tldr/pages/common/opt.md

opt

A tool that takes LLVM source files and runs specified optimizations and/or analyses on them.

• Run an optimization or analysis on a bitcode file:

opt -{{passname}} {{path/to/file.bc}} -S -o {{file_opt.bc}}

• Output the Control Flow Graph of a function to a "dot" file:

opt {{-dot-cfg}} -S {{path/to/file.bc}} -disable-output

• Optimize the program at level 2 and output the result to another file:

opt -O2 {{path/to/file.bc}} -S -o {{path/to/output_file.bc}}