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).

       -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
              LLVM_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

       -print-passes
              Print all available passes and exit.

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 (https://llvm.org/).

COPYRIGHT

       2003-2024, LLVM Project

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