Fix set of even probabilities (PR middle-end/89737).

2019-03-19  Martin Liska  <mliska@suse.cz>

	PR middle-end/89737
	* predict.c (combine_predictions_for_bb): Empty likely_edges and
	unlikely_edges if there's an edge that belongs to both these sets.
2019-03-19  Martin Liska  <mliska@suse.cz>

	PR middle-end/89737
	* gcc.dg/pr89737.c: New test.

From-SVN: r269804

gcc/ChangeLog

+2019-03-19  Martin Liska  <mliska@suse.cz>
+
+	PR middle-end/89737
+	* predict.c (combine_predictions_for_bb): Empty likely_edges and
+	unlikely_edges if there's an edge that belongs to both these sets.
+
 2018-03-19  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR target/89746

gcc/predict.c

@@ -1229,12 +1229,23 @@ combine_predictions_for_bb (basic_block bb, bool dry_run)
 	    if (pred->ep_probability <= PROB_VERY_UNLIKELY
 		|| pred->ep_predictor == PRED_COLD_LABEL)
 	      unlikely_edges.add (pred->ep_edge);
-	    if (pred->ep_probability >= PROB_VERY_LIKELY
-		|| pred->ep_predictor == PRED_BUILTIN_EXPECT
-		|| pred->ep_predictor == PRED_HOT_LABEL)
+	    else if (pred->ep_probability >= PROB_VERY_LIKELY
+		     || pred->ep_predictor == PRED_BUILTIN_EXPECT
+		     || pred->ep_predictor == PRED_HOT_LABEL)
 	      likely_edges.add (pred);
 	  }
 
+      /* It can happen that an edge is both in likely_edges and unlikely_edges.
+	 Clear both sets in that situation.  */
+      for (hash_set<edge_prediction *>::iterator it = likely_edges.begin ();
+	   it != likely_edges.end (); ++it)
+	if (unlikely_edges.contains ((*it)->ep_edge))
+	  {
+	    likely_edges.empty ();
+	    unlikely_edges.empty ();
+	    break;
+	  }
+
       if (!dry_run)
 	set_even_probabilities (bb, &unlikely_edges, &likely_edges);
       clear_bb_predictions (bb);

gcc/testsuite/ChangeLog

+2019-03-19  Martin Liska  <mliska@suse.cz>
+
+	PR middle-end/89737
+	* gcc.dg/pr89737.c: New test.
+
 2019-03-19  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR lto/87809

gcc/testsuite/gcc.dg/pr89737.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-profile_estimate" } */
+
+int a, b;
+
+void c() {
+  &&d;
+  void *e = &&f, *g = &&h;
+f:
+  __attribute__((hot)) h : __attribute__((cold)) for (; a;) goto *g;
+d:
+  for (; b;)
+    goto *e;
+}
+
+/* { dg-final { scan-tree-dump-times "predicted to even probabilities" 4 "profile_estimate"} } */
+