OPT(1)

💅 NAME 💅

okay so this is opt(1), the page for opt — LLVM optimizer. It optimizes, it analyzes, it does the most. ✨

📜 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. 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. No cap — -help is your bestie for discovery. 🫶

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). Stdin is valid, bestie. 🌸

If an output filename is not specified with the -o option, opt writes its output to standard output. That's the default vibe. ⭐

✨ 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. It's giving “bestie, I know I'm in a terminal, do it anyway.” 💅
• -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). Main character energy: your flag order literally matters. 👑
• -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. Debug info? Gone first, before the other glow-ups. 🧚
• -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. It's the “who broke it?” detector, bestie. 🔍
• -stats — Print statistics.
• -time-passes — Record the amount of time needed for each pass and print it to standard error. Timing tea, served on stderr. ⏱️
• -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 (<../ProgrammersManual.html>), 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. Then it dips. 🦋

🚪 EXIT STATUS 🚪

If opt succeeds, it will exit with 0. Otherwise, if an error occurs, it will exit with a non-zero value. So 0 is the slay, non-zero is the “something's off” moment. 💀

👑 Author 👑

Maintained by the LLVM Team (https://llvm.org/).

🎀 Copyright 🎀

2003-2026, LLVM Project

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okay bye bestie — this page's source/version footer says 15, the date is 2026-09-09, and the page is OPT(1). Mwah 💋