view src/share/vm/ci/ciNullObject.hpp @ 3700:f13867c41f73

7199742: A lot of C2 OSR compilations of the same method's bci Summary: Don't clone head of OSR loop. Reviewed-by: jrose, twisti
author kvn
date Tue, 02 Oct 2012 14:49:21 -0700
parents c18cbe5936b8
children
line wrap: on
line source
/*
 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_CI_CINULLOBJECT_HPP
#define SHARE_VM_CI_CINULLOBJECT_HPP

#include "ci/ciClassList.hpp"
#include "ci/ciObject.hpp"
#include "ci/ciUtilities.hpp"

// ciNullObject
//
// This class represents a null reference in the VM.
class ciNullObject : public ciObject {
  CI_PACKAGE_ACCESS

private:
  ciNullObject() : ciObject() {}

  const char* type_string() { return "ciNullObject"; }

  void print_impl(outputStream* st);

public:
  // Is this ciObject a Java Language Object?  That is,
  // is the ciObject an instance or an array
  bool is_java_object() { return true; }

  // What kind of ciObject is this?
  bool is_null_object() const { return true; }
  bool is_classless() const   { return true; }

  // Get the distinguished instance of this klass.
  static ciNullObject* make();
};

#endif // SHARE_VM_CI_CINULLOBJECT_HPP