Add boolean flag to HChange and LNumberUntagD to not convert undefined to NaN.

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 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 3541 matching lines @@
   if (instr->needs_check()) {
     Condition is_smi = __ CheckSmi(input);
     DeoptimizeIf(NegateCondition(is_smi), instr->environment());
   }
   __ SmiToInteger32(input, input);
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 XMMRegister result_reg,
+                                bool deoptimize_on_undefined,
                                 LEnvironment* env) {
-  Label load_smi, heap_number, done;
+  Label load_smi, done;
 
   // Smi check.
   __ JumpIfSmi(input_reg, &load_smi, Label::kNear);
 
   // Heap number map check.
   __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                  Heap::kHeapNumberMapRootIndex);
-  __ j(equal, &heap_number, Label::kNear);
+  if (deoptimize_on_undefined) {
+    DeoptimizeIf(not_equal, env);
+  } else {
+    Label heap_number;
+    __ j(equal, &heap_number, Label::kNear);
 
-  __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
-  DeoptimizeIf(not_equal, env);
+    __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
+    DeoptimizeIf(not_equal, env);
 
-  // Convert undefined to NaN. Compute NaN as 0/0.
-  __ xorps(result_reg, result_reg);
-  __ divsd(result_reg, result_reg);
-  __ jmp(&done, Label::kNear);
+    // Convert undefined to NaN. Compute NaN as 0/0.
+    __ xorps(result_reg, result_reg);
+    __ divsd(result_reg, result_reg);
+    __ jmp(&done, Label::kNear);
 
+    __ bind(&heap_number);
+  }
   // Heap number to XMM conversion.
-  __ bind(&heap_number);
   __ movsd(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
   __ jmp(&done, Label::kNear);
 
   // Smi to XMM conversion
   __ bind(&load_smi);
   __ SmiToInteger32(kScratchRegister, input_reg);
   __ cvtlsi2sd(result_reg, kScratchRegister);
   __ bind(&done);
 }
 
@@ skipping 70 matching lines @@
 
 void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
   LOperand* input = instr->InputAt(0);
   ASSERT(input->IsRegister());
   LOperand* result = instr->result();
   ASSERT(result->IsDoubleRegister());
 
   Register input_reg = ToRegister(input);
   XMMRegister result_reg = ToDoubleRegister(result);
 
-  EmitNumberUntagD(input_reg, result_reg, instr->environment());
+  EmitNumberUntagD(input_reg, result_reg,
+                   instr->hydrogen()->deoptimize_on_undefined(),
+                   instr->environment());
 }
 
 
 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
   LOperand* input = instr->InputAt(0);
   ASSERT(input->IsDoubleRegister());
   LOperand* result = instr->result();
   ASSERT(result->IsRegister());
 
   XMMRegister input_reg = ToDoubleRegister(input);
@@ skipping 569 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64