[turbofan] Remove the TryLowerDirectJSCall hack from generic lowering.

src/compiler/js-generic-lowering.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 "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 496 matching lines @@
   Node* stub_code = jsgraph()->HeapConstant(stub.GetCode());
   Node* construct = NodeProperties::GetValueInput(node, 0);
   node->InsertInput(zone(), 0, stub_code);
   node->InsertInput(zone(), 1, jsgraph()->Int32Constant(arity - 1));
   node->InsertInput(zone(), 2, construct);
   node->InsertInput(zone(), 3, jsgraph()->UndefinedConstant());
   node->set_op(common()->Call(desc));
 }
 
 
-bool JSGenericLowering::TryLowerDirectJSCall(Node* node) {
-  // Lower to a direct call to a constant JSFunction if legal.
-  const CallFunctionParameters& p = CallFunctionParametersOf(node->op());
-  int arg_count = static_cast<int>(p.arity() - 2);
-
-  // Check the function is a constant and is really a JSFunction.
-  HeapObjectMatcher<Object> function_const(node->InputAt(0));
-  if (!function_const.HasValue()) return false;  // not a constant.
-  Handle<Object> func = function_const.Value().handle();
-  if (!func->IsJSFunction()) return false;  // not a function.
-  Handle<JSFunction> function = Handle<JSFunction>::cast(func);
-  if (arg_count != function->shared()->internal_formal_parameter_count()) {
-    return false;
-  }
-
-  // Check the receiver doesn't need to be wrapped.
-  Node* receiver = node->InputAt(1);
-  if (!NodeProperties::IsTyped(receiver)) return false;
-  Type* ok_receiver = Type::Union(Type::Undefined(), Type::Receiver(), zone());
-  if (!NodeProperties::GetBounds(receiver).upper->Is(ok_receiver)) return false;
-
-  // Update to the function context.
-  NodeProperties::ReplaceContextInput(
-      node, jsgraph()->HeapConstant(Handle<Context>(function->context())));
-  CallDescriptor::Flags flags = FlagsForNode(node);
-  if (is_strict(p.language_mode())) flags |= CallDescriptor::kSupportsTailCalls;
-  CallDescriptor* desc =
-      Linkage::GetJSCallDescriptor(zone(), false, 1 + arg_count, flags);
-  node->set_op(common()->Call(desc));
-  return true;
-}
-
-
 void JSGenericLowering::LowerJSCallFunction(Node* node) {
-  // Fast case: call function directly.
-  if (TryLowerDirectJSCall(node)) return;
-
-  // General case: CallFunctionStub.
   const CallFunctionParameters& p = CallFunctionParametersOf(node->op());
   int arg_count = static_cast<int>(p.arity() - 2);
   CallFunctionStub stub(isolate(), arg_count, p.flags());
   CallInterfaceDescriptor d = stub.GetCallInterfaceDescriptor();
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   CallDescriptor* desc = Linkage::GetStubCallDescriptor(
       isolate(), zone(), d, static_cast<int>(p.arity() - 1), flags);
   Node* stub_code = jsgraph()->HeapConstant(stub.GetCode());
   node->InsertInput(zone(), 0, stub_code);
   node->set_op(common()->Call(desc));
@@ skipping 269 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8