| From: | Jesse McClusky |
| Date: | 11 Sep 2000 at 19:17:21 |
| Subject: | AMIOPEN: Re: 64-bit pointers |
> From: "Alexander G. M. Smith" <agmsmith@home.com>
>
> Guillermo Rodriguez Garcia <guille@iies.es> wrote on
> Fri, 08 Sep 2000 10:49:01 +0200:
> >>I believe that VP by design uses 64-bit registers.
> >>I.e., a C "long" integer in VP is represented by a
> >>64 bit register. Presumably the same goes for
> >>pointers. So there is no problem of addressing
> >>more than 4 gigabytes of memory.
> >
> >longs are 64 bits in VP, but both ints and
> >pointer regs are 32 bit.
>
> While reading the SDK book (2nd edition, page 167),
> I noticed that the kernel device ID is a 64 bit value
> with the least significant 32 bits being a pointer to
> an instance, and the high 32 bits being a processor ID.
>
> So, even if they switch pointers to 64 bits, other things
> will break. Looks like we'll be stuck with 32 bit pointers
> for a while.
On the other hand, using virtual memory a task can have
everything it needs mapped consecutively. By the time
more than 4GB of RAM becomes standard on computers,
and tasks exist that make use of all of it, they'll also have
the processing power and bandwidth by which to use
indirect calls for everything via an abstract ID, which
can be a 64-bit long.
Jesse
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