https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114855
--- Comment #56 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:942bbb2357656019caa3f8ebd2d23b09222f039a commit r15-3896-g942bbb2357656019caa3f8ebd2d23b09222f039a Author: Richard Biener <rguent...@suse.de> Date: Wed Sep 25 10:38:12 2024 +0200 tree-optimization/114855 - speed up dom_oracle::register_transitives dom_oracle::register_transitives contains an unbound dominator walk which for the testcase in PR114855 dominates the profile. The following fixes the unbound work done by assigning a constant work budget to the loop, bounding the number of dominators visited but also the number of relations processed. This gets both dom_oracle::register_transitives and get_immediate_dominator off the profile. I'll note that we're still doing an unbound dominator walk via equiv_set in find_equiv_dom at the start of the function and when we register a relation that also looks up the same way. At least for the testcase at hand this isn't an issue. I've also amended the guard to register_transitives with the per-basic-block limit for the number of relations registered not being exhausted. PR tree-optimization/114855 * params.opt (--param transitive-relations-work-bound): New. * doc/invoke.texi (--param transitive-relations-work-bound): Document. * value-relation.cc (dom_oracle::register_transitives): Assing an overall work budget, bounding the dominator walk and the number of relations processed. (dom_oracle::record): Only register_transitives when the number of already registered relations does not yet exceed the per-BB limit.
