Use a root array register for constant loads and stack guards on x64....

src/x64/ic-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 321 matching lines @@
   __ cmpl(rbx, Immediate(kLengthFieldLimit));
   __ j(above_equal, &slow);
   __ movl(rax, rbx);
   __ and_(rax, Immediate((1 << String::kShortLengthShift) - 1));
   __ shrl(rax, Immediate(String::kLongLengthShift));
   __ jmp(&index_int);
   // Fast case: Do the load.
   __ bind(&fast);
   __ movq(rax, Operand(rcx, rax, times_pointer_size,
                       FixedArray::kHeaderSize - kHeapObjectTag));
-  __ Cmp(rax, Factory::the_hole_value());
+  __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
   // In case the loaded value is the_hole we have to consult GetProperty
   // to ensure the prototype chain is searched.
   __ j(equal, &slow);
   __ IncrementCounter(&Counters::keyed_load_generic_smi, 1);
   __ ret(0);
 }
 
 
 void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ skipping 253 matching lines @@
   // Check for string.
   __ bind(&non_number);
   __ CmpInstanceType(rbx, FIRST_NONSTRING_TYPE);
   __ j(above_equal, &non_string);
   StubCompiler::GenerateLoadGlobalFunctionPrototype(
       masm, Context::STRING_FUNCTION_INDEX, rdx);
   __ jmp(&probe);
 
   // Check for boolean.
   __ bind(&non_string);
-  __ Cmp(rdx, Factory::true_value());
+  __ CompareRoot(rdx, Heap::kTrueValueRootIndex);
   __ j(equal, &boolean);
-  __ Cmp(rdx, Factory::false_value());
+  __ CompareRoot(rdx, Heap::kFalseValueRootIndex);
   __ j(not_equal, &miss);
   __ bind(&boolean);
   StubCompiler::GenerateLoadGlobalFunctionPrototype(
       masm, Context::BOOLEAN_FUNCTION_INDEX, rdx);
 
   // Probe the stub cache for the value object.
   __ bind(&probe);
   StubCache::GenerateProbe(masm, flags, rdx, rcx, rbx, no_reg);
 
   // Cache miss: Jump to runtime.
@@ skipping 350 matching lines @@
 
   // Cache miss: Jump to runtime.
   Generate(masm, ExternalReference(IC_Utility(kStoreIC_Miss)));
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal