src/hotspot/share/gc/shared/blockOffsetTable.hpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 *
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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#ifndef SHARE_GC_SHARED_BLOCKOFFSETTABLE_HPP
#define SHARE_GC_SHARED_BLOCKOFFSETTABLE_HPP

#include "gc/shared/cardTable.hpp"
#include "memory/allStatic.hpp"
#include "utilities/globalDefinitions.hpp"

class BOTConstants : public AllStatic {
public:
  // entries "e" of at least N_words mean "go back by Base^(e-N_words)."
  // All entries are less than "N_words + N_powers".
  static const uint LogBase = 4;
  static const uint Base = (1 << LogBase);
  static const uint N_powers = 14;

  static size_t power_to_cards_back(uint i) {
    return (size_t)1 << (LogBase * i);
  }

  static size_t entry_to_cards_back(u_char entry) {
    assert(entry >= CardTable::card_size_in_words(), "Precondition");
    return power_to_cards_back(entry - CardTable::card_size_in_words());
  }
};

#endif // SHARE_GC_SHARED_BLOCKOFFSETTABLE_HPP