How to express the fact that arguments don't escape?

[Janne Blomqvist]

Tobias Schlüter wrote:
> 
> Hi,
> 
> I reviewed some old discussions on argument passing, but I found nothing 
> which addressed a seemingly simple optimization for Fortran: what I 
> would like to see is a way to tell the compiler that a function argument 
> (which will be a pointer) will not have escaped after the function has 
> returned.  I.e.
>   call f(i)
>   i = 1
>   call g(j)  ! won't know about i
>   if (i != 1) then
>      can't happen
>   end if
> 
> Is there a way to do this?  Unless I'm mistaken, this assumption holds 
> for all non-POINTER arguments.

Shouldn't the recent patch by Michael Matz fix this?

http://gcc.gnu.org/ml/fortran/2009-08/msg00104.html

By marking j as a restricted pointer it should know that it can't escape 
and alias i.

-- 
Janne Blomqvist