Re: restrict and char pointers

[Jeroen Dobbelaere <jeroen.dobbelaere@gmail.com>]

On 5/4/05, James E Wilson wrote:
[..]
> The standard says "A translator is free to ignore any or all aliasing
> implications of restrict".  So there is no conflict with the standard
> here.  We are free to do as little optimization as we want, and in the
> case of a restricted char pointer, we do none.

I'm aware of that. The reason are asked for more clarity is that I
think gcc should
do better (as in the example I gave), but I want to be sure that this
is still allowed
by the standard.

[..]
>           /* No two restricted pointers can point at the same thing.
>              However, a restricted pointer can point at the same thing
>              as an unrestricted pointer, if that unrestricted pointer
>              is based on the restricted pointer.  So, we make the
>              alias set for the restricted pointer a subset of the
>              alias set for the type pointed to by the type of the
>              decl.  */
[..]

From what I found on these pages I refered to, this could be made more strict :
accesses through restricted pointers would not interfere with other accesses,
which would allow some more aggressive optimizations.

Greetings,
-- 
Jeroen Dobbelaere