! test_flang_nan
program test_flang_nan
use ieee_arithmetic, only : ieee_value, ieee_signaling_nan, ieee_quiet_nan
! The problem occurs with REAL64 and REAL32, not REAL16 or REAL128.
use iso_fortran_env, only : RP => REAL32 !REAL64

implicit none
real(RP) :: nan

nan = ieee_value(0.0_RP, ieee_signaling_nan)
! nan = ieee_value(0.0_RP, ieee_quiet_nan)  ! The same problem

print *, nan > 0, nan > 1, nan < 0, nan < 1

if (nan > 0 .or. nan > 1 .or. nan < 0 .or. nan < 1) then
    error stop 1
end if

end program test_flang_nan