Re: Help restricting args of an intrinsic function

[Mike Stump <mrs at apple dot com>]

On Friday, January 30, 2004, at 08:29  PM, Diego Novillo wrote:
> > So, does your scheme work when the optimizer is off (-O0)?
> Of course not.

Then that's a problem, because the code should work regardless of the 
optimization setting.

> Syd's problem can only be addressed if you have some
> minimal data flow information available.

No.  Enumeration constants don't require data flow.  Intergral constant 
expressions don't require data flow.  I don't think Syd needs anything 
as powerful as dataflow, just as powerful as fold.  The problem is 
these are frontend concepts and they may need to be handled by frontend 
code.  Machine specific builtins don't have easy access to the frontend 
and it seems that to solve this problem, we'd probably need access to 
the frontend, that, or those constructs have to be language independent 
enough to be handled by language independent code, or they need to be 
simplified by the fronend before that.

Now, I've not checked to see what all isn't handled, but it might be 
the case that something as simple as t = fold (t); will do everything 
Syd needs....  but, in general, I suspect we might need a frontend 
hook...