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RE: GCC not (optimally) exploiting restrict pointers?
- From: "Dave Korn" <dave dot korn at artimi dot com>
- To: "'Richard Guenther'" <rguenth at tat dot physik dot uni-tuebingen dot de>,"'Steven Bosscher'" <stevenb at suse dot de>
- Cc: <gcc at gcc dot gnu dot org>
- Date: Wed, 15 Dec 2004 17:10:14 -0000
- Subject: RE: GCC not (optimally) exploiting restrict pointers?
> -----Original Message-----
> From: gcc-owner On Behalf Of Richard Guenther
> Sent: 15 December 2004 12:52
> On Wed, 15 Dec 2004, Steven Bosscher wrote:
>
> > On Wednesday 15 December 2004 13:34, Richard Guenther wrote:
> > Perhaps you can explain why? :-)
>
> It reads:
>
> (7) An object that is accessed through a restrict-qualified
> pointer has a
> special association with that pointer. This association, defined in
> 6.7.3.1 below, requires that all accesses to that object
> use, directly or
> indirectly, the value of that particular pointer.
>
> So, the value in *a has to be accessed through a exclusively and
> cannot be accessed through b, regardless of any type qualifiers
> present on b or not.
.... unless of course b was derived from a in the function that calls foo(),
perhaps?
> Though all examples given in 6.7.3.1 have
> both pointers restrict qualified - this is why I am not 100% sure.
It's highly suggestive.
cheers,
DaveK
--
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