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