https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63155
--- Comment #22 from Richard Biener <rguenth at gcc dot gnu.org> --- Created attachment 44692 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44692&action=edit patch that does not help The attached patch changes the partition view so that members of bases are adjacent. This should improve the locality of the initial conflict set bits (we only record conflicts within same base variables). This doesn't help memory usage for either testcase. For the 2nd testcase we have 187988 partitions and 500 bases. The conflict bitmaps still end up very sparse (but large). There are also a lot of duplicate bitmaps (if you'd add self-conflicts). Restricting anonymous coalesces to abnormal coalescing only increases the number of bases to 747 and doesn't help memory use significantly. There may be cases where the patch helps since it should improve locality.
