view src/share/vm/ci/ciType.hpp @ 9126:bc26f978b0ce

HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly don't use the (wrong) cached value, but ask the runtime on each request. Fixes regression on xml.* benchmarks @ specjvm2008. The problem was: After the constructor of Object was deoptimized due to an assumption violation, it was recompiled again after some time. However, on recompilation, the value of hasFinalizeSubclass for the class was not updated and it was compiled again with a, now wrong, assumption, which then triggers deoptimization again. This was repeated until it hit the recompilation limit (defined by PerMethodRecompilationCutoff), and therefore only executed by the interpreter from now on, causing the performance regression.
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 15 Apr 2013 19:54:58 +0200
parents f1de9dbc914e
children de6a9e811145
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/*
 * Copyright (c) 2000, 2012, 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
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 * questions.
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 */

#ifndef SHARE_VM_CI_CITYPE_HPP
#define SHARE_VM_CI_CITYPE_HPP

#include "ci/ciMetadata.hpp"

// ciType
//
// This class represents either a class (T_OBJECT), array (T_ARRAY),
// or one of the primitive types such as T_INT.
class ciType : public ciMetadata {
  CI_PACKAGE_ACCESS
  friend class ciKlass;
  friend class ciReturnAddress;

private:
  BasicType _basic_type;

  ciType(BasicType t);     // for primitive and unloaded types
  ciType(KlassHandle k);   // for subclasses (reference types)

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

  void print_impl(outputStream* st);

  // Distinguished instances of primitive ciTypes..
  static ciType* _basic_types[T_CONFLICT+1];

public:
  BasicType basic_type() const              { return _basic_type; }

  // Returns true iff the types are identical, or if both are klasses
  // and the is_subtype_of relation holds between the klasses.
  bool is_subtype_of(ciType* type);

  // Get the instance of java.lang.Class corresponding to this type.
  // There are mirrors for instance, array, and primitive types (incl. void).
  virtual ciInstance*    java_mirror();

  // Get the class which "boxes" (or "wraps") values of this type.
  // Example:  short is boxed by java.lang.Short, etc.
  // Returns self if it is a reference type.
  // Returns NULL for void, since null is used in such cases.
  ciKlass*  box_klass();

  // Returns true if this is not a klass or array (i.e., not a reference type).
  bool is_primitive_type() const            { return basic_type() != T_OBJECT && basic_type() != T_ARRAY; }
  int size() const                          { return type2size[basic_type()]; }
  bool is_void() const                      { return basic_type() == T_VOID; }
  bool is_one_word() const                  { return size() == 1; }
  bool is_two_word() const                  { return size() == 2; }

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

  const char* name();
  virtual void print_name_on(outputStream* st);
  void print_name() {
    print_name_on(tty);
  }

  static ciType* make(BasicType t);
};


// ciReturnAddress
//
// This class represents the type of a specific return address in the
// bytecodes.
class ciReturnAddress : public ciType {
  CI_PACKAGE_ACCESS

private:
  // The bci of this return address.
  int _bci;

  ciReturnAddress(int bci);

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

  void print_impl(outputStream* st);

public:
  bool is_return_address() const { return true; }

  int  bci() { return _bci; }

  static ciReturnAddress* make(int bci);
};

#endif // SHARE_VM_CI_CITYPE_HPP