ceph/src/boost/libs/spirit/doc/karma/numeric_performance.qbk

   1 [/==============================================================================
   2     Copyright (C) 2001-2011 Joel de Guzman
   3     Copyright (C) 2001-2011 Hartmut Kaiser
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ===============================================================================/]
   8
   9 [section:numeric_performance Performance of Numeric Generators]
  10
  11 [section:int_performance Comparing the performance of a single int_ generator]
  12
  13 These performance measurements are centered around default formatting of a
  14 single `int` integer number using different libraries and methods.
  15 The overall execution times for those examples are compared below. We compare
  16 using `sprintf`, C++ iostreams, __boost_format__, and __karma__.
  17
  18 For the full source code of the performance test please see here:
  19 [@../../workbench/karma/int_generator.cpp int_generator.cpp]. All the
  20 measurements have been done by executing `1e7` iterations for each
  21 formatting type (NUMITERATIONS is set to `1e7` in the code shown below).
  22
  23 [import ../../workbench/karma/int_generator.cpp]
  24
  25 Code used to measure the performance for `ltoa`:
  26
  27 [karma_int_performance_ltoa]
  28
  29 Code used to measure the performance for standard C++ iostreams:
  30
  31 [karma_int_performance_iostreams]
  32
  33 Code used to measure the performance for __boost_format__:
  34
  35 [karma_int_performance_format]
  36
  37 Code used to measure the performance for __karma__ using a plain character buffer:
  38
  39 [karma_int_performance_plain]
  40
  41 The following table shows the overall performance results collected
  42 while using different compilers. All times are in seconds measured for `1e7`
  43 iterations (platform: Windows7, Intel Core Duo(tm) Processor, 2.8GHz, 4GByte RAM).
  44 For a more readable comparison of the results see this
  45 [link spirit.karma.int_performance figure].
  46
  47 [table Performance comparison for a single int (all times in [s], `1e7` iterations)
  48     [[Library]              [gcc 4.4.0 (32 bit)] [VC++ 10 (32 bit)] [Intel 11.1 (32 bit)] [gcc 4.4.0 (64 bit)] [VC++ 10 (64 bit)] [Intel 11.1 (64 bit)]]
  49     [[ltoa]                 [1.542]              [0.895]            [0.884]               [1.163]              [1.099]            [0.906]]
  50     [[iostreams]            [6.548]              [13.727]           [11.898]              [3.464]              [8.316]            [8.115]]
  51     [[__boost_format__]     [16.998]             [21.813]           [20.477]              [17.464]             [14.662]           [13.646]]
  52     [[__karma__ int_]       [1.421]              [0.744]            [0.697]               [1.072]              [0.953]            [0.606]]
  53 ]
  54
  55 [fig int_performance.png..Performance comparison for a single int..spirit.karma.int_performance]
  56
  57 [endsect]
  58
  59 [/////////////////////////////////////////////////////////////////////////////]
  60 [section:double_performance Comparing the performance of a single double_ generator]
  61
  62 These performance measurements are centered around default formatting of a
  63 single `double` floating point number using different libraries and methods.
  64 The overall execution times for those examples are compared below. We compare
  65 using `sprintf`, C++ iostreams, __boost_format__, and __karma__.
  66
  67 For the full source code of the performance test please see here:
  68 [@../../workbench/karma/double_performance.cpp double_performance.cpp]. All the
  69 measurements have been done by executing `1e6` iterations for each
  70 formatting type (NUMITERATIONS is set to `1e6` in the code shown below).
  71
  72 [import ../../workbench/karma/double_performance.cpp]
  73
  74 Code used to measure the performance for `sprintf`:
  75
  76 [karma_double_performance_printf]
  77
  78 Code used to measure the performance for standard C++ iostreams:
  79
  80 [karma_double_performance_iostreams]
  81
  82 Code used to measure the performance for __boost_format__:
  83
  84 [karma_double_performance_format]
  85
  86 The following code shows the common definitions used by all __karma__ performance
  87 measurements as listed below:
  88
  89 [karma_double_performance_definitions]
  90
  91 Code used to measure the performance for __karma__ using a plain character buffer:
  92
  93 [karma_double_performance_plain]
  94
  95 The following table shows the overall performance results collected
  96 while using different compilers. All times are in seconds measured for `1e6`
  97 iterations (platform: Windows7, Intel Core Duo(tm) Processor, 2.8GHz, 4GByte RAM).
  98 For a more readable comparison of the results see this
  99 [link spirit.karma.double_performance figure].
 100
 101 [table Performance comparison for a single double (all times in [s], `1e6` iterations)
 102     [[Library]              [gcc 4.4.0 (32 bit)] [VC++ 10 (32 bit)] [Intel 11.1 (32 bit)] [gcc 4.4.0 (64 bit)] [VC++ 10 (64 bit)] [Intel 11.1 (64 bit)]]
 103     [[sprintf]              [0.755]              [0.965]            [0.880]               [0.713]              [0.807]            [0.694]]
 104     [[iostreams]            [2.316]              [2.624]            [1.964]               [1.634]              [1.468]            [1.354]]
 105     [[__boost_format__]     [3.188]              [3.737]            [2.878]               [3.217]              [2.672]            [2.011]]
 106     [[__karma__ double_]    [0.813]              [0.561]            [0.368]               [0.426]              [0.260]            [0.218]]
 107 ]
 108
 109 [fig double_performance.png..Performance comparison for a single double..spirit.karma.double_performance]
 110
 111 [endsect]
 112
 113 [////////////////////////////////////////////////////////////////////////////]
 114 [section:format_performance Comparing the performance of a sequence of several generators]
 115
 116 These performance measurements are centered around formatting of a sequence of
 117 different items, including 2 `double` floating point numbers using different
 118 libraries and methods. The overall execution times for those examples are
 119 compared below. We compare using `sprintf`, C++ iostreams, __boost_format__,
 120 and __karma__.
 121
 122 For the full source code of the performance test please see here:
 123 [@../../workbench/karma/format_performance.cpp format_performance.cpp]. All the
 124 measurements have been done by doing `1e6` iterations for each formatting
 125 type (NUMITERATIONS is set to `1e6`).
 126
 127 [import ../../workbench/karma/format_performance.cpp]
 128
 129 Code used to measure the performance for sprintf:
 130
 131 [karma_format_performance_printf]
 132
 133 Code used to measure the performance for standard iostreams:
 134
 135 [karma_format_performance_iostreams]
 136
 137 Code used to measure the performance for __boost_format__:
 138
 139 [karma_format_performance_format]
 140
 141 The following code shows the common definitions used by all __karma__
 142 performance measurements as listed below:
 143
 144 [karma_format_performance_definitions]
 145
 146 Code used to measure the performance for __karma__ using a plain character
 147 buffer:
 148
 149 [karma_format_performance_plain]
 150
 151 The following table shows the overall performance results collected
 152 while using different compilers. All times are in seconds measured for `1e6`
 153 iterations (platform: Windows7, Intel Core Duo(tm) Processor, 2.8GHz, 4GByte RAM).
 154 For a more readable comparison of the results see this
 155 [link spirit.karma.format_performance figure].
 156
 157 [table Performance comparison for a sequence of several items (all times in [s], `1e6` iterations)
 158     [[Library]              [gcc 4.4.0 (32 bit)] [VC++ 10 (32 bit)] [Intel 11.1 (32 bit)] [gcc 4.4.0 (64 bit)] [VC++ 10 (64 bit)] [Intel 11.1 (64 bit)]]
 159     [[sprintf]              [1.725]              [1.892]            [1.903]               [1.469]              [1.608]            [1.493]]
 160     [[iostreams]            [4.827]              [5.287]            [4.444]               [3.112]              [3.319]            [2.877]]
 161     [[__boost_format__]     [5.881]              [7.089]            [5.801]               [5.455]              [5.254]            [4.164]]
 162     [[__karma__]            [1.942]              [1.242]            [0.999]               [1.334]              [0.758]            [0.686]]
 163 ]
 164
 165 [fig format_performance.png..Performance comparison for a sequence of several items..spirit.karma.format_performance]
 166
 167 [endsect]
 168
 169 [endsect]