Put direct code pointers into JSFunction objects. This is a first step...

src/x64/builtins-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 292 matching lines @@
     __ bind(&function);
   }
 
   // 5b. Get the code to call from the function and check that the number of
   //     expected arguments matches what we're providing.  If so, jump
   //     (tail-call) to the code in register edx without checking arguments.
   __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
   __ movsxlq(rbx,
              FieldOperand(rdx,
                           SharedFunctionInfo::kFormalParameterCountOffset));
-  __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
+  __ movq(rdx, FieldOperand(rdi, JSFunction::kCodeOffset));
   __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize));
   __ cmpq(rax, rbx);
   __ j(not_equal,
        Handle<Code>(builtin(ArgumentsAdaptorTrampoline)),
        RelocInfo::CODE_TARGET);
 
   ParameterCount expected(0);
   __ InvokeCode(rdx, expected, expected, JUMP_FUNCTION);
 }
 
@@ skipping 963 matching lines @@
 }
 
 
 void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
   Generate_JSEntryTrampolineHelper(masm, true);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64