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diff --git a/share/doc/gcc/Gcov_002dtool-Intro.html b/share/doc/gcc/Gcov_002dtool-Intro.html new file mode 100644 index 0000000..fa38cca --- /dev/null +++ b/share/doc/gcc/Gcov_002dtool-Intro.html @@ -0,0 +1,145 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- This file documents the use of the GNU compilers. + +Copyright (C) 1988-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with the +Invariant Sections being "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + +A GNU Manual + +(b) The FSF's Back-Cover Text is: + +You have freedom to copy and modify this GNU Manual, like GNU + software. Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Using the GNU Compiler Collection (GCC): Gcov-tool Intro</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Gcov-tool Intro"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Gcov-tool Intro"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Indices.html#Indices" rel="index" title="Indices"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Gcov_002dtool.html#Gcov_002dtool" rel="up" title="Gcov-tool"> +<link href="Invoking-Gcov_002dtool.html#Invoking-Gcov_002dtool" rel="next" title="Invoking Gcov-tool"> +<link href="Gcov_002dtool.html#Gcov_002dtool" rel="previous" title="Gcov-tool"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en_US" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Gcov_002dtool-Intro"></a> +<div class="header"> +<p> +Next: <a href="Invoking-Gcov_002dtool.html#Invoking-Gcov_002dtool" accesskey="n" rel="next">Invoking Gcov-tool</a>, Up: <a href="Gcov_002dtool.html#Gcov_002dtool" accesskey="u" rel="up">Gcov-tool</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Introduction-to-gcov_002dtool"></a> +<h3 class="section">11.1 Introduction to <code>gcov-tool</code></h3> + +<p><code>gcov-tool</code> is an offline tool to process gcc’s gcda profile files. +</p> +<p>Current gcov-tool supports the following functionalities: +</p> +<ul> +<li> merge two sets of profiles with weights. + +</li><li> read a stream of profiles with associated filenames and merge it with a set of +profiles with weights. + +</li><li> read one set of profile and rewrite profile contents. One can scale or +normalize the count values. +</li></ul> + +<p>Examples of the use cases for this tool are: +</p><ul> +<li> Collect the profiles for different set of inputs, and use this tool to merge +them. One can specify the weight to factor in the relative importance of +each input. + +</li><li> Collect profiles from target systems without a filesystem (freestanding +environments). Merge the collected profiles with associated profiles +present on the host system. One can specify the weight to factor in the +relative importance of each input. + +</li><li> Rewrite the profile after removing a subset of the gcda files, while maintaining +the consistency of the summary and the histogram. + +</li><li> It can also be used to debug or libgcov code as the tools shares the majority +code as the runtime library. +</li></ul> + +<p>Note that for the merging operation, this profile generated offline may +contain slight different values from the online merged profile. Here are +a list of typical differences: +</p> +<ul> +<li> histogram difference: This offline tool recomputes the histogram after merging +the counters. The resulting histogram, therefore, is precise. The online +merging does not have this capability – the histogram is merged from two +histograms and the result is an approximation. + +</li><li> summary checksum difference: Summary checksum uses a CRC32 operation. The value +depends on the link list order of gcov-info objects. This order is different in +gcov-tool from that in the online merge. It’s expected to have different +summary checksums. It does not really matter as the compiler does not use this +checksum anywhere. + +</li><li> value profile counter values difference: Some counter values for value profile +are runtime dependent, like heap addresses. It’s normal to see some difference +in these kind of counters. +</li></ul> + + +<hr> +<div class="header"> +<p> +Next: <a href="Invoking-Gcov_002dtool.html#Invoking-Gcov_002dtool" accesskey="n" rel="next">Invoking Gcov-tool</a>, Up: <a href="Gcov_002dtool.html#Gcov_002dtool" accesskey="u" rel="up">Gcov-tool</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |