FFTW wrapper not available in offload mode

[Nathanael_S_]

Hello,

We are trying to offload the main computations to the MIC, which includes FFT via the MKL and its fftw wrappers.
We are now running into this compilation error:

function "fftw_execute_dft" called in offload region must have been declared with compatible "target" attribute

Is this a bug, or is this intended ? Or do we link with the wrong library here ?

Any help appreciated.

[Dmitry_B_Intel]

It may help if you wrap [#include "fftw3.h"] between [#pragma offload_attribute(push) target(mic)] and [#pragma offload_attribute(pop)]

[Nathanael_S_]

Hello,

Thank you for your suggestion. There is a typo in your answer, the correct pragma is [#pragma offload_attribute(push target(mic))].
Compilation now works, but at runtime I get this error:

Hello,

Thank you for your suggestion.

Compilation now works, but at runtime I get this error:

On the remote process, dlopen() failed. The error message sent back from the sink is /tmp/coi_procs/1/6438/load_lib/iccoutNOEXQX: undefined symbol: fftw_execute_dft
offload error: cannot load library to the device 0 (error code 20)
On the sink, dlopen() returned NULL. The result of dlerror() is "/tmp/coi_procs/1/6438/load_lib/iccoutNOEXQX: undefined symbol: fftw_execute_dft"

[Ravi_N_Intel]

Did you use -mkl option on the command line.

[Nathanael_S_]

Using -mkl option solved the problem. Many thanks.