https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100492
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:cedce283c319103e039ae2659d0d7473dd8efeca commit r10-9920-gcedce283c319103e039ae2659d0d7473dd8efeca Author: Richard Biener <rguent...@suse.de> Date: Mon May 10 11:37:27 2021 +0200 tree-optimization/100492 - avoid irreducible regions in loop distribution When we distribute away a condition we rely on the ability to change it to either 1 != 0 or 0 != 0 depending on the direction of the exit branch in the respective loop. But when the loop contains an irreducible sub-region then for the conditions inside this this fails and can lead to infinite loops being generated. Avoid distibuting loops with irreducible sub-regions. 2021-05-10 Richard Biener <rguent...@suse.de> PR tree-optimization/100492 * tree-loop-distribution.c (find_seed_stmts_for_distribution): Find nothing when the loop contains an irreducible region. * gcc.dg/torture/pr100492.c: New testcase. (cherry picked from commit 60af2db18013a0339302928ba98fee893ccc1957)
