[Bug tree-optimization/33302] dead-store not eliminated

["rakdver at kam dot mff dot cuni dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from rakdver at kam dot mff dot cuni dot cz  2007-09-05 14:30 -------
Subject: Re:  dead-store not eliminated

> > > Ah, I only found add_noreturn_fake_exit_edges which obviously didn't help.
> > > connect_infinite_loops_to_exit does.  Thx.
> > 
> > dominance.c contains code (probably buggy) that adds such edges implicitly, so
> > this should not be needed.
> 
> Maybe, but then domwalk.c is buggy as walk_dominator_tree does
> 
>   while (true)
>     {
>       /* Don't worry about unreachable blocks.  */
>       if (EDGE_COUNT (bb->preds) > 0 || bb == ENTRY_BLOCK_PTR)
>         {
> 
> and obviously in my case bb (the exit block) has no preds.  Maybe
> simply special-casing EXIT_BLOCK_PTR as well helps.

Yes, that seems reasonable (I think domwalk was originally only used
for dominator tree walks, so it may contain this kind of bugs for
post-dominator walks)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33302