On 01/04/2010 04:17 PM, Nathan Froyd wrote: > On Mon, Jan 04, 2010 at 04:08:17PM +0000, Andrew Haley wrote: >> On 01/04/2010 12:07 PM, Jakub Jelinek wrote: >>> IMHO we really should have some late tree pass that converts adjacent >>> bitfield operations into integral operations on non-bitfields (likely with >>> alias set of the whole containing aggregate), as at the RTL level many cases >>> are simply too many instructions for combine etc. to optimize them properly, >>> while at the tree level it could be simpler. >> >> Yabbut, how come RTL cse can handle it in x86_64, but PPC not? > > Probably because the RTL on x86_64 uses and's and ior's, but PPC uses > set's of zero_extract's (insvsi).
Aha! Yes, that'll probably be it. It should be easy to fix cse to recognize those too. Andrew.
