1opt - LLVM optimizer 2==================== 3 4.. program:: opt 5 6SYNOPSIS 7-------- 8 9:program:`opt` [*options*] [*filename*] 10 11DESCRIPTION 12----------- 13 14The :program:`opt` command is the modular LLVM optimizer and analyzer. It 15takes LLVM source files as input, runs the specified optimizations or analyses 16on it, and then outputs the optimized file or the analysis results. The 17function of :program:`opt` depends on whether the `-analyze` option is 18given. 19 20When `-analyze` is specified, :program:`opt` performs various analyses 21of the input source. It will usually print the results on standard output, but 22in a few cases, it will print output to standard error or generate a file with 23the analysis output, which is usually done when the output is meant for another 24program. 25 26While `-analyze` is *not* given, :program:`opt` attempts to produce an 27optimized output file. The optimizations available via :program:`opt` depend 28upon what libraries were linked into it as well as any additional libraries 29that have been loaded with the :option:`-load` option. Use the :option:`-help` 30option to determine what optimizations you can use. 31 32If ``filename`` is omitted from the command line or is "``-``", :program:`opt` 33reads its input from standard input. Inputs can be in either the LLVM assembly 34language format (``.ll``) or the LLVM bitcode format (``.bc``). 35 36If an output filename is not specified with the :option:`-o` option, 37:program:`opt` writes its output to the standard output. 38 39OPTIONS 40------- 41 42.. option:: -f 43 44 Enable binary output on terminals. Normally, :program:`opt` will refuse to 45 write raw bitcode output if the output stream is a terminal. With this option, 46 :program:`opt` will write raw bitcode regardless of the output device. 47 48.. option:: -help 49 50 Print a summary of command line options. 51 52.. option:: -o <filename> 53 54 Specify the output filename. 55 56.. option:: -S 57 58 Write output in LLVM intermediate language (instead of bitcode). 59 60.. option:: -{passname} 61 62 :program:`opt` provides the ability to run any of LLVM's optimization or 63 analysis passes in any order. The :option:`-help` option lists all the passes 64 available. The order in which the options occur on the command line are the 65 order in which they are executed (within pass constraints). 66 67.. option:: -disable-inlining 68 69 This option simply removes the inlining pass from the standard list. 70 71.. option:: -disable-opt 72 73 This option is only meaningful when `-std-link-opts` is given. It 74 disables most passes. 75 76.. option:: -strip-debug 77 78 This option causes opt to strip debug information from the module before 79 applying other optimizations. It is essentially the same as `-strip` 80 but it ensures that stripping of debug information is done first. 81 82.. option:: -verify-each 83 84 This option causes opt to add a verify pass after every pass otherwise 85 specified on the command line (including `-verify`). This is useful 86 for cases where it is suspected that a pass is creating an invalid module but 87 it is not clear which pass is doing it. 88 89.. option:: -stats 90 91 Print statistics. 92 93.. option:: -time-passes 94 95 Record the amount of time needed for each pass and print it to standard 96 error. 97 98.. option:: -debug 99 100 If this is a debug build, this option will enable debug printouts from passes 101 which use the ``LLVM_DEBUG()`` macro. See the `LLVM Programmer's Manual 102 <../ProgrammersManual.html>`_, section ``#DEBUG`` for more information. 103 104.. option:: -load=<plugin> 105 106 Load the dynamic object ``plugin``. This object should register new 107 optimization or analysis passes. Once loaded, the object will add new command 108 line options to enable various optimizations or analyses. To see the new 109 complete list of optimizations, use the :option:`-help` and :option:`-load` 110 options together. For example: 111 112 .. code-block:: sh 113 114 opt -load=plugin.so -help 115 116.. option:: -p 117 118 Print module after each transformation. 119 120EXIT STATUS 121----------- 122 123If :program:`opt` succeeds, it will exit with 0. Otherwise, if an error 124occurs, it will exit with a non-zero value. 125