[Interpreter] Adds logical and, logical or and comma operators to interpreter

src/interpreter/bytecode-generator.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/interpreter/bytecode-generator.h"
 
 #include <stack>
 
 #include "src/compiler.h"
 #include "src/interpreter/control-flow-builders.h"
@@ skipping 759 matching lines @@
 
 
 void BytecodeGenerator::VisitCountOperation(CountOperation* expr) {
   UNIMPLEMENTED();
 }
 
 
 void BytecodeGenerator::VisitBinaryOperation(BinaryOperation* binop) {
   switch (binop->op()) {
     case Token::COMMA:
+      VisitCommaExpression(binop);
+      break;
     case Token::OR:
+      VisitLogicalOrExpression(binop);
+      break;
     case Token::AND:
-      UNIMPLEMENTED();
+      VisitLogicalAndExpression(binop);
       break;
     default:
       VisitArithmeticExpression(binop);
       break;
   }
 }
 
 
 void BytecodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Token::Value op = expr->op();
@@ skipping 42 matching lines @@
   TemporaryRegisterScope temporary_register_scope(&builder_);
   Register temporary = temporary_register_scope.NewRegister();
 
   Visit(left);
   builder()->StoreAccumulatorInRegister(temporary);
   Visit(right);
   builder()->BinaryOperation(op, temporary, language_mode_strength());
 }
 
 
+void BytecodeGenerator::VisitCommaExpression(BinaryOperation* binop) {
+  Expression* left = binop->left();
+  Expression* right = binop->right();
+
+  TemporaryRegisterScope temporary_register_scope(&builder_);
+  Register temporary = temporary_register_scope.NewRegister();
+
+  Visit(left);
+  builder()->StoreAccumulatorInRegister(temporary);
+  Visit(right);
+}
+
+
+void BytecodeGenerator::VisitLogicalOrExpression(BinaryOperation* binop) {
+  Expression* left = binop->left();
+  Expression* right = binop->right();
+
+  TemporaryRegisterScope temporary_register_scope(&builder_);
+  Register temporary = temporary_register_scope.NewRegister();
+
+  // Short-circuit evaluation- If it is known that left is always true,
+  // no need to visit right
+  if (left->ToBooleanIsTrue()) {
+    Visit(left);
+  } else {
+    BytecodeLabel else_label, end_label;
+
+    Visit(left);
+    builder()->StoreAccumulatorInRegister(temporary);
+    builder()->CastAccumulatorToBoolean();
+    builder()->JumpIfFalse(&else_label);
+    builder()->LoadAccumulatorWithRegister(temporary);
+    builder()->Jump(&end_label);
+    builder()->Bind(&else_label);

[rmcilroy, 2015/10/12 07:24:13]

I think we should add a pair of bytecodes which performs ToBoolean on the
accumulator, jumps if true / false, but keeps the original value in the
accumulator. With this bytecode this sequence could be shortened to:

Visit(left);
builder()->JumpIfToBooleanTrue(&end_label);
Visit(right);
builder()->Bind(&end_label);

We could also use these bytecodes (in a future CL) to avoid having to explicitly
call ToBoolean before JumpIfTrue / False when dealing with a non-boolean test in
if / else / while conditions.

[mythria, 2015/10/13 15:00:00]

Done.

+    Visit(right);
+    builder()->Bind(&end_label);
+  }
+}
+
+
+void BytecodeGenerator::VisitLogicalAndExpression(BinaryOperation* binop) {
+  Expression* left = binop->left();
+  Expression* right = binop->right();
+
+  TemporaryRegisterScope temporary_register_scope(&builder_);
+  Register temporary = temporary_register_scope.NewRegister();
+
+  // Short-circuit evaluation- If it is known that left is always false,
+  // no need to visit right
+  if (left->ToBooleanIsFalse()) {
+    Visit(left);
+  } else {
+    BytecodeLabel else_label, end_label;
+
+    Visit(left);
+    builder()->StoreAccumulatorInRegister(temporary);
+    builder()->CastAccumulatorToBoolean();
+    builder()->JumpIfTrue(&else_label);
+    builder()->LoadAccumulatorWithRegister(temporary);
+    builder()->Jump(&end_label);
+    builder()->Bind(&else_label);
+    Visit(right);
+    builder()->Bind(&end_label);
+  }
+}
+
+
 LanguageMode BytecodeGenerator::language_mode() const {
   return info()->language_mode();
 }
 
 
 Strength BytecodeGenerator::language_mode_strength() const {
   return strength(language_mode());
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 
 Register BytecodeGenerator::current_context() const { return current_context_; }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8