[turbofan] Fix tail call optimization.

test/unittests/compiler/scheduler-unittest.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node.h"
@@ skipping 120 matching lines @@
 
 
 namespace {
 
 const Operator kHeapConstant(IrOpcode::kHeapConstant, Operator::kPure,
                              "HeapConstant", 0, 0, 0, 1, 0, 0);
 const Operator kIntAdd(IrOpcode::kInt32Add, Operator::kPure, "Int32Add", 2, 0,
                        0, 1, 0, 0);
 const Operator kMockCall(IrOpcode::kCall, Operator::kNoProperties, "MockCall",
                          0, 0, 1, 1, 0, 2);
+const Operator kMockTailCall(IrOpcode::kTailCall, Operator::kNoProperties,
+                             "MockTailCall", 1, 1, 1, 0, 0, 1);
 
 }  // namespace
 
 
 // -----------------------------------------------------------------------------
 // Special reverse-post-order block ordering.
 
 
 TEST_F(SchedulerRPOTest, Degenerate1) {
   Schedule schedule(zone());
@@ skipping 2248 matching lines @@
 
   Schedule* schedule = ComputeAndVerifySchedule(17);
   // Make sure the exception blocks as well as the handler are deferred.
   EXPECT_TRUE(schedule->block(ex1)->deferred());
   EXPECT_TRUE(schedule->block(ex2)->deferred());
   EXPECT_TRUE(schedule->block(hdl)->deferred());
   EXPECT_FALSE(schedule->block(m)->deferred());
 }
 
 
+TARGET_TEST_F(SchedulerTest, TailCall) {
+  Node* start = graph()->NewNode(common()->Start(1));
+  graph()->SetStart(start);
+
+  Node* p0 = graph()->NewNode(common()->Parameter(0), start);
+  Node* call = graph()->NewNode(&kMockTailCall, p0, start, start);
+  Node* end = graph()->NewNode(common()->End(), call);
+
+  graph()->SetEnd(end);
+
+  ComputeAndVerifySchedule(4);
+}
+
+
 TARGET_TEST_F(SchedulerTest, Switch) {
   Node* start = graph()->NewNode(common()->Start(1));
   graph()->SetStart(start);
 
   Node* p0 = graph()->NewNode(common()->Parameter(0), start);
   Node* sw = graph()->NewNode(common()->Switch(3), p0, start);
   Node* c0 = graph()->NewNode(common()->IfValue(0), sw);
   Node* v0 = graph()->NewNode(common()->Int32Constant(11));
   Node* c1 = graph()->NewNode(common()->IfValue(1), sw);
   Node* v1 = graph()->NewNode(common()->Int32Constant(22));
@@ skipping 28 matching lines @@
   Node* end = graph()->NewNode(common()->End(), ret);
 
   graph()->SetEnd(end);
 
   ComputeAndVerifySchedule(16);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8