Emit slightly more compact code in untag double.

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 49 matching lines @@
 #endif  // Target architecture.
 #endif  // V8_INTERPRETED_REGEXP
 
 namespace v8 {
 namespace internal {
 
 
 const double DoubleConstant::min_int = kMinInt;
 const double DoubleConstant::one_half = 0.5;
 const double DoubleConstant::minus_zero = -0.0;
+const double DoubleConstant::nan = OS::nan_value();
 const double DoubleConstant::negative_infinity = -V8_INFINITY;
 const char* RelocInfo::kFillerCommentString = "DEOPTIMIZATION PADDING";
 
 // -----------------------------------------------------------------------------
 // Implementation of Label
 
 int Label::pos() const {
   if (pos_ < 0) return -pos_ - 1;
   if (pos_ > 0) return  pos_ - 1;
   UNREACHABLE();
@@ skipping 658 matching lines @@
       const_cast<double*>(&DoubleConstant::minus_zero)));
 }
 
 
 ExternalReference ExternalReference::address_of_negative_infinity() {
   return ExternalReference(reinterpret_cast<void*>(
       const_cast<double*>(&DoubleConstant::negative_infinity)));
 }
 
 
+ExternalReference ExternalReference::address_of_nan() {
+  return ExternalReference(reinterpret_cast<void*>(
+      const_cast<double*>(&DoubleConstant::nan)));
+}
+
+
 #ifndef V8_INTERPRETED_REGEXP
 
 ExternalReference ExternalReference::re_check_stack_guard_state() {
   Address function;
 #ifdef V8_TARGET_ARCH_X64
   function = FUNCTION_ADDR(RegExpMacroAssemblerX64::CheckStackGuardState);
 #elif V8_TARGET_ARCH_IA32
   function = FUNCTION_ADDR(RegExpMacroAssemblerIA32::CheckStackGuardState);
 #elif V8_TARGET_ARCH_ARM
   function = FUNCTION_ADDR(RegExpMacroAssemblerARM::CheckStackGuardState);
@@ skipping 239 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