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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gcc/Developer-Options.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
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diff --git a/share/doc/gcc/Developer-Options.html b/share/doc/gcc/Developer-Options.html new file mode 100644 index 0000000..021daca --- /dev/null +++ b/share/doc/gcc/Developer-Options.html @@ -0,0 +1,1472 @@ +<!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): Developer Options</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Developer Options"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Developer Options"> +<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="Invoking-GCC.html#Invoking-GCC" rel="up" title="Invoking GCC"> +<link href="Submodel-Options.html#Submodel-Options" rel="next" title="Submodel Options"> +<link href="Code-Gen-Options.html#Code-Gen-Options" rel="previous" title="Code Gen Options"> +<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="Developer-Options"></a> +<div class="header"> +<p> +Next: <a href="Submodel-Options.html#Submodel-Options" accesskey="n" rel="next">Submodel Options</a>, Previous: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="p" rel="previous">Code Gen Options</a>, Up: <a href="Invoking-GCC.html#Invoking-GCC" accesskey="u" rel="up">Invoking GCC</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="GCC-Developer-Options"></a> +<h3 class="section">3.18 GCC Developer Options</h3> +<a name="index-developer-options"></a> +<a name="index-debugging-GCC"></a> +<a name="index-debug-dump-options"></a> +<a name="index-dump-options"></a> +<a name="index-compilation-statistics"></a> + +<p>This section describes command-line options that are primarily of +interest to GCC developers, including options to support compiler +testing and investigation of compiler bugs and compile-time +performance problems. This includes options that produce debug dumps +at various points in the compilation; that print statistics such as +memory use and execution time; and that print information about GCC’s +configuration, such as where it searches for libraries. You should +rarely need to use any of these options for ordinary compilation and +linking tasks. +</p> +<p>Many developer options that cause GCC to dump output to a file take an +optional ‘<samp>=<var>filename</var></samp>’ suffix. You can specify ‘<samp>stdout</samp>’ +or ‘<samp>-</samp>’ to dump to standard output, and ‘<samp>stderr</samp>’ for standard +error. +</p> +<p>If ‘<samp>=<var>filename</var></samp>’ is omitted, a default dump file name is +constructed by concatenating the base dump file name, a pass number, +phase letter, and pass name. The base dump file name is the name of +output file produced by the compiler if explicitly specified and not +an executable; otherwise it is the source file name. +The pass number is determined by the order passes are registered with +the compiler’s pass manager. +This is generally the same as the order of execution, but passes +registered by plugins, target-specific passes, or passes that are +otherwise registered late are numbered higher than the pass named +‘<samp>final</samp>’, even if they are executed earlier. The phase letter is +one of ‘<samp>i</samp>’ (inter-procedural analysis), ‘<samp>l</samp>’ +(language-specific), ‘<samp>r</samp>’ (RTL), or ‘<samp>t</samp>’ (tree). +The files are created in the directory of the output file. +</p> +<dl compact="compact"> +<dd> +<a name="index-fcallgraph_002dinfo"></a> +</dd> +<dt><code>-fcallgraph-info</code></dt> +<dt><code>-fcallgraph-info=<var>MARKERS</var></code></dt> +<dd><p>Makes the compiler output callgraph information for the program, on a +per-object-file basis. The information is generated in the common VCG +format. It can be decorated with additional, per-node and/or per-edge +information, if a list of comma-separated markers is additionally +specified. When the <code>su</code> marker is specified, the callgraph is +decorated with stack usage information; it is equivalent to +<samp>-fstack-usage</samp>. When the <code>da</code> marker is specified, the +callgraph is decorated with information about dynamically allocated +objects. +</p> +<p>When compiling with <samp>-flto</samp>, no callgraph information is output +along with the object file. At LTO link time, <samp>-fcallgraph-info</samp> +may generate multiple callgraph information files next to intermediate +LTO output files. +</p> +<a name="index-d-1"></a> +<a name="index-fdump_002drtl_002dpass"></a> +</dd> +<dt><code>-d<var>letters</var></code></dt> +<dt><code>-fdump-rtl-<var>pass</var></code></dt> +<dt><code>-fdump-rtl-<var>pass</var>=<var>filename</var></code></dt> +<dd><p>Says to make debugging dumps during compilation at times specified by +<var>letters</var>. This is used for debugging the RTL-based passes of the +compiler. +</p> +<p>Some <samp>-d<var>letters</var></samp> switches have different meaning when +<samp>-E</samp> is used for preprocessing. See <a href="Preprocessor-Options.html#Preprocessor-Options">Preprocessor Options</a>, +for information about preprocessor-specific dump options. +</p> +<p>Debug dumps can be enabled with a <samp>-fdump-rtl</samp> switch or some +<samp>-d</samp> option <var>letters</var>. Here are the possible +letters for use in <var>pass</var> and <var>letters</var>, and their meanings: +</p> +<dl compact="compact"> +<dd> +<a name="index-fdump_002drtl_002dalignments"></a> +</dd> +<dt><code>-fdump-rtl-alignments</code></dt> +<dd><p>Dump after branch alignments have been computed. +</p> +<a name="index-fdump_002drtl_002dasmcons"></a> +</dd> +<dt><code>-fdump-rtl-asmcons</code></dt> +<dd><p>Dump after fixing rtl statements that have unsatisfied in/out constraints. +</p> +<a name="index-fdump_002drtl_002dauto_005finc_005fdec"></a> +</dd> +<dt><code>-fdump-rtl-auto_inc_dec</code></dt> +<dd><p>Dump after auto-inc-dec discovery. This pass is only run on +architectures that have auto inc or auto dec instructions. +</p> +<a name="index-fdump_002drtl_002dbarriers"></a> +</dd> +<dt><code>-fdump-rtl-barriers</code></dt> +<dd><p>Dump after cleaning up the barrier instructions. +</p> +<a name="index-fdump_002drtl_002dbbpart"></a> +</dd> +<dt><code>-fdump-rtl-bbpart</code></dt> +<dd><p>Dump after partitioning hot and cold basic blocks. +</p> +<a name="index-fdump_002drtl_002dbbro"></a> +</dd> +<dt><code>-fdump-rtl-bbro</code></dt> +<dd><p>Dump after block reordering. +</p> +<a name="index-fdump_002drtl_002dbtl2"></a> +<a name="index-fdump_002drtl_002dbtl2-1"></a> +</dd> +<dt><code>-fdump-rtl-btl1</code></dt> +<dt><code>-fdump-rtl-btl2</code></dt> +<dd><p><samp>-fdump-rtl-btl1</samp> and <samp>-fdump-rtl-btl2</samp> enable dumping +after the two branch +target load optimization passes. +</p> +<a name="index-fdump_002drtl_002dbypass"></a> +</dd> +<dt><code>-fdump-rtl-bypass</code></dt> +<dd><p>Dump after jump bypassing and control flow optimizations. +</p> +<a name="index-fdump_002drtl_002dcombine"></a> +</dd> +<dt><code>-fdump-rtl-combine</code></dt> +<dd><p>Dump after the RTL instruction combination pass. +</p> +<a name="index-fdump_002drtl_002dcompgotos"></a> +</dd> +<dt><code>-fdump-rtl-compgotos</code></dt> +<dd><p>Dump after duplicating the computed gotos. +</p> +<a name="index-fdump_002drtl_002dce1"></a> +<a name="index-fdump_002drtl_002dce2"></a> +<a name="index-fdump_002drtl_002dce3"></a> +</dd> +<dt><code>-fdump-rtl-ce1</code></dt> +<dt><code>-fdump-rtl-ce2</code></dt> +<dt><code>-fdump-rtl-ce3</code></dt> +<dd><p><samp>-fdump-rtl-ce1</samp>, <samp>-fdump-rtl-ce2</samp>, and +<samp>-fdump-rtl-ce3</samp> enable dumping after the three +if conversion passes. +</p> +<a name="index-fdump_002drtl_002dcprop_005fhardreg"></a> +</dd> +<dt><code>-fdump-rtl-cprop_hardreg</code></dt> +<dd><p>Dump after hard register copy propagation. +</p> +<a name="index-fdump_002drtl_002dcsa"></a> +</dd> +<dt><code>-fdump-rtl-csa</code></dt> +<dd><p>Dump after combining stack adjustments. +</p> +<a name="index-fdump_002drtl_002dcse1"></a> +<a name="index-fdump_002drtl_002dcse2"></a> +</dd> +<dt><code>-fdump-rtl-cse1</code></dt> +<dt><code>-fdump-rtl-cse2</code></dt> +<dd><p><samp>-fdump-rtl-cse1</samp> and <samp>-fdump-rtl-cse2</samp> enable dumping after +the two common subexpression elimination passes. +</p> +<a name="index-fdump_002drtl_002ddce"></a> +</dd> +<dt><code>-fdump-rtl-dce</code></dt> +<dd><p>Dump after the standalone dead code elimination passes. +</p> +<a name="index-fdump_002drtl_002ddbr"></a> +</dd> +<dt><code>-fdump-rtl-dbr</code></dt> +<dd><p>Dump after delayed branch scheduling. +</p> +<a name="index-fdump_002drtl_002ddce1"></a> +<a name="index-fdump_002drtl_002ddce2"></a> +</dd> +<dt><code>-fdump-rtl-dce1</code></dt> +<dt><code>-fdump-rtl-dce2</code></dt> +<dd><p><samp>-fdump-rtl-dce1</samp> and <samp>-fdump-rtl-dce2</samp> enable dumping after +the two dead store elimination passes. +</p> +<a name="index-fdump_002drtl_002deh"></a> +</dd> +<dt><code>-fdump-rtl-eh</code></dt> +<dd><p>Dump after finalization of EH handling code. +</p> +<a name="index-fdump_002drtl_002deh_005franges"></a> +</dd> +<dt><code>-fdump-rtl-eh_ranges</code></dt> +<dd><p>Dump after conversion of EH handling range regions. +</p> +<a name="index-fdump_002drtl_002dexpand"></a> +</dd> +<dt><code>-fdump-rtl-expand</code></dt> +<dd><p>Dump after RTL generation. +</p> +<a name="index-fdump_002drtl_002dfwprop1"></a> +<a name="index-fdump_002drtl_002dfwprop2"></a> +</dd> +<dt><code>-fdump-rtl-fwprop1</code></dt> +<dt><code>-fdump-rtl-fwprop2</code></dt> +<dd><p><samp>-fdump-rtl-fwprop1</samp> and <samp>-fdump-rtl-fwprop2</samp> enable +dumping after the two forward propagation passes. +</p> +<a name="index-fdump_002drtl_002dgcse1"></a> +<a name="index-fdump_002drtl_002dgcse2"></a> +</dd> +<dt><code>-fdump-rtl-gcse1</code></dt> +<dt><code>-fdump-rtl-gcse2</code></dt> +<dd><p><samp>-fdump-rtl-gcse1</samp> and <samp>-fdump-rtl-gcse2</samp> enable dumping +after global common subexpression elimination. +</p> +<a name="index-fdump_002drtl_002dinit_002dregs"></a> +</dd> +<dt><code>-fdump-rtl-init-regs</code></dt> +<dd><p>Dump after the initialization of the registers. +</p> +<a name="index-fdump_002drtl_002dinitvals"></a> +</dd> +<dt><code>-fdump-rtl-initvals</code></dt> +<dd><p>Dump after the computation of the initial value sets. +</p> +<a name="index-fdump_002drtl_002dinto_005fcfglayout"></a> +</dd> +<dt><code>-fdump-rtl-into_cfglayout</code></dt> +<dd><p>Dump after converting to cfglayout mode. +</p> +<a name="index-fdump_002drtl_002dira"></a> +</dd> +<dt><code>-fdump-rtl-ira</code></dt> +<dd><p>Dump after iterated register allocation. +</p> +<a name="index-fdump_002drtl_002djump"></a> +</dd> +<dt><code>-fdump-rtl-jump</code></dt> +<dd><p>Dump after the second jump optimization. +</p> +<a name="index-fdump_002drtl_002dloop2"></a> +</dd> +<dt><code>-fdump-rtl-loop2</code></dt> +<dd><p><samp>-fdump-rtl-loop2</samp> enables dumping after the rtl +loop optimization passes. +</p> +<a name="index-fdump_002drtl_002dmach"></a> +</dd> +<dt><code>-fdump-rtl-mach</code></dt> +<dd><p>Dump after performing the machine dependent reorganization pass, if that +pass exists. +</p> +<a name="index-fdump_002drtl_002dmode_005fsw"></a> +</dd> +<dt><code>-fdump-rtl-mode_sw</code></dt> +<dd><p>Dump after removing redundant mode switches. +</p> +<a name="index-fdump_002drtl_002drnreg"></a> +</dd> +<dt><code>-fdump-rtl-rnreg</code></dt> +<dd><p>Dump after register renumbering. +</p> +<a name="index-fdump_002drtl_002doutof_005fcfglayout"></a> +</dd> +<dt><code>-fdump-rtl-outof_cfglayout</code></dt> +<dd><p>Dump after converting from cfglayout mode. +</p> +<a name="index-fdump_002drtl_002dpeephole2"></a> +</dd> +<dt><code>-fdump-rtl-peephole2</code></dt> +<dd><p>Dump after the peephole pass. +</p> +<a name="index-fdump_002drtl_002dpostreload"></a> +</dd> +<dt><code>-fdump-rtl-postreload</code></dt> +<dd><p>Dump after post-reload optimizations. +</p> +<a name="index-fdump_002drtl_002dpro_005fand_005fepilogue"></a> +</dd> +<dt><code>-fdump-rtl-pro_and_epilogue</code></dt> +<dd><p>Dump after generating the function prologues and epilogues. +</p> +<a name="index-fdump_002drtl_002dsched1"></a> +<a name="index-fdump_002drtl_002dsched2"></a> +</dd> +<dt><code>-fdump-rtl-sched1</code></dt> +<dt><code>-fdump-rtl-sched2</code></dt> +<dd><p><samp>-fdump-rtl-sched1</samp> and <samp>-fdump-rtl-sched2</samp> enable dumping +after the basic block scheduling passes. +</p> +<a name="index-fdump_002drtl_002dree"></a> +</dd> +<dt><code>-fdump-rtl-ree</code></dt> +<dd><p>Dump after sign/zero extension elimination. +</p> +<a name="index-fdump_002drtl_002dseqabstr"></a> +</dd> +<dt><code>-fdump-rtl-seqabstr</code></dt> +<dd><p>Dump after common sequence discovery. +</p> +<a name="index-fdump_002drtl_002dshorten"></a> +</dd> +<dt><code>-fdump-rtl-shorten</code></dt> +<dd><p>Dump after shortening branches. +</p> +<a name="index-fdump_002drtl_002dsibling"></a> +</dd> +<dt><code>-fdump-rtl-sibling</code></dt> +<dd><p>Dump after sibling call optimizations. +</p> +<a name="index-fdump_002drtl_002dsplit1"></a> +<a name="index-fdump_002drtl_002dsplit2"></a> +<a name="index-fdump_002drtl_002dsplit3"></a> +<a name="index-fdump_002drtl_002dsplit4"></a> +<a name="index-fdump_002drtl_002dsplit5"></a> +</dd> +<dt><code>-fdump-rtl-split1</code></dt> +<dt><code>-fdump-rtl-split2</code></dt> +<dt><code>-fdump-rtl-split3</code></dt> +<dt><code>-fdump-rtl-split4</code></dt> +<dt><code>-fdump-rtl-split5</code></dt> +<dd><p>These options enable dumping after five rounds of +instruction splitting. +</p> +<a name="index-fdump_002drtl_002dsms"></a> +</dd> +<dt><code>-fdump-rtl-sms</code></dt> +<dd><p>Dump after modulo scheduling. This pass is only run on some +architectures. +</p> +<a name="index-fdump_002drtl_002dstack"></a> +</dd> +<dt><code>-fdump-rtl-stack</code></dt> +<dd><p>Dump after conversion from GCC’s “flat register file” registers to the +x87’s stack-like registers. This pass is only run on x86 variants. +</p> +<a name="index-fdump_002drtl_002dsubreg1"></a> +<a name="index-fdump_002drtl_002dsubreg2"></a> +</dd> +<dt><code>-fdump-rtl-subreg1</code></dt> +<dt><code>-fdump-rtl-subreg2</code></dt> +<dd><p><samp>-fdump-rtl-subreg1</samp> and <samp>-fdump-rtl-subreg2</samp> enable dumping after +the two subreg expansion passes. +</p> +<a name="index-fdump_002drtl_002dunshare"></a> +</dd> +<dt><code>-fdump-rtl-unshare</code></dt> +<dd><p>Dump after all rtl has been unshared. +</p> +<a name="index-fdump_002drtl_002dvartrack"></a> +</dd> +<dt><code>-fdump-rtl-vartrack</code></dt> +<dd><p>Dump after variable tracking. +</p> +<a name="index-fdump_002drtl_002dvregs"></a> +</dd> +<dt><code>-fdump-rtl-vregs</code></dt> +<dd><p>Dump after converting virtual registers to hard registers. +</p> +<a name="index-fdump_002drtl_002dweb"></a> +</dd> +<dt><code>-fdump-rtl-web</code></dt> +<dd><p>Dump after live range splitting. +</p> +<a name="index-fdump_002drtl_002dregclass"></a> +<a name="index-fdump_002drtl_002dsubregs_005fof_005fmode_005finit"></a> +<a name="index-fdump_002drtl_002dsubregs_005fof_005fmode_005ffinish"></a> +<a name="index-fdump_002drtl_002ddfinit"></a> +<a name="index-fdump_002drtl_002ddfinish"></a> +</dd> +<dt><code>-fdump-rtl-regclass</code></dt> +<dt><code>-fdump-rtl-subregs_of_mode_init</code></dt> +<dt><code>-fdump-rtl-subregs_of_mode_finish</code></dt> +<dt><code>-fdump-rtl-dfinit</code></dt> +<dt><code>-fdump-rtl-dfinish</code></dt> +<dd><p>These dumps are defined but always produce empty files. +</p> +<a name="index-da"></a> +<a name="index-fdump_002drtl_002dall"></a> +</dd> +<dt><code>-da</code></dt> +<dt><code>-fdump-rtl-all</code></dt> +<dd><p>Produce all the dumps listed above. +</p> +<a name="index-dA"></a> +</dd> +<dt><code>-dA</code></dt> +<dd><p>Annotate the assembler output with miscellaneous debugging information. +</p> +<a name="index-dD-1"></a> +</dd> +<dt><code>-dD</code></dt> +<dd><p>Dump all macro definitions, at the end of preprocessing, in addition to +normal output. +</p> +<a name="index-dH"></a> +</dd> +<dt><code>-dH</code></dt> +<dd><p>Produce a core dump whenever an error occurs. +</p> +<a name="index-dp"></a> +</dd> +<dt><code>-dp</code></dt> +<dd><p>Annotate the assembler output with a comment indicating which +pattern and alternative is used. The length and cost of each instruction are +also printed. +</p> +<a name="index-dP"></a> +</dd> +<dt><code>-dP</code></dt> +<dd><p>Dump the RTL in the assembler output as a comment before each instruction. +Also turns on <samp>-dp</samp> annotation. +</p> +<a name="index-dx"></a> +</dd> +<dt><code>-dx</code></dt> +<dd><p>Just generate RTL for a function instead of compiling it. Usually used +with <samp>-fdump-rtl-expand</samp>. +</p></dd> +</dl> + +<a name="index-fdump_002ddebug"></a> +</dd> +<dt><code>-fdump-debug</code></dt> +<dd><p>Dump debugging information generated during the debug +generation phase. +</p> +<a name="index-fdump_002dearlydebug"></a> +</dd> +<dt><code>-fdump-earlydebug</code></dt> +<dd><p>Dump debugging information generated during the early debug +generation phase. +</p> +<a name="index-fdump_002dnoaddr"></a> +</dd> +<dt><code>-fdump-noaddr</code></dt> +<dd><p>When doing debugging dumps, suppress address output. This makes it more +feasible to use diff on debugging dumps for compiler invocations with +different compiler binaries and/or different +text / bss / data / heap / stack / dso start locations. +</p> +<a name="index-freport_002dbug"></a> +</dd> +<dt><code>-freport-bug</code></dt> +<dd><p>Collect and dump debug information into a temporary file if an +internal compiler error (ICE) occurs. +</p> +<a name="index-fdump_002dunnumbered"></a> +</dd> +<dt><code>-fdump-unnumbered</code></dt> +<dd><p>When doing debugging dumps, suppress instruction numbers and address output. +This makes it more feasible to use diff on debugging dumps for compiler +invocations with different options, in particular with and without +<samp>-g</samp>. +</p> +<a name="index-fdump_002dunnumbered_002dlinks"></a> +</dd> +<dt><code>-fdump-unnumbered-links</code></dt> +<dd><p>When doing debugging dumps (see <samp>-d</samp> option above), suppress +instruction numbers for the links to the previous and next instructions +in a sequence. +</p> +<a name="index-fdump_002dipa"></a> +</dd> +<dt><code>-fdump-ipa-<var>switch</var></code></dt> +<dt><code>-fdump-ipa-<var>switch</var>-<var>options</var></code></dt> +<dd><p>Control the dumping at various stages of inter-procedural analysis +language tree to a file. The file name is generated by appending a +switch specific suffix to the source file name, and the file is created +in the same directory as the output file. The following dumps are +possible: +</p> +<dl compact="compact"> +<dt>‘<samp>all</samp>’</dt> +<dd><p>Enables all inter-procedural analysis dumps. +</p> +</dd> +<dt>‘<samp>cgraph</samp>’</dt> +<dd><p>Dumps information about call-graph optimization, unused function removal, +and inlining decisions. +</p> +</dd> +<dt>‘<samp>inline</samp>’</dt> +<dd><p>Dump after function inlining. +</p> +</dd> +</dl> + +<p>Additionally, the options <samp>-optimized</samp>, <samp>-missed</samp>, +<samp>-note</samp>, and <samp>-all</samp> can be provided, with the same meaning +as for <samp>-fopt-info</samp>, defaulting to <samp>-optimized</samp>. +</p> +<p>For example, <samp>-fdump-ipa-inline-optimized-missed</samp> will emit +information on callsites that were inlined, along with callsites +that were not inlined. +</p> +<p>By default, the dump will contain messages about successful +optimizations (equivalent to <samp>-optimized</samp>) together with +low-level details about the analysis. +</p> +<a name="index-fdump_002dlang"></a> +</dd> +<dt><code>-fdump-lang</code></dt> +<dd><p>Dump language-specific information. The file name is made by appending +<samp>.lang</samp> to the source file name. +</p> +<a name="index-fdump_002dlang_002dall"></a> +<a name="index-fdump_002dlang-1"></a> +</dd> +<dt><code>-fdump-lang-all</code></dt> +<dt><code>-fdump-lang-<var>switch</var></code></dt> +<dt><code>-fdump-lang-<var>switch</var>-<var>options</var></code></dt> +<dt><code>-fdump-lang-<var>switch</var>-<var>options</var>=<var>filename</var></code></dt> +<dd><p>Control the dumping of language-specific information. The <var>options</var> +and <var>filename</var> portions behave as described in the +<samp>-fdump-tree</samp> option. The following <var>switch</var> values are +accepted: +</p> +<dl compact="compact"> +<dt>‘<samp>all</samp>’</dt> +<dd> +<p>Enable all language-specific dumps. +</p> +</dd> +<dt>‘<samp>class</samp>’</dt> +<dd><p>Dump class hierarchy information. Virtual table information is emitted +unless ’<samp>slim</samp>’ is specified. This option is applicable to C++ only. +</p> +</dd> +<dt>‘<samp>module</samp>’</dt> +<dd><p>Dump module information. Options <samp>lineno</samp> (locations), +<samp>graph</samp> (reachability), <samp>blocks</samp> (clusters), +<samp>uid</samp> (serialization), <samp>alias</samp> (mergeable), +<samp>asmname</samp> (Elrond), <samp>eh</samp> (mapper) & <samp>vops</samp> +(macros) may provide additional information. This option is +applicable to C++ only. +</p> +</dd> +<dt>‘<samp>raw</samp>’</dt> +<dd><p>Dump the raw internal tree data. This option is applicable to C++ only. +</p> +</dd> +</dl> + +<a name="index-fdump_002dpasses"></a> +</dd> +<dt><code>-fdump-passes</code></dt> +<dd><p>Print on <samp>stderr</samp> the list of optimization passes that are turned +on and off by the current command-line options. +</p> +<a name="index-fdump_002dstatistics"></a> +</dd> +<dt><code>-fdump-statistics-<var>option</var></code></dt> +<dd><p>Enable and control dumping of pass statistics in a separate file. The +file name is generated by appending a suffix ending in +‘<samp>.statistics</samp>’ to the source file name, and the file is created in +the same directory as the output file. If the ‘<samp>-<var>option</var></samp>’ +form is used, ‘<samp>-stats</samp>’ causes counters to be summed over the +whole compilation unit while ‘<samp>-details</samp>’ dumps every event as +the passes generate them. The default with no option is to sum +counters for each function compiled. +</p> +<a name="index-fdump_002dtree_002dall"></a> +<a name="index-fdump_002dtree"></a> +</dd> +<dt><code>-fdump-tree-all</code></dt> +<dt><code>-fdump-tree-<var>switch</var></code></dt> +<dt><code>-fdump-tree-<var>switch</var>-<var>options</var></code></dt> +<dt><code>-fdump-tree-<var>switch</var>-<var>options</var>=<var>filename</var></code></dt> +<dd><p>Control the dumping at various stages of processing the intermediate +language tree to a file. If the ‘<samp>-<var>options</var></samp>’ +form is used, <var>options</var> is a list of ‘<samp>-</samp>’ separated options +which control the details of the dump. Not all options are applicable +to all dumps; those that are not meaningful are ignored. The +following options are available +</p> +<dl compact="compact"> +<dt>‘<samp>address</samp>’</dt> +<dd><p>Print the address of each node. Usually this is not meaningful as it +changes according to the environment and source file. Its primary use +is for tying up a dump file with a debug environment. +</p></dd> +<dt>‘<samp>asmname</samp>’</dt> +<dd><p>If <code>DECL_ASSEMBLER_NAME</code> has been set for a given decl, use that +in the dump instead of <code>DECL_NAME</code>. Its primary use is ease of +use working backward from mangled names in the assembly file. +</p></dd> +<dt>‘<samp>slim</samp>’</dt> +<dd><p>When dumping front-end intermediate representations, inhibit dumping +of members of a scope or body of a function merely because that scope +has been reached. Only dump such items when they are directly reachable +by some other path. +</p> +<p>When dumping pretty-printed trees, this option inhibits dumping the +bodies of control structures. +</p> +<p>When dumping RTL, print the RTL in slim (condensed) form instead of +the default LISP-like representation. +</p></dd> +<dt>‘<samp>raw</samp>’</dt> +<dd><p>Print a raw representation of the tree. By default, trees are +pretty-printed into a C-like representation. +</p></dd> +<dt>‘<samp>details</samp>’</dt> +<dd><p>Enable more detailed dumps (not honored by every dump option). Also +include information from the optimization passes. +</p></dd> +<dt>‘<samp>stats</samp>’</dt> +<dd><p>Enable dumping various statistics about the pass (not honored by every dump +option). +</p></dd> +<dt>‘<samp>blocks</samp>’</dt> +<dd><p>Enable showing basic block boundaries (disabled in raw dumps). +</p></dd> +<dt>‘<samp>graph</samp>’</dt> +<dd><p>For each of the other indicated dump files (<samp>-fdump-rtl-<var>pass</var></samp>), +dump a representation of the control flow graph suitable for viewing with +GraphViz to <samp><var>file</var>.<var>passid</var>.<var>pass</var>.dot</samp>. Each function in +the file is pretty-printed as a subgraph, so that GraphViz can render them +all in a single plot. +</p> +<p>This option currently only works for RTL dumps, and the RTL is always +dumped in slim form. +</p></dd> +<dt>‘<samp>vops</samp>’</dt> +<dd><p>Enable showing virtual operands for every statement. +</p></dd> +<dt>‘<samp>lineno</samp>’</dt> +<dd><p>Enable showing line numbers for statements. +</p></dd> +<dt>‘<samp>uid</samp>’</dt> +<dd><p>Enable showing the unique ID (<code>DECL_UID</code>) for each variable. +</p></dd> +<dt>‘<samp>verbose</samp>’</dt> +<dd><p>Enable showing the tree dump for each statement. +</p></dd> +<dt>‘<samp>eh</samp>’</dt> +<dd><p>Enable showing the EH region number holding each statement. +</p></dd> +<dt>‘<samp>scev</samp>’</dt> +<dd><p>Enable showing scalar evolution analysis details. +</p></dd> +<dt>‘<samp>optimized</samp>’</dt> +<dd><p>Enable showing optimization information (only available in certain +passes). +</p></dd> +<dt>‘<samp>missed</samp>’</dt> +<dd><p>Enable showing missed optimization information (only available in certain +passes). +</p></dd> +<dt>‘<samp>note</samp>’</dt> +<dd><p>Enable other detailed optimization information (only available in +certain passes). +</p></dd> +<dt>‘<samp>all</samp>’</dt> +<dd><p>Turn on all options, except <samp>raw</samp>, <samp>slim</samp>, <samp>verbose</samp> +and <samp>lineno</samp>. +</p></dd> +<dt>‘<samp>optall</samp>’</dt> +<dd><p>Turn on all optimization options, i.e., <samp>optimized</samp>, +<samp>missed</samp>, and <samp>note</samp>. +</p></dd> +</dl> + +<p>To determine what tree dumps are available or find the dump for a pass +of interest follow the steps below. +</p> +<ol> +<li> Invoke GCC with <samp>-fdump-passes</samp> and in the <samp>stderr</samp> output +look for a code that corresponds to the pass you are interested in. +For example, the codes <code>tree-evrp</code>, <code>tree-vrp1</code>, and +<code>tree-vrp2</code> correspond to the three Value Range Propagation passes. +The number at the end distinguishes distinct invocations of the same pass. +</li><li> To enable the creation of the dump file, append the pass code to +the <samp>-fdump-</samp> option prefix and invoke GCC with it. For example, +to enable the dump from the Early Value Range Propagation pass, invoke +GCC with the <samp>-fdump-tree-evrp</samp> option. Optionally, you may +specify the name of the dump file. If you don’t specify one, GCC +creates as described below. +</li><li> Find the pass dump in a file whose name is composed of three components +separated by a period: the name of the source file GCC was invoked to +compile, a numeric suffix indicating the pass number followed by the +letter ‘<samp>t</samp>’ for tree passes (and the letter ‘<samp>r</samp>’ for RTL passes), +and finally the pass code. For example, the Early VRP pass dump might +be in a file named <samp>myfile.c.038t.evrp</samp> in the current working +directory. Note that the numeric codes are not stable and may change +from one version of GCC to another. +</li></ol> + +<a name="index-fopt_002dinfo"></a> +</dd> +<dt><code>-fopt-info</code></dt> +<dt><code>-fopt-info-<var>options</var></code></dt> +<dt><code>-fopt-info-<var>options</var>=<var>filename</var></code></dt> +<dd><p>Controls optimization dumps from various optimization passes. If the +‘<samp>-<var>options</var></samp>’ form is used, <var>options</var> is a list of +‘<samp>-</samp>’ separated option keywords to select the dump details and +optimizations. +</p> +<p>The <var>options</var> can be divided into three groups: +</p><ol> +<li> options describing what kinds of messages should be emitted, +</li><li> options describing the verbosity of the dump, and +</li><li> options describing which optimizations should be included. +</li></ol> +<p>The options from each group can be freely mixed as they are +non-overlapping. However, in case of any conflicts, +the later options override the earlier options on the command +line. +</p> +<p>The following options control which kinds of messages should be emitted: +</p> +<dl compact="compact"> +<dt>‘<samp>optimized</samp>’</dt> +<dd><p>Print information when an optimization is successfully applied. It is +up to a pass to decide which information is relevant. For example, the +vectorizer passes print the source location of loops which are +successfully vectorized. +</p></dd> +<dt>‘<samp>missed</samp>’</dt> +<dd><p>Print information about missed optimizations. Individual passes +control which information to include in the output. +</p></dd> +<dt>‘<samp>note</samp>’</dt> +<dd><p>Print verbose information about optimizations, such as certain +transformations, more detailed messages about decisions etc. +</p></dd> +<dt>‘<samp>all</samp>’</dt> +<dd><p>Print detailed optimization information. This includes +‘<samp>optimized</samp>’, ‘<samp>missed</samp>’, and ‘<samp>note</samp>’. +</p></dd> +</dl> + +<p>The following option controls the dump verbosity: +</p> +<dl compact="compact"> +<dt>‘<samp>internals</samp>’</dt> +<dd><p>By default, only “high-level” messages are emitted. This option enables +additional, more detailed, messages, which are likely to only be of interest +to GCC developers. +</p></dd> +</dl> + +<p>One or more of the following option keywords can be used to describe a +group of optimizations: +</p> +<dl compact="compact"> +<dt>‘<samp>ipa</samp>’</dt> +<dd><p>Enable dumps from all interprocedural optimizations. +</p></dd> +<dt>‘<samp>loop</samp>’</dt> +<dd><p>Enable dumps from all loop optimizations. +</p></dd> +<dt>‘<samp>inline</samp>’</dt> +<dd><p>Enable dumps from all inlining optimizations. +</p></dd> +<dt>‘<samp>omp</samp>’</dt> +<dd><p>Enable dumps from all OMP (Offloading and Multi Processing) optimizations. +</p></dd> +<dt>‘<samp>vec</samp>’</dt> +<dd><p>Enable dumps from all vectorization optimizations. +</p></dd> +<dt>‘<samp>optall</samp>’</dt> +<dd><p>Enable dumps from all optimizations. This is a superset of +the optimization groups listed above. +</p></dd> +</dl> + +<p>If <var>options</var> is +omitted, it defaults to ‘<samp>optimized-optall</samp>’, which means to dump messages +about successful optimizations from all the passes, omitting messages +that are treated as “internals”. +</p> +<p>If the <var>filename</var> is provided, then the dumps from all the +applicable optimizations are concatenated into the <var>filename</var>. +Otherwise the dump is output onto <samp>stderr</samp>. Though multiple +<samp>-fopt-info</samp> options are accepted, only one of them can include +a <var>filename</var>. If other filenames are provided then all but the +first such option are ignored. +</p> +<p>Note that the output <var>filename</var> is overwritten +in case of multiple translation units. If a combined output from +multiple translation units is desired, <samp>stderr</samp> should be used +instead. +</p> +<p>In the following example, the optimization info is output to +<samp>stderr</samp>: +</p> +<div class="smallexample"> +<pre class="smallexample">gcc -O3 -fopt-info +</pre></div> + +<p>This example: +</p><div class="smallexample"> +<pre class="smallexample">gcc -O3 -fopt-info-missed=missed.all +</pre></div> + +<p>outputs missed optimization report from all the passes into +<samp>missed.all</samp>, and this one: +</p> +<div class="smallexample"> +<pre class="smallexample">gcc -O2 -ftree-vectorize -fopt-info-vec-missed +</pre></div> + +<p>prints information about missed optimization opportunities from +vectorization passes on <samp>stderr</samp>. +Note that <samp>-fopt-info-vec-missed</samp> is equivalent to +<samp>-fopt-info-missed-vec</samp>. The order of the optimization group +names and message types listed after <samp>-fopt-info</samp> does not matter. +</p> +<p>As another example, +</p><div class="smallexample"> +<pre class="smallexample">gcc -O3 -fopt-info-inline-optimized-missed=inline.txt +</pre></div> + +<p>outputs information about missed optimizations as well as +optimized locations from all the inlining passes into +<samp>inline.txt</samp>. +</p> +<p>Finally, consider: +</p> +<div class="smallexample"> +<pre class="smallexample">gcc -fopt-info-vec-missed=vec.miss -fopt-info-loop-optimized=loop.opt +</pre></div> + +<p>Here the two output filenames <samp>vec.miss</samp> and <samp>loop.opt</samp> are +in conflict since only one output file is allowed. In this case, only +the first option takes effect and the subsequent options are +ignored. Thus only <samp>vec.miss</samp> is produced which contains +dumps from the vectorizer about missed opportunities. +</p> +<a name="index-fsave_002doptimization_002drecord"></a> +</dd> +<dt><code>-fsave-optimization-record</code></dt> +<dd><p>Write a SRCFILE.opt-record.json.gz file detailing what optimizations +were performed, for those optimizations that support <samp>-fopt-info</samp>. +</p> +<p>This option is experimental and the format of the data within the +compressed JSON file is subject to change. +</p> +<p>It is roughly equivalent to a machine-readable version of +<samp>-fopt-info-all</samp>, as a collection of messages with source file, +line number and column number, with the following additional data for +each message: +</p> +<ul> +<li> the execution count of the code being optimized, along with metadata about +whether this was from actual profile data, or just an estimate, allowing +consumers to prioritize messages by code hotness, + +</li><li> the function name of the code being optimized, where applicable, + +</li><li> the “inlining chain” for the code being optimized, so that when +a function is inlined into several different places (which might +themselves be inlined), the reader can distinguish between the copies, + +</li><li> objects identifying those parts of the message that refer to expressions, +statements or symbol-table nodes, which of these categories they are, and, +when available, their source code location, + +</li><li> the GCC pass that emitted the message, and + +</li><li> the location in GCC’s own code from which the message was emitted + +</li></ul> + +<p>Additionally, some messages are logically nested within other +messages, reflecting implementation details of the optimization +passes. +</p> +<a name="index-fsched_002dverbose"></a> +</dd> +<dt><code>-fsched-verbose=<var>n</var></code></dt> +<dd><p>On targets that use instruction scheduling, this option controls the +amount of debugging output the scheduler prints to the dump files. +</p> +<p>For <var>n</var> greater than zero, <samp>-fsched-verbose</samp> outputs the +same information as <samp>-fdump-rtl-sched1</samp> and <samp>-fdump-rtl-sched2</samp>. +For <var>n</var> greater than one, it also output basic block probabilities, +detailed ready list information and unit/insn info. For <var>n</var> greater +than two, it includes RTL at abort point, control-flow and regions info. +And for <var>n</var> over four, <samp>-fsched-verbose</samp> also includes +dependence info. +</p> + + +<a name="index-fdisable_002d"></a> +<a name="index-fenable_002d"></a> +</dd> +<dt><code>-fenable-<var>kind</var>-<var>pass</var></code></dt> +<dt><code>-fdisable-<var>kind</var>-<var>pass</var>=<var>range-list</var></code></dt> +<dd> +<p>This is a set of options that are used to explicitly disable/enable +optimization passes. These options are intended for use for debugging GCC. +Compiler users should use regular options for enabling/disabling +passes instead. +</p> +<dl compact="compact"> +<dt><code>-fdisable-ipa-<var>pass</var></code></dt> +<dd><p>Disable IPA pass <var>pass</var>. <var>pass</var> is the pass name. If the same pass is +statically invoked in the compiler multiple times, the pass name should be +appended with a sequential number starting from 1. +</p> +</dd> +<dt><code>-fdisable-rtl-<var>pass</var></code></dt> +<dt><code>-fdisable-rtl-<var>pass</var>=<var>range-list</var></code></dt> +<dd><p>Disable RTL pass <var>pass</var>. <var>pass</var> is the pass name. If the same pass is +statically invoked in the compiler multiple times, the pass name should be +appended with a sequential number starting from 1. <var>range-list</var> is a +comma-separated list of function ranges or assembler names. Each range is a number +pair separated by a colon. The range is inclusive in both ends. If the range +is trivial, the number pair can be simplified as a single number. If the +function’s call graph node’s <var>uid</var> falls within one of the specified ranges, +the <var>pass</var> is disabled for that function. The <var>uid</var> is shown in the +function header of a dump file, and the pass names can be dumped by using +option <samp>-fdump-passes</samp>. +</p> +</dd> +<dt><code>-fdisable-tree-<var>pass</var></code></dt> +<dt><code>-fdisable-tree-<var>pass</var>=<var>range-list</var></code></dt> +<dd><p>Disable tree pass <var>pass</var>. See <samp>-fdisable-rtl</samp> for the description of +option arguments. +</p> +</dd> +<dt><code>-fenable-ipa-<var>pass</var></code></dt> +<dd><p>Enable IPA pass <var>pass</var>. <var>pass</var> is the pass name. If the same pass is +statically invoked in the compiler multiple times, the pass name should be +appended with a sequential number starting from 1. +</p> +</dd> +<dt><code>-fenable-rtl-<var>pass</var></code></dt> +<dt><code>-fenable-rtl-<var>pass</var>=<var>range-list</var></code></dt> +<dd><p>Enable RTL pass <var>pass</var>. See <samp>-fdisable-rtl</samp> for option argument +description and examples. +</p> +</dd> +<dt><code>-fenable-tree-<var>pass</var></code></dt> +<dt><code>-fenable-tree-<var>pass</var>=<var>range-list</var></code></dt> +<dd><p>Enable tree pass <var>pass</var>. See <samp>-fdisable-rtl</samp> for the description +of option arguments. +</p> +</dd> +</dl> + +<p>Here are some examples showing uses of these options. +</p> +<div class="smallexample"> +<pre class="smallexample"> +# disable ccp1 for all functions + -fdisable-tree-ccp1 +# disable complete unroll for function whose cgraph node uid is 1 + -fenable-tree-cunroll=1 +# disable gcse2 for functions at the following ranges [1,1], +# [300,400], and [400,1000] +# disable gcse2 for functions foo and foo2 + -fdisable-rtl-gcse2=foo,foo2 +# disable early inlining + -fdisable-tree-einline +# disable ipa inlining + -fdisable-ipa-inline +# enable tree full unroll + -fenable-tree-unroll + +</pre></div> + +<a name="index-fchecking"></a> +<a name="index-fno_002dchecking"></a> +</dd> +<dt><code>-fchecking</code></dt> +<dt><code>-fchecking=<var>n</var></code></dt> +<dd><p>Enable internal consistency checking. The default depends on +the compiler configuration. <samp>-fchecking=2</samp> enables further +internal consistency checking that might affect code generation. +</p> +<a name="index-frandom_002dseed"></a> +</dd> +<dt><code>-frandom-seed=<var>string</var></code></dt> +<dd><p>This option provides a seed that GCC uses in place of +random numbers in generating certain symbol names +that have to be different in every compiled file. It is also used to +place unique stamps in coverage data files and the object files that +produce them. You can use the <samp>-frandom-seed</samp> option to produce +reproducibly identical object files. +</p> +<p>The <var>string</var> can either be a number (decimal, octal or hex) or an +arbitrary string (in which case it’s converted to a number by +computing CRC32). +</p> +<p>The <var>string</var> should be different for every file you compile. +</p> +<a name="index-save_002dtemps"></a> +</dd> +<dt><code>-save-temps</code></dt> +<dd><p>Store the usual “temporary” intermediate files permanently; name them +as auxiliary output files, as specified described under +<samp>-dumpbase</samp> and <samp>-dumpdir</samp>. +</p> +<p>When used in combination with the <samp>-x</samp> command-line option, +<samp>-save-temps</samp> is sensible enough to avoid overwriting an +input source file with the same extension as an intermediate file. +The corresponding intermediate file may be obtained by renaming the +source file before using <samp>-save-temps</samp>. +</p> +<a name="index-save_002dtemps_003dcwd"></a> +</dd> +<dt><code>-save-temps=cwd</code></dt> +<dd><p>Equivalent to <samp>-save-temps -dumpdir ./</samp>. +</p> +<a name="index-save_002dtemps_003dobj"></a> +</dd> +<dt><code>-save-temps=obj</code></dt> +<dd><p>Equivalent to <samp>-save-temps -dumpdir <samp>outdir/</samp></samp>, where +<samp>outdir/</samp> is the directory of the output file specified after the +<samp>-o</samp> option, including any directory separators. If the +<samp>-o</samp> option is not used, the <samp>-save-temps=obj</samp> switch +behaves like <samp>-save-temps=cwd</samp>. +</p> +<a name="index-time"></a> +</dd> +<dt><code>-time<span class="roman">[</span>=<var>file</var><span class="roman">]</span></code></dt> +<dd><p>Report the CPU time taken by each subprocess in the compilation +sequence. For C source files, this is the compiler proper and assembler +(plus the linker if linking is done). +</p> +<p>Without the specification of an output file, the output looks like this: +</p> +<div class="smallexample"> +<pre class="smallexample"># cc1 0.12 0.01 +# as 0.00 0.01 +</pre></div> + +<p>The first number on each line is the “user time”, that is time spent +executing the program itself. The second number is “system time”, +time spent executing operating system routines on behalf of the program. +Both numbers are in seconds. +</p> +<p>With the specification of an output file, the output is appended to the +named file, and it looks like this: +</p> +<div class="smallexample"> +<pre class="smallexample">0.12 0.01 cc1 <var>options</var> +0.00 0.01 as <var>options</var> +</pre></div> + +<p>The “user time” and the “system time” are moved before the program +name, and the options passed to the program are displayed, so that one +can later tell what file was being compiled, and with which options. +</p> +<a name="index-fdump_002dfinal_002dinsns"></a> +</dd> +<dt><code>-fdump-final-insns<span class="roman">[</span>=<var>file</var><span class="roman">]</span></code></dt> +<dd><p>Dump the final internal representation (RTL) to <var>file</var>. If the +optional argument is omitted (or if <var>file</var> is <code>.</code>), the name +of the dump file is determined by appending <code>.gkd</code> to the +dump base name, see <samp>-dumpbase</samp>. +</p> +<a name="index-fcompare_002ddebug"></a> +<a name="index-fno_002dcompare_002ddebug"></a> +</dd> +<dt><code>-fcompare-debug<span class="roman">[</span>=<var>opts</var><span class="roman">]</span></code></dt> +<dd><p>If no error occurs during compilation, run the compiler a second time, +adding <var>opts</var> and <samp>-fcompare-debug-second</samp> to the arguments +passed to the second compilation. Dump the final internal +representation in both compilations, and print an error if they differ. +</p> +<p>If the equal sign is omitted, the default <samp>-gtoggle</samp> is used. +</p> +<p>The environment variable <code>GCC_COMPARE_DEBUG</code>, if defined, non-empty +and nonzero, implicitly enables <samp>-fcompare-debug</samp>. If +<code>GCC_COMPARE_DEBUG</code> is defined to a string starting with a dash, +then it is used for <var>opts</var>, otherwise the default <samp>-gtoggle</samp> +is used. +</p> +<p><samp>-fcompare-debug=</samp>, with the equal sign but without <var>opts</var>, +is equivalent to <samp>-fno-compare-debug</samp>, which disables the dumping +of the final representation and the second compilation, preventing even +<code>GCC_COMPARE_DEBUG</code> from taking effect. +</p> +<p>To verify full coverage during <samp>-fcompare-debug</samp> testing, set +<code>GCC_COMPARE_DEBUG</code> to say <samp>-fcompare-debug-not-overridden</samp>, +which GCC rejects as an invalid option in any actual compilation +(rather than preprocessing, assembly or linking). To get just a +warning, setting <code>GCC_COMPARE_DEBUG</code> to ‘<samp>-w%n-fcompare-debug +not overridden</samp>’ will do. +</p> +<a name="index-fcompare_002ddebug_002dsecond"></a> +</dd> +<dt><code>-fcompare-debug-second</code></dt> +<dd><p>This option is implicitly passed to the compiler for the second +compilation requested by <samp>-fcompare-debug</samp>, along with options to +silence warnings, and omitting other options that would cause the compiler +to produce output to files or to standard output as a side effect. Dump +files and preserved temporary files are renamed so as to contain the +<code>.gk</code> additional extension during the second compilation, to avoid +overwriting those generated by the first. +</p> +<p>When this option is passed to the compiler driver, it causes the +<em>first</em> compilation to be skipped, which makes it useful for little +other than debugging the compiler proper. +</p> +<a name="index-gtoggle"></a> +</dd> +<dt><code>-gtoggle</code></dt> +<dd><p>Turn off generation of debug info, if leaving out this option +generates it, or turn it on at level 2 otherwise. The position of this +argument in the command line does not matter; it takes effect after all +other options are processed, and it does so only once, no matter how +many times it is given. This is mainly intended to be used with +<samp>-fcompare-debug</samp>. +</p> +<a name="index-fvar_002dtracking_002dassignments_002dtoggle"></a> +<a name="index-fno_002dvar_002dtracking_002dassignments_002dtoggle"></a> +</dd> +<dt><code>-fvar-tracking-assignments-toggle</code></dt> +<dd><p>Toggle <samp>-fvar-tracking-assignments</samp>, in the same way that +<samp>-gtoggle</samp> toggles <samp>-g</samp>. +</p> +<a name="index-Q"></a> +</dd> +<dt><code>-Q</code></dt> +<dd><p>Makes the compiler print out each function name as it is compiled, and +print some statistics about each pass when it finishes. +</p> +<a name="index-ftime_002dreport"></a> +</dd> +<dt><code>-ftime-report</code></dt> +<dd><p>Makes the compiler print some statistics about the time consumed by each +pass when it finishes. +</p> +<a name="index-ftime_002dreport_002ddetails"></a> +</dd> +<dt><code>-ftime-report-details</code></dt> +<dd><p>Record the time consumed by infrastructure parts separately for each pass. +</p> +<a name="index-fira_002dverbose"></a> +</dd> +<dt><code>-fira-verbose=<var>n</var></code></dt> +<dd><p>Control the verbosity of the dump file for the integrated register allocator. +The default value is 5. If the value <var>n</var> is greater or equal to 10, +the dump output is sent to stderr using the same format as <var>n</var> minus 10. +</p> +<a name="index-flto_002dreport"></a> +</dd> +<dt><code>-flto-report</code></dt> +<dd><p>Prints a report with internal details on the workings of the link-time +optimizer. The contents of this report vary from version to version. +It is meant to be useful to GCC developers when processing object +files in LTO mode (via <samp>-flto</samp>). +</p> +<p>Disabled by default. +</p> +<a name="index-flto_002dreport_002dwpa"></a> +</dd> +<dt><code>-flto-report-wpa</code></dt> +<dd><p>Like <samp>-flto-report</samp>, but only print for the WPA phase of link-time +optimization. +</p> +<a name="index-fmem_002dreport"></a> +</dd> +<dt><code>-fmem-report</code></dt> +<dd><p>Makes the compiler print some statistics about permanent memory +allocation when it finishes. +</p> +<a name="index-fmem_002dreport_002dwpa"></a> +</dd> +<dt><code>-fmem-report-wpa</code></dt> +<dd><p>Makes the compiler print some statistics about permanent memory +allocation for the WPA phase only. +</p> +<a name="index-fpre_002dipa_002dmem_002dreport"></a> +<a name="index-fpost_002dipa_002dmem_002dreport"></a> +</dd> +<dt><code>-fpre-ipa-mem-report</code></dt> +<dt><code>-fpost-ipa-mem-report</code></dt> +<dd><p>Makes the compiler print some statistics about permanent memory +allocation before or after interprocedural optimization. +</p> +<a name="index-fmultiflags"></a> +</dd> +<dt><code>-fmultiflags</code></dt> +<dd><p>This option enables multilib-aware <code>TFLAGS</code> to be used to build +target libraries with options different from those the compiler is +configured to use by default, through the use of specs (See <a href="Spec-Files.html#Spec-Files">Spec Files</a>) set up by compiler internals, by the target, or by builders at +configure time. +</p> +<p>Like <code>TFLAGS</code>, this allows the target libraries to be built for +portable baseline environments, while the compiler defaults to more +demanding ones. That’s useful because users can easily override the +defaults the compiler is configured to use to build their own programs, +if the defaults are not ideal for their target environment, whereas +rebuilding the runtime libraries is usually not as easy or desirable. +</p> +<p>Unlike <code>TFLAGS</code>, the use of specs enables different flags to be +selected for different multilibs. The way to accomplish that is to +build with ‘<samp>make TFLAGS=-fmultiflags</samp>’, after configuring +‘<samp>--with-specs=%{fmultiflags:...}</samp>’. +</p> +<p>This option is discarded by the driver once it’s done processing driver +self spec. +</p> +<p>It is also useful to check that <code>TFLAGS</code> are being used to build +all target libraries, by configuring a non-bootstrap compiler +‘<samp>--with-specs='%{!fmultiflags:%emissing TFLAGS}'</samp>’ and building +the compiler and target libraries. +</p> +<a name="index-fprofile_002dreport"></a> +</dd> +<dt><code>-fprofile-report</code></dt> +<dd><p>Makes the compiler print some statistics about consistency of the +(estimated) profile and effect of individual passes. +</p> +<a name="index-fstack_002dusage"></a> +</dd> +<dt><code>-fstack-usage</code></dt> +<dd><p>Makes the compiler output stack usage information for the program, on a +per-function basis. The filename for the dump is made by appending +<samp>.su</samp> to the <var>auxname</var>. <var>auxname</var> is generated from the name of +the output file, if explicitly specified and it is not an executable, +otherwise it is the basename of the source file. An entry is made up +of three fields: +</p> +<ul> +<li> The name of the function. +</li><li> A number of bytes. +</li><li> One or more qualifiers: <code>static</code>, <code>dynamic</code>, <code>bounded</code>. +</li></ul> + +<p>The qualifier <code>static</code> means that the function manipulates the stack +statically: a fixed number of bytes are allocated for the frame on function +entry and released on function exit; no stack adjustments are otherwise made +in the function. The second field is this fixed number of bytes. +</p> +<p>The qualifier <code>dynamic</code> means that the function manipulates the stack +dynamically: in addition to the static allocation described above, stack +adjustments are made in the body of the function, for example to push/pop +arguments around function calls. If the qualifier <code>bounded</code> is also +present, the amount of these adjustments is bounded at compile time and +the second field is an upper bound of the total amount of stack used by +the function. If it is not present, the amount of these adjustments is +not bounded at compile time and the second field only represents the +bounded part. +</p> +<a name="index-fstats"></a> +</dd> +<dt><code>-fstats</code></dt> +<dd><p>Emit statistics about front-end processing at the end of the compilation. +This option is supported only by the C++ front end, and +the information is generally only useful to the G++ development team. +</p> +<a name="index-fdbg_002dcnt_002dlist"></a> +</dd> +<dt><code>-fdbg-cnt-list</code></dt> +<dd><p>Print the name and the counter upper bound for all debug counters. +</p> + +<a name="index-fdbg_002dcnt"></a> +</dd> +<dt><code>-fdbg-cnt=<var>counter-value-list</var></code></dt> +<dd><p>Set the internal debug counter lower and upper bound. <var>counter-value-list</var> +is a comma-separated list of <var>name</var>:<var>lower_bound1</var>-<var>upper_bound1</var> +[:<var>lower_bound2</var>-<var>upper_bound2</var>...] tuples which sets +the name of the counter and list of closed intervals. +The <var>lower_bound</var> is optional and is zero +initialized if not set. +For example, with <samp>-fdbg-cnt=dce:2-4:10-11,tail_call:10</samp>, +<code>dbg_cnt(dce)</code> returns true only for second, third, fourth, tenth and +eleventh invocation. +For <code>dbg_cnt(tail_call)</code> true is returned for first 10 invocations. +</p> +<a name="index-print_002dfile_002dname"></a> +</dd> +<dt><code>-print-file-name=<var>library</var></code></dt> +<dd><p>Print the full absolute name of the library file <var>library</var> that +would be used when linking—and don’t do anything else. With this +option, GCC does not compile or link anything; it just prints the +file name. +</p> +<a name="index-print_002dmulti_002ddirectory"></a> +</dd> +<dt><code>-print-multi-directory</code></dt> +<dd><p>Print the directory name corresponding to the multilib selected by any +other switches present in the command line. This directory is supposed +to exist in <code>GCC_EXEC_PREFIX</code>. +</p> +<a name="index-print_002dmulti_002dlib"></a> +</dd> +<dt><code>-print-multi-lib</code></dt> +<dd><p>Print the mapping from multilib directory names to compiler switches +that enable them. The directory name is separated from the switches by +‘<samp>;</samp>’, and each switch starts with an ‘<samp>@</samp>’ instead of the +‘<samp>-</samp>’, without spaces between multiple switches. This is supposed to +ease shell processing. +</p> +<a name="index-print_002dmulti_002dos_002ddirectory"></a> +</dd> +<dt><code>-print-multi-os-directory</code></dt> +<dd><p>Print the path to OS libraries for the selected +multilib, relative to some <samp>lib</samp> subdirectory. If OS libraries are +present in the <samp>lib</samp> subdirectory and no multilibs are used, this is +usually just <samp>.</samp>, if OS libraries are present in <samp>lib<var>suffix</var></samp> +sibling directories this prints e.g. <samp>../lib64</samp>, <samp>../lib</samp> or +<samp>../lib32</samp>, or if OS libraries are present in <samp>lib/<var>subdir</var></samp> +subdirectories it prints e.g. <samp>amd64</samp>, <samp>sparcv9</samp> or <samp>ev6</samp>. +</p> +<a name="index-print_002dmultiarch"></a> +</dd> +<dt><code>-print-multiarch</code></dt> +<dd><p>Print the path to OS libraries for the selected multiarch, +relative to some <samp>lib</samp> subdirectory. +</p> +<a name="index-print_002dprog_002dname"></a> +</dd> +<dt><code>-print-prog-name=<var>program</var></code></dt> +<dd><p>Like <samp>-print-file-name</samp>, but searches for a program such as <code>cpp</code>. +</p> +<a name="index-print_002dlibgcc_002dfile_002dname"></a> +</dd> +<dt><code>-print-libgcc-file-name</code></dt> +<dd><p>Same as <samp>-print-file-name=libgcc.a</samp>. +</p> +<p>This is useful when you use <samp>-nostdlib</samp> or <samp>-nodefaultlibs</samp> +but you do want to link with <samp>libgcc.a</samp>. You can do: +</p> +<div class="smallexample"> +<pre class="smallexample">gcc -nostdlib <var>files</var>… `gcc -print-libgcc-file-name` +</pre></div> + +<a name="index-print_002dsearch_002ddirs"></a> +</dd> +<dt><code>-print-search-dirs</code></dt> +<dd><p>Print the name of the configured installation directory and a list of +program and library directories <code>gcc</code> searches—and don’t do anything else. +</p> +<p>This is useful when <code>gcc</code> prints the error message +‘<samp>installation problem, cannot exec cpp0: No such file or directory</samp>’. +To resolve this you either need to put <samp>cpp0</samp> and the other compiler +components where <code>gcc</code> expects to find them, or you can set the environment +variable <code>GCC_EXEC_PREFIX</code> to the directory where you installed them. +Don’t forget the trailing ‘<samp>/</samp>’. +See <a href="Environment-Variables.html#Environment-Variables">Environment Variables</a>. +</p> +<a name="index-print_002dsysroot"></a> +</dd> +<dt><code>-print-sysroot</code></dt> +<dd><p>Print the target sysroot directory that is used during +compilation. This is the target sysroot specified either at configure +time or using the <samp>--sysroot</samp> option, possibly with an extra +suffix that depends on compilation options. If no target sysroot is +specified, the option prints nothing. +</p> +<a name="index-print_002dsysroot_002dheaders_002dsuffix"></a> +</dd> +<dt><code>-print-sysroot-headers-suffix</code></dt> +<dd><p>Print the suffix added to the target sysroot when searching for +headers, or give an error if the compiler is not configured with such +a suffix—and don’t do anything else. +</p> +<a name="index-dumpmachine"></a> +</dd> +<dt><code>-dumpmachine</code></dt> +<dd><p>Print the compiler’s target machine (for example, +‘<samp>i686-pc-linux-gnu</samp>’)—and don’t do anything else. +</p> +<a name="index-dumpversion"></a> +</dd> +<dt><code>-dumpversion</code></dt> +<dd><p>Print the compiler version (for example, <code>3.0</code>, <code>6.3.0</code> or <code>7</code>)—and don’t do +anything else. This is the compiler version used in filesystem paths and +specs. Depending on how the compiler has been configured it can be just +a single number (major version), two numbers separated by a dot (major and +minor version) or three numbers separated by dots (major, minor and patchlevel +version). +</p> +<a name="index-dumpfullversion"></a> +</dd> +<dt><code>-dumpfullversion</code></dt> +<dd><p>Print the full compiler version—and don’t do anything else. The output is +always three numbers separated by dots, major, minor and patchlevel version. +</p> +<a name="index-dumpspecs"></a> +</dd> +<dt><code>-dumpspecs</code></dt> +<dd><p>Print the compiler’s built-in specs—and don’t do anything else. (This +is used when GCC itself is being built.) See <a href="Spec-Files.html#Spec-Files">Spec Files</a>. +</p></dd> +</dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Submodel-Options.html#Submodel-Options" accesskey="n" rel="next">Submodel Options</a>, Previous: <a href="Code-Gen-Options.html#Code-Gen-Options" accesskey="p" rel="previous">Code Gen Options</a>, Up: <a href="Invoking-GCC.html#Invoking-GCC" accesskey="u" rel="up">Invoking GCC</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> |