[flang-commits] [flang] [Flang] Make a private copy for the common block variables in copyin clause (PR #111359)

[Thirumalai Shaktivel via flang-commits]

Thirumalai-Shaktivel wrote:

I have updated the branch.

I'm getting the following output:
```console
$ ./a.out 
 sub  : b( 1 ) =  1.  a( 1 ) =  1.
 sub  : b( 2 ) =  3.  a( 2 ) =  2.
 OK
```
, for the following example: 
```fortran
program main
    integer err
    real,dimension(2):: a, b, c
    common /blk/ a, b
  !$omp threadprivate(/blk/)
    a = (/(i,i=1,2)/)
    b = (/(i*(i+1)/2,i=1,2)/)
    c = 0
  !$omp parallel do private(sum), copyin(/blk/)
    do i=1, 2
       sum = i
       call sub(sum, i, c(i))
    end do
  !$omp end parallel do
    err = 0
    do i=1, 2
       if(c(i) .ne. b(i)) err = err+1
    end do
    if(err .ne. 0) then
       write(6,*) "NG"
    else
       write(6,*) "OK"
    end if
  end program main

  subroutine sub(sum, i, c)
    real,dimension(2):: a, b
    common /blk/ a, b
    real c
  !$omp threadprivate(/blk/)
    c = b(i)-a(i)+sum
    write(6,*) "sub  : b(",i,") = ",b(i), " a(",i,") = ", a(i)
  end subroutine sub
```

https://github.com/llvm/llvm-project/pull/111359