c (add_to_predicate_list): Delete wrong assertion that
	DOM_BB has non-true predicate, conditionally set non-true predicate
	for BB.

gcc/testsuite/

	PR tree-optimization/63941
	* gcc.dg/torture/pr63941.c: New test.

From-SVN: r218206

gcc/ChangeLog

+2014-12-01  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/63941
+	* tree-if-conv.c (add_to_predicate_list): Delete wrong assertion that
+	DOM_BB has non-true predicate, conditionally set non-true predicate
+	for BB.
+
 2014-12-01  Martin Jambor  <mjambor@suse.cz>
 
 	PR ipa/63551

gcc/testsuite/ChangeLog

+2014-12-01  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/63941
+	* gcc.dg/torture/pr63941.c: New test.
+
 2014-12-01  Martin Jambor  <mjambor@suse.cz>
 
 	PR ipa/63551

gcc/testsuite/gcc.dg/torture/pr63941.c

+/* { dg-do compile } */
+
+int a, b, c, d[1], e, f, g, h;
+
+void
+fn1 ()
+{
+  char i = 0;
+  for (b = 0; b >= 0;)
+    for (b = 0; b < 2; b++)
+      {
+	d[f] && (e = 0);
+	h = 1 & a - i ? 0 : a;
+	c = i = h;
+	char j = c;
+	int k = 0;
+	g = j || j > k;
+	d[0] = 0;
+      }
+}

gcc/tree-if-conv.c

@@ -435,8 +435,10 @@ add_to_predicate_list (struct loop *loop, basic_block bb, tree nc)
     {
       gcc_assert (flow_bb_inside_loop_p (loop, dom_bb));
       bc = bb_predicate (dom_bb);
-      gcc_assert (!is_true_predicate (bc));
-      set_bb_predicate (bb, bc);
+      if (!is_true_predicate (bc))
+	set_bb_predicate (bb, bc);
+      else
+	gcc_assert (is_true_predicate (bb_predicate (bb)));
       if (dump_file && (dump_flags & TDF_DETAILS))
 	fprintf (dump_file, "Use predicate of bb#%d for bb#%d\n",
 		 dom_bb->index, bb->index);