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prefetch.hh
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1 // -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 // vi: set et ts=4 sw=4 sts=4:
3 /*
4  This file is part of the Open Porous Media project (OPM).
5 
6  OPM is free software: you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation, either version 2 of the License, or
9  (at your option) any later version.
10 
11  OPM is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  GNU General Public License for more details.
15 
16  You should have received a copy of the GNU General Public License
17  along with OPM. If not, see <http://www.gnu.org/licenses/>.
18 
19  Consult the COPYING file in the top-level source directory of this
20  module for the precise wording of the license and the list of
21  copyright holders.
22 */
27 #ifndef EWOMS_PREFETCH_HH
28 #define EWOMS_PREFETCH_HH
29 
30 namespace Ewoms {
37 template <int temporalLocality = 3, int writeOnly = 0, class T = void>
38 void prefetch(const T& val, unsigned n = 1)
39 {
40 #if __clang__ || __GNUC__
41  // this value is architecture specific, but a cache line size of 64 bytes seems to be
42  // used by all contemporary architectures.
43  static const int cacheLineSize = 64;
44 
45  const char *beginPtr = reinterpret_cast<const char*>(&val);
46  const char *endPtr = reinterpret_cast<const char*>(&val + n);
47  for (; beginPtr < endPtr; beginPtr += cacheLineSize)
48  __builtin_prefetch(beginPtr, writeOnly, temporalLocality);
49 #endif
50 }
51 
52 } // namespace Ewoms
53 
54 #endif