Merge changes to LTemplateInstruction to X64 (Issue 1048).

src/hydrogen-instructions.cc

 // Copyright 2010 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 978 matching lines @@
     : handle_(handle),
       constant_type_(HType::TypeFromValue(handle)),
       has_int32_value_(false),
       int32_value_(0),
       has_double_value_(false),
       double_value_(0)  {
   set_representation(r);
   SetFlag(kUseGVN);
   if (handle_->IsNumber()) {
     double n = handle_->Number();
-    has_int32_value_ = static_cast<double>(static_cast<int32_t>(n)) == n;
+    double roundtrip_value = static_cast<double>(static_cast<int32_t>(n));
+    has_int32_value_ = BitCast<int64_t>(roundtrip_value) == BitCast<int64_t>(n);
     if (has_int32_value_) int32_value_ = static_cast<int32_t>(n);
     double_value_ = n;
     has_double_value_ = true;
   }
 }
 
 
 HConstant* HConstant::CopyToRepresentation(Representation r) const {
   if (r.IsInteger32() && !has_int32_value_) return NULL;
   if (r.IsDouble() && !has_double_value_) return NULL;
@@ skipping 432 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() const {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal