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Re: Reproducible Research Hackathon: Friday, July 3rd
From: |
Ludovic Courtès |
Subject: |
Re: Reproducible Research Hackathon: Friday, July 3rd |
Date: |
Tue, 14 Jul 2020 15:18:12 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) |
Hi Konrad,
Konrad Hinsen <konrad.hinsen@fastmail.net> skribis:
> Indeed. The details are here:
>
> https://gitlab.inria.fr/guix-hpc/guix-past/-/issues/1
Oooh, thank you! It looks like an “interesting” bug, one of those that
can help make the case for precise software environment control. :-)
bonfacemunyoki@gmail.com (Bonface M. K.) skribis:
> That's strange. To get the right results, you'd have to do a `2L ** 64`.
> When I tried `2 ** 63` I got `-9223372036854775808`. There's also an
> overflow error. Here's a snippet of what fails from
> Python-2.4.6/Lib/test:
>
> ```
> # If this fails, probably using a strict IEEE-754 conforming libm, and x
> # is +Inf afterwards. But Python wants overflows detected by default.
> try:
> x = math.exp(1000000000)
> except OverflowError:
> pass
> else:
> raise TestFailed("overflowing exp() didn't trigger OverflowError")
> ```
>
> Maybe there's an overflow somewhere and we'd have to tweak libm? I'm
> speculating though. I'd have to investigate this later.
Uh, weird! We could check whether building Python with ‘-fwrapv’ helps.
See also <https://lwn.net/Articles/511259/>.
Ludo’.
- Re: Reproducible Research Hackathon: Friday, July 3rd, (continued)
Re: Reproducible Research Hackathon: Friday, July 3rd, Konrad Hinsen, 2020/07/04
- Re: Reproducible Research Hackathon: Friday, July 3rd, Ludovic Courtès, 2020/07/13
- Re: Reproducible Research Hackathon: Friday, July 3rd, Konrad Hinsen, 2020/07/14
- Re: Reproducible Research Hackathon: Friday, July 3rd, Bonface M. K., 2020/07/14
- Re: Reproducible Research Hackathon: Friday, July 3rd, Konrad Hinsen, 2020/07/14
Re: Reproducible Research Hackathon: Friday, July 3rd,
Ludovic Courtès <=