Bug report: `associated` function of ifort and ifx behave differently

[zoziha]

In the following code, the `associated` function of ifort and ifx does not behave the same. There should be a bug in ifort:

program main
    
    abstract interface
        subroutine foo_fcn()
        end subroutine
    end interface
    
    procedure(foo_fcn), pointer :: fcn_ptr
    fcn_ptr => prt
    
    call fcn_ptr()
    print *, associated(fcn_ptr, prt), associated(fcn_ptr)
    
contains
    
    subroutine prt()
        print *, 'Hello, World!'
    end subroutine
    
end program

The results of ifort and ifx:

>> ifort main.f90 && ./a
 Hello, World!
 F T
>> ifx main.f90 && ./a
 Hello, World!
 T T

[Barbara_P_Intel]

I like these nice short reproducers! Thank you.

Which compiler version are you using? I used ifort 2021.8.0 and got this. 

$ ifort --version
ifort (IFORT) 2021.8.0 20221119
Copyright (C) 1985-2022 Intel Corporation.  All rights reserved.

$ ifort main.f90
$ a.out
 Hello, World!
 T T
$ ifx --version
ifx (IFORT) 2023.0.0 20221201
Copyright (C) 1985-2022 Intel Corporation. All rights reserved.

$ ifx main.f90
$ a.out
 Hello, World!
 T T

 These compilers were released as part of oneAPI HPC Toolkit 2023.0 in December 2022. Download it here.

[zoziha]

Locally, my version is Visual-Studio 2022 + Intel-Fortran 2023.0.0:

Similarly, in godbolt, click this link to see the results of the example source file.

Interestingly, I compiled the example using the visual-studio release mode, and ifort gave the correct results!

[andrew_4619]

Just to confirm I did a debug build (on windows) with Intel® Fortran Compiler Classic 2021.8.0 [Intel(R) 64] and got the 'bad' result.

[Barbara_P_Intel]

Ah! The devil's in the details! Debug mode!

I get the wrong answers on both Windows and Linux when I compile with -g or -O0. Other optimization levels are just fine.

I filed a bug, CMPLRIL0-35148. I'll let you know when it's fixed.

[Barbara_P_Intel]

In the meantime, use ifx. It works!

[Barbara_P_Intel]

We value your input and helping us improve our products. However, the Intel® Fortran Compiler Classic with this issue will not receive a fix. We are concentrating our efforts on our new Intel® Fortran Compiler to make it the best in the industry. For this reason, we will close this issue at this time. We encourage you to try our new oneAPI Compilers. Your feedback and suggestions are important to us. Thank you for your efforts to help us improve our products.

Your reproducer works just fine with ifx. Please use ifx as ifort is now deprecated. Please see this information.

There is an ifort to ifx Porting Guide to help you in this transition.