KeyedLoadIC should have same register spec as LoadIC.

src/x64/code-stubs-x64.cc

 // Copyright 2013 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/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 762 matching lines @@
 
     __ bind(&done);
     __ IncrementCounter(counters->math_pow(), 1);
     __ ret(0);
   }
 }
 
 
 void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
   Label miss;
-  Register receiver;
+  Register receiver = LoadIC::ReceiverRegister();
+  Register name = LoadIC::NameRegister();
+
+  ASSERT(kind() == Code::LOAD_IC ||
+         kind() == Code::KEYED_LOAD_IC);
+
   if (kind() == Code::KEYED_LOAD_IC) {
-    // ----------- S t a t e -------------
-    //  -- rax    : key
-    //  -- rdx    : receiver
-    //  -- rsp[0] : return address
-    // -----------------------------------
-    __ Cmp(rax, isolate()->factory()->prototype_string());
+    __ Cmp(name, isolate()->factory()->prototype_string());
     __ j(not_equal, &miss);
-    receiver = rdx;
-  } else {
-    ASSERT(kind() == Code::LOAD_IC);
-    // ----------- S t a t e -------------
-    //  -- rax    : receiver
-    //  -- rcx    : name
-    //  -- rsp[0] : return address
-    // -----------------------------------
-    receiver = rax;
   }
 
   StubCompiler::GenerateLoadFunctionPrototype(masm, receiver, r8, r9, &miss);
   __ bind(&miss);
   StubCompiler::TailCallBuiltin(
       masm, BaseLoadStoreStubCompiler::MissBuiltin(kind()));
 }
 
 
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
@@ skipping 4139 matching lines @@
                               return_value_operand,
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64