On Sat, May 20, 2017 at 11:27 AM, Marc Glisse <marc.gli...@inria.fr> wrote: > Hello, > > as asked, I am adding some replacement in match.pd instead of just deleting > this (redundant with CCP). It is not clear how general the match.pd version > needs to be. (for instance it could handle some casts in addition to what I > have written) > > The expansion results in a few non-canonical patterns (thus unreachable > code), but avoiding them would make the code longer and less readable. > > I wondered about naming with_possible_nonzero_bits INTEGER_CST_or_SSA_NAME > instead. > > I would like to rename get_nonzero_bits to get_possible_nonzero_bits or > get_possibly_nonzero_bits, something more explicit, and introduce > get_certain(ly)_nonzero_bits that would always return 0 for SSA_NAME for a > start (but hopefully the next person who rewrites this stuff (merge CCP with > VRP for instance?) will implement it). It would allow for more symmetry in > the transformations and make the intent clearer. > > Bootstrap+testsuite on powerpc64le-unknown-linux-gnu. > > 2017-05-22 Marc Glisse <marc.gli...@inria.fr> > > * fold-const.c (fold_binary_loc) [(A & C) == D]: Remove > transformation. > * match.pd (X == C): Rewrite it here. > (with_possible_nonzero_bits, with_possible_nonzero_bits2, > with_certain_nonzero_bits2): New predicates. > * tree-ssanames.c (get_nonzero_bits): Handle INTEGER_CST. > > -- > Marc Glisse
This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80894 -- H.J.
