https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114480
--- Comment #12 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:0bad303944a1d2311c07d59912b4dfa7bff988c8 commit r14-9701-g0bad303944a1d2311c07d59912b4dfa7bff988c8 Author: Richard Biener <rguent...@suse.de> Date: Wed Mar 27 16:19:01 2024 +0100 middle-end/114480 - IDF compute is slow The testcase in this PR shows very slow IDF compute: tree SSA rewrite : 76.99 ( 31%) 24.78% 243663 cc1plus cc1plus [.] compute_idf which can be mitigated to some extent by refactoring the bitmap operations to simpler variants. With the patch below this becomes tree SSA rewrite : 15.23 ( 8%) when not optimizing and in addition to that tree SSA incremental : 181.52 ( 30%) to tree SSA incremental : 24.09 ( 6%) when optimizing. PR middle-end/114480 * cfganal.cc (compute_idf): Use simpler bitmap iteration, touch work_set only when phi_insertion_points changed.
