[turbofan] Add support for relevant ES6 type conversion intrinsics.

src/compiler/js-typed-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/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 125 matching lines @@
     node_->ReplaceInput(0, left_input);
     node_->ReplaceInput(1, right_input);
   }
 
   void ConvertInputsToUI32(Signedness left_signedness,
                            Signedness right_signedness) {
     node_->ReplaceInput(0, ConvertToUI32(left(), left_signedness));
     node_->ReplaceInput(1, ConvertToUI32(right(), right_signedness));
   }
 
-  void ConvertInputsToString() {
-    node_->ReplaceInput(0, ConvertToString(left()));
-    node_->ReplaceInput(1, ConvertToString(right()));
-  }
-
   void SwapInputs() {
     Node* l = left();
     Node* r = right();
     node_->ReplaceInput(0, r);
     node_->ReplaceInput(1, l);
   }
 
   // Remove all effect and control inputs and outputs to this node and change
   // to the pure operator {op}, possibly inserting a boolean inversion.
   Reduction ChangeToPureOperator(const Operator* op, bool invert = false,
@@ skipping 89 matching lines @@
   JSGraph* jsgraph() { return lowering_->jsgraph(); }
   JSOperatorBuilder* javascript() { return lowering_->javascript(); }
   MachineOperatorBuilder* machine() { return lowering_->machine(); }
   CommonOperatorBuilder* common() { return jsgraph()->common(); }
   Zone* zone() const { return graph()->zone(); }
 
  private:
   JSTypedLowering* lowering_;  // The containing lowering instance.
   Node* node_;                 // The original node.
 
-  Node* ConvertToString(Node* node) {
-    // Avoid introducing too many eager ToString() operations.
-    Reduction reduced = lowering_->ReduceJSToStringInput(node);
-    if (reduced.Changed()) return reduced.replacement();
-    Node* n = graph()->NewNode(javascript()->ToString(), node, context(),
-                               effect(), control());
-    update_effect(n);
-    return n;
-  }
-
   Node* CreateFrameStateForLeftInput(Node* frame_state) {
     FrameStateInfo state_info = OpParameter<FrameStateInfo>(frame_state);
 
     if (state_info.bailout_id() == BailoutId::None()) {
       // Dummy frame state => just leave it as is.
       return frame_state;
     }
 
     // If the frame state is already the right one, just return it.
     if (state_info.state_combine().kind() == OutputFrameStateCombine::kPokeAt &&
@@ skipping 533 matching lines @@
   if (input->opcode() == IrOpcode::kJSToString) {
     // Recursively try to reduce the input first.
     Reduction result = ReduceJSToString(input);
     if (result.Changed()) return result;
     return Changed(input);  // JSToString(JSToString(x)) => JSToString(x)
   }
   Type* input_type = NodeProperties::GetType(input);
   if (input_type->Is(Type::String())) {
     return Changed(input);  // JSToString(x:string) => x
   }
+  if (input_type->Is(Type::Boolean())) {
+    return Replace(
+        graph()->NewNode(common()->Select(kMachAnyTagged), input,
+                         jsgraph()->HeapConstant(factory()->true_string()),
+                         jsgraph()->HeapConstant(factory()->false_string())));
+  }
   if (input_type->Is(Type::Undefined())) {
     return Replace(jsgraph()->HeapConstant(factory()->undefined_string()));
   }
   if (input_type->Is(Type::Null())) {
     return Replace(jsgraph()->HeapConstant(factory()->null_string()));
   }
-  // TODO(turbofan): js-typed-lowering of ToString(x:boolean)
   // TODO(turbofan): js-typed-lowering of ToString(x:number)
   return NoChange();
 }
 
 
 Reduction JSTypedLowering::ReduceJSToString(Node* node) {
   // Try to reduce the input first.
   Node* const input = node->InputAt(0);
   Reduction reduction = ReduceJSToStringInput(input);
   if (reduction.Changed()) {
@@ skipping 1302 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSTypedLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8