# opt > A tool that takes LLVM source files and runs specified optimizations and/or analyses on them. > More information: . - 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}}`