This is the mail archive of the
mailing list for the GCC project.
Re: Ada subtypes and base types
On Tue, 2006-03-21 at 18:13 +0100, Duncan Sands wrote:
> Is memory use a problem here? VR_VARYING has the advantage of using
> a bit less memory. On the other hand, I guess you could introduce the
> convention that VR_RANGE with null min/mae means to use TYPE_MIN/
> TYPE_MAX, or something along those lines.
Well, more than anything, I just don't think we really thought
about the issue of what the best representation would be in this
kind of case.
If I was to lean any particular direction I would tend to lean
towards exposing the range and removing VR_VARYING. The net
result would be good consistency in the transformations within
VRP. ie, we would not need to special case stuff like
VR_VARYING | ~[0, 0] -> ~[0, 0]
SImilarly for typecasts and a variety of other stuff.