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<a name="Developer-Options"></a>
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<p>
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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="prev">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="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
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<a name="GCC-Developer-Options"></a>
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<h3 class="section">3.17 GCC Developer Options</h3>
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<a name="index-developer-options"></a>
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<a name="index-debugging-GCC"></a>
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<a name="index-debug-dump-options"></a>
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<a name="index-dump-options"></a>
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<a name="index-compilation-statistics"></a>
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<p>This section describes command-line options that are primarily of
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interest to GCC developers, including options to support compiler
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testing and investigation of compiler bugs and compile-time
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performance problems. This includes options that produce debug dumps
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at various points in the compilation; that print statistics such as
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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.
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</p>
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<dl compact="compact">
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<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><a name="index-d"></a>
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<a name="index-fdump_002drtl_002dpass"></a>
|
<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. The file names for most of the dumps are made by appending
|
a pass number and a word to the <var>dumpname</var>, and the files are
|
created in the directory of the output file. In case of
|
<samp>=<var>filename</var></samp> option, the dump is output on the given file
|
instead of the pass numbered dump files. Note that the pass number is
|
assigned as passes are registered into the pass manager. Most passes
|
are registered in the order that they will execute and for these passes
|
the number corresponds to the pass execution order. However, passes
|
registered by plugins, passes specific to compilation targets, or
|
passes that are otherwise registered after all the other passes are
|
numbered higher than a pass named "final", even if they are executed
|
earlier. <var>dumpname</var> is generated from the name of the output
|
file if explicitly specified and not an executable, otherwise it is
|
the basename of the source file. These switches may have different
|
effects when <samp>-E</samp> is used for preprocessing.
|
</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>
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<dl compact="compact">
|
<dt><code>-fdump-rtl-alignments</code></dt>
|
<dd><a name="index-fdump_002drtl_002dalignments"></a>
|
<p>Dump after branch alignments have been computed.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-asmcons</code></dt>
|
<dd><a name="index-fdump_002drtl_002dasmcons"></a>
|
<p>Dump after fixing rtl statements that have unsatisfied in/out constraints.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-auto_inc_dec</code></dt>
|
<dd><a name="index-fdump_002drtl_002dauto_005finc_005fdec"></a>
|
<p>Dump after auto-inc-dec discovery. This pass is only run on
|
architectures that have auto inc or auto dec instructions.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-barriers</code></dt>
|
<dd><a name="index-fdump_002drtl_002dbarriers"></a>
|
<p>Dump after cleaning up the barrier instructions.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-bbpart</code></dt>
|
<dd><a name="index-fdump_002drtl_002dbbpart"></a>
|
<p>Dump after partitioning hot and cold basic blocks.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-bbro</code></dt>
|
<dd><a name="index-fdump_002drtl_002dbbro"></a>
|
<p>Dump after block reordering.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-btl1</code></dt>
|
<dt><code>-fdump-rtl-btl2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dbtl2"></a>
|
<a name="index-fdump_002drtl_002dbtl2-1"></a>
|
<p><samp>-fdump-rtl-btl1</samp> and <samp>-fdump-rtl-btl2</samp> enable dumping
|
after the two branch
|
target load optimization passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-bypass</code></dt>
|
<dd><a name="index-fdump_002drtl_002dbypass"></a>
|
<p>Dump after jump bypassing and control flow optimizations.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-combine</code></dt>
|
<dd><a name="index-fdump_002drtl_002dcombine"></a>
|
<p>Dump after the RTL instruction combination pass.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-compgotos</code></dt>
|
<dd><a name="index-fdump_002drtl_002dcompgotos"></a>
|
<p>Dump after duplicating the computed gotos.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-ce1</code></dt>
|
<dt><code>-fdump-rtl-ce2</code></dt>
|
<dt><code>-fdump-rtl-ce3</code></dt>
|
<dd><a name="index-fdump_002drtl_002dce1"></a>
|
<a name="index-fdump_002drtl_002dce2"></a>
|
<a name="index-fdump_002drtl_002dce3"></a>
|
<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>
|
</dd>
|
<dt><code>-fdump-rtl-cprop_hardreg</code></dt>
|
<dd><a name="index-fdump_002drtl_002dcprop_005fhardreg"></a>
|
<p>Dump after hard register copy propagation.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-csa</code></dt>
|
<dd><a name="index-fdump_002drtl_002dcsa"></a>
|
<p>Dump after combining stack adjustments.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-cse1</code></dt>
|
<dt><code>-fdump-rtl-cse2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dcse1"></a>
|
<a name="index-fdump_002drtl_002dcse2"></a>
|
<p><samp>-fdump-rtl-cse1</samp> and <samp>-fdump-rtl-cse2</samp> enable dumping after
|
the two common subexpression elimination passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-dce</code></dt>
|
<dd><a name="index-fdump_002drtl_002ddce"></a>
|
<p>Dump after the standalone dead code elimination passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-dbr</code></dt>
|
<dd><a name="index-fdump_002drtl_002ddbr"></a>
|
<p>Dump after delayed branch scheduling.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-dce1</code></dt>
|
<dt><code>-fdump-rtl-dce2</code></dt>
|
<dd><a name="index-fdump_002drtl_002ddce1"></a>
|
<a name="index-fdump_002drtl_002ddce2"></a>
|
<p><samp>-fdump-rtl-dce1</samp> and <samp>-fdump-rtl-dce2</samp> enable dumping after
|
the two dead store elimination passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-eh</code></dt>
|
<dd><a name="index-fdump_002drtl_002deh"></a>
|
<p>Dump after finalization of EH handling code.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-eh_ranges</code></dt>
|
<dd><a name="index-fdump_002drtl_002deh_005franges"></a>
|
<p>Dump after conversion of EH handling range regions.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-expand</code></dt>
|
<dd><a name="index-fdump_002drtl_002dexpand"></a>
|
<p>Dump after RTL generation.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-fwprop1</code></dt>
|
<dt><code>-fdump-rtl-fwprop2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dfwprop1"></a>
|
<a name="index-fdump_002drtl_002dfwprop2"></a>
|
<p><samp>-fdump-rtl-fwprop1</samp> and <samp>-fdump-rtl-fwprop2</samp> enable
|
dumping after the two forward propagation passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-gcse1</code></dt>
|
<dt><code>-fdump-rtl-gcse2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dgcse1"></a>
|
<a name="index-fdump_002drtl_002dgcse2"></a>
|
<p><samp>-fdump-rtl-gcse1</samp> and <samp>-fdump-rtl-gcse2</samp> enable dumping
|
after global common subexpression elimination.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-init-regs</code></dt>
|
<dd><a name="index-fdump_002drtl_002dinit_002dregs"></a>
|
<p>Dump after the initialization of the registers.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-initvals</code></dt>
|
<dd><a name="index-fdump_002drtl_002dinitvals"></a>
|
<p>Dump after the computation of the initial value sets.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-into_cfglayout</code></dt>
|
<dd><a name="index-fdump_002drtl_002dinto_005fcfglayout"></a>
|
<p>Dump after converting to cfglayout mode.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-ira</code></dt>
|
<dd><a name="index-fdump_002drtl_002dira"></a>
|
<p>Dump after iterated register allocation.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-jump</code></dt>
|
<dd><a name="index-fdump_002drtl_002djump"></a>
|
<p>Dump after the second jump optimization.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-loop2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dloop2"></a>
|
<p><samp>-fdump-rtl-loop2</samp> enables dumping after the rtl
|
loop optimization passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-mach</code></dt>
|
<dd><a name="index-fdump_002drtl_002dmach"></a>
|
<p>Dump after performing the machine dependent reorganization pass, if that
|
pass exists.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-mode_sw</code></dt>
|
<dd><a name="index-fdump_002drtl_002dmode_005fsw"></a>
|
<p>Dump after removing redundant mode switches.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-rnreg</code></dt>
|
<dd><a name="index-fdump_002drtl_002drnreg"></a>
|
<p>Dump after register renumbering.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-outof_cfglayout</code></dt>
|
<dd><a name="index-fdump_002drtl_002doutof_005fcfglayout"></a>
|
<p>Dump after converting from cfglayout mode.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-peephole2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dpeephole2"></a>
|
<p>Dump after the peephole pass.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-postreload</code></dt>
|
<dd><a name="index-fdump_002drtl_002dpostreload"></a>
|
<p>Dump after post-reload optimizations.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-pro_and_epilogue</code></dt>
|
<dd><a name="index-fdump_002drtl_002dpro_005fand_005fepilogue"></a>
|
<p>Dump after generating the function prologues and epilogues.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-sched1</code></dt>
|
<dt><code>-fdump-rtl-sched2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dsched1"></a>
|
<a name="index-fdump_002drtl_002dsched2"></a>
|
<p><samp>-fdump-rtl-sched1</samp> and <samp>-fdump-rtl-sched2</samp> enable dumping
|
after the basic block scheduling passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-ree</code></dt>
|
<dd><a name="index-fdump_002drtl_002dree"></a>
|
<p>Dump after sign/zero extension elimination.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-seqabstr</code></dt>
|
<dd><a name="index-fdump_002drtl_002dseqabstr"></a>
|
<p>Dump after common sequence discovery.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-shorten</code></dt>
|
<dd><a name="index-fdump_002drtl_002dshorten"></a>
|
<p>Dump after shortening branches.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-sibling</code></dt>
|
<dd><a name="index-fdump_002drtl_002dsibling"></a>
|
<p>Dump after sibling call optimizations.
|
</p>
|
</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><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>
|
<p>These options enable dumping after five rounds of
|
instruction splitting.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-sms</code></dt>
|
<dd><a name="index-fdump_002drtl_002dsms"></a>
|
<p>Dump after modulo scheduling. This pass is only run on some
|
architectures.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-stack</code></dt>
|
<dd><a name="index-fdump_002drtl_002dstack"></a>
|
<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>
|
</dd>
|
<dt><code>-fdump-rtl-subreg1</code></dt>
|
<dt><code>-fdump-rtl-subreg2</code></dt>
|
<dd><a name="index-fdump_002drtl_002dsubreg1"></a>
|
<a name="index-fdump_002drtl_002dsubreg2"></a>
|
<p><samp>-fdump-rtl-subreg1</samp> and <samp>-fdump-rtl-subreg2</samp> enable dumping after
|
the two subreg expansion passes.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-unshare</code></dt>
|
<dd><a name="index-fdump_002drtl_002dunshare"></a>
|
<p>Dump after all rtl has been unshared.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-vartrack</code></dt>
|
<dd><a name="index-fdump_002drtl_002dvartrack"></a>
|
<p>Dump after variable tracking.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-vregs</code></dt>
|
<dd><a name="index-fdump_002drtl_002dvregs"></a>
|
<p>Dump after converting virtual registers to hard registers.
|
</p>
|
</dd>
|
<dt><code>-fdump-rtl-web</code></dt>
|
<dd><a name="index-fdump_002drtl_002dweb"></a>
|
<p>Dump after live range splitting.
|
</p>
|
</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><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>
|
<p>These dumps are defined but always produce empty files.
|
</p>
|
</dd>
|
<dt><code>-da</code></dt>
|
<dt><code>-fdump-rtl-all</code></dt>
|
<dd><a name="index-da"></a>
|
<a name="index-fdump_002drtl_002dall"></a>
|
<p>Produce all the dumps listed above.
|
</p>
|
</dd>
|
<dt><code>-dA</code></dt>
|
<dd><a name="index-dA"></a>
|
<p>Annotate the assembler output with miscellaneous debugging information.
|
</p>
|
</dd>
|
<dt><code>-dD</code></dt>
|
<dd><a name="index-dD-1"></a>
|
<p>Dump all macro definitions, at the end of preprocessing, in addition to
|
normal output.
|
</p>
|
</dd>
|
<dt><code>-dH</code></dt>
|
<dd><a name="index-dH"></a>
|
<p>Produce a core dump whenever an error occurs.
|
</p>
|
</dd>
|
<dt><code>-dp</code></dt>
|
<dd><a name="index-dp"></a>
|
<p>Annotate the assembler output with a comment indicating which
|
pattern and alternative is used. The length of each instruction is
|
also printed.
|
</p>
|
</dd>
|
<dt><code>-dP</code></dt>
|
<dd><a name="index-dP"></a>
|
<p>Dump the RTL in the assembler output as a comment before each instruction.
|
Also turns on <samp>-dp</samp> annotation.
|
</p>
|
</dd>
|
<dt><code>-dx</code></dt>
|
<dd><a name="index-dx"></a>
|
<p>Just generate RTL for a function instead of compiling it. Usually used
|
with <samp>-fdump-rtl-expand</samp>.
|
</p></dd>
|
</dl>
|
|
</dd>
|
<dt><code>-fdump-noaddr</code></dt>
|
<dd><a name="index-fdump_002dnoaddr"></a>
|
<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>
|
</dd>
|
<dt><code>-freport-bug</code></dt>
|
<dd><a name="index-freport_002dbug"></a>
|
<p>Collect and dump debug information into a temporary file if an
|
internal compiler error (ICE) occurs.
|
</p>
|
</dd>
|
<dt><code>-fdump-unnumbered</code></dt>
|
<dd><a name="index-fdump_002dunnumbered"></a>
|
<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>
|
</dd>
|
<dt><code>-fdump-unnumbered-links</code></dt>
|
<dd><a name="index-fdump_002dunnumbered_002dlinks"></a>
|
<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>
|
</dd>
|
<dt><code>-fdump-translation-unit <span class="roman">(C++ only)</span></code></dt>
|
<dt><code>-fdump-translation-unit-<var>options</var> <span class="roman">(C++ only)</span></code></dt>
|
<dd><a name="index-fdump_002dtranslation_002dunit"></a>
|
<p>Dump a representation of the tree structure for the entire translation
|
unit to a file. The file name is made by appending <samp>.tu</samp> to the
|
source file name, and the file is created in the same directory as the
|
output file. If the ‘<samp>-<var>options</var></samp>’ form is used, <var>options</var>
|
controls the details of the dump as described for the
|
<samp>-fdump-tree</samp> options.
|
</p>
|
</dd>
|
<dt><code>-fdump-class-hierarchy <span class="roman">(C++ only)</span></code></dt>
|
<dt><code>-fdump-class-hierarchy-<var>options</var> <span class="roman">(C++ only)</span></code></dt>
|
<dd><a name="index-fdump_002dclass_002dhierarchy"></a>
|
<p>Dump a representation of each class’s hierarchy and virtual function
|
table layout to a file. The file name is made by appending
|
<samp>.class</samp> to the source file name, and the file is created in the
|
same directory as the output file. If the ‘<samp>-<var>options</var></samp>’ form
|
is used, <var>options</var> controls the details of the dump as described
|
for the <samp>-fdump-tree</samp> options.
|
</p>
|
</dd>
|
<dt><code>-fdump-ipa-<var>switch</var></code></dt>
|
<dd><a name="index-fdump_002dipa"></a>
|
<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>
|
|
</dd>
|
<dt><code>-fdump-passes</code></dt>
|
<dd><a name="index-fdump_002dpasses"></a>
|
<p>Dump the list of optimization passes that are turned on and off by
|
the current command-line options.
|
</p>
|
</dd>
|
<dt><code>-fdump-statistics-<var>option</var></code></dt>
|
<dd><a name="index-fdump_002dstatistics"></a>
|
<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>
|
</dd>
|
<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><a name="index-fdump_002dtree"></a>
|
<p>Control the dumping at various stages of processing the intermediate
|
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. In case of
|
<samp>=<var>filename</var></samp> option, the dump is output on the given file
|
instead of the auto named dump files. 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>=<var>filename</var></samp>’</dt>
|
<dd><p>Instead of an auto named dump file, output into the given file
|
name. The file names <samp>stdout</samp> and <samp>stderr</samp> are treated
|
specially and are considered already open standard streams. For
|
example,
|
</p>
|
<div class="smallexample">
|
<pre class="smallexample">gcc -O2 -ftree-vectorize -fdump-tree-vect-blocks=foo.dump
|
-fdump-tree-pre=stderr file.c
|
</pre></div>
|
|
<p>outputs vectorizer dump into <samp>foo.dump</samp>, while the PRE dump is
|
output on to <samp>stderr</samp>. If two conflicting dump filenames are
|
given for the same pass, then the latter option overrides the earlier
|
one.
|
</p>
|
</dd>
|
<dt>‘<samp>split-paths</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dsplit_002dpaths"></a>
|
<p>Dump each function after splitting paths to loop backedges. The file
|
name is made by appending <samp>.split-paths</samp> to the source file name.
|
</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>The following tree dumps are possible:
|
</p><dl compact="compact">
|
<dt>‘<samp>original</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002doriginal"></a>
|
<p>Dump before any tree based optimization, to <samp><var>file</var>.original</samp>.
|
</p>
|
</dd>
|
<dt>‘<samp>optimized</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002doptimized"></a>
|
<p>Dump after all tree based optimization, to <samp><var>file</var>.optimized</samp>.
|
</p>
|
</dd>
|
<dt>‘<samp>gimple</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dgimple"></a>
|
<p>Dump each function before and after the gimplification pass to a file. The
|
file name is made by appending <samp>.gimple</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>cfg</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dcfg"></a>
|
<p>Dump the control flow graph of each function to a file. The file name is
|
made by appending <samp>.cfg</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>ch</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dch"></a>
|
<p>Dump each function after copying loop headers. The file name is made by
|
appending <samp>.ch</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>ssa</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dssa"></a>
|
<p>Dump SSA related information to a file. The file name is made by appending
|
<samp>.ssa</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>alias</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dalias"></a>
|
<p>Dump aliasing information for each function. The file name is made by
|
appending <samp>.alias</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>ccp</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dccp"></a>
|
<p>Dump each function after CCP. The file name is made by appending
|
<samp>.ccp</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>storeccp</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dstoreccp"></a>
|
<p>Dump each function after STORE-CCP. The file name is made by appending
|
<samp>.storeccp</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>pre</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dpre"></a>
|
<p>Dump trees after partial redundancy elimination. The file name is made
|
by appending <samp>.pre</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>fre</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dfre"></a>
|
<p>Dump trees after full redundancy elimination. The file name is made
|
by appending <samp>.fre</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>copyprop</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dcopyprop"></a>
|
<p>Dump trees after copy propagation. The file name is made
|
by appending <samp>.copyprop</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>store_copyprop</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dstore_005fcopyprop"></a>
|
<p>Dump trees after store copy-propagation. The file name is made
|
by appending <samp>.store_copyprop</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>dce</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002ddce"></a>
|
<p>Dump each function after dead code elimination. The file name is made by
|
appending <samp>.dce</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>sra</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dsra"></a>
|
<p>Dump each function after performing scalar replacement of aggregates. The
|
file name is made by appending <samp>.sra</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>sink</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dsink"></a>
|
<p>Dump each function after performing code sinking. The file name is made
|
by appending <samp>.sink</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>dom</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002ddom"></a>
|
<p>Dump each function after applying dominator tree optimizations. The file
|
name is made by appending <samp>.dom</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>dse</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002ddse"></a>
|
<p>Dump each function after applying dead store elimination. The file
|
name is made by appending <samp>.dse</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>phiopt</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dphiopt"></a>
|
<p>Dump each function after optimizing PHI nodes into straightline code. The file
|
name is made by appending <samp>.phiopt</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>backprop</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dbackprop"></a>
|
<p>Dump each function after back-propagating use information up the definition
|
chain. The file name is made by appending <samp>.backprop</samp> to the
|
source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>forwprop</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dforwprop"></a>
|
<p>Dump each function after forward propagating single use variables. The file
|
name is made by appending <samp>.forwprop</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>nrv</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dnrv"></a>
|
<p>Dump each function after applying the named return value optimization on
|
generic trees. The file name is made by appending <samp>.nrv</samp> to the source
|
file name.
|
</p>
|
</dd>
|
<dt>‘<samp>vect</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dvect"></a>
|
<p>Dump each function after applying vectorization of loops. The file name is
|
made by appending <samp>.vect</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>slp</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dslp"></a>
|
<p>Dump each function after applying vectorization of basic blocks. The file name
|
is made by appending <samp>.slp</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>vrp</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dvrp"></a>
|
<p>Dump each function after Value Range Propagation (VRP). The file name
|
is made by appending <samp>.vrp</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>oaccdevlow</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002doaccdevlow"></a>
|
<p>Dump each function after applying device-specific OpenACC transformations.
|
The file name is made by appending <samp>.oaccdevlow</samp> to the source file name.
|
</p>
|
</dd>
|
<dt>‘<samp>all</samp>’</dt>
|
<dd><a name="index-fdump_002dtree_002dall"></a>
|
<p>Enable all the available tree dumps with the flags provided in this option.
|
</p></dd>
|
</dl>
|
|
</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><a name="index-fopt_002dinfo"></a>
|
<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 two groups: options describing the
|
verbosity of the dump, and options describing which optimizations
|
should be included. The options from both the groups 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 the dump verbosity:
|
</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>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>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 all
|
info about successful optimizations from all the passes.
|
</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>.
|
</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>
|
</dd>
|
<dt><code>-fsched-verbose=<var>n</var></code></dt>
|
<dd><a name="index-fsched_002dverbose"></a>
|
<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>
|
|
|
</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><a name="index-fdisable_002d"></a>
|
<a name="index-fenable_002d"></a>
|
|
<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>
|
|
</dd>
|
<dt><code>-fchecking</code></dt>
|
<dd><a name="index-fchecking"></a>
|
<a name="index-fno_002dchecking"></a>
|
<p>Enable internal consistency checking. The default depends on
|
the compiler configuration.
|
</p>
|
</dd>
|
<dt><code>-frandom-seed=<var>string</var></code></dt>
|
<dd><a name="index-frandom_002dseed"></a>
|
<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>
|
</dd>
|
<dt><code>-save-temps</code></dt>
|
<dt><code>-save-temps=cwd</code></dt>
|
<dd><a name="index-save_002dtemps"></a>
|
<p>Store the usual “temporary” intermediate files permanently; place them
|
in the current directory and name them based on the source file. Thus,
|
compiling <samp>foo.c</samp> with <samp>-c -save-temps</samp> produces files
|
<samp>foo.i</samp> and <samp>foo.s</samp>, as well as <samp>foo.o</samp>. This creates a
|
preprocessed <samp>foo.i</samp> output file even though the compiler now
|
normally uses an integrated preprocessor.
|
</p>
|
<p>When used in combination with the <samp>-x</samp> command-line option,
|
<samp>-save-temps</samp> is sensible enough to avoid over writing 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>
|
<p>If you invoke GCC in parallel, compiling several different source
|
files that share a common base name in different subdirectories or the
|
same source file compiled for multiple output destinations, it is
|
likely that the different parallel compilers will interfere with each
|
other, and overwrite the temporary files. For instance:
|
</p>
|
<div class="smallexample">
|
<pre class="smallexample">gcc -save-temps -o outdir1/foo.o indir1/foo.c&
|
gcc -save-temps -o outdir2/foo.o indir2/foo.c&
|
</pre></div>
|
|
<p>may result in <samp>foo.i</samp> and <samp>foo.o</samp> being written to
|
simultaneously by both compilers.
|
</p>
|
</dd>
|
<dt><code>-save-temps=obj</code></dt>
|
<dd><a name="index-save_002dtemps_003dobj"></a>
|
<p>Store the usual “temporary” intermediate files permanently. If the
|
<samp>-o</samp> option is used, the temporary files are based on the
|
object file. If the <samp>-o</samp> option is not used, the
|
<samp>-save-temps=obj</samp> switch behaves like <samp>-save-temps</samp>.
|
</p>
|
<p>For example:
|
</p>
|
<div class="smallexample">
|
<pre class="smallexample">gcc -save-temps=obj -c foo.c
|
gcc -save-temps=obj -c bar.c -o dir/xbar.o
|
gcc -save-temps=obj foobar.c -o dir2/yfoobar
|
</pre></div>
|
|
<p>creates <samp>foo.i</samp>, <samp>foo.s</samp>, <samp>dir/xbar.i</samp>,
|
<samp>dir/xbar.s</samp>, <samp>dir2/yfoobar.i</samp>, <samp>dir2/yfoobar.s</samp>, and
|
<samp>dir2/yfoobar.o</samp>.
|
</p>
|
</dd>
|
<dt><code>-time<span class="roman">[</span>=<var>file</var><span class="roman">]</span></code></dt>
|
<dd><a name="index-time"></a>
|
<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>
|
</dd>
|
<dt><code>-fdump-final-insns<span class="roman">[</span>=<var>file</var><span class="roman">]</span></code></dt>
|
<dd><a name="index-fdump_002dfinal_002dinsns"></a>
|
<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
|
compilation output file name.
|
</p>
|
</dd>
|
<dt><code>-fcompare-debug<span class="roman">[</span>=<var>opts</var><span class="roman">]</span></code></dt>
|
<dd><a name="index-fcompare_002ddebug"></a>
|
<a name="index-fno_002dcompare_002ddebug"></a>
|
<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>
|
</dd>
|
<dt><code>-fcompare-debug-second</code></dt>
|
<dd><a name="index-fcompare_002ddebug_002dsecond"></a>
|
<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
|
side-effect compiler outputs to files or to the standard output. 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>
|
</dd>
|
<dt><code>-gtoggle</code></dt>
|
<dd><a name="index-gtoggle"></a>
|
<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>
|
</dd>
|
<dt><code>-fvar-tracking-assignments-toggle</code></dt>
|
<dd><a name="index-fvar_002dtracking_002dassignments_002dtoggle"></a>
|
<a name="index-fno_002dvar_002dtracking_002dassignments_002dtoggle"></a>
|
<p>Toggle <samp>-fvar-tracking-assignments</samp>, in the same way that
|
<samp>-gtoggle</samp> toggles <samp>-g</samp>.
|
</p>
|
</dd>
|
<dt><code>-Q</code></dt>
|
<dd><a name="index-Q"></a>
|
<p>Makes the compiler print out each function name as it is compiled, and
|
print some statistics about each pass when it finishes.
|
</p>
|
</dd>
|
<dt><code>-ftime-report</code></dt>
|
<dd><a name="index-ftime_002dreport"></a>
|
<p>Makes the compiler print some statistics about the time consumed by each
|
pass when it finishes.
|
</p>
|
</dd>
|
<dt><code>-fira-verbose=<var>n</var></code></dt>
|
<dd><a name="index-fira_002dverbose"></a>
|
<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>
|
</dd>
|
<dt><code>-flto-report</code></dt>
|
<dd><a name="index-flto_002dreport"></a>
|
<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>
|
</dd>
|
<dt><code>-flto-report-wpa</code></dt>
|
<dd><a name="index-flto_002dreport_002dwpa"></a>
|
<p>Like <samp>-flto-report</samp>, but only print for the WPA phase of Link
|
Time Optimization.
|
</p>
|
</dd>
|
<dt><code>-fmem-report</code></dt>
|
<dd><a name="index-fmem_002dreport"></a>
|
<p>Makes the compiler print some statistics about permanent memory
|
allocation when it finishes.
|
</p>
|
</dd>
|
<dt><code>-fmem-report-wpa</code></dt>
|
<dd><a name="index-fmem_002dreport_002dwpa"></a>
|
<p>Makes the compiler print some statistics about permanent memory
|
allocation for the WPA phase only.
|
</p>
|
</dd>
|
<dt><code>-fpre-ipa-mem-report</code></dt>
|
<dd><a name="index-fpre_002dipa_002dmem_002dreport"></a>
|
</dd>
|
<dt><code>-fpost-ipa-mem-report</code></dt>
|
<dd><a name="index-fpost_002dipa_002dmem_002dreport"></a>
|
<p>Makes the compiler print some statistics about permanent memory
|
allocation before or after interprocedural optimization.
|
</p>
|
</dd>
|
<dt><code>-fprofile-report</code></dt>
|
<dd><a name="index-fprofile_002dreport"></a>
|
<p>Makes the compiler print some statistics about consistency of the
|
(estimated) profile and effect of individual passes.
|
</p>
|
</dd>
|
<dt><code>-fstack-usage</code></dt>
|
<dd><a name="index-fstack_002dusage"></a>
|
<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>
|
</dd>
|
<dt><code>-fstats</code></dt>
|
<dd><a name="index-fstats"></a>
|
<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>
|
</dd>
|
<dt><code>-fdbg-cnt-list</code></dt>
|
<dd><a name="index-fdbg_002dcnt_002dlist"></a>
|
<p>Print the name and the counter upper bound for all debug counters.
|
</p>
|
|
</dd>
|
<dt><code>-fdbg-cnt=<var>counter-value-list</var></code></dt>
|
<dd><a name="index-fdbg_002dcnt"></a>
|
<p>Set the internal debug counter upper bound. <var>counter-value-list</var>
|
is a comma-separated list of <var>name</var>:<var>value</var> pairs
|
which sets the upper bound of each debug counter <var>name</var> to <var>value</var>.
|
All debug counters have the initial upper bound of <code>UINT_MAX</code>;
|
thus <code>dbg_cnt</code> returns true always unless the upper bound
|
is set by this option.
|
For example, with <samp>-fdbg-cnt=dce:10,tail_call:0</samp>,
|
<code>dbg_cnt(dce)</code> returns true only for first 10 invocations.
|
</p>
|
</dd>
|
<dt><code>-print-file-name=<var>library</var></code></dt>
|
<dd><a name="index-print_002dfile_002dname"></a>
|
<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>
|
</dd>
|
<dt><code>-print-multi-directory</code></dt>
|
<dd><a name="index-print_002dmulti_002ddirectory"></a>
|
<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>
|
</dd>
|
<dt><code>-print-multi-lib</code></dt>
|
<dd><a name="index-print_002dmulti_002dlib"></a>
|
<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>
|
</dd>
|
<dt><code>-print-multi-os-directory</code></dt>
|
<dd><a name="index-print_002dmulti_002dos_002ddirectory"></a>
|
<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>
|
</dd>
|
<dt><code>-print-multiarch</code></dt>
|
<dd><a name="index-print_002dmultiarch"></a>
|
<p>Print the path to OS libraries for the selected multiarch,
|
relative to some <samp>lib</samp> subdirectory.
|
</p>
|
</dd>
|
<dt><code>-print-prog-name=<var>program</var></code></dt>
|
<dd><a name="index-print_002dprog_002dname"></a>
|
<p>Like <samp>-print-file-name</samp>, but searches for a program such as <code>cpp</code>.
|
</p>
|
</dd>
|
<dt><code>-print-libgcc-file-name</code></dt>
|
<dd><a name="index-print_002dlibgcc_002dfile_002dname"></a>
|
<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>
|
|
</dd>
|
<dt><code>-print-search-dirs</code></dt>
|
<dd><a name="index-print_002dsearch_002ddirs"></a>
|
<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>
|
</dd>
|
<dt><code>-print-sysroot</code></dt>
|
<dd><a name="index-print_002dsysroot"></a>
|
<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>
|
</dd>
|
<dt><code>-print-sysroot-headers-suffix</code></dt>
|
<dd><a name="index-print_002dsysroot_002dheaders_002dsuffix"></a>
|
<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>
|
</dd>
|
<dt><code>-dumpmachine</code></dt>
|
<dd><a name="index-dumpmachine"></a>
|
<p>Print the compiler’s target machine (for example,
|
‘<samp>i686-pc-linux-gnu</samp>’)—and don’t do anything else.
|
</p>
|
</dd>
|
<dt><code>-dumpversion</code></dt>
|
<dd><a name="index-dumpversion"></a>
|
<p>Print the compiler version (for example, <code>3.0</code>)—and don’t do
|
anything else.
|
</p>
|
</dd>
|
<dt><code>-dumpspecs</code></dt>
|
<dd><a name="index-dumpspecs"></a>
|
<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="prev">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="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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