duke@435: /*
stefank@2314:  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_RUNTIME_PREFETCH_HPP
stefank@2314: #define SHARE_VM_RUNTIME_PREFETCH_HPP
stefank@2314: 
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: 
duke@435: // If calls to prefetch methods are in a loop, the loop should be cloned
duke@435: // such that if Prefetch{Scan,Copy}Interval and/or PrefetchFieldInterval
duke@435: // say not to do prefetching, these methods aren't called.  At the very
duke@435: // least, they take up a memory issue slot.  They should be implemented
duke@435: // as inline assembly code: doing an actual call isn't worth the cost.
duke@435: 
duke@435: class Prefetch : AllStatic {
duke@435:  public:
duke@435:   enum style {
duke@435:     do_none,  // Do no prefetching
duke@435:     do_read,  // Do read prefetching
duke@435:     do_write  // Do write prefetching
duke@435:   };
duke@435: 
duke@435:   // Prefetch anticipating read; must not fault, semantically a no-op
duke@435:   static void read(void* loc, intx interval);
duke@435: 
duke@435:   // Prefetch anticipating write; must not fault, semantically a no-op
duke@435:   static void write(void* loc, intx interval);
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_RUNTIME_PREFETCH_HPP