[flang-commits] [flang] [flang][openmp]Add UserReductionDetails and use in DECLARE REDUCTION (PR #131628)

[Kiran Chandramohan via flang-commits]

kiranchandramohan wrote:

Can you check whether the declare reduction works with renamed operators. I am giving an example below for reference, but please think through in general about the possibility of renamed operators.

```
module my_module
    implicit none

    type :: my_type
        real :: value
    end type my_type

    interface operator(.mul.)
        module procedure my_mul
    end interface

contains

    function my_mul(a, b) result(c)
        type(my_type), intent(in) :: a, b
        type(my_type) :: c
        c%value = a%value * b%value
    end function my_mul

end module my_module

!------------------------------

program test_omp_reduction
  use omp_lib
  use my_module, only: my_type, operator(.submul.) => operator(.mul.)
  implicit none

  type(my_type) :: result
  integer :: i
  !$omp declare reduction (.submul. : my_type : omp_out = omp_out .submul. omp_in) initializer(omp_priv = my_type(1.0))

  result = my_type(1.0)

  
  !$omp parallel do reduction(.submul.:result)
  do i = 1, 10
      result = result .submul. my_type(real(i))
  end do
  !$omp end parallel do

  print *, 'Final result: ', result%value
end program test_omp_reduction
```

https://github.com/llvm/llvm-project/pull/131628