From: Xavier Leroy <xavier.leroy@inria.fr>
To: caml-list@inria.fr
Subject: Re: [Caml-list] Zarith problems on ppc64le
Date: Mon, 7 Nov 2016 16:58:24 +0100 [thread overview]
Message-ID: <6a64a161-4ed0-fb07-caa1-4bf3c7f91c23@inria.fr> (raw)
In-Reply-To: <20161107154843.GH27249@annexia.org>
On 07/11/2016 16:48, Richard W.M. Jones wrote:
> On Mon, Nov 07, 2016 at 01:22:01PM +0000, Richard W.M. Jones wrote:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1392247
>>
>> Zarith fails tests on OCaml 4.04.0 + ppc64le with some fairly gross
>> errors, eg:
>>
>> of_float -1.
>> - = -1
>> + = 0
>>
>> (It passes fine on OCaml 4.04.0 + ppc64)
>>
>> The implementation of Zarith is quite complex and I've so far failed
>> to understand what's going on.
>
> FWIW this seems like it is invoking undefined behaviour in C. See
> my analysis here:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1392247#c3
Yes, something is weird here. You can try to put
return Val_long((intnat) x);
on line 524: it should fix the issue that you suspect.
If this is the source of the problem, I'm surprised that it doesn't
break on other platforms as well.
- Xavier Leroy
next prev parent reply other threads:[~2016-11-07 15:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-07 13:22 Richard W.M. Jones
2016-11-07 13:31 ` Nicolas Ojeda Bar
2016-11-07 13:55 ` Francois BERENGER
2016-11-07 14:11 ` Sylvain Le Gall
2016-11-07 14:59 ` Simon Cruanes
2016-11-15 9:11 ` Bernhard Schommer
2016-11-07 15:48 ` Richard W.M. Jones
2016-11-07 15:58 ` Xavier Leroy [this message]
2016-11-07 16:19 ` Richard W.M. Jones
2016-11-08 10:00 ` Goswin von Brederlow
2016-11-08 11:10 ` Richard W.M. Jones
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a64a161-4ed0-fb07-caa1-4bf3c7f91c23@inria.fr \
--to=xavier.leroy@inria.fr \
--cc=caml-list@inria.fr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox