On May 20, 2016 6:08:34 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote: >On Fri, May 20, 2016 at 08:54:39AM -0700, Andi Kleen wrote: >> I thought I had filed a bugzilla at some point, but can't >> find it right now. If you compare bitfield code >> compiled for Haswell on LLVM and GCC it is very visible >> how much worse gcc is. > >We really need to lower bitfield operations (especially when there are >multiple adjacent ones) to integer arithmetics on the underlying >DECL_BIT_FIELD_REPRESENTATIVE fields somewhere in (late?) gimple and >perform some cleanups after it and only after that expand.
Yes, I still have patches for this and plan to resurrect them now that one prerequisite is in. Richard. > Jakub
