/*

 * 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

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 */

#ifndef SHARE_VM_CI_CICALLPROFILE_HPP

#define SHARE_VM_CI_CICALLPROFILE_HPP

#include "ci/ciClassList.hpp"

#include "memory/allocation.hpp"

// ciCallProfile

//

// This class is used to determine the frequently called method

// at some call site

class ciCallProfile : StackObj {

private:

  // Fields are initialized directly by ciMethod::call_profile_at_bci.

  friend class ciMethod;

  friend class ciMethodHandle;

  enum { MorphismLimit = 2 }; // Max call site's morphism we care about

  int  _limit;                // number of receivers have been determined

  int  _morphism;             // determined call site's morphism

  int  _count;                // # times has this call been executed

  int  _receiver_count[MorphismLimit + 1]; // # times receivers have been seen

  ciMethod* _method[MorphismLimit + 1];    // receivers methods

  ciKlass*  _receiver[MorphismLimit + 1];  // receivers (exact)

  ciCallProfile() {

    _limit = 0;

    _morphism    = 0;

    _count = -1;

    _receiver_count[0] = -1;

    _method[0]   = NULL;

    _receiver[0] = NULL;

  }

  void add_receiver(ciKlass* receiver, int receiver_count);

public:

  // Note:  The following predicates return false for invalid profiles:

  bool      has_receiver(int i) const { return _limit > i; }

  int       morphism() const          { return _morphism; }

  int       count() const             { return _count; }

  int       receiver_count(int i)  {

    assert(i < _limit, "out of Call Profile MorphismLimit");

    return _receiver_count[i];

  }

  float     receiver_prob(int i)  {

    assert(i < _limit, "out of Call Profile MorphismLimit");

    return (float)_receiver_count[i]/(float)_count;

  }

  ciMethod* method(int i)          {

    assert(i < _limit, "out of Call Profile MorphismLimit");

    return _method[i];

  }

  ciKlass*  receiver(int i)        {

    assert(i < _limit, "out of Call Profile MorphismLimit");

    return _receiver[i];

  }

  // Rescale the current profile based on the incoming scale

  ciCallProfile rescale(double scale) {

    assert(scale >= 0 && scale <= 1.0, "out of range");

    ciCallProfile call = *this;

    call._count = (int)(call._count * scale);

    for (int i = 0; i < _morphism; i++) {

      call._receiver_count[i] = (int)(call._receiver_count[i] * scale);

    }

    return call;

  }

};

#endif // SHARE_VM_CI_CICALLPROFILE_HPP