/*

 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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,

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#ifndef SHARE_VM_RUNTIME_PREFETCH_HPP

#define SHARE_VM_RUNTIME_PREFETCH_HPP

#include "memory/allocation.hpp"

// If calls to prefetch methods are in a loop, the loop should be cloned

// such that if Prefetch{Scan,Copy}Interval and/or PrefetchFieldInterval

// say not to do prefetching, these methods aren't called.  At the very

// least, they take up a memory issue slot.  They should be implemented

// as inline assembly code: doing an actual call isn't worth the cost.

class Prefetch : AllStatic {

 public:

  enum style {

    do_none,  // Do no prefetching

    do_read,  // Do read prefetching

    do_write  // Do write prefetching

  };

  // Prefetch anticipating read; must not fault, semantically a no-op

  static void read(void* loc, intx interval);

  // Prefetch anticipating write; must not fault, semantically a no-op

  static void write(void* loc, intx interval);

};

#endif // SHARE_VM_RUNTIME_PREFETCH_HPP