Fix first match heuristics

	* predict.c (combine_predictions_for_bb): Fix first match in
	cases where a first predictor contains more than one occurence
	in list of predictors.  Take the best value in such case.
	* gcc.dg/predict-9.c: New test.

From-SVN: r237036

gcc/ChangeLog

+2016-06-02  Martin Liska  <mliska@suse.cz>
+
+	* predict.c (combine_predictions_for_bb): Fix first match in
+	cases where a first predictor contains more than one occurence
+	in list of predictors.  Take the best value in such case.
+
 2016-06-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR rtl-optimization/71295

gcc/predict.c

@@ -939,7 +939,7 @@ combine_predictions_for_bb (basic_block bb, bool dry_run)
 		   pred2; pred2 = pred2->ep_next)
 	       if (pred2 != pred && pred2->ep_predictor == pred->ep_predictor)
 	         {
-	           int probability2 = pred->ep_probability;
+		   int probability2 = pred2->ep_probability;
 
 		   if (pred2->ep_edge != first)
 		     probability2 = REG_BR_PROB_BASE - probability2;

gcc/testsuite/ChangeLog

+2016-06-02  Martin Liska  <mliska@suse.cz>
+
+	* gcc.dg/predict-9.c: New test.
+
 2016-06-02  Jakub Jelinek  <jakub@redhat.com>
 
 	* lib/gcc-dg.exp (cleanup-after-saved-dg-test): Add missing

gcc/testsuite/gcc.dg/predict-9.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-profile_estimate" } */
+
+extern int global;
+extern int global2;
+extern int global3;
+
+void foo (int base)
+{
+  int i;
+  while (global < 10)
+  {
+    if(global || global2 || global3)
+      return;
+
+    for (i = base; i < 10; i++)
+      if (i > 123)
+	return;
+  }
+}
+
+/* { dg-final { scan-tree-dump-times "first match heuristics: 2.0%" 4 "profile_estimate"} } */
+/* { dg-final { scan-tree-dump-times "first match heuristics: 4.5%" 0 "profile_estimate"} } */