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

   1 // Copyright (C) 2004 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 <fstream>
  29 #include <sstream>
  30 #include <testsuite_performance.h>
  31
  32 void test_extraction(int p = 6)
  33 {
  34   using namespace std;
  35   using namespace __gnu_test;
  36
  37   const char* filename = "tmp_perf_float.txt";
  38   const int iterations = 10000000;
  39
  40   ostringstream oss;
  41   oss << "precision " << p;
  42
  43   // Construct data.
  44   {
  45     ofstream out(filename);
  46     out.precision(p);
  47     for (int i = 0; i < iterations; ++i)
  48       {
  49         float f = i * 3.14159265358979323846;
  50         out << f << '\n';
  51       }
  52   }
  53
  54   {
  55     time_counter time;
  56     resource_counter resource;
  57
  58     ifstream in(filename);
  59     in.precision(p);
  60     float f;
  61     start_counters(time, resource);
  62     for (int j, i = 0; i < iterations; ++i)
  63       in >> f;
  64     stop_counters(time, resource);
  65     report_performance(__FILE__, oss.str(), time, resource);
  66   }
  67
  68   unlink(filename);
  69 };
  70
  71 int main()
  72 {
  73   test_extraction(6);
  74   test_extraction(12);
  75   return 0;
  76 }