Re: Canonical type nodes, or, comptypes considered harmful

[Mark Mitchell <mark at codesourcery dot com>]

Richard Kenner wrote:
> > Like when int and long have the same range on a platform?
> > The answer is they are different, even when they imply the same object
> > representation.
> >
> > The notion of unified type nodes is closer to syntax than semantics.
>
> I'm more than a little confused, then, as to what we are talking about
> canonicalizing.  We already have only one pointer to each type, for example.

Yes, but to compare two types, you have to recur on them, because of 
typedefs.  In:

  typedef int I;

"int *" and "I *" are distinct types, and you have to drill down to "I" 
to figure that out.

--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713