https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106809
--- Comment #11 from CVS 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:e08dd36f90e74cd5be615b1ca82a38896434d48c commit r12-8751-ge08dd36f90e74cd5be615b1ca82a38896434d48c Author: Richard Biener <rguent...@suse.de> Date: Fri Sep 2 13:36:13 2022 +0200 tree-optimization/106809 - compile time hog in VN The dominated_by_p_w_unex function is prone to high compile time. With GCC 12 we introduced a VN run for uninit diagnostics which now runs into a degenerate case with bison generated code. Fortunately this case is easy to fix with a simple extra check - a more general fix needs more work. PR tree-optimization/106809 * tree-ssa-sccvn.cc (dominaged_by_p_w_unex): Check we have more than one successor before doing extra work. * gcc.dg/torture/pr106809.c: New testcase. (cherry picked from commit be1b42de9c151d46c89f9a8f82d4c5839a19ea94)
