[turbofan] Fix tail call optimization.

test/unittests/compiler/instruction-selector-unittest.cc

 // Copyright 2014 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 "test/unittests/compiler/instruction-selector-unittest.h"
 
-#include "src/code-stubs.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/schedule.h"
 #include "src/flags.h"
 #include "test/unittests/compiler/compiler-test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 namespace {
@@ skipping 568 matching lines @@
   // Function.
   EXPECT_EQ(s.ToVreg(function_node), s.ToVreg(call_instr->InputAt(11)));
   // Context.
   EXPECT_EQ(s.ToVreg(context2), s.ToVreg(call_instr->InputAt(12)));
   // Continuation.
 
   EXPECT_EQ(kArchRet, s[index++]->arch_opcode());
   EXPECT_EQ(index, s.size());
 }
 
-
-// -----------------------------------------------------------------------------
-// Tail calls.
-
-TARGET_TEST_F(InstructionSelectorTest, TailCall) {
-  for (int mode = 0; mode < 2; ++mode) {
-    bool supports_tail_calls = FLAG_turbo_tail_calls && (mode == 0);
-
-    StreamBuilder m(this, kMachAnyTagged);
-    Node* start = m.graph()->start();
-    Node* undefined = m.UndefinedConstant();
-
-    StringLengthStub stub(isolate());
-    CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-        isolate(), zone(), stub.GetCallInterfaceDescriptor(), 0,
-        supports_tail_calls ? CallDescriptor::kSupportsTailCalls
-                            : CallDescriptor::kNoFlags,
-        Operator::kNoProperties);
-    Node* stub_node = m.NewNode(m.common()->HeapConstant(
-        Unique<Code>::CreateUninitialized(stub.GetCode())));
-
-    Node* call = m.NewNode(m.common()->Call(desc), stub_node, undefined,
-                           undefined, undefined, undefined, undefined);
-    call->AppendInput(zone(), start);  // effect
-    call->AppendInput(zone(), start);  // control
-
-    m.Return(call);
-    Node* ret = *call->uses().begin();
-    ret->AppendInput(zone(), call);   // effect
-    ret->AppendInput(zone(), start);  // control
-
-    Stream s = m.Build(kAllInstructions);
-    if (supports_tail_calls) {
-      ASSERT_EQ(3U, s.size());
-      EXPECT_EQ(kArchNop, s[0]->arch_opcode());
-      EXPECT_EQ(kArchTailCallCodeObject, s[1]->arch_opcode());
-      EXPECT_EQ(kArchNop, s[2]->arch_opcode());
-    } else {
-      ASSERT_EQ(4U, s.size());
-      EXPECT_EQ(kArchNop, s[0]->arch_opcode());
-      EXPECT_EQ(kArchCallCodeObject, s[1]->arch_opcode());
-      EXPECT_EQ(kArchRet, s[2]->arch_opcode());
-      EXPECT_EQ(kArchNop, s[3]->arch_opcode());
-    }
-  }
-}
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8