https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112859
--- Comment #12 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:6258d3f06740c3a77cd7a91606107451d71df68d commit r12-11221-g6258d3f06740c3a77cd7a91606107451d71df68d Author: Richard Biener <rguent...@suse.de> Date: Thu Jan 23 13:10:17 2025 +0100 tree-optimization/112859 - bogus loop distribution When we get a zero distance vector we still have to check for the situation of a common inner loop with zero distance. But we can still allow a zero distance for the loop we distribute (gcc.dg/tree-ssa/ldist-33.c is such a case). This is because zero distances in non-outermost loops are a misrepresentation of dependence by dependence analysis. Note that test coverage of loop distribution of loop nests is very low. PR tree-optimization/112859 PR tree-optimization/115347 * tree-loop-distribution.cc (loop_distribution::pg_add_dependence_edges): For a zero distance vector still make sure to not have an inner loop with zero distance. * gcc.dg/torture/pr112859.c: New testcase. * gcc.dg/torture/pr115347.c: Likewise. * gcc.dg/tree-ssa/ldist-36.c: Adjust. (cherry picked from commit 04ba1300407f106a6dd10d346f58a51d87e6d43e)
