!======================================================================
! This simulates NaN detection from the IEEE 754 standard for floating point numbers. 
!  If your compiler supports the standard, then you should *not* use this simulation.
!
! Copyright (c) 2008 Charles O'Neill
! 
! Permission is hereby granted, free of charge, to any person
! obtaining a copy of this software and associated documentation
! files (the "Software"), to deal in the Software without
! restriction, including without limitation the rights to use,
! copy, modify, merge, publish, distribute, sublicense, and/or sell
! copies of the Software, and to permit persons to whom the
! Software is furnished to do so, subject to the following
! conditions:
! 
! The above copyright notice and this permission notice shall be
! included in all copies or substantial portions of the Software.
! 
! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
! EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
! OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
! NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
! HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
! WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
! FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
! OTHER DEALINGS IN THE SOFTWARE.

module IEEEStandard
  use Precisions
  implicit none

  interface ieee_is_nan
     module procedure IEEEIsNanSimulateDP
     module procedure IEEEIsNanSimulateSP
  end interface

contains
    
    pure function IEEEIsNanSimulateSP(Number)
        logical  :: IEEEIsNanSimulateSP
        real(SP),intent(in) :: Number
        if(Number>=0.0 .OR. Number<=0.0)then
            IEEEIsNanSimulateSP = .false.
        else
            IEEEIsNanSimulateSP = .true.
        endif            
    end function 

    pure function IEEEIsNanSimulateDP(Number)
        logical  :: IEEEIsNanSimulateDP
        real(DP),intent(in) :: Number
        if(Number>=0.0d0 .OR. Number<=0.0d0)then
            IEEEIsNanSimulateDP = .false.
        else
            IEEEIsNanSimulateDP = .true.
        endif            
    end function 

end module