[Lapack] [bug report] dsyevr does not seem to be thread-safe
From: julie langou
Date: Mon, 19 Aug 2013 09:31:59 -0700
Thank you for reporting the issue, and proving a full example program.
We listed you bug on http://www.netlib.org/lapack/Errata/index2.html
We will take a look at it very soon.
On Aug 18, 2013, at 3:34 AM, Daniel Strobusch <daniel.strobusch@Domain.Removed>
Dear LAPACK Team,
according to my testing LAPACKs dsyevr does not seem to be thread-safe. This
is in contrast to the statement "all routines in LAPACK-3.3 are now
thread-safe." from "http://www.netlib.org/lapack/lapack-3.3.0.html).
In multi-threaded application the routine produces (arbitrarily wrong
eigenvectors, although eigenvalues are ok).
I tried to discuss the problem on http://stackoverflow.comhttp://stackoverflow.com/q/18216314/1458343
where also a full example program is given, which demonstrates the issue. As
I'm not a Fortran programmer I can only provide an example in C. It was
tested to call the routine dsyevr via the LAPACKE interface and also
directly. After the test failed with optimized OpenBLAS, the netlib reference
LAPACK/BLAS was used to confirm the misbehavior of the program. The tests
were run on two different platform.
I assume there is still a bug in LAPACK concerning thread-safety. I would
appreciate if you could confirm the bug and of course correct it in further
versions. Contributions to the stackoverflow discussion are also welcome.
With best regards
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