Do not compute alias sets for types that don't need them

[Richard Biener]

On Wed, 27 May 2015, Jan Hubicka wrote:

> > > 
> > > I am not sure if TYPE_MAIN_VARIANT is really needed here.  What I know is that
> > > complete types may have incomplete variants.
> > 
> > How can that be?  TYPE_FIELDS is shared across variants and all variants
> > should be layed out.
> 
> Because TYPE_FILEDS are not always shared across variants.  For example 
> gfc_nonrestricted_type builds variants of types that have their own 
> TYPE_FIELDS lists whose types are variants of the original TYPE_FIELDs.  
> C++ FE used to do the same for member pointers, but I noticed that last 
> stage1 with early version of type verifier and as far as I can remember 
> Jason changed that.

The fortran one needs to be "fixed" to use the new MEM_REF restrict
support.

Richard.

-- 
Richard Biener <rguenther@suse.de>
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