libstdc++-v3/testsuite/performance/complex_norm.cc

   1 // Copyright (C) 2003 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 2, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // As a special exception, you may use this file as part of a free software
  20 // library without restriction.  Specifically, if other files instantiate
  21 // templates or use macros or inline functions from this file, or you compile
  22 // this file and link it with other files to produce an executable, this
  23 // file does not by itself cause the resulting executable to be covered by
  24 // the GNU General Public License.  This exception does not however
  25 // invalidate any other reasons why the executable file might be covered by
  26 // the GNU General Public License.
  27
  28 #include <complex>
  29 #include <testsuite_performance.h>
  30
  31 // based on libstdc++/5730, use --fast-math
  32 int main()
  33 {
  34   using namespace std;
  35   using namespace __gnu_test;
  36
  37   time_counter time;
  38   resource_counter resource;
  39   const int iterations = 2000;
  40
  41   typedef complex<double> complex_type;
  42   complex_type u[2048];
  43
  44   for (int i = 0; i < 2048; ++i)
  45     u[i] = 1.0;
  46
  47   start_counters(time, resource);
  48   for (int i = 0; i < iterations; ++i)
  49     {
  50       complex_type * p = u;
  51       for (int j = 0; j < 2048; ++j)
  52         {
  53           double u2 = norm(*p);
  54           double t = u2 * 0.1;
  55           *p *= complex_type(cos(t), sin(t));
  56           ++p;
  57         }
  58     }
  59   stop_counters(time, resource);
  60   report_performance(__FILE__, "norm", time, resource);
  61   clear_counters(time, resource);
  62
  63   start_counters(time, resource);
  64   for (int i = 0; i < iterations; ++i)
  65     {
  66       complex_type * p = u;
  67       for (int j = 0; j < 2048; ++j)
  68         {
  69           // Shouldn't be slower than the above.
  70           double ur = real(*p);
  71           double ui = imag(*p);
  72           double u2 = ur * ur + ui * ui;
  73           double t = u2 * 0.1;
  74           *p *= complex_type(cos(t), sin(t));
  75           ++p;
  76         }
  77     }
  78   stop_counters(time, resource);
  79   report_performance(__FILE__, "", time, resource);
  80
  81   return 0;
  82 }
  83