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OPT(1)				     LLVM				OPT(1)

       opt - LLVM optimizer

       opt [options] [filename]

       The  opt	 command is the	modular	LLVM optimizer and analyzer.  It takes
       LLVM source files as input, runs	the specified optimizations or	analy-
       ses 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  out-
       put  file.   The	 optimizations	available via opt depend upon what li-
       braries were linked into	it as well as any  additional  libraries  that
       have been loaded	with the -load option.	Use the	-help option to	deter-
       mine 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.

       -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).

	      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).

	      This option simply removes the inlining pass from	 the  standard

	      This option is only meaningful when -std-link-opts is given.  It
	      disables most passes.

	      This option causes opt to	strip debug information	from the  mod-
	      ule  before applying other optimizations.	 It is essentially the
	      same as -strip but it ensures that stripping of  debug  informa-
	      tion is done first.

	      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 do-
	      ing it.

       -stats Print statistics.

	      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	print-
	      outs from	passes which use the LLVM_DEBUG() macro.  See the LLVM
	      Programmer's Manual, section #DEBUG for more information.

	      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 -help

       -p     Print module after each transformation.

       If opt succeeds,	it will	exit with 0.  Otherwise, if an	error  occurs,
       it will exit with a non-zero value.

       Maintained by The LLVM Team (

       2003-2021, LLVM Project

7				  2021-02-28				OPT(1)


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