Hi,

On Mon, 2 May 2011, Richard Guenther wrote:

> >> --- 348,367 ----
> >>                            bool insert_at_next_slot_p)
> >>   {
> >>     void **slot;
> >>     unsigned ix;
> >>     bool existed_p;
> >>
> >>     gcc_assert (t);
> >>
> >> !   slot = pointer_map_insert (cache->node_map, t);
> >> !   if (!*slot)
> >
> > ix might legitimately be zero.  Hence this transformation is not
> > equivalent.  You might want to enter ix+1 into the cache with the
> > appropriate adjustment at read-out.  Same for the other places.
> 
> Or not use index zero.

I never like these sentinals.

> Maybe better than also have to deal with ix + 1 wrapping ...

We don't handle ix wrapping, why should we now suddenly care about ix+1 
wrapping?


Ciao,
Michael.

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