https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64365
--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 30 Jan 2015, brooks at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64365 > > --- Comment #13 from Brooks Moses <brooks at gcc dot gnu.org> --- > FWIW, if you haven't done the 4.9 backport yet, this is what I ended up with. > I'm not sure it's optimal, but it seems to work. Looks optimal to me - so if you bootstrapped and tested this it is ok to apply to the branch (with the testcase also backported of course). > Index: gcc/tree-data-ref.c > =================================================================== > --- gcc/tree-data-ref.c (revision 220259) > +++ gcc/tree-data-ref.c (working copy) > @@ -973,6 +973,24 @@ > fold_convert (ssizetype, memoff)); > memoff = build_int_cst (TREE_TYPE (memoff), 0); > } > + /* Adjust the offset so it is a multiple of the access type > + size and thus we separate bases that can possibly be used > + to produce partial overlaps (which the access_fn machinery > + cannot handle). */ > + double_int rem; > + if (TYPE_SIZE_UNIT (TREE_TYPE (ref)) > + && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (ref))) == INTEGER_CST > + && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (ref)))) > + rem = tree_to_double_int (off).mod > + (tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (ref))), > false, > + TRUNC_MOD_EXPR); > + else > + /* If we can't compute the remainder simply force the initial > + condition to zero. */ > + rem = tree_to_double_int (off); > + off = double_int_to_tree (ssizetype, tree_to_double_int (off) - > rem); > + memoff = double_int_to_tree (TREE_TYPE (memoff), rem); > + /* And finally replace the initial condition. */ > access_fn = chrec_replace_initial_condition > (access_fn, fold_convert (orig_type, off)); > /* ??? This is still not a suitable base object for > >
