[Interpreter] Optimize code of the form 'if (x === undefined)'.

src/compiler/bytecode-graph-builder.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/bytecode-graph-builder.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/compiler-source-position-table.h"
@@ skipping 1925 matching lines @@
 
 void BytecodeGraphBuilder::VisitTestIn() {
   BuildTestingOp(javascript()->HasProperty());
 }
 
 void BytecodeGraphBuilder::VisitTestInstanceOf() {
   BuildTestingOp(javascript()->InstanceOf());
 }
 
 void BytecodeGraphBuilder::VisitTestUndetectable() {
-  Node* object =
-      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+  Node* object = environment()->LookupAccumulator();
   Node* node = NewNode(jsgraph()->simplified()->ObjectIsUndetectable(), object);
   environment()->BindAccumulator(node);
 }
 
 void BytecodeGraphBuilder::VisitTestNull() {
-  Node* object =
-      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+  Node* object = environment()->LookupAccumulator();
   Node* result = NewNode(simplified()->ReferenceEqual(), object,
                          jsgraph()->NullConstant());
   environment()->BindAccumulator(result);
 }
 
 void BytecodeGraphBuilder::VisitTestUndefined() {
-  Node* object =
-      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+  Node* object = environment()->LookupAccumulator();
   Node* result = NewNode(simplified()->ReferenceEqual(), object,
                          jsgraph()->UndefinedConstant());
   environment()->BindAccumulator(result);
 }
 
 void BytecodeGraphBuilder::VisitTestTypeOf() {
   Node* object = environment()->LookupAccumulator();
   auto literal_flag = interpreter::TestTypeOfFlags::Decode(
       bytecode_iterator().GetFlagOperand(0));
   Node* result;
@@ skipping 102 matching lines @@
 }
 
 void BytecodeGraphBuilder::VisitJumpIfNull() {
   BuildJumpIfEqual(jsgraph()->NullConstant());
 }
 
 void BytecodeGraphBuilder::VisitJumpIfNullConstant() {
   BuildJumpIfEqual(jsgraph()->NullConstant());
 }
 
+void BytecodeGraphBuilder::VisitJumpIfNotNull() {
+  BuildJumpIfNotEqual(jsgraph()->NullConstant());
+}
+
+void BytecodeGraphBuilder::VisitJumpIfNotNullConstant() {
+  BuildJumpIfNotEqual(jsgraph()->NullConstant());
+}
+
 void BytecodeGraphBuilder::VisitJumpIfUndefined() {
   BuildJumpIfEqual(jsgraph()->UndefinedConstant());
 }
 
 void BytecodeGraphBuilder::VisitJumpIfUndefinedConstant() {
   BuildJumpIfEqual(jsgraph()->UndefinedConstant());
 }
 
+void BytecodeGraphBuilder::VisitJumpIfNotUndefined() {
+  BuildJumpIfNotEqual(jsgraph()->UndefinedConstant());
+}
+
+void BytecodeGraphBuilder::VisitJumpIfNotUndefinedConstant() {
+  BuildJumpIfNotEqual(jsgraph()->UndefinedConstant());
+}
+
 void BytecodeGraphBuilder::VisitJumpLoop() { BuildJump(); }
 
 void BytecodeGraphBuilder::VisitStackCheck() {
   PrepareEagerCheckpoint();
   Node* node = NewNode(javascript()->StackCheck());
   environment()->RecordAfterState(node, Environment::kAttachFrameState);
 }
 
 void BytecodeGraphBuilder::VisitSetPendingMessage() {
   Node* previous_message = NewNode(javascript()->LoadMessage());
@@ skipping 255 matching lines @@
   NewIfTrue();
 }
 
 void BytecodeGraphBuilder::BuildJumpIfEqual(Node* comperand) {
   Node* accumulator = environment()->LookupAccumulator();
   Node* condition =
       NewNode(simplified()->ReferenceEqual(), accumulator, comperand);
   BuildJumpIf(condition);
 }
 
+void BytecodeGraphBuilder::BuildJumpIfNotEqual(Node* comperand) {
+  Node* accumulator = environment()->LookupAccumulator();
+  Node* condition =
+      NewNode(simplified()->ReferenceEqual(), accumulator, comperand);
+  BuildJumpIfNot(condition);
+}
+
 void BytecodeGraphBuilder::BuildJumpIfFalse() {
   NewBranch(environment()->LookupAccumulator());
   Environment* if_true_environment = environment()->Copy();
   environment()->BindAccumulator(jsgraph()->FalseConstant());
   NewIfFalse();
   MergeIntoSuccessorEnvironment(bytecode_iterator().GetJumpTargetOffset());
   if_true_environment->BindAccumulator(jsgraph()->TrueConstant());
   set_environment(if_true_environment);
   NewIfTrue();
 }
@@ skipping 336 matching lines @@
         it->source_position().ScriptOffset(), start_position_.InliningId()));
     it->Advance();
   } else {
     DCHECK_GT(it->code_offset(), offset);
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8