Revert of [compiler] Drop the CompareNilIC.

src/compiler/change-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/compiler/change-lowering.h"
 
 #include "src/address-map.h"
 #include "src/code-factory.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 37 matching lines @@
     case IrOpcode::kStoreElement:
       return StoreElement(node);
     case IrOpcode::kAllocate:
       return Allocate(node);
     case IrOpcode::kObjectIsReceiver:
       return ObjectIsReceiver(node);
     case IrOpcode::kObjectIsSmi:
       return ObjectIsSmi(node);
     case IrOpcode::kObjectIsNumber:
       return ObjectIsNumber(node);
-    case IrOpcode::kObjectIsUndetectable:
-      return ObjectIsUndetectable(node);
     default:
       return NoChange();
   }
   UNREACHABLE();
   return NoChange();
 }
 
 
 Node* ChangeLowering::HeapNumberValueIndexConstant() {
   return jsgraph()->IntPtrConstant(HeapNumber::kValueOffset - kHeapObjectTag);
@@ skipping 528 matching lines @@
       jsgraph()->IntPtrConstant(kSmiTag));
 }
 
 Node* ChangeLowering::LoadHeapObjectMap(Node* object, Node* control) {
   return graph()->NewNode(
       machine()->Load(MachineType::AnyTagged()), object,
       jsgraph()->IntPtrConstant(HeapObject::kMapOffset - kHeapObjectTag),
       graph()->start(), control);
 }
 
-Node* ChangeLowering::LoadMapBitField(Node* map) {
-  return graph()->NewNode(
-      machine()->Load(MachineType::Uint8()), map,
-      jsgraph()->IntPtrConstant(Map::kBitFieldOffset - kHeapObjectTag),
-      graph()->start(), graph()->start());
-}
-
 Node* ChangeLowering::LoadMapInstanceType(Node* map) {
   return graph()->NewNode(
       machine()->Load(MachineType::Uint8()), map,
       jsgraph()->IntPtrConstant(Map::kInstanceTypeOffset - kHeapObjectTag),
       graph()->start(), graph()->start());
 }
 
 Reduction ChangeLowering::ObjectIsNumber(Node* node) {
   Node* input = NodeProperties::GetValueInput(node, 0);
   // TODO(bmeurer): Optimize somewhat based on input type.
@@ skipping 27 matching lines @@
                        jsgraph()->Uint32Constant(FIRST_JS_RECEIVER_TYPE),
                        LoadMapInstanceType(LoadHeapObjectMap(input, if_false)));
   Node* control = graph()->NewNode(common()->Merge(2), if_true, if_false);
   node->ReplaceInput(0, vtrue);
   node->AppendInput(graph()->zone(), vfalse);
   node->AppendInput(graph()->zone(), control);
   NodeProperties::ChangeOp(node, common()->Phi(MachineRepresentation::kBit, 2));
   return Changed(node);
 }
 
-Reduction ChangeLowering::ObjectIsUndetectable(Node* node) {
-  Node* input = NodeProperties::GetValueInput(node, 0);
-  // TODO(bmeurer): Optimize somewhat based on input type.
-  Node* check = IsSmi(input);
-  Node* branch = graph()->NewNode(common()->Branch(), check, graph()->start());
-  Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-  Node* vtrue = jsgraph()->Int32Constant(0);
-  Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-  Node* vfalse = graph()->NewNode(
-      machine()->Word32Equal(),
-      graph()->NewNode(
-          machine()->Word32Equal(),
-          graph()->NewNode(machine()->Word32And(),
-                           jsgraph()->Uint32Constant(1 << Map::kIsUndetectable),
-                           LoadMapBitField(LoadHeapObjectMap(input, if_false))),
-          jsgraph()->Int32Constant(0)),
-      jsgraph()->Int32Constant(0));
-  Node* control = graph()->NewNode(common()->Merge(2), if_true, if_false);
-  node->ReplaceInput(0, vtrue);
-  node->AppendInput(graph()->zone(), vfalse);
-  node->AppendInput(graph()->zone(), control);
-  NodeProperties::ChangeOp(node, common()->Phi(MachineRepresentation::kBit, 2));
-  return Changed(node);
-}
-
 Reduction ChangeLowering::ObjectIsSmi(Node* node) {
   node->ReplaceInput(0,
                      graph()->NewNode(machine()->WordAnd(), node->InputAt(0),
                                       jsgraph()->IntPtrConstant(kSmiTagMask)));
   node->AppendInput(graph()->zone(), jsgraph()->IntPtrConstant(kSmiTag));
   NodeProperties::ChangeOp(node, machine()->WordEqual());
   return Changed(node);
 }
 
 Isolate* ChangeLowering::isolate() const { return jsgraph()->isolate(); }
 
 
 Graph* ChangeLowering::graph() const { return jsgraph()->graph(); }
 
 
 CommonOperatorBuilder* ChangeLowering::common() const {
   return jsgraph()->common();
 }
 
 
 MachineOperatorBuilder* ChangeLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8