[Wien] fftw 3.3.10 cycle counter warning during configure

[Laurence Marks]

Ín Wien2k the time spent in the FFT is small in all cases that I know of,
particularly if you exploit mpi/omp, plus we don't use the algorithms that
explore different methods. If you are going to use it for other codes
(plane wave) then you might want to post to the fftw list for help. Or read
configure.ac to work out what is being looked for, then check your
gcc/icc/icx. The second option requires a fair bit of coding expertise, be
warned!

___
Emeritus Professor Laurence Marks (Laurie)
Department of Materials Science and Engineering, Northwestern University
www.numis.northwestern.edu
"Research is to see what everybody else has seen, and to think what nobody
else has thought" Albert Szent-Györgyi

On Tue, Mar 4, 2025, 08:39 Michael Fechtelkord via Wien <
wien at zeus.theochem.tuwien.ac.at> wrote:

> Dear all,
>
> when I configure fftw 3.3.10 using:
>
> C=ifx F77=ifx CC=gcc CFLAGS="-O3 -march=native -mavx2" FCFLAGS="-O3
> -xAVX2"\
>   ./configure --prefix=/usr/local/ --enable-shared --enable-mpi
> --enable-openmp --enable-threads --enable-avx --enable-avx2
>
>
> I get a warning from configure:
>
>
> checking whether a cycle counter is available... no
> ***************************************************************
> WARNING: No cycle counter found.  FFTW will use ESTIMATE mode
>         for all plans.  See the manual for more information.
> ***************************************************************
>
> I am using gcc 14.2, ifx 2025.0 on opensuse leap 15.6
>
> I am not sure if I had this in older versions of gcc / ifort.
>
> My question: Is the estimate mode a performance problem or can I just
> neglect the warning?
>
>
> Best regards,
>
> Michael
>
>
> --
> Dr. Michael Fechtelkord
>
> Institut für Geologie, Mineralogie und Geophysik
> Ruhr-Universität BochumUniversitätsstr. 150 <https://www.google.com/maps/search/Universit%C3%A4tsstr.+150?entry=gmail&source=g>
> D-44780 Bochum
>
> Phone: +49 (234) 32-24380
> Fax:  +49 (234) 32-04380
> Email: Michael.Fechtelkord at ruhr-uni-bochum.de
> Web Page: https://www.ruhr-uni-bochum.de/kristallographie/kc/mitarbeiter/fechtelkord/
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20250304/e556cd4f/attachment.htm>