[flang][OpenMP] Parallel region failure

[psteinfeld]

Here's a test program:

program bug
  use omp_lib
  implicit none
  integer ivar
  real :: table(10)
  !$OMP PARALLEL NUM_THREADS(3) PRIVATE(table)
    table = 1
    !$OMP PARALLEL NUM_THREADS(3) SHARED(table)
      !$OMP DO LASTPRIVATE(table)
        do ivar=1,size(table)
          table(:ivar) = ivar*5
        end do
    !$OMP END PARALLEL
    if (any(table/=size(table)*5)) then
      stop 'fail 3'
    end if

  !$OMP END PARALLEL
  print *,'ok'
End Program

Here's my compilation command -- flang-new -g -fopenmp -fopenmp-version=31 bug.f90
When I execute the result, I get the output:

Fortran STOP: fail 3
Fortran STOP: fail 3

When I compile this with gfortran (gfortran -fopenmp bug.f90) or ifort (ifort -fopenmp -qopenmp-lib=compat bug.f90), I get the output:

 ok

[llvmbot]

@llvm/issue-subscribers-bug

Author: Pete Steinfeld (psteinfeld)

Here's a test program: ``` program bug use omp_lib implicit none integer ivar real :: table(10) !$OMP PARALLEL NUM_THREADS(3) PRIVATE(table) table = 1 !$OMP PARALLEL NUM_THREADS(3) SHARED(table) !$OMP DO LASTPRIVATE(table) do ivar=1,size(table) table(:ivar) = ivar*5 end do !$OMP END PARALLEL if (any(table/=size(table)*5)) then stop 'fail 3' end if

!$OMP END PARALLEL
print *,'ok'
End Program

Here's my compilation command -- `flang-new -g -fopenmp -fopenmp-version=31 bug.f90`
When I execute the result, I get the output:

Fortran STOP: fail 3
Fortran STOP: fail 3

When I compile this with gfortran (`gfortran -fopenmp  bug.f90`) or ifort (`ifort -fopenmp -qopenmp-lib=compat bug.f90`), I get the output:

ok

</details>

[llvmbot]

@llvm/issue-subscribers-openmp

Author: Pete Steinfeld (psteinfeld)

Here's a test program: ``` program bug use omp_lib implicit none integer ivar real :: table(10) !$OMP PARALLEL NUM_THREADS(3) PRIVATE(table) table = 1 !$OMP PARALLEL NUM_THREADS(3) SHARED(table) !$OMP DO LASTPRIVATE(table) do ivar=1,size(table) table(:ivar) = ivar*5 end do !$OMP END PARALLEL if (any(table/=size(table)*5)) then stop 'fail 3' end if

!$OMP END PARALLEL
print *,'ok'
End Program

Here's my compilation command -- `flang-new -g -fopenmp -fopenmp-version=31 bug.f90`
When I execute the result, I get the output:

Fortran STOP: fail 3
Fortran STOP: fail 3

When I compile this with gfortran (`gfortran -fopenmp  bug.f90`) or ifort (`ifort -fopenmp -qopenmp-lib=compat bug.f90`), I get the output:

ok

</details>

[tblah]

RFC describing the problem and discussing solutions https://discourse.llvm.org/t/rfc-openmp-fix-issue-in-mlir-to-llvmir-translation-for-delayed-privatisation/81225