https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79671
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Repeated on current trunk r245696, this time with: --- gcc/tree-ssa-alias.c.jj 2017-01-10 08:12:48.000000000 +0100 +++ gcc/tree-ssa-alias.c 2017-02-24 12:15:17.869368974 +0100 @@ -387,7 +387,13 @@ ptrs_compare_unequal (tree ptr1, tree pt || ! decl_binds_to_current_def_p (obj1)) return false; } - return !pt_solution_includes (&pi->pt, obj1); + if (!pt_solution_includes (&pi->pt, obj1)) +{ +gcc_assert (TREE_CODE (ptr2) == SSA_NAME); +int x = atoi (getenv ("PTRS_COMPARE_UNEQUAL")); +debug_generic_stmt (ptr2); +return SSA_NAME_VERSION (ptr2) == x; +} } /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2 hack. Unpatched trunk fails, with -fno-tree-pre succeeds and with this hack and PTRS_COMPARE_UNEQUAL=111111 succeeds as well. Let me try the various ssa name versions next.