Do not embed function in DirectLoadGlobalFunctionPrototype.

src/ic/x64/handler-compiler-x64.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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ic/call-optimization.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 38 matching lines @@
 
   Label done;
   NameDictionaryLookupStub::GenerateNegativeLookup(masm, miss_label, &done,
                                                    properties, name, scratch1);
   __ bind(&done);
   __ DecrementCounter(counters->negative_lookups_miss(), 1);
 }
 
 
 void NamedLoadHandlerCompiler::GenerateDirectLoadGlobalFunctionPrototype(
-    MacroAssembler* masm, int index, Register prototype, Label* miss) {
+    MacroAssembler* masm, int index, Register prototype, Register scratch,
+    Label* miss) {
   Isolate* isolate = masm->isolate();
   // Get the global function with the given index.
-  Handle<JSFunction> function(
+  Handle<JSFunction> jsfunction(
       JSFunction::cast(isolate->native_context()->get(index)));
-
+  Handle<WeakCell> cell = isolate->factory()->NewWeakCell(jsfunction);
   // Check we're still in the same context.
-  Register scratch = prototype;
+  Register function = prototype;
   const int offset = Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX);
   __ movp(scratch, Operand(rsi, offset));
   __ movp(scratch, FieldOperand(scratch, GlobalObject::kNativeContextOffset));
-  __ Cmp(Operand(scratch, Context::SlotOffset(index)), function);
+  __ movp(function, Operand(scratch, Context::SlotOffset(index)));
+  __ CmpWeakValue(function, cell, scratch);
   __ j(not_equal, miss);
-
   // Load its initial map. The global functions all have initial maps.
-  __ Move(prototype, Handle<Map>(function->initial_map()));
+  __ movp(scratch,
+          FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
   // Load the prototype from the initial map.
-  __ movp(prototype, FieldOperand(prototype, Map::kPrototypeOffset));
+  __ movp(prototype, FieldOperand(scratch, Map::kPrototypeOffset));
 }
 
 
 void NamedLoadHandlerCompiler::GenerateLoadFunctionPrototype(
     MacroAssembler* masm, Register receiver, Register result, Register scratch,
     Label* miss_label) {
   __ TryGetFunctionPrototype(receiver, result, miss_label);
   if (!result.is(rax)) __ movp(rax, result);
   __ ret(0);
 }
@@ skipping 602 matching lines @@
   // Return the generated code.
   return GetCode(kind(), Code::NORMAL, name);
 }
 
 
 #undef __
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64