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). -Nathan
