opt(1)
NAME
opt - LLVM optimizer
SYNOPSIS
opt [options] [filename]
DESCRIPTION
The 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 opt depends on whether the -analyze option is given. When -analyze is specified, 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 -analyze is not given, opt attempts to produce an optimized output file. The optimizations available via opt depend upon what libraries were linked into it as well as any additional libraries that have been loaded with the -load option. Use the -help option to determine what optimizations you can use. If filename is omitted from the command line or is "-", 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 -o option, opt writes its output to the standard output.
OPTIONS
-f Enable binary output on terminals. Normally, opt will refuse to
write raw bitcode output if the output stream is a terminal.
With this option, opt will write raw bitcode regardless of the
output device.
-help Print a summary of command line options.
-o <filename>
Specify the output filename.
-S Write output in LLVM intermediate language (instead of bitcode).
-{passname}
opt provides the ability to run any of LLVM's optimization or
analysis passes in any order. The -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).
-disable-inlining
This option simply removes the inlining pass from the standard
list.
-disable-opt
This option is only meaningful when -std-link-opts is given. It
disables most passes.
-strip-debug
This option causes opt to strip debug information from the
module before applying other optimizations. It is essentially
the same as -strip but it ensures that stripping of debug
information is done first.
-verify-each
This option causes opt to add a verify pass after every pass
otherwise specified on the command line (including -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.
-stats Print statistics.
-time-passes
Record the amount of time needed for each pass and print it to
standard error.
-debug If this is a debug build, this option will enable debug
printouts from passes which use the DEBUG() macro. See the LLVM
Programmer's Manual, section #DEBUG for more information.
-load=<plugin>
Load the dynamic object 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 -help and -load options together. For example:
opt -load=plugin.so -help
-p Print module after each transformation.
EXIT STATUS
If opt succeeds, it will exit with 0. Otherwise, if an error occurs, it will exit with a non-zero value.
AUTHOR
Maintained by The LLVM Team (http://llvm.org/).
COPYRIGHT
2003-2016, LLVM Project
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