Intel® Fortran Compiler
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ifort fails to respect the OpenMP task despendency

BSC_support
Beginner
573 Views

Build Number: OneApi 2021.3.0
Environment: Linux 4.4.59-92.20
Reason: Defect

Description: The binary generated by ifort fails to respect the OpenMP task dependencies between tasks instantiated in a subroutine and the ones instantiated in its internal subroutines.

Observations: Works properly when the variable that creates the dependency is ALLOCATABLE or the array has constant explicit shape.

Steps to Reproduce:
1) Compile the attached test (test.f90) with:
     ifort -qopenmp -f test.exe test.f90
2) Set OMP_NUM_THREADS biger than 1
3) Run the test.exe
4) The output of the second task is printed before the first one, which implies that the dependency is not respected.

Expected Result: The tasks execution respects the order specified by the dependencies: the first task completes its execution before the second one starts.

Labels (2)
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3 Replies
ShanmukhS_Intel
Moderator
531 Views

Hi,


Thanks for reaching out to us. We are working on your issue. We'll get back to you soon.


Best Regards,

Shanmukh.SS


Khalik_K_Intel
Moderator
485 Views

Hello,


Thank you for contacting Intel Support.


We have reproduced the behavior on our end and it looks like a bug in Intel Fortran Compiler.

I have now passed the information to Intel Fortran development team to have a look.


I will post an update once we get information from the development team.

In the meantime we are glad that you have a workaround available.


Regards,

Khalik.


BSC_support
Beginner
475 Views

Thank you Shanmukh and Khalik. 

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