1 @c Copyright (C) 2014 Free Software Foundation, Inc.
2 @c This is part of the GCC manual.
3 @c For copying conditions, see the file gcc.texi.
7 Copyright @copyright{} 2014 Free Software Foundation, Inc.
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10 under the terms of the GNU Free Documentation License, Version 1.3 or
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14 the Back-Cover Texts being (b) (see below). A copy of the license is
15 included in the gfdl(7) man page.
17 (a) The FSF's Front-Cover Text is:
21 (b) The FSF's Back-Cover Text is:
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27 @c Set file name and title for the man page.
28 @setfilename gcov-tool
29 @settitle offline gcda profile processing tool
33 @chapter @command{gcov-tool}---an Offline Gcda Profile Processing Tool
35 @command{gcov-tool} is a tool you can use in conjunction with GCC to
36 manipulate or process gcda profile files offline.
39 * Gcov-tool Intro:: Introduction to gcov-tool.
40 * Invoking Gcov-tool:: How to use gcov-tool.
44 @section Introduction to @command{gcov-tool}
45 @c man begin DESCRIPTION
47 @command{gcov-tool} is an offline tool to process gcc's gcda profile files.
49 Current gcov-tool supports the following functionalities:
53 merge two sets of profiles with weights.
56 read one set of profile and rewrite profile contents. One can scale or
57 normalize the count values.
60 Examples of the use cases for this tool are:
63 Collect the profiles for different set of inputs, and use this tool to merge
64 them. One can specify the weight to factor in the relative importance of
68 Rewrite the profile after removing a subset of the gcda files, while maintaining
69 the consistency of the summary and the histogram.
72 It can also be used to debug or libgcov code as the tools shares the majority
73 code as the runtime library.
76 Note that for the merging operation, this profile generated offline may
77 contain slight different values from the online merged profile. Here are
78 a list of typical differences:
82 histogram difference: This offline tool recomputes the histogram after merging
83 the counters. The resulting histogram, therefore, is precise. The online
84 merging does not have this capability -- the histogram is merged from two
85 histograms and the result is an approximation.
88 summary checksum difference: Summary checksum uses a CRC32 operation. The value
89 depends on the link list order of gcov-info objects. This order is different in
90 gcov-tool from that in the online merge. It's expected to have different
91 summary checksums. It does not really matter as the compiler does not use this
95 value profile counter values difference: Some counter values for value profile
96 are runtime dependent, like heap addresses. It's normal to see some difference
97 in these kind of counters.
102 @node Invoking Gcov-tool
103 @section Invoking @command{gcov-tool}
106 gcov-tool @r{[}@var{global-options}@r{]} SUB_COMMAND
107 @r{[}@var{sub_command-options}@r{]} @var{profile_dir}
110 @command{gcov-tool} accepts the following options:
113 @c man begin SYNOPSIS
114 gcov-tool [@option{-v}|@option{--version}] [@option{-h}|@option{--help}]
116 gcov-tool merge [merge-options] @var{directory1} @var{directory2}
117 [@option{-v}|@option{--verbose}]
118 [@option{-o}|@option{ --output} @var{directory}]
119 [@option{-w}|@option{--weight} @var{w1,w2}]
121 gcov-tool rewrite [rewrite-options] @var{directory}
122 [@option{-v}|@option{--verbose}]
123 [@option{-o}|@option{--output} @var{directory}]
124 [@option{-s}|@option{--scale} @var{float_or_simple-frac_value}]
125 [@option{-n}|@option{--normalize} @var{long_long_value}]
128 gpl(7), gfdl(7), fsf-funding(7), gcc(1), gcov(1) and the Info entry for
137 Display help about using @command{gcov-tool} (on the standard output), and
138 exit without doing any further processing.
142 Display the @command{gcov-tool} version number (on the standard output),
143 and exit without doing any further processing.
146 Merge two profile directories.
151 Set the verbose mode.
153 @item -o @var{directory}
154 @itemx --output @var{directory}
155 Set the output profile directory. Default output directory name is
156 @var{merged_profile}.
158 @item -w @var{w1},@var{w2}
159 @itemx --weight @var{w1},@var{w2}
160 Set the merge weights of the @var{directory1} and @var{directory2},
161 respectively. The default weights are 1 for both.
165 Read the specified profile directory and rewrite to a new directory.
170 Set the verbose mode.
172 @item -o @var{directory}
173 @itemx --output @var{directory}
174 Set the output profile directory. Default output name is @var{rewrite_profile}.
176 @item -s @var{float_or_simple-frac_value}
177 @itemx --scale @var{float_or_simple-frac_value}
178 Scale the profile counters. The specified value can be in floating point value,
179 or simple fraction value form, such 1, 2, 2/3, and 5/3.
181 @item -n @var{long_long_value}
182 @itemx --normalize <long_long_value>
183 Normalize the profile. The specified value is the max counter value