PARDISO Error=-4

[Emil_J_]

I have a strange problem with PARDISO solver. Trying to factorize a symmetrical matrix (phase=12, mtype=2). The call returns with error=-4, which suggests a zero pivot, however iparm(30)=-1.

It seems that a particular combination of switches is creating this error. The error occurs when the Fortran DLL I am working on is built with optimisation disabled (/Od) and variables not initialised. If optimisation is turned on to maximise speed or variables are initialised (/Qinit:zero), then the error disappears.

I have tried to create a small project to illustrate the issue, but it runs for me without issues. The project I am working on is inside a large mixed-language solution, so I can't provide a code sample at the moment.

I am using the latest version of OneAPI MKL inside Visual Studio 2019, Intel(R) Visual Fortran Compiler 17.0.6.270 [Intel(R) 64] (latest)

Has anyone else experienced anything similar? My hunch is that some variable might not be initialised correctly, but not sure how to locate it.

[VarshaS_Intel]

Hi,

Thanks for posting in Intel Communities.

When we tried using the sample(pardiso_sym.f90) example, we could run successfully without any errors with optimization and without optimization. Please find the attached screenshots for more details.

Could you please let us know if you were getting errors for running the sample code(pardiso_sym.f90)?

Also, it will be great if you could provide us with the minimal sample code(along with the steps if any) for the error you are facing so that we can investigate your issue.

And also, could you please let us know the Intel MKL you are using?

Thanks & Regards,

Varsha

[Emil_J_]

Varsha,

So far we had not been able to reproduce the error on a small project. We have tried adding more code from the real solution, but still the small project works without issues. I have also tried using your sample code and it runs without errors when using our compiler switches switches. 

We are using the latest MKL (oneAPI Base Toolkit 2023.1.0.47256  +  oneAPI HPC Toolkit 2023.1.0.46357) .

For the time being, we have a set of switches that work on the real real solution. If we are able to repeat the issue with a small project, I will pass it on to you.  

[VarshaS_Intel]

Hi,

>> I have also tried using your sample code and it runs without errors when using our compiler switches

Thanks for the confirmation that you did not face any errors.

>>If we are able to repeat the issue with a small project, I will pass it on to you.  

Sure, thanks! Whenever you are able to create a sample reproducer, please create a new thread and we can investigate this issue further.

Have a Good Day!

Thanks & Regards,

Varsha