[ic] Let LoadGlobalIC load the variable name from TypeFeedbackMetadata.

src/ic/ic.cc

 // Copyright 2012 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/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api-arguments-inl.h"
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 2244 matching lines @@
   return *function;
 }
 
 
 // Used from ic-<arch>.cc.
 RUNTIME_FUNCTION(Runtime_LoadIC_Miss) {
   TimerEventScope<TimerEventIcMiss> timer(isolate);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8"), "V8.IcMiss");
   HandleScope scope(isolate);
   Handle<Object> receiver = args.at<Object>(0);
-  Handle<Name> key = args.at<Name>(1);
 
   DCHECK_EQ(4, args.length());
   Handle<Smi> slot = args.at<Smi>(2);
   Handle<TypeFeedbackVector> vector = args.at<TypeFeedbackVector>(3);
   FeedbackVectorSlot vector_slot = vector->ToSlot(slot->value());
   // A monomorphic or polymorphic KeyedLoadIC with a string key can call the
   // LoadIC miss handler if the handler misses. Since the vector Nexus is
   // set up outside the IC, handle that here.
   FeedbackVectorSlotKind kind = vector->GetKind(vector_slot);
   if (kind == FeedbackVectorSlotKind::LOAD_IC) {
+    Handle<Name> key = args.at<Name>(1);
     LoadICNexus nexus(vector, vector_slot);
     LoadIC ic(IC::NO_EXTRA_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     RETURN_RESULT_OR_FAILURE(isolate, ic.Load(receiver, key));
 
   } else if (kind == FeedbackVectorSlotKind::LOAD_GLOBAL_IC) {
+    Handle<Name> key(vector->GetName(vector_slot), isolate);
+    DCHECK_NE(*key, *isolate->factory()->empty_string());
     DCHECK_EQ(*isolate->global_object(), *receiver);
     LoadGlobalICNexus nexus(vector, vector_slot);
     LoadGlobalIC ic(IC::NO_EXTRA_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     RETURN_RESULT_OR_FAILURE(isolate, ic.Load(key));
 
   } else {
+    Handle<Name> key = args.at<Name>(1);
     DCHECK_EQ(FeedbackVectorSlotKind::KEYED_LOAD_IC, kind);
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::NO_EXTRA_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     RETURN_RESULT_OR_FAILURE(isolate, ic.Load(receiver, key));
   }
 }
 
 // Used from ic-<arch>.cc.
 RUNTIME_FUNCTION(Runtime_LoadGlobalIC_Miss) {
   TimerEventScope<TimerEventIcMiss> timer(isolate);
   HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
+  DCHECK_EQ(2, args.length());
   Handle<JSGlobalObject> global = isolate->global_object();
-  Handle<Name> name = args.at<Name>(0);
-  Handle<Smi> slot = args.at<Smi>(1);
-  Handle<TypeFeedbackVector> vector = args.at<TypeFeedbackVector>(2);
+  Handle<Smi> slot = args.at<Smi>(0);
+  Handle<TypeFeedbackVector> vector = args.at<TypeFeedbackVector>(1);
   FeedbackVectorSlot vector_slot = vector->ToSlot(slot->value());
   DCHECK_EQ(FeedbackVectorSlotKind::LOAD_GLOBAL_IC,
             vector->GetKind(vector_slot));
+  Handle<String> name(vector->GetName(vector_slot), isolate);
+  DCHECK_NE(*name, *isolate->factory()->empty_string());
 
   LoadGlobalICNexus nexus(vector, vector_slot);
   LoadGlobalIC ic(IC::NO_EXTRA_FRAME, isolate, &nexus);
   ic.UpdateState(global, name);
 
   Handle<Object> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(name));
   return *result;
 }
 
@@ skipping 670 matching lines @@
     DCHECK_EQ(FeedbackVectorSlotKind::KEYED_LOAD_IC,
               vector->GetKind(vector_slot));
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     RETURN_RESULT_OR_FAILURE(isolate, ic.Load(receiver, key));
   }
 }
 }  // namespace internal
 }  // namespace v8