re PR tree-optimization/45709 (internal compiler error: in add_phi_arg, at tree-phinodes.c:395)

2010-09-18  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/45709
	* tree-inline.c (copy_phis_for_bb): Fixup new_edge when
	we splitted it.

	* g++.dg/torture/pr45709.C: New testcase.

From-SVN: r164390

gcc/ChangeLog

+2010-09-18  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/45709
+	* tree-inline.c (copy_phis_for_bb): Fixup new_edge when
+	we splitted it.
+
 2010-09-17  Sebastian Pop  <sebastian.pop@amd.com>
 
 	* graphite-dependences.c (dot_deps): Add DEBUG_FUNCTION.

gcc/testsuite/g++.dg/torture/pr45709.C

+// { dg-do compile }
+
+struct Region {
+    int storage[4];
+    int count;
+};
+static inline Region subtract(int lhs)
+{
+  Region reg;
+  int* storage = reg.storage;
+  if (lhs > 0)
+    storage++;
+  reg.count = storage - reg.storage;
+  return reg;
+}
+void bar(int a)
+{
+  const Region copyBack(subtract(a));
+}

gcc/tree-inline.c

@@ -2021,8 +2021,11 @@ copy_phis_for_bb (basic_block bb, copy_body_data *id)
 		  && !is_gimple_val (new_arg))
 		{
 		  gimple_seq stmts = NULL;
+		  basic_block tem;
 		  new_arg = force_gimple_operand (new_arg, &stmts, true, NULL);
-		  gsi_insert_seq_on_edge_immediate (new_edge, stmts);
+		  tem = gsi_insert_seq_on_edge_immediate (new_edge, stmts);
+		  if (tem)
+		    new_edge = single_succ_edge (tem);
 		}
 	      add_phi_arg (new_phi, new_arg, new_edge,
 			   gimple_phi_arg_location_from_edge (phi, old_edge));