Lazily save double registers for HCallRuntime instructions within Hydrogen code stubs.

src/hydrogen-instructions.h

 // Copyright 2012 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 2342 matching lines @@
                            const Runtime::Function* c_function,
                            int argument_count) {
     return new(zone) HCallRuntime(context, name, c_function, argument_count);
   }
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   HValue* context() { return OperandAt(0); }
   const Runtime::Function* function() const { return c_function_; }
   Handle<String> name() const { return name_; }
+  SaveFPRegsMode save_doubles() const { return save_doubles_; }
+  void set_save_doubles(SaveFPRegsMode save_doubles) {
+    save_doubles_ = save_doubles;
+  }
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(CallRuntime)
 
  private:
   HCallRuntime(HValue* context,
                Handle<String> name,
                const Runtime::Function* c_function,
                int argument_count)
-      : HCall<1>(argument_count), c_function_(c_function), name_(name) {
+      : HCall<1>(argument_count), c_function_(c_function), name_(name),
+        save_doubles_(kDontSaveFPRegs) {
     SetOperandAt(0, context);
   }
 
   const Runtime::Function* c_function_;
   Handle<String> name_;
+  SaveFPRegsMode save_doubles_;
 };
 
 
 class HMapEnumLength V8_FINAL : public HUnaryOperation {
  public:
   DECLARE_INSTRUCTION_FACTORY_P1(HMapEnumLength, HValue*);
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     return Representation::Tagged();
   }
@@ skipping 4643 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_