Re: Patch: cse "library" routines

[Bernd Schmidt <bernds at balti dot cygnus dot co dot uk>]

> > + /* A table that enables us to look up elts by their value.  */
> > + #define NBUCKETS 32
> > + #define VALUE_HASH(V) ((V) % NBUCKETS)
> > + 
> > + static cselib_val *table[NBUCKETS];
> 
> Why your own hash table implementation rather than one of the
> couple of dictionary-type widgets we already have in libiberty?

I think the main reason is that I duplicated some parts from cse.c.  I've
had a brief look at hashtab.c now.  I could probably use it but some parts
might get more complicated; e.g. the code needs to compute the hash value
before inserting a new element into the table (to avoid entering particular
expressions which can't be hashed), so we'd compute the hash value twice.
IMO not using hashtab.c avoids some complications, but I won't object if you
want this changed.

> 
> > + static struct elt_list *
> > + new_elt_list (next, elt)
> [...]
> > +     el = (struct elt_list *) xmalloc (sizeof (struct elt_list));
> [...]
> > + new_elt_loc_list (next, loc)
> [...]
> > +     el = (struct elt_loc_list *) xmalloc (sizeof (struct elt_loc_list));
> 
> I don't see a free to go along with these mallocs.  Perhaps
> you meant to do it in clear_table?

Indeed, that seems to be missing.  I'll send an update tomorrow.  Do you
think the hash table should use the implementation from libiberty?

Thanks for looking at this,


Bernd