[turbofan] Avoid introducing useless JSConvertReceiver during inlining.

src/compiler/js-inlining.cc

Index: src/compiler/js-inlining.cc
diff --git a/src/compiler/js-inlining.cc b/src/compiler/js-inlining.cc
index c199620364b1bd48a7563861c88816c9cadaf5db..3f1f98be072c62ed8f1e3ed2cdf307668385043f 100644
--- a/src/compiler/js-inlining.cc
+++ b/src/compiler/js-inlining.cc
@@ -290,6 +290,27 @@ namespace {
 // function, which either returns the map set from the CheckMaps or
 // a singleton set from a StoreField.
 bool NeedsConvertReceiver(Node* receiver, Node* effect) {
+  // Check if the {receiver} is already a JSReceiver.
+  switch (receiver->opcode()) {
+    case IrOpcode::kJSConstruct:
+    case IrOpcode::kJSConstructWithSpread:
+    case IrOpcode::kJSCreate:
+    case IrOpcode::kJSCreateArguments:
+    case IrOpcode::kJSCreateArray:
+    case IrOpcode::kJSCreateClosure:
+    case IrOpcode::kJSCreateIterResultObject:
+    case IrOpcode::kJSCreateKeyValueArray:
+    case IrOpcode::kJSCreateLiteralArray:
+    case IrOpcode::kJSCreateLiteralObject:
+    case IrOpcode::kJSCreateLiteralRegExp:
+    case IrOpcode::kJSConvertReceiver:
+    case IrOpcode::kJSGetSuperConstructor:
+    case IrOpcode::kJSToObject:
+      return false;
+    default:
+      break;
+  }
+  if (receiver->opcode() == IrOpcode::kJSCreate) return false;

[Jarin, 2017/02/17 10:07:46]

This line is not necessary anymore, no?

[Benedikt Meurer, 2017/02/17 10:09:40]

Done.

   for (Node* dominator = effect;;) {
     if (dominator->opcode() == IrOpcode::kCheckMaps &&
         NodeProperties::IsSame(dominator->InputAt(0), receiver)) {