On Tue, Feb 14, 2017 at 10:41 PM, Jeff Law <l...@redhat.com> wrote: > On 02/14/2017 01:58 AM, Richard Biener wrote: >>> >>> >>> I spoke with Andrew a bit today, he's consistently seeing cases where the >>> union of 3 ranges is necessary to resolve the kinds of queries we're >>> interested in. He's made a design decision not to use anti-ranges in his >>> work, so y'all are in sync on that long term. >> >> >> Ok. I'd also not hard-code the number of union ranges but make the code >> agnostic. Still the actual implementation might take a #define / template >> param >> for an upper bound. > > Andrew was in-sync on not hard-coding the number of ranges either -- > essentially he's considering the possibility that consumers might want > different levels of detail and thus a different number of recorded union > ranges. > > I'm not 100% sure that level of engineering is needed, but a design which > accounts for that inherently avoids hard-coding the upper bound.
Yeah. And then there's (independently) SSA_NAME_RANGE_INFO which needs a memory-compact representation which means it might make sense to retain anti-ranges for that and use at most one range/anti-range. Richard. > Jeff
