[Bug rtl-optimization/67731] Combine of OR'ed bitfields should use bit-test

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67731

--- Comment #3 from rguenther at suse dot de <rguenther at suse dot de> ---
On Mon, 28 Sep 2015, olegendo at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67731
> 
> --- Comment #2 from Oleg Endo <olegendo at gcc dot gnu.org> ---
> (In reply to Richard Biener from comment #1)
> > Ok, so usually this gets optimized by fold-const.c
> > optimize_bit_field_compare but
> > appearantly that doesn't work here.  Not that I like this function very
> > much...
> 
> Can this one be handled by match.pd then?  If so, can you please change 
> this to tree-opt?

No, match.pd doesn't work with memory.  The various patches to
lower bitfield accesses made this work automagically.  Thus this
PR is probably a dup of some other(s).