[Interpreter] Removes ToBoolean bytecode.

ToBoolean was used with conditional jumps. An earlier cl
(https://codereview.chromium.org/1426913002/) merges jumps
and ToBoolean into a single bytecode. So, we no longer need
ToBoolean bytecode.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1507683005

Cr-Commit-Position: refs/heads/master@{#32707}

src/compiler/bytecode-graph-builder.cc

@@ -1092,12 +1092,6 @@ void BytecodeGraphBuilder::BuildCastOperator(
 }
 
 
-void BytecodeGraphBuilder::VisitToBoolean(
-    const interpreter::BytecodeArrayIterator& iterator) {
-  BuildCastOperator(javascript()->ToBoolean(ToBooleanHint::kAny), iterator);
-}
-
-
 void BytecodeGraphBuilder::VisitToName(
     const interpreter::BytecodeArrayIterator& iterator) {
   BuildCastOperator(javascript()->ToName(), iterator);

src/interpreter/bytecode-array-builder.cc

@@ -593,8 +593,6 @@ bool BytecodeArrayBuilder::NeedToBooleanCast() {
   }
   PreviousBytecodeHelper previous_bytecode(*this);
   switch (previous_bytecode.GetBytecode()) {
-    case Bytecode::kToBoolean:
-      UNREACHABLE();
     // If the previous bytecode puts a boolean in the accumulator return true.
     case Bytecode::kLdaTrue:
     case Bytecode::kLdaFalse:
@@ -617,38 +615,6 @@ bool BytecodeArrayBuilder::NeedToBooleanCast() {
 }
 
 
-BytecodeArrayBuilder& BytecodeArrayBuilder::CastAccumulatorToBoolean() {
-  if (!LastBytecodeInSameBlock()) {
-    Output(Bytecode::kToBoolean);
-    return *this;
-  }
-  // If the previous bytecode puts a boolean in the accumulator
-  // there is no need to emit an instruction.
-  if (NeedToBooleanCast()) {
-    PreviousBytecodeHelper previous_bytecode(*this);
-    switch (previous_bytecode.GetBytecode()) {
-      // If the previous bytecode is a constant evaluate it and return false.
-      case Bytecode::kLdaZero: {
-        LoadFalse();
-        break;
-      }
-      case Bytecode::kLdaSmi8: {
-        LoadBooleanConstant(previous_bytecode.GetOperand(0) != 0);
-        break;
-      }
-      case Bytecode::kLdaConstant: {
-        Handle<Object> object = previous_bytecode.GetConstantForIndexOperand(0);
-        LoadBooleanConstant(object->BooleanValue());
-        break;
-      }
-      default:
-        Output(Bytecode::kToBoolean);
-    }
-  }
-  return *this;
-}
-
-
 BytecodeArrayBuilder& BytecodeArrayBuilder::CastAccumulatorToJSObject() {
   Output(Bytecode::kToObject);
   return *this;

src/interpreter/bytecodes.h

@@ -150,7 +150,6 @@ namespace interpreter {
   V(TestIn, OperandType::kReg8)                                                \
                                                                                \
   /* Cast operators */                                                         \
-  V(ToBoolean, OperandType::kNone)                                             \
   V(ToName, OperandType::kNone)                                                \
   V(ToNumber, OperandType::kNone)                                              \
   V(ToObject, OperandType::kNone)                                              \

src/interpreter/interpreter.cc

@@ -1074,17 +1074,6 @@ void Interpreter::DoTestInstanceOf(compiler::InterpreterAssembler* assembler) {
 }
 
 
-// ToBoolean
-//
-// Cast the object referenced by the accumulator to a boolean.
-void Interpreter::DoToBoolean(compiler::InterpreterAssembler* assembler) {
-  Node* accumulator = __ GetAccumulator();
-  Node* result = __ CallRuntime(Runtime::kInterpreterToBoolean, accumulator);
-  __ SetAccumulator(result);
-  __ Dispatch();
-}
-
-
 // ToName
 //
 // Cast the object referenced by the accumulator to a name.

test/cctest/interpreter/test-interpreter.cc

@@ -1562,43 +1562,6 @@ static void LoadAny(BytecodeArrayBuilder* builder,
 }
 
 
-TEST(InterpreterToBoolean) {
-  HandleAndZoneScope handles;
-  i::Factory* factory = handles.main_isolate()->factory();
-
-  std::pair<Handle<Object>, bool> object_type_tuples[] = {
-      std::make_pair(factory->undefined_value(), false),
-      std::make_pair(factory->null_value(), false),
-      std::make_pair(factory->false_value(), false),
-      std::make_pair(factory->true_value(), true),
-      std::make_pair(factory->NewNumber(9.1), true),
-      std::make_pair(factory->NewNumberFromInt(0), false),
-      std::make_pair(
-          Handle<Object>::cast(factory->NewStringFromStaticChars("hello")),
-          true),
-      std::make_pair(
-          Handle<Object>::cast(factory->NewStringFromStaticChars("")), false),
-  };
-
-  for (size_t i = 0; i < arraysize(object_type_tuples); i++) {
-    BytecodeArrayBuilder builder(handles.main_isolate(), handles.main_zone());
-    Register r0(0);
-    builder.set_locals_count(0);
-    builder.set_context_count(0);
-    builder.set_parameter_count(0);
-    LoadAny(&builder, factory, object_type_tuples[i].first);
-    builder.CastAccumulatorToBoolean();
-    builder.Return();
-    Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray();
-    InterpreterTester tester(handles.main_isolate(), bytecode_array);
-    auto callable = tester.GetCallable<>();
-    Handle<Object> return_value = callable().ToHandleChecked();
-    CHECK(return_value->IsBoolean());
-    CHECK_EQ(return_value->BooleanValue(), object_type_tuples[i].second);
-  }
-}
-
-
 TEST(InterpreterUnaryNotNonBoolean) {
   HandleAndZoneScope handles;
   i::Factory* factory = handles.main_isolate()->factory();

test/unittests/interpreter/bytecode-array-builder-unittest.cc

@@ -159,7 +159,6 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
 
   // Emit cast operator invocations.
   builder.CastAccumulatorToNumber()
-      .CastAccumulatorToBoolean()
       .CastAccumulatorToJSObject()
       .CastAccumulatorToName();
 
@@ -658,68 +657,6 @@ TEST_F(BytecodeArrayBuilderTest, LabelAddressReuse) {
   CHECK(iterator.done());
 }
 
-
-TEST_F(BytecodeArrayBuilderTest, ToBoolean) {
-  BytecodeArrayBuilder builder(isolate(), zone());
-  builder.set_parameter_count(0);
-  builder.set_locals_count(0);
-  builder.set_context_count(0);
-
-  // Check ToBoolean emitted at start of a basic block.
-  builder.CastAccumulatorToBoolean();
-
-  // Check ToBoolean emitted preceding bytecode is non-boolean.
-  builder.LoadNull().CastAccumulatorToBoolean();
-
-  // Check ToBoolean omitted if preceding bytecode is boolean.
-  builder.LoadFalse().CastAccumulatorToBoolean();
-
-  // Check ToBoolean emitted if it is at the start of a basic block caused by a
-  // bound label.
-  BytecodeLabel label;
-  builder.LoadFalse()
-      .Bind(&label)
-      .CastAccumulatorToBoolean();
-
-  // Check ToBoolean emitted if it is at the start of a basic block caused by a
-  // jump.
-  builder.LoadFalse()
-      .JumpIfTrue(&label)
-      .CastAccumulatorToBoolean();
-
-  builder.Return();
-
-  Handle<BytecodeArray> array = builder.ToBytecodeArray();
-  BytecodeArrayIterator iterator(array);
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kToBoolean);
-  iterator.Advance();
-
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaNull);
-  iterator.Advance();
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kToBoolean);
-  iterator.Advance();
-
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaFalse);
-  iterator.Advance();
-
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaFalse);
-  iterator.Advance();
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kToBoolean);
-  iterator.Advance();
-
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaFalse);
-  iterator.Advance();
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kJumpIfTrue);
-  iterator.Advance();
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kToBoolean);
-  iterator.Advance();
-
-  CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
-  iterator.Advance();
-  CHECK(iterator.done());
-}
-
-
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8