Reduction routines in Intel Fortran 2020 beta do not work for real coarrays

[Arjen_Markus]

Hello,

while experimenting with the reduction routines in Intel Fortran 2020 beta I ran into a problem with real coarrays. For integer coarrays it works fine (unless you leave out the target image - that results in an error about image 0). For real coarrays the result is simply the value on the target image it seems. Here is my sample program:

! chk_coarrays_reduction.f90 --
!     Check: does the compiler support reduction operations with coarrays
!
program chk_coarrays_reduction
    implicit none

    real, dimension(10), codimension
    :: rvalue
    integer, dimension(10), codimension
 :: value
    integer                                :: i

    if ( this_image() == 1 ) then
        write( *, '(a)' ) 'Using co-reduction routines for integer values: '
    endif

    !
    ! Fill the integer coarray
    !
    value = [ (this_image() * i, i = 1,size(value)) ]

    sync all

    call co_sum( value(1), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,10i5)' ) 'Cosum: ', value(1)
    endif

    call co_max( value(2), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,10i5)' ) 'Comax: ', value(2)
    endif

    call co_min( value(3), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,10i5)' ) 'Comin: ', value(3)
    endif

    !
    ! Fill the real coarray
    !
    rvalue = [ (this_image() * 0.1, i = 1,size(value)) ]

    sync all

    if ( this_image() == 1 ) then
        write( *, '(a)' ) 'Using co-reduction routines for real values: '
    endif

    call co_sum( rvalue(1), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,f10.5)' ) 'Cosum: ', rvalue(1)
    endif

    call co_max( rvalue(2), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,f10.5)' ) 'Comax: ', rvalue(2)
    endif

    call co_min( rvalue(3), 1 )
    if ( this_image() == 1 ) then
        write( *, '(a,f10.5)' ) 'Comin: ', rvalue(3)
    endif

end program chk_coarrays_reduction

And here is the output I got:

Using co-reduction routines for integer values: 
Cosum:    36
Comax:    16
Comin:     3
Using co-reduction routines for real values: 
Cosum:    0.10000
Comax:    0.10000
Comin:    0.10000

As you can see all real values are the same, whereas you would expect 3.6, 0.8 and 0.1. The integer values are conform the expectation.