Hi,
> We ICEd on attached testcase because we didn't properly detected the
> latch edge. Furthermore, I think the code for re-computing latches
> is somehow broken at the moment. In fix_loop_structure we have
> /* If there was no latch, schedule the loop for removal. */
> if (!first_latch)
> loop->header = NULL;
> /* If there was a single latch and it belongs to the loop of the
> header, record it. */
> else if (latch
> && latch->src->loop_father == loop)
> loop->latch = latch->src;
> /* Otherwise there are multiple latches which are eventually
> disambiguated below. */
> else
> loop->latch = NULL;
> but I don't think we can use the ->loop_father info, because that is
> already cleared by
> FOR_EACH_BB (bb)
> {
> if (changed_bbs)
> bb->aux = (void *) (size_t) loop_depth (bb->loop_father);
> bb->loop_father = current_loops->tree_root;
> }
> earlier on.
I am not quite sure why we test "&& latch->src->loop_father == loop" in
the first place. Would things work if that condition is removed?
I don't much like your proposed patch (as well as the current state),
as according to the specification of fix_loop_structure, we are not
allowed to assume anything about the bb --> loop mapping,
Zdenek
