server/supernova/utilities/branch_hints.hpp

   1 //  $Id$
   2 //
   3 //  branch hints
   4 //  Copyright (C) 2007 Tim Blechmann
   5 //
   6 //  This program 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 //  This program 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 this program; see the file COPYING.  If not, write to
  18 //  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 //  Boston, MA 02111-1307, USA.
  20
  21 //  $Revision$
  22 //  $LastChangedRevision$
  23 //  $LastChangedDate$
  24 //  $LastChangedBy$
  25
  26 #ifndef BRANCH_HINTS_HPP
  27 #define BRANCH_HINTS_HPP
  28
  29
  30 namespace nova
  31 {
  32     /** \brief hint for the branch prediction */
  33     inline bool likely(bool expr)
  34     {
  35 #ifdef __GNUC__
  36         return __builtin_expect(expr, true);
  37 #else
  38         return expr;
  39 #endif
  40     }
  41
  42     /** \brief hint for the branch prediction */
  43     inline bool unlikely(bool expr)
  44     {
  45 #ifdef __GNUC__
  46         return __builtin_expect(expr, false);
  47 #else
  48         return expr;
  49 #endif
  50     }
  51 }
  52
  53 #endif /* BRANCH_HINTS_HPP */