https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114589
--- Comment #7 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:99b1daae18c095d6c94d32efb77442838e11cbfb commit r15-518-g99b1daae18c095d6c94d32efb77442838e11cbfb Author: Richard Biener <rguent...@suse.de> Date: Fri May 3 14:04:41 2024 +0200 tree-optimization/114589 - remove profile based sink heuristics The following removes the profile based heuristic limiting sinking and instead uses post-dominators to avoid sinking to places that are executed under the same conditions as the earlier location which the profile based heuristic should have guaranteed as well. To avoid regressing this moves the empty-latch check to cover all sink cases. It also stream-lines the resulting select_best_block a bit but avoids adjusting heuristics more with this change. gfortran.dg/streamio_9.f90 starts execute failing with this on x86_64 with -m32 because the (float)i * 9.9999...e-7 compute is sunk across a STOP causing it to be no longer spilled and thus the compare failing due to excess precision. The patch adds -ffloat-store to avoid this, following other similar testcases. This change fixes the testcase in the PR only when using -fno-ivopts as otherwise VRP is confused. PR tree-optimization/114589 * tree-ssa-sink.cc (select_best_block): Remove profile-based heuristics. Instead reject sink locations that sink to post-dominators. Move empty latch check here from statement_sink_location. Also consider early_bb for the loop depth check. (statement_sink_location): Remove superfluous check. Remove empty latch check. (pass_sink_code::execute): Compute/release post-dominators. * gfortran.dg/streamio_9.f90: Use -ffloat-store to avoid excess precision when not spilling. * g++.dg/tree-ssa/pr114589.C: New testcase.
