[tail-merge] Don't merge bbs with bb_has_abnormal_pred

2018-03-22  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/84956
	* tree-ssa-tail-merge.c (find_clusters_1): Skip bbs with
	bb_has_abnormal_pred.

	* gcc.dg/pr84956.c: New test.

From-SVN: r258758

gcc/ChangeLog

+2018-03-22  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/84956
+	* tree-ssa-tail-merge.c (find_clusters_1): Skip bbs with
+	bb_has_abnormal_pred.
+
 2018-03-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/85018

gcc/testsuite/ChangeLog

+2018-03-22  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/84956
+	* gcc.dg/pr84956.c: New test.
+
 2018-03-22  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/84854

gcc/testsuite/gcc.dg/pr84956.c

+/* { dg-options "-O2 -ftree-tail-merge" } */
+
+char a;
+int c;
+unsigned b ();
+
+unsigned
+setjmp ()
+{
+}
+
+static void
+d ()
+{
+  if (b ())
+    c = 3;
+}
+
+void
+e ()
+{
+  d ();
+  a && ({ setjmp (); });
+  a && ({ setjmp (); });
+  a && ({ setjmp (); });
+}
+

gcc/tree-ssa-tail-merge.c

@@ -1455,7 +1455,8 @@ find_clusters_1 (same_succ *same_succ)
       /* TODO: handle blocks with phi-nodes.  We'll have to find corresponding
 	 phi-nodes in bb1 and bb2, with the same alternatives for the same
 	 preds.  */
-      if (bb_has_non_vop_phi (bb1) || bb_has_eh_pred (bb1))
+      if (bb_has_non_vop_phi (bb1) || bb_has_eh_pred (bb1)
+	  || bb_has_abnormal_pred (bb1))
 	continue;
 
       nr_comparisons = 0;
@@ -1463,7 +1464,8 @@ find_clusters_1 (same_succ *same_succ)
 	{
 	  bb2 = BASIC_BLOCK_FOR_FN (cfun, j);
 
-	  if (bb_has_non_vop_phi (bb2) || bb_has_eh_pred (bb2))
+	  if (bb_has_non_vop_phi (bb2) || bb_has_eh_pred (bb2)
+	      || bb_has_abnormal_pred (bb2))
 	    continue;
 
 	  if (BB_CLUSTER (bb1) != NULL && BB_CLUSTER (bb1) == BB_CLUSTER (bb2))