ghc -O

[Matthew Naylor]

Hello GHC gurus,

specifying "-O" or "-O2" to GHC enables various optimisations to the
frontend of the compiler, but I wonder does it turn on any
optimistions to the backend/code-generator that are independent of the
frontend?

I can imagine that knowledge such as strictness which is computed by
frontend would enable optimisations in the backend, but I'm more
interested in whether the backend would do anything independent (e.g.
peephole optimistion, C compiler options) with "-O" but not without.

Thanks,

Matt.