diff options
| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
|---|---|---|
| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gccint/Regular-IPA-passes.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
Diffstat (limited to 'share/doc/gccint/Regular-IPA-passes.html')
| -rw-r--r-- | share/doc/gccint/Regular-IPA-passes.html | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/share/doc/gccint/Regular-IPA-passes.html b/share/doc/gccint/Regular-IPA-passes.html new file mode 100644 index 0000000..6f01714 --- /dev/null +++ b/share/doc/gccint/Regular-IPA-passes.html @@ -0,0 +1,201 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- 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>GNU Compiler Collection (GCC) Internals: Regular IPA passes</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Regular IPA passes"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Regular IPA passes"> +<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="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="IPA-passes.html#IPA-passes" rel="up" title="IPA passes"> +<link href="Late-IPA-passes.html#Late-IPA-passes" rel="next" title="Late IPA passes"> +<link href="Small-IPA-passes.html#Small-IPA-passes" rel="previous" title="Small IPA passes"> +<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" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Regular-IPA-passes"></a> +<div class="header"> +<p> +Next: <a href="Late-IPA-passes.html#Late-IPA-passes" accesskey="n" rel="next">Late IPA passes</a>, Previous: <a href="Small-IPA-passes.html#Small-IPA-passes" accesskey="p" rel="previous">Small IPA passes</a>, Up: <a href="IPA-passes.html#IPA-passes" accesskey="u" rel="up">IPA passes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Regular-IPA-passes-1"></a> +<h4 class="subsection">9.4.2 Regular IPA passes</h4> +<a name="index-regular-IPA-passes"></a> + +<p>A regular IPA pass is a pass derived from <code>ipa_opt_pass_d</code> that +is executed in WHOPR compilation. Regular IPA passes may have summary +hooks implemented in any of the LGEN, WPA or LTRANS stages (see <a href="IPA.html#IPA">IPA</a>). +</p> +<ul> +<li> IPA whole program visibility + +<p>This pass performs various optimizations involving symbol visibility +with <samp>-fwhole-program</samp>, including symbol privatization, +discovering local functions, and dismantling comdat groups. It is +located in <samp>ipa-visibility.cc</samp> and is described by +<code>pass_ipa_whole_program_visibility</code>. +</p> +</li><li> IPA profile + +<p>The IPA profile pass propagates profiling frequencies across the call +graph. It is located in <samp>ipa-profile.cc</samp> and is described by +<code>pass_ipa_profile</code>. +</p> +</li><li> IPA identical code folding + +<p>This is the inter-procedural identical code folding pass. +The goal of this transformation is to discover functions +and read-only variables that have exactly the same semantics. It is +located in <samp>ipa-icf.cc</samp> and is described by <code>pass_ipa_icf</code>. +</p> +</li><li> IPA devirtualization + +<p>This pass performs speculative devirtualization based on the type +inheritance graph. When a polymorphic call has only one likely target +in the unit, it is turned into a speculative call. It is located in +<samp>ipa-devirt.cc</samp> and is described by <code>pass_ipa_devirt</code>. +</p> +</li><li> IPA constant propagation + +<p>The goal of this pass is to discover functions that are always invoked +with some arguments with the same known constant values and to modify +the functions accordingly. It can also do partial specialization and +type-based devirtualization. It is located in <samp>ipa-cp.cc</samp> and is +described by <code>pass_ipa_cp</code>. +</p> +</li><li> IPA scalar replacement of aggregates + +<p>This pass can replace an aggregate parameter with a set of other parameters +representing part of the original, turning those passed by reference +into new ones which pass the value directly. It also removes unused +function return values and unused function parameters. This pass is +located in <samp>ipa-sra.cc</samp> and is described by <code>pass_ipa_sra</code>. +</p> +</li><li> IPA constructor/destructor merge + +<p>This pass merges multiple constructors and destructors for static +objects into single functions. It’s only run at LTO time unless the +target doesn’t support constructors and destructors natively. The +pass is located in <samp>ipa.cc</samp> and is described by +<code>pass_ipa_cdtor_merge</code>. +</p> +</li><li> IPA function summary + +<p>This pass provides function analysis for inter-procedural passes. +It collects estimates of function body size, execution time, and frame +size for each function. It also estimates information about function +calls: call statement size, time and how often the parameters change +for each call. It is located in <samp>ipa-fnsummary.cc</samp> and is +described by <code>pass_ipa_fn_summary</code>. +</p> +</li><li> IPA inline + +<p>The IPA inline pass handles function inlining with whole-program +knowledge. Small functions that are candidates for inlining are +ordered in increasing badness, bounded by unit growth parameters. +Unreachable functions are removed from the call graph. Functions called +once and not exported from the unit are inlined. This pass is located in +<samp>ipa-inline.cc</samp> and is described by <code>pass_ipa_inline</code>. +</p> +</li><li> IPA pure/const analysis + +<p>This pass marks functions as being either const (<code>TREE_READONLY</code>) or +pure (<code>DECL_PURE_P</code>). The per-function information is produced +by <code>pure_const_generate_summary</code>, then the global information is computed +by performing a transitive closure over the call graph. It is located in +<samp>ipa-pure-const.cc</samp> and is described by <code>pass_ipa_pure_const</code>. +</p> +</li><li> IPA free function summary + +<p>This pass is a regular IPA pass when argument <code>small_p</code> is false. +It releases inline function summaries and call summaries. +It is located in <samp>ipa-fnsummary.cc</samp> and is described by +<code>pass_ipa_free_fn_summary</code>. +</p> +</li><li> IPA reference + +<p>This pass gathers information about how variables whose scope is +confined to the compilation unit are used. It is located in +<samp>ipa-reference.cc</samp> and is described by <code>pass_ipa_reference</code>. +</p> +</li><li> IPA single use + +<p>This pass checks whether variables are used by a single function. +It is located in <samp>ipa.cc</samp> and is described by +<code>pass_ipa_single_use</code>. +</p> +</li><li> IPA comdats + +<p>This pass looks for static symbols that are used exclusively +within one comdat group, and moves them into that comdat group. It is +located in <samp>ipa-comdats.cc</samp> and is described by +<code>pass_ipa_comdats</code>. +</p> +</li></ul> + +<hr> +<div class="header"> +<p> +Next: <a href="Late-IPA-passes.html#Late-IPA-passes" accesskey="n" rel="next">Late IPA passes</a>, Previous: <a href="Small-IPA-passes.html#Small-IPA-passes" accesskey="p" rel="previous">Small IPA passes</a>, Up: <a href="IPA-passes.html#IPA-passes" accesskey="u" rel="up">IPA passes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |