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

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 423c438cf2c17910227d08fd4b873294538d2dbb..708109251c7788201b01bbe5608ba4cd833296ab 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -777,9 +777,13 @@ void BytecodeGenerator::VisitCountOperation(CountOperation* expr) {
 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);
@@ -842,6 +846,73 @@ void BytecodeGenerator::VisitArithmeticExpression(BinaryOperation* binop) {
 }
 
 
+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();
 }