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1 /* |
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2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #ifndef SHARE_VM_RUNTIME_PREFETCH_HPP |
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26 #define SHARE_VM_RUNTIME_PREFETCH_HPP |
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27 |
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28 #include "memory/allocation.hpp" |
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29 |
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30 // If calls to prefetch methods are in a loop, the loop should be cloned |
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31 // such that if Prefetch{Scan,Copy}Interval and/or PrefetchFieldInterval |
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32 // say not to do prefetching, these methods aren't called. At the very |
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33 // least, they take up a memory issue slot. They should be implemented |
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34 // as inline assembly code: doing an actual call isn't worth the cost. |
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35 |
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36 class Prefetch : AllStatic { |
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37 public: |
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38 enum style { |
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39 do_none, // Do no prefetching |
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40 do_read, // Do read prefetching |
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41 do_write // Do write prefetching |
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42 }; |
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43 |
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44 // Prefetch anticipating read; must not fault, semantically a no-op |
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45 static void read(void* loc, intx interval); |
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46 |
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47 // Prefetch anticipating write; must not fault, semantically a no-op |
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48 static void write(void* loc, intx interval); |
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49 }; |
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50 |
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51 #endif // SHARE_VM_RUNTIME_PREFETCH_HPP |