On Tue, Oct 4, 2022 at 9:55 AM Richard Biener <richard.guent...@gmail.com> wrote: > > > Am 04.10.2022 um 09:36 schrieb Aldy Hernandez via Gcc-patches > <gcc-patches@gcc.gnu.org>: > > > > The reason the nonzero mask was kept in a tree was basically inertia, > > as everything in irange is a tree. However, there's no need to keep > > it in a tree, as the conversions to and from wide ints are very > > annoying. That, plus special casing NULL masks to be -1 is prone > > to error. > > > > I have not only rewritten all the uses to assume a wide int, but > > have corrected a few places where we weren't propagating the masks, or > > rather pessimizing them to -1. This will become more important in > > upcoming patches where we make better use of the masks. > > > > Performance testing shows a trivial improvement in VRP, as things like > > irange::contains_p() are tied to a tree. Ughh, can't wait for trees in > > iranges to go away. > > You want trailing wide int storage though. A wide_int is quite large.
Absolutely, this is only for short term storage. Any time we need long term storage, say global ranges in SSA_NAME_RANGE_INFO, we go through vrange_storage which will stream things in a more memory efficient manner. For irange, vrange_storage will stream all the sub-ranges, including the nonzero bitmask which is the first entry in such storage, as trailing_wide_ints. See irange_storage_slot to see how it lives in GC memory. Aldy
