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

src/arm64/lithium-codegen-arm64.cc

Index: src/arm64/lithium-codegen-arm64.cc
diff --git a/src/arm64/lithium-codegen-arm64.cc b/src/arm64/lithium-codegen-arm64.cc
index 9eb7d7b83d2bdf26cab8f4a85550f3ee3b1e747a..abae911512cace247fdfd25a3f267048bc21e760 100644
--- a/src/arm64/lithium-codegen-arm64.cc
+++ b/src/arm64/lithium-codegen-arm64.cc
@@ -5879,61 +5879,14 @@ void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
 }
 
 
-void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
-                                           Register result,
-                                           Register object,
-                                           Register index) {
-  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
-  __ Push(object);
-  __ Push(index);
-  __ Mov(cp, 0);
-  __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
-  RecordSafepointWithRegisters(
-      instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
-  __ StoreToSafepointRegisterSlot(x0, result);
-}
-
-
 void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
-  class DeferredLoadMutableDouble V8_FINAL : public LDeferredCode {
-   public:
-    DeferredLoadMutableDouble(LCodeGen* codegen,
-                              LLoadFieldByIndex* instr,
-                              Register result,
-                              Register object,
-                              Register index)
-        : LDeferredCode(codegen),
-          instr_(instr),
-          result_(result),
-          object_(object),
-          index_(index) {
-    }
-    virtual void Generate() V8_OVERRIDE {
-      codegen()->DoDeferredLoadMutableDouble(instr_, result_, object_, index_);
-    }
-    virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
-   private:
-    LLoadFieldByIndex* instr_;
-    Register result_;
-    Register object_;
-    Register index_;
-  };
   Register object = ToRegister(instr->object());
   Register index = ToRegister(instr->index());
   Register result = ToRegister(instr->result());
 
   __ AssertSmi(index);
 
-  DeferredLoadMutableDouble* deferred;
-  deferred = new(zone()) DeferredLoadMutableDouble(
-      this, instr, result, object, index);
-
   Label out_of_object, done;
-
-  __ TestAndBranchIfAnySet(
-      index, reinterpret_cast<uint64_t>(Smi::FromInt(1)), deferred->entry());
-  __ Mov(index, Operand(index, ASR, 1));
-
   __ Cmp(index, Smi::FromInt(0));
   __ B(lt, &out_of_object);
 
@@ -5949,7 +5902,6 @@ void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
   __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
   __ Ldr(result, FieldMemOperand(result,
                                  FixedArray::kHeaderSize - kPointerSize));
-  __ Bind(deferred->exit());
   __ Bind(&done);
 }