This is a Rust crate doc, but it's a nice place to browse for different cpu features and what they unlock: https://docs.rs/target-features/latest/target_features/docs/...

If you go to the x86 cpu list it will tell you what features are enabled if you would optimize for a particular one https://docs.rs/target-features/latest/target_features/docs/...

On linux you can run lscpu to check what cpu features are detected.