2011/6/27 Richard Guenther <richard.guent...@gmail.com>: > On Wed, Jun 22, 2011 at 3:09 PM, Kai Tietz <ktiet...@googlemail.com> wrote: >> Hello, >> >> This patch improves via type-sinking folding of binary and, or, and >> xor operations. >> First we do sinking also for compatible types with same precision, as >> those don't need to be preserved for these operations. >> Additional try to fold patterns (TYPE) X bin-op (Y CMP Z) and (TYPE) X >> bin-op !Y, if type of X is >> compatible to Y. >> >> ChangeLog gcc >> >> 2011-06-22 Kai Tietz <kti...@redhat.com> >> >> * tree-ssa-forwprop.c (simplify_bitwise_binary): >> Improve binary folding regarding casts. >> >> >> ChangeLog gcc/testsuite >> >> 2011-06-22 Kai Tietz <kti...@redhat.com> >> >> * gcc.dg/binop-notand1a.c: New test. >> * gcc.dg/binop-notand2a.c: New test. >> * gcc.dg/binop-notand3a.c: New test. >> * gcc.dg/binop-notand4a.c: New test. >> * gcc.dg/binop-notand5a.c: New test. >> * gcc.dg/binop-notand6a.c: New test. >> >> Bootstrapped and regression tested for all standard languages, Ada, >> and Obj-C++. Ok for apply? > > The first hunk is ok, the 2nd not - please don't use fold here. Also > your comment says what it tries to match, but not what it tries > to produce. So - what is the transformation you are trying to do? > The code is also two duplicates of exactly the same stuff. > > Btw, I see TRUTH_NOT_EXPR is still around, why's that so? > > Thanks, > Richard.
Ok, I will sent first hunk as separate patch. The second hunk shall try to do simple simple folding like X & !X -> 0 (which is handled by fold-const, too). As special case we have here also (type) X & !X, and for case X & (type) !X. Later case can happen as soon as we preserve casts from boolean-type. I was thinking about implementing here the optimizations for all binary and/or/xor the foldings to constant directly in forward-propagate. This might be the better choice. Should I put this into a separate function in forward-propagation, or should I put this folding function into a different file? Regards, Kai
