Use signaling NaN for holes in fixed double arrays.

src/ia32/lithium-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sstream>
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
@@ skipping 2078 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   Representation r = instr->representation();
   if (r.IsSmi()) {
     return DefineAsRegister(new(zone()) LConstantS);
   } else if (r.IsInteger32()) {
     return DefineAsRegister(new(zone()) LConstantI);
   } else if (r.IsDouble()) {
-    double value = instr->DoubleValue();
-    bool value_is_zero = bit_cast<uint64_t, double>(value) == 0;
-    LOperand* temp = value_is_zero ? NULL : TempRegister();
+    uint64_t const bits = instr->DoubleValueAsBits();
+    LOperand* temp = bits ? TempRegister() : nullptr;
     return DefineAsRegister(new(zone()) LConstantD(temp));
   } else if (r.IsExternal()) {
     return DefineAsRegister(new(zone()) LConstantE);
   } else if (r.IsTagged()) {
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();
     return NULL;
   }
 }
@@ skipping 602 matching lines @@
   LOperand* function = UseRegisterAtStart(instr->function());
   LAllocateBlockContext* result =
       new(zone()) LAllocateBlockContext(context, function);
   return MarkAsCall(DefineFixed(result, esi), instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32