[PPL-devel] Bug affecting PPL 0.10 on big-endian architectures

[Roberto Bagnara]

Michael Tautschnig wrote:
> Hmm, this workaround looks quite ugly, I'd rather wait for a proper fix than
> hacking the build script in an architecture-specific way.

Hi Michael,

you are right.  A much better workaround (a trivial patch) is now available
at http://www.cs.unipr.it/ppl/Bugs/

> In the statement on the web page you don't give any details on what actually
> breaks on big endian architectures. If you could provide us with some details we
> could file a bug with high severity, which would hopefully allow us to ship an
> updated version with lenny or at least with lenny r1.

Well, the bug affects all the floating point computations of the PPL.
Luckily, GCC 4.4 does not use the affected code, but other applications
would (silently) obtain wrong results.

>> P.S. The bug proves that no one ever ran `make check' on PPL 0.10
>>      on a PowerPC machine and reported back the results.  If you
>>      have any idea how to make sure this does not happen again...
>>
> 
> We should probably not ignore errors from make check ... See, e.g., here:
> 
> http://buildd.debian.org/fetch.cgi?&pkg=ppl&ver=0.10-1&arch=powerpc&stamp=1225939952&file=log
> 
> There were quite a few errors, but we ignored all of them. In our packaging git
> repository I've got a 0.10-2 version sitting around where the errors wouldn't
> have been ignored, but apparently I never uploaded that one :-(

I see.  It is very important `make check' is run on every architecture you care about.
Particularly for those we do not have access to (such as ppc and ppc64).
All the best,

    Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it