ifx, coarrays, and evaluation of array indices

[Harald1]

Hello,

the following code gives different results with ifx as compared to NAG:

program p
  implicit none
  integer :: img, data
  integer :: cnt[*] = 0
  integer, allocatable :: res(:)[:]
  allocate(res(num_images())[*], source=-1)
  img = this_image()
  data = 10 * img           ! Something different on each image
  res(get_val())[1] = data
  sync all
  if (this_image() == 1) print *, res
  sync all
  res(this_image())[1] = cnt ! gather count of invocations of get_val
  sync all
  if (this_image() == 1) print *, res
contains
  function get_val()
    integer :: get_val
    get_val = img
    cnt = cnt + 1 ! Count invocations of get_val
  end function
end program

 Compiling it and running with 2 images gives:

% ifx -coarray ifx-coarray-gather.f90 -coarray-num-images=2 && ./a.out
          10          20
           4           4

 OTOH NAG calls get_val only once on each image:

% nagfor -coarray ifx-coarray-gather.f90 && ./a.out 
NAG Fortran Compiler Release 7.2(Shin-Urayasu) Build 7200
[NAG Fortran Compiler normal termination]
 10 20
 1 1

 Is this a bug in ifx?

Best regards,

Harald

[Ron_Green]

yes, it is a bug.  Nag output is correct.  I think this is related to a previously reported bug in host-associated coarray objects ( cnt in this example ).

I will get a separate bug report for this example.  it may be 'same as' the previously reported but it is different enough to warrant a separate investigation. 

[Ron_Green]

bug ID is CMPLRLLVM-69390