Are complex*16 variables static by default?

[N.M. Maclaren]

On Jan 28 2017, Steffen Boerm wrote:
>
>>>> how are complex*16 variables handled by gfortran if "-frecursive" is
>>>> not specified?
>> 
>> AFAIK they are handled just like other primitive types.
>
>That's what I would have expected.
>
>Still, if I replace zlarfg/zlarf by my own code or disable OpenMP, the
>program seems to work. Wouldn't this indicate that zlarfg/zlarf may
>introduce strange side effects?

No.  What it would indicate is that the code has falled foul of OpenMP's
shared/private rules, which are 'interestingly complicated'.  Note that
'thread safe' isn't a well-defined term but, given that OpenMP is currently
the dominant shared-memory threading paradigm, should include being safe
for OpenMP.

>I am using the LAPACK version of Ubuntu 16.04.1 (version
>3.6.0-2ubuntu2). Does it make a difference whether the library is
>compiled with "-fopenmp" or just with "-frecursive"?

Almost certainly.  The requirements are different, though they overlap.

>Ill try downloading LAPACK 3.7 and compiling it myself with "-fopenmp".
>May that will fix the problem.

That's the best start.  If that fails, there will be solutions, but the
best one would be to improve LAPACK.


Regards,
Nick Maclaren.