Thema "Re: Bug with host associated array in contained subroutine with openmp" in Intel® Fortran Compiler

Bug with host associated array in contained subroutine with openmp

MarkBuehner — Tue, 24 Feb 2026 18:11:18 GMT

Hello,

First time post here... we seem to have encountered a problem when switching to a newer version of the compiler (ifx (IFX) 2025.1.0 20250317). Now array variables declared in the main program are not correctly seen in contained subroutines. But this only occurs when compiling with openmp. There is no problem for scalar variables. Here is a simple example:

program test implicit none save real(4), save :: arr1(2) real(4) :: arr2(2) real(4) :: scalar ! Initialize to something obvious arr1 = -999.9 arr2 = -999.9 scalar = -123.4 print *, "Before :", scalar, arr1, arr2, loc(arr1), loc(arr2) call foo1() print *, "After :", scalar, arr1, arr2, loc(arr1), loc(arr2) contains subroutine foo1() implicit none print *, "Inside 1:", scalar, arr1, arr2, loc(arr1), loc(arr2) end subroutine foo1 end program

Below is the output when compiled with and without openmp. Sorry it's a bit messy. The important part is that with openmp the values of arr2 are zero inside the subroutine while they should be equal to -999.9.

By adding the "save" attribute with arr1 variable it seems we can trick the compiler into doing things correctly and it does equal -999.9 inside the subroutine.

The "loc()" function shows very different addresses for arr1 and arr2 in the body of the program whereas inside the subroutine loc(arr1) is the same as in the program, but loc(arr2) is completely different than in the program.

$ ifx -O2 -fiopenmp test.f90 $ ./a.out Before : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756992 140732410846224 Inside 1: -123.4000 -999.9000 -999.9000 0.0000000E+00 0.0000000E+00 4756992 4757024 After : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756992 140732410846224 $ ifx -O2 test.f90 $ ./a.out Before : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 4756928 Inside 1: -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 4756928 After : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 4756928

Has this bug already been identified and corrected in a later version?

Thanks,

Mark

Re: Bug with host associated array in contained subroutine with openmp

andrew_4619 — Tue, 24 Feb 2026 20:57:00 GMT

C:\temp>ifx /O2 /Qiopenmp testomp.f90 Intel(R) Fortran Compiler for applications running on Intel(R) 64, Version 2025.3.0 Build 20251010 Copyright (C) 1985-2025 Intel Corporation. All rights reserved. Microsoft (R) Incremental Linker Version 14.44.35214.0 Copyright (C) Microsoft Corporation. All rights reserved. -out:testomp.exe -subsystem:console -defaultlib:libiomp5md.lib -nodefaultlib:vcomp.lib -nodefaultlib:vcompd.lib testomp.obj C:\temp>testomp Before : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 140700539849984 303005957592 Inside 1: -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 140700539849984 303005957592 After : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 140700539849984 303005957592 C:\temp>

Windows + later version seems OK

Re: Bug with host associated array in contained subroutine with openmp

MarkBuehner — Tue, 24 Feb 2026 21:47:16 GMT

Sorry, I didn't mention that I'm using Linux version. Not sure it makes a difference.

Re: Bug with host associated array in contained subroutine with openmp

andrew_4619 — Tue, 24 Feb 2026 22:55:54 GMT

I could see you are using Linux, clearly my test changes more than one thing. You really need a Linux test on the latest version. Maybe if at is not an option for you someone else can test.

Re: Bug with host associated array in contained subroutine with openmp

Mark_Lewy — Thu, 26 Feb 2026 14:05:32 GMT

On Linux using IFX 2025.3.2 20260112, it looks like this bug is fixed:

Before : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 140731586795424 Inside 1: -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 140731586795424 After : -123.4000 -999.9000 -999.9000 -999.9000 -999.9000 4756960 140731586795424