https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123225
--- Comment #21 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <[email protected]>: https://gcc.gnu.org/g:27c86eb6e7e277e55ca8c257fc3a9d1c1a2a126e commit r16-7410-g27c86eb6e7e277e55ca8c257fc3a9d1c1a2a126e Author: Richard Biener <[email protected]> Date: Fri Feb 6 15:47:08 2026 +0100 tree-optimization/123225 - require iteration estimate for uncounted loops The following makes uncounted loops not profitable to vectorize unless there's an estimate on the number of iterations, either from array sizes, overflow, or PGO, that indicates proftiability. Or trivial profitability, but that's impossible to reach - Tamars pending patch might change this in some cases. I have verified that with PGO we do vectorize the testcase in the PR. PR tree-optimization/123225 * tree-vect-loop.cc (vect_analyze_loop_costing): For uncounted loops reject not trivially profitable loops that have no estimate on the number of scalar iterations. * gcc.dg/vect/costmodel/x86_64/costmodel-pr123225.c: New testcase.
