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

src/hydrogen.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 1615 matching lines @@
 }
 
 
 template<>
 inline HInstruction* HGraphBuilder::AddUncasted<HReturn>(HConstant* value) {
   return AddUncasted<HReturn>(static_cast<HValue*>(value));
 }
 
 
 template<>
+inline HInstruction* HGraphBuilder::AddUncasted<HCallRuntime>(
+    Handle<String> name,
+    const Runtime::Function* c_function,
+    int argument_count) {
+  HCallRuntime* instr = New<HCallRuntime>(name, c_function, argument_count);
+  if (graph()->info()->IsStub()) {
+    // When compiling code stubs, we don't want to save all double registers
+    // upon entry to the stub, but instead have the call runtime instruction
+    // save the double registers only on-demand (in the fallback case).
+    instr->set_save_doubles(kSaveFPRegs);
+  }
+  AddInstruction(instr);
+  return instr;
+}
+
+
+template<>
 inline HInstruction* HGraphBuilder::NewUncasted<HContext>() {
   return HContext::New(zone());
 }
 
 
 class HOptimizedGraphBuilder V8_FINAL
     : public HGraphBuilder, public AstVisitor {
  public:
   // A class encapsulating (lazily-allocated) break and continue blocks for
   // a breakable statement.  Separated from BreakAndContinueScope so that it
@@ skipping 719 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_