restrict and char pointers
Jeroen Dobbelaere
jeroen.dobbelaere@gmail.com
Thu May 5 00:04:00 GMT 2005
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
More information about the Gcc
mailing list