Revert 20348 - "Fix LoadFieldByIndex to take mutable heap-numbers into account."

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index bc6fdfd8145b78b6289607dffde7caed3d489dcc..849e2d4ecaa6bf131dc13a938dba82b667e1dd81 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -5564,55 +5564,11 @@ void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
 }
 
 
-void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
-                                           Register object,
-                                           Register index) {
-  PushSafepointRegistersScope scope(this);
-  __ Push(object);
-  __ Push(index);
-  __ xorp(rsi, rsi);
-  __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
-  RecordSafepointWithRegisters(
-      instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
-  __ StoreToSafepointRegisterSlot(object, rax);
-}
-
-
 void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
-  class DeferredLoadMutableDouble V8_FINAL : public LDeferredCode {
-   public:
-    DeferredLoadMutableDouble(LCodeGen* codegen,
-                              LLoadFieldByIndex* instr,
-                              Register object,
-                              Register index)
-        : LDeferredCode(codegen),
-          instr_(instr),
-          object_(object),
-          index_(index) {
-    }
-    virtual void Generate() V8_OVERRIDE {
-      codegen()->DoDeferredLoadMutableDouble(instr_, object_, index_);
-    }
-    virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
-   private:
-    LLoadFieldByIndex* instr_;
-    Register object_;
-    Register index_;
-  };
-
   Register object = ToRegister(instr->object());
   Register index = ToRegister(instr->index());
 
-  DeferredLoadMutableDouble* deferred;
-  deferred = new(zone()) DeferredLoadMutableDouble(this, instr, object, index);
-
   Label out_of_object, done;
-  __ Move(kScratchRegister, Smi::FromInt(1));
-  __ testp(index, kScratchRegister);
-  __ j(not_zero, deferred->entry());
-
-  __ sarp(index, Immediate(1));
-
   __ SmiToInteger32(index, index);
   __ cmpl(index, Immediate(0));
   __ j(less, &out_of_object, Label::kNear);
@@ -5630,7 +5586,6 @@ void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
                                index,
                                times_pointer_size,
                                FixedArray::kHeaderSize - kPointerSize));
-  __ bind(deferred->exit());
   __ bind(&done);
 }