mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-24 03:33:20 +01:00
144 lines
4.5 KiB
Plaintext
144 lines
4.5 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
opt - LLVM optimizer
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
B<opt> [I<options>] [I<filename>]
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The B<opt> command is the modular LLVM optimizer and analyzer. It takes LLVM
|
|
source files as input, runs the specified optimizations or analyses on it, and then
|
|
outputs the optimized file or the analysis results. The function of
|
|
B<opt> depends on whether the B<-analyze> option is given.
|
|
|
|
When B<-analyze> is specified, B<opt> performs various analyses of the input
|
|
source. It will usually print the results on standard output, but in a few
|
|
cases, it will print output to standard error or generate a file with the
|
|
analysis output, which is usually done when the output is meant for another
|
|
program.
|
|
|
|
While B<-analyze> is I<not> given, B<opt> attempts to produce an optimized
|
|
output file. The optimizations available via B<opt> depend upon what
|
|
libraries were linked into it as well as any additional libraries that have
|
|
been loaded with the B<-load> option. Use the B<-help> option to determine
|
|
what optimizations you can use.
|
|
|
|
If I<filename> is omitted from the command line or is I<->, B<opt> reads its
|
|
input from standard input. Inputs can be in either the LLVM assembly language
|
|
format (.ll) or the LLVM bitcode format (.bc).
|
|
|
|
If an output filename is not specified with the B<-o> option, B<opt>
|
|
writes its output to the standard output.
|
|
|
|
=head1 OPTIONS
|
|
|
|
=over
|
|
|
|
=item B<-f>
|
|
|
|
Enable binary output on terminals. Normally, B<opt> will refuse to
|
|
write raw bitcode output if the output stream is a terminal. With this option,
|
|
B<opt> will write raw bitcode regardless of the output device.
|
|
|
|
=item B<-help>
|
|
|
|
Print a summary of command line options.
|
|
|
|
=item B<-o> I<filename>
|
|
|
|
Specify the output filename.
|
|
|
|
=item B<-S>
|
|
|
|
Write output in LLVM intermediate language (instead of bitcode).
|
|
|
|
=item B<-{passname}>
|
|
|
|
B<opt> provides the ability to run any of LLVM's optimization or analysis passes
|
|
in any order. The B<-help> option lists all the passes available. The order in
|
|
which the options occur on the command line are the order in which they are
|
|
executed (within pass constraints).
|
|
|
|
=item B<-std-compile-opts>
|
|
|
|
This is short hand for a standard list of I<compile time optimization> passes.
|
|
This is typically used to optimize the output from the llvm-gcc front end. It
|
|
might be useful for other front end compilers as well. To discover the full set
|
|
of options available, use the following command:
|
|
|
|
llvm-as < /dev/null | opt -std-compile-opts -disable-output -debug-pass=Arguments
|
|
|
|
=item B<-disable-inlining>
|
|
|
|
This option is only meaningful when B<-std-compile-opts> is given. It simply
|
|
removes the inlining pass from the standard list.
|
|
|
|
=item B<-disable-opt>
|
|
|
|
This option is only meaningful when B<-std-compile-opts> is given. It disables
|
|
most, but not all, of the B<-std-compile-opts>. The ones that remain are
|
|
B<-verify>, B<-lower-setjmp>, and B<-funcresolve>.
|
|
|
|
=item B<-strip-debug>
|
|
|
|
This option causes opt to strip debug information from the module before
|
|
applying other optimizations. It is essentially the same as B<-strip> but it
|
|
ensures that stripping of debug information is done first.
|
|
|
|
=item B<-verify-each>
|
|
|
|
This option causes opt to add a verify pass after every pass otherwise specified
|
|
on the command line (including B<-verify>). This is useful for cases where it
|
|
is suspected that a pass is creating an invalid module but it is not clear which
|
|
pass is doing it. The combination of B<-std-compile-opts> and B<-verify-each>
|
|
can quickly track down this kind of problem.
|
|
|
|
=item B<-profile-info-file> I<filename>
|
|
|
|
Specify the name of the file loaded by the -profile-loader option.
|
|
|
|
=item B<-stats>
|
|
|
|
Print statistics.
|
|
|
|
=item B<-time-passes>
|
|
|
|
Record the amount of time needed for each pass and print it to standard
|
|
error.
|
|
|
|
=item B<-debug>
|
|
|
|
If this is a debug build, this option will enable debug printouts
|
|
from passes which use the I<DEBUG()> macro. See the B<LLVM Programmer's
|
|
Manual>, section I<#DEBUG> for more information.
|
|
|
|
=item B<-load>=I<plugin>
|
|
|
|
Load the dynamic object I<plugin>. This object should register new optimization
|
|
or analysis passes. Once loaded, the object will add new command line options to
|
|
enable various optimizations or analyses. To see the new complete list of
|
|
optimizations, use the B<-help> and B<-load> options together. For example:
|
|
|
|
opt -load=plugin.so -help
|
|
|
|
=item B<-p>
|
|
|
|
Print module after each transformation.
|
|
|
|
=back
|
|
|
|
=head1 EXIT STATUS
|
|
|
|
If B<opt> succeeds, it will exit with 0. Otherwise, if an error
|
|
occurs, it will exit with a non-zero value.
|
|
|
|
=head1 AUTHORS
|
|
|
|
Maintained by the LLVM Team (L<http://llvm.org>).
|
|
|
|
=cut
|