[Bug middle-end/64083] [5 Regression] ICE: in fix_loop_structure, at loop-init.c:252 compiling Linux Kernel

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64083

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Seems I have an (untested) fix in my dev tree:

Index: gcc/tree-ssa-threadupdate.c
===================================================================
--- gcc/tree-ssa-threadupdate.c (revision 218078)
+++ gcc/tree-ssa-threadupdate.c (working copy)
@@ -2431,13 +2431,7 @@ thread_through_all_blocks (bool may_peel
                    struct loop *loop = (*path)[0]->e->dest->loop_father;

                    if (thread_block ((*path)[0]->e->dest, false))
-                     {
-                       /* This jump thread likely totally scrambled this loop.
-                          So arrange for it to be fixed up.  */
-                       loop->header = NULL;
-                       loop->latch = NULL;
-                       e->aux = NULL;
-                     }
+                     e->aux = NULL;
                    else
                      {
                        delete_jump_thread_path (path);

or else it should use mark_loop_for_removal (loop).  But the above is of course
prefered.