GCC and GMP 5.0.1

[bodrato at mail.dm.unipi.it]

Ciao!

On Sat, February 26, 2011 11:28 pm, Torbjorn Granlund wrote:
> "Steve M. Robbins" <steve at sumost.ca> writes:
>
>   I'm curious if any distributions have begun shipping with GMP 5?
>   Debian Linux's GMP (which I maintain) is presently 4.3.2 and we're
>   having a bit of a debate whether to upgrade to GMP 5.

I'm very happy to thank Steve for his work on Debian's GMP. I'm a Debian
user :-) ... I have to test the non-Linux flavour of Debian, if I find the
necessary courage.

>   Any experience good or bad with building GCC using GMP 5 would
>   be appreciated.
>
> You need to understand that GMP is something such anachronistic as
> carefully designed, carefully written, and carefully tested software.

Dear Torbjörn,

When we released the 5.0 versions of GMP, we basically announced it as
"experimental". We wrote:
"The amount of new code means that there might be more bugs in GMP 5.0
 than in most GMP releases in the past.  We therefore still maintain
 GMP 4.3 and advice users concerned about stability to use the latest
 release from that release series."
This means that people are authorised to suspect of possible regressions,
aren't they?

> The likelihood that GCC's constant folding should strike a GMP bug is
> extremely slim.

GCC uses GMP also for loop optimization, through PPL.

Of course, I do consider GMP 5 very stable now, and I'd suggest switching.
Unfortunately I never tested its interaction with GCC build.

Regards,
Marco

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