WIP [esnext] implement async iteration proposal

src/compiler/js-intrinsic-lowering.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/js-intrinsic-lowering.h"
 
 #include <stack>
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
@@ skipping 22 matching lines @@
     case Runtime::kInlineCreateIterResultObject:
       return ReduceCreateIterResultObject(node);
     case Runtime::kInlineDebugIsActive:
       return ReduceDebugIsActive(node);
     case Runtime::kInlineDeoptimizeNow:
       return ReduceDeoptimizeNow(node);
     case Runtime::kInlineGeneratorClose:
       return ReduceGeneratorClose(node);
     case Runtime::kInlineGeneratorGetInputOrDebugPos:
       return ReduceGeneratorGetInputOrDebugPos(node);
+    case Runtime::kInlineAsyncGeneratorGetAwaitInput:
+      return ReduceAsyncGeneratorGetAwaitInput(node);
     case Runtime::kInlineGeneratorGetResumeMode:
       return ReduceGeneratorGetResumeMode(node);
     case Runtime::kInlineIsArray:
       return ReduceIsInstanceType(node, JS_ARRAY_TYPE);
     case Runtime::kInlineIsTypedArray:
       return ReduceIsInstanceType(node, JS_TYPED_ARRAY_TYPE);
     case Runtime::kInlineIsJSReceiver:
       return ReduceIsJSReceiver(node);
     case Runtime::kInlineIsSmi:
       return ReduceIsSmi(node);
@@ skipping 80 matching lines @@
 Reduction JSIntrinsicLowering::ReduceGeneratorGetInputOrDebugPos(Node* node) {
   Node* const generator = NodeProperties::GetValueInput(node, 0);
   Node* const effect = NodeProperties::GetEffectInput(node);
   Node* const control = NodeProperties::GetControlInput(node);
   Operator const* const op = simplified()->LoadField(
       AccessBuilder::ForJSGeneratorObjectInputOrDebugPos());
 
   return Change(node, op, generator, effect, control);
 }
 
+Reduction JSIntrinsicLowering::ReduceAsyncGeneratorGetAwaitInput(Node* node) {
+  Node* const generator = NodeProperties::GetValueInput(node, 0);
+  Node* const effect = NodeProperties::GetEffectInput(node);
+  Node* const control = NodeProperties::GetControlInput(node);
+  Operator const* const op = simplified()->LoadField(
+      AccessBuilder::ForJSAsyncGeneratorObjectAwaitInput());
+
+  return Change(node, op, generator, effect, control);
+}
+
+Reduction JSIntrinsicLowering::ReduceGeneratorSaveInputForAwait(Node* node) {
+  Node* const generator = NodeProperties::GetValueInput(node, 0);
+  Node* const effect = NodeProperties::GetEffectInput(node);
+  Node* const control = NodeProperties::GetControlInput(node);
+
+  Node* const input = graph()->NewNode(
+      simplified()->LoadField(
+          AccessBuilder::ForJSAsyncGeneratorObjectAwaitInput()),
+      generator, effect, control);
+
+  Operator const* const op = simplified()->StoreField(
+      AccessBuilder::ForJSGeneratorObjectContinuation());
+  return Change(node, op, generator, input, effect, control);
+}
+
 Reduction JSIntrinsicLowering::ReduceGeneratorGetResumeMode(Node* node) {
   Node* const generator = NodeProperties::GetValueInput(node, 0);
   Node* const effect = NodeProperties::GetEffectInput(node);
   Node* const control = NodeProperties::GetControlInput(node);
   Operator const* const op =
       simplified()->LoadField(AccessBuilder::ForJSGeneratorObjectResumeMode());
 
   return Change(node, op, generator, effect, control);
 }
 
@@ skipping 204 matching lines @@
   return jsgraph_->javascript();
 }
 
 SimplifiedOperatorBuilder* JSIntrinsicLowering::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8