optimized complex number kernel

[Barry Smith]

    Craig,

     Thanks for pointing this out. I have updated the manual and  
installation.html in PETSc-dev to explicitly provide this information.

    Barry

On Dec 2, 2009, at 11:09 AM, Satish Balay wrote:

> The performance difference between c/c++ kernels and fortran kernels -
> or c-complex/c++-complex can be compiler specific. You can build all
> relavent versions [each with a different PETSC_ARCH] and see if it
> makes a difference for you code.
>
> The relavent configure options are:
> --with-fortran-kernels=generic [default 'none']
> --with-clanguage=cxx [or default 'c']
> --with-scalar-type=complex [default 'real']
>
> Satish
>
> On Wed, 2 Dec 2009, Craig Tanis wrote:
>
>> Hi,
>>
>> The Petsc 3 manual (pdf)mentions using an optimized fortran kernel  
>> for complex numbers, that somehow uses the same C interface.  It  
>> refers to a document on how to build these kernels, but that  
>> document does not appear to be in the tarball (or on the anl.gov  
>> website).
>>
>> Furthermore, the FAQ on the website only mentions C and C++ in the  
>> section on complex number performance...
>>
>> If someone could clarify what was possible, and where to look for  
>> more information, that would be great!
>> thanks,
>> Craig
>