topic Re: ifx compiler error #8945: Generalized I/O not supported in an offload region. in Intel® Fortran Compiler

ifx compiler error #8945: Generalized I/O not supported in an offload region.

John_Michalakes — Tue, 04 Jan 2022 09:52:46 GMT

Compiling the snippet:

!$omp target write(*,*)1234 !$omp end target

generates the error:

ifx -qopenmp -fopenmp-targets=spir64 -g -traceback -c tbp.F90 tbp.F90(53): error #8945: Generalized I/O not supported in an offload region. write(*,*)1234 ------^ compilation aborted for tbp.F90 (code 1)

Note: Simple write statements to standard output from an OpenACC offload region are supported by the Nvidia (PGI) compiler.

Questions:

Is it possible to have debugging output in a target region of a Fortran program using OpenMP offload and compiling with ifx?
If this is not currently supported, are there plans for ifx to support simple output from target regions in the future?
Any other suggestions for inspecting the values of variables in running device code?

Thank you,

John

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

Barbara_P_Intel — Wed, 05 Jan 2022 21:29:11 GMT

This snippet compiles for me .

$ cat snippet.f90 program snippet !$omp target x = 1234. print *, x print *, 1234 !$omp end target stop end $ ifx -qopenmp -fopenmp-targets=spir64 snippet.f90 $ ifx -what --version ifx (IFORT) 2022.0.0 20211123 Copyright (C) 1985-2021 Intel Corporation. All rights reserved.

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

John_Michalakes — Wed, 05 Jan 2022 22:44:17 GMT

Thanks for looking into this. It must be because I was using a write(*,*) instead of print*

If I change one of the prints in your snippet I get:

$ cat snip.F90 program snippet !$omp target x = 1234. write(*,*) x print *, 1234 !$omp end target stop end $ ifx -qopenmp -fopenmp-targets=spir64 snip.F90 snip.F90(4): error #8945: Generalized I/O not supported in an offload region. write(*,*) x ^ compilation aborted for snip.F90 (code 1) $

Mystery solved, thank you.

John

Re:ifx compiler error #8945: Generalized I/O not supported in an offload region.

Barbara_P_Intel — Wed, 05 Jan 2022 22:56:45 GMT

You're welcome.

I tried variations of the write, like write(6,*) and write(6,5). All got that same message. But print does compile.

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

Steve_Lionel — Thu, 06 Jan 2022 15:33:38 GMT

Of course, this IS a bug. If one is accepted, all of these should be.

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

Barbara_P_Intel — Thu, 06 Jan 2022 16:22:49 GMT

According to the Fortran developers, "At this time, the only I/O we’re allowing in an offload region is 'print *' and even that is limited to numeric and character strings."

I'll add that tidbit to the Porting Guide for ifort Users to ifx.

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

John_Michalakes — Thu, 06 Jan 2022 16:35:48 GMT

Thanks all for following up. For what it's worth, write(*,*) and print* are analogous. But I'm in good shape, now that I know the rule.

Also FWIW, I think output of numeric and character strings to stdout from print and write(*,*) is all that the Nvidia compiler supports from an offload region.

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

jimdempseyatthecove — Thu, 06 Jan 2022 18:07:34 GMT

Barbara,

What about

PRINT '("Value=",F6.2)', 123.456

(my oneAPI system is not fired up)

Jim Dempsey

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

jimdempseyatthecove — Thu, 06 Jan 2022 18:09:42 GMT

WRITE(CharacterVariable, '("Value=",F6.2)') 123.456

Jim Dempsey

Re: ifx compiler error #8945: Generalized I/O not supported in an offload region.

Barbara_P_Intel — Thu, 06 Jan 2022 18:36:19 GMT

Doesn't look like it inside an OpenMP TARGET region.

+ ifx -qopenmp -fopenmp-targets=spir64 snippet.f90 snippet.f90(7): error #8945: Generalized I/O not supported in an offload region. PRINT '("Value=",F6.2)', 123.456 ^ snippet.f90(8): error #8945: Generalized I/O not supported in an offload region. WRITE(CharacterVariable, '("Value=",F6.2)') 123.456 ^ compilation aborted for snippet.f90 (code 1)