! This file:
! http://ftp.aset.psu.edu/pub/ger/fortran/hdk/QorDPrecision.f90
!
! This code allows the compiler to automatically use QP Working
! Precision (wp) if quadruple precision available; or if QP is not
! available, compile using DP Working Precision.
!
! Public domain 2004 by James Van Buskirk
!
 module mykinds
   implicit none
   integer, parameter :: dp = selected_real_kind(15,300)
   integer, parameter :: qp_preferred = selected_real_kind(30,1000)
   integer, parameter :: wp = (1+sign(1,qp_preferred))/2*qp_preferred+ &
                              (1-sign(1,qp_preferred))/2*dp
 end module mykinds

 program testq
   use mykinds
   real(wp) pi
   pi = 4*atan(1.0_wp)
   print *, "pi = ",pi
   print *,"wp =",wp

!
!  Output:
!
!  CVF (Windows)
!  pi = 3.14159265358979
!  wp = 8
!
!  Intel Fortran (32- and 64-bit Linux)
!  pi= 3.14159265358979323846264338327950
!  wp= 16
!
!  Lahey Fortran (Windows, 32-bit Linux)
!  pi= 3.1415926535897932384626433832795028
!  wp= 16
!
!  PathScale Fortran (64-bit Linux)
!  pi= 3.1415926535897931
!  wp=  8
!
!  Absoft Fortran (32-bit Linux)
!  pi= 3.14159265358979
!  wp=  8
!
!  Portland Fortran (32-bit Linux)
!  pi= 3.141592653589793
!  wp=  8

 end program testq