Could we agree to disagree and come together on improvements andclean-up?

Vincent Lefevre vincent at vinc17.org
Mon Jun 2 13:32:16 CEST 2008


On 2008-06-02 20:34:59 +1000, Joerg Arndt wrote:
> * Paul Leyland <paul at leyland.vispa.com> [Jun 02. 2008 20:08]:
> > On Mon, 2008-06-02 at 10:00, Vincent Lefevre wrote:
> > 
> > > > > No, long should just fit the needs. What if a processor has 32-bit
> > > > > words and use pointers on 64 bits (two words)?
> > > > 
> > > > Would you expect to see such CPU?
> > > 
> > > Strangest CPUs have been seen in the past. And some CPUs such as DSPs
> > > have particular features.
> 
> @Vincent: I _knew_ you'd mention DSPs, bad boy!

In fact, I thought that future conventional CPUs could also have
particular features, e.g. reserve 1 bit (a padding bit in C) for
trap values (i.e. uninitialized variables and things like that).
This can be useful for security reasons (dynamical checking for
uninitialized variables and overflows can also be done in software,
but this is slow). I've heard that some SPARC processors had such
a kind of (optional) feature.

> GMP uses assembler inlines, this is the single most nonportable
> way of doing things, nobody complained about that one so far  8-)

However it *also* provides generic C code.

-- 
Vincent Lefèvre <vincent at vinc17.org> - Web: <http://www.vinc17.org/>
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Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)


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