Fix bit-test expansion for single cluster (PR tree-optimization/86263).

2018-06-29  Martin Liska  <mliska@suse.cz>

        PR tree-optimization/86263
	* tree-switch-conversion.c (switch_decision_tree::try_switch_expansion):
        Make edge redirection.
2018-06-29  Martin Liska  <mliska@suse.cz>

        PR tree-optimization/86263
	* gcc.dg/tree-ssa/pr86263.c: New test.

From-SVN: r262247

gcc/ChangeLog

+2018-06-29  Martin Liska  <mliska@suse.cz>
+
+        PR tree-optimization/86263
+	* tree-switch-conversion.c (switch_decision_tree::try_switch_expansion):
+        Make edge redirection.
+
 2018-06-29  David Malcolm  <dmalcolm@redhat.com>
 
 	* dumpfile.c (dump_loc): Add indentation based on scope depth.

gcc/testsuite/ChangeLog

+2018-06-29  Martin Liska  <mliska@suse.cz>
+
+        PR tree-optimization/86263
+	* gcc.dg/tree-ssa/pr86263.c: New test.
+
 2018-06-28  Carl Love  <cel@us.ibm.com>
 
 	* gcc.target/p9-extract-1.c: Add test case.

gcc/testsuite/gcc.dg/tree-ssa/pr86263.c

+/* { dg-do compile } */
+
+void f1 (void *);
+void f2 (void *);
+void f3 (void *);
+void f4 (void *);
+
+char
+_dcvt (void *ptr, char type, int opt, int val)
+{
+  switch (type)
+    {
+    case 'f':
+      f4 (ptr);
+    case 'F':
+      f1 (ptr);
+      break;
+    case 'g':
+    case 'G':
+      if (opt == 0)
+	opt = 1;
+      f2 (ptr);
+      break;
+    case 'e':
+    case 'E':
+      f3 (ptr);
+    }
+  return val;
+}

gcc/tree-switch-conversion.c

@@ -1732,8 +1732,12 @@ switch_decision_tree::try_switch_expansion (vec<cluster *> &clusters)
   /* Do not do an extra work for a single cluster.  */
   if (clusters.length () == 1
       && clusters[0]->get_type () != SIMPLE_CASE)
-    clusters[0]->emit (index_expr, index_type,
-		       gimple_switch_default_label (m_switch), m_default_bb);
+    {
+      cluster *c = clusters[0];
+      c->emit (index_expr, index_type,
+	       gimple_switch_default_label (m_switch), m_default_bb);
+      redirect_edge_succ (single_succ_edge (bb), c->m_case_bb);
+    }
   else
     {
       emit (bb, index_expr, default_edge->probability, index_type);