Use signaling NaN for holes in fixed double arrays.

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 93 matching lines @@
 namespace internal {
 
 // -----------------------------------------------------------------------------
 // Common double constants.
 
 struct DoubleConstant BASE_EMBEDDED {
 double min_int;
 double one_half;
 double minus_one_half;
 double negative_infinity;
-double canonical_non_hole_nan;
 double the_hole_nan;
 double uint32_bias;
 };
 
 static DoubleConstant double_constants;
 
 const char* const RelocInfo::kFillerCommentString = "DEOPTIMIZATION PADDING";
 
 static bool math_exp_data_initialized = false;
 static base::Mutex* math_exp_data_mutex = NULL;
@@ skipping 756 matching lines @@
 #endif  // VERIFY_HEAP
 
 
 // -----------------------------------------------------------------------------
 // Implementation of ExternalReference
 
 void ExternalReference::SetUp() {
   double_constants.min_int = kMinInt;
   double_constants.one_half = 0.5;
   double_constants.minus_one_half = -0.5;
-  double_constants.canonical_non_hole_nan = base::OS::nan_value();
   double_constants.the_hole_nan = bit_cast<double>(kHoleNanInt64);
   double_constants.negative_infinity = -V8_INFINITY;
   double_constants.uint32_bias =
     static_cast<double>(static_cast<uint32_t>(0xFFFFFFFF)) + 1;
 
   math_exp_data_mutex = new base::Mutex();
 }
 
 
 void ExternalReference::InitializeMathExpData() {
@@ skipping 337 matching lines @@
       reinterpret_cast<void*>(&double_constants.minus_one_half));
 }
 
 
 ExternalReference ExternalReference::address_of_negative_infinity() {
   return ExternalReference(
       reinterpret_cast<void*>(&double_constants.negative_infinity));
 }
 
 
-ExternalReference ExternalReference::address_of_canonical_non_hole_nan() {
-  return ExternalReference(
-      reinterpret_cast<void*>(&double_constants.canonical_non_hole_nan));
-}
-
-
 ExternalReference ExternalReference::address_of_the_hole_nan() {
   return ExternalReference(
       reinterpret_cast<void*>(&double_constants.the_hole_nan));
 }
 
 
 ExternalReference ExternalReference::address_of_uint32_bias() {
   return ExternalReference(
       reinterpret_cast<void*>(&double_constants.uint32_bias));
 }
@@ skipping 331 matching lines @@
     assembler_->RecordRelocInfo(RelocInfo::POSITION, state_.current_position);
     state_.written_position = state_.current_position;
     written = true;
   }
 
   // Return whether something was written.
   return written;
 }
 
 } }  // namespace v8::internal