[Flang][OpenMP] assumed-shape array of character type with allocatable attribute in task private construct in parallel private construct does not execute correctly

[ohno-fj]

Version of flang-new : 20.0.0(77f8297c6fdaa62121ddb108043dcaad5c45c7ad)/AArch64

assumed-shape array of character type with allocatable attribute in task private construct in parallel private construct does not execute correctly.
The above program is dw2_007_tsk_231.f90.

Correct execution results are obtained in the following cases.

• The length of the character type is a constant instead of *
  The above program is dw2_007_tsk_232.f90.
• Remove task private construct
• Do not specify compilation options (-fopenmp)

The following are the test program, Flang-new, Gfortran and ifx compilation/execution result.

dw2_007_tsk_231.f90:

subroutine sub01(arg01)
  character(*),allocatable :: arg01(:)
  allocate(arg01(1))
  arg01(1) = "abcde12345"
  write(6,*) "1:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng1'
!$omp parallel private(arg01)
!$omp task private(arg01)
  write(6,*) "2:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng2',len(arg01)
!$omp end task
!$omp end parallel
end subroutine sub01

program main
  interface
     subroutine sub01(arg01)
       character(*),allocatable :: arg01(:)
     end subroutine sub01
  end interface

  character(10),allocatable :: cha01(:)
  call sub01(cha01)
end program main

$ export OMP_NUM_THREADS=2; flang-new -fopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =  10
 2:len(arg01) =  0
 2:len(arg01) =  0
$

$ export OMP_NUM_THREADS=2; gfortran -fopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

$ export OMP_NUM_THREADS=2; ifx -qopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

dw2_007_tsk_232.f90:

subroutine sub01(arg01)
  character(10),allocatable :: arg01(:)
  allocate(arg01(1))
  arg01(1) = "abcde12345"
  write(6,*) "1:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng1'
!$omp parallel private(arg01)
!$omp task private(arg01)
  write(6,*) "2:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng2',len(arg01)
!$omp end task
!$omp end parallel
end subroutine sub01

program main
  interface
     subroutine sub01(arg01)
       character(10),allocatable :: arg01(:)
     end subroutine sub01
  end interface

  character(10),allocatable :: cha01(:)
  call sub01(cha01)
end program main

$ export OMP_NUM_THREADS=2; flang-new -fopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =  10
 2:len(arg01) =  10
 2:len(arg01) =  10
$

$ export OMP_NUM_THREADS=2; gfortran -fopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

$ export OMP_NUM_THREADS=2; ifx -qopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

[luporl]

This issue doesn't occur with current flang anymore. It must have been fixed by #125307.

[llvmbot]

@llvm/issue-subscribers-flang-ir

Author: None (ohno-fj)

``` Version of flang-new : 20.0.0(77f8297)/AArch64 ```

assumed-shape array of character type with allocatable attribute in task private construct in parallel private construct does not execute correctly.
The above program is dw2_007_tsk_231.f90.

Correct execution results are obtained in the following cases.

• The length of the character type is a constant instead of *
  The above program is dw2_007_tsk_232.f90.
• Remove task private construct
• Do not specify compilation options (-fopenmp)

The following are the test program, Flang-new, Gfortran and ifx compilation/execution result.

dw2_007_tsk_231.f90:

subroutine sub01(arg01)
  character(*),allocatable :: arg01(:)
  allocate(arg01(1))
  arg01(1) = "abcde12345"
  write(6,*) "1:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng1'
!$omp parallel private(arg01)
!$omp task private(arg01)
  write(6,*) "2:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng2',len(arg01)
!$omp end task
!$omp end parallel
end subroutine sub01

program main
  interface
     subroutine sub01(arg01)
       character(*),allocatable :: arg01(:)
     end subroutine sub01
  end interface

  character(10),allocatable :: cha01(:)
  call sub01(cha01)
end program main

$ export OMP_NUM_THREADS=2; flang-new -fopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =  10
 2:len(arg01) =  0
 2:len(arg01) =  0
$

$ export OMP_NUM_THREADS=2; gfortran -fopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

$ export OMP_NUM_THREADS=2; ifx -qopenmp dw2_007_tsk_231.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

dw2_007_tsk_232.f90:

subroutine sub01(arg01)
  character(10),allocatable :: arg01(:)
  allocate(arg01(1))
  arg01(1) = "abcde12345"
  write(6,*) "1:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng1'
!$omp parallel private(arg01)
!$omp task private(arg01)
  write(6,*) "2:len(arg01) = ", len(arg01)
!  if ( 10 .ne. len(arg01)) print *,'ng2',len(arg01)
!$omp end task
!$omp end parallel
end subroutine sub01

program main
  interface
     subroutine sub01(arg01)
       character(10),allocatable :: arg01(:)
     end subroutine sub01
  end interface

  character(10),allocatable :: cha01(:)
  call sub01(cha01)
end program main

$ export OMP_NUM_THREADS=2; flang-new -fopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =  10
 2:len(arg01) =  10
 2:len(arg01) =  10
$

$ export OMP_NUM_THREADS=2; gfortran -fopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$

$ export OMP_NUM_THREADS=2; ifx -qopenmp dw2_007_tsk_232.f90; ./a.out
 1:len(arg01) =           10
 2:len(arg01) =           10
 2:len(arg01) =           10
$