[Bug middle-end/114579] RTL expansion add_scope_conflicts is slow
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114579 Richard Biener changed: What|Removed |Added Target Milestone|--- |15.0 Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #4 from Richard Biener --- Fixed for GCC 15, I don't have a testcase that's slow here anymore.
[Bug middle-end/114579] RTL expansion add_scope_conflicts is slow
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114579 --- Comment #3 from GCC Commits --- The master branch has been updated by Richard Biener : https://gcc.gnu.org/g:bbe83599320288025a417c54d9afcb3885cb2766 commit r15-99-gbbe83599320288025a417c54d9afcb3885cb2766 Author: Richard Biener Date: Thu Apr 4 14:00:10 2024 +0200 middle-end/114579 - speed up add_scope_conflicts The following speeds up stack variable conflict detection by recognizing that the all-to-all conflict recording is only necessary for CFG merges as it's the unioning of the live variable sets that doesn't come with explicit mentions we record conflicts for. If we employ this optimization we have to make sure to perform the all-to-all conflict recording for all CFG merges even those into empty blocks where we might previously have skipped this. I have reworded the comment before the all-to-all conflict recording since it seemed to be confusing and missing the point - but maybe I am also missing something here. Nevertheless for the testcase in the PR the compile-time spend in add_scope_conflicts at -O1 drops from previously 67s (39%) to 10s (9%). PR middle-end/114579 * cfgexpand.cc (add_scope_conflicts_1): Record all-to-all conflicts only when there's a CFG merge but for all CFG merges.
[Bug middle-end/114579] RTL expansion add_scope_conflicts is slow
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114579 Andrew Pinski changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2024-04-05 Ever confirmed|0 |1 --- Comment #2 from Andrew Pinski --- Confirmed.
[Bug middle-end/114579] RTL expansion add_scope_conflicts is slow
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114579 --- Comment #1 from Richard Biener --- Created attachment 57872 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57872=edit patch Doing this no longer will be able to handle A conflicts B, B conflicts C but A does not conflict C. But it might be something for -O1.
