re PR tree-optimization/78224 (g++ ICE at -O2(-O1 on gcc6) and above in…

re PR tree-optimization/78224 (g++ ICE at -O2(-O1 on gcc6) and above in verify_loop_structure, at cfgloop.c:1646)

2016-11-08  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78224
	* tree-call-cdce.c (shrink_wrap_one_built_in_call_with_conds):
	Split the fallthru edge in case its successor may have PHIs.
	Do not free dominance info.

	* g++.dg/torture/pr78224.C: New testcase.

From-SVN: r241955

gcc/ChangeLog

+2016-11-08  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/78224
+	* tree-call-cdce.c (shrink_wrap_one_built_in_call_with_conds):
+	Split the fallthru edge in case its successor may have PHIs.
+	Do not free dominance info.
+
 2016-11-07  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/78229

gcc/testsuite/ChangeLog

+2016-11-08  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/78224
+	* g++.dg/torture/pr78224.C: New testcase.
+
 2016-11-08  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
 
 	* gcc.dg/store_merging_1.c: Require store_merge.

gcc/testsuite/g++.dg/torture/pr78224.C

+// { dg-do compile }
+
+extern "C"{
+  float sqrtf(float);
+}
+
+inline float squareroot(const float f)
+{
+  return sqrtf(f);
+}
+
+inline int squareroot(const int f)
+{
+  return static_cast<int>(sqrtf(static_cast<float>(f)));
+}
+
+template <class T>
+class vector2d
+{
+public:
+  vector2d(T nx, T ny) : X(nx), Y(ny) {}
+  T getLength() const { return squareroot( X*X + Y*Y ); }
+  T X;
+  T Y;
+};
+
+vector2d<int> getMousePos();
+
+class Client
+{
+public:
+  Client();
+  ~Client();
+};
+
+void the_game(float turn_amount)
+{
+  Client client;
+  bool first = true;
+
+  while (1) {
+      if (first) {
+        first = false;
+      } else {
+        int dx = getMousePos().X;
+        int dy = getMousePos().Y;
+
+        turn_amount = vector2d<float>(dx, dy).getLength();
+      }
+  }
+}

gcc/tree-call-cdce.c

@@ -807,15 +807,20 @@ shrink_wrap_one_built_in_call_with_conds (gcall *bi_call, vec <gimple *> conds,
 	 can_guard_call_p.  */
       join_tgt_in_edge_from_call = find_fallthru_edge (bi_call_bb->succs);
       gcc_assert (join_tgt_in_edge_from_call);
-      free_dominance_info (CDI_DOMINATORS);
+      /* We don't want to handle PHIs.  */
+      if (EDGE_COUNT (join_tgt_in_edge_from_call->dest->preds) > 1)
+	join_tgt_bb = split_edge (join_tgt_in_edge_from_call);
+      else
+	join_tgt_bb = join_tgt_in_edge_from_call->dest;
     }
   else
-    join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call);
+    {
+      join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call);
+      join_tgt_bb = join_tgt_in_edge_from_call->dest;
+    }
 
   bi_call_bsi = gsi_for_stmt (bi_call);
 
-  join_tgt_bb = join_tgt_in_edge_from_call->dest;
-
   /* Now it is time to insert the first conditional expression
      into bi_call_bb and split this bb so that bi_call is
      shrink-wrapped.  */