Type_Kinds.f90

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!
! Type_Kinds
!
! Module to hold specification kinds for variable declaration, as well as 
! associated descriptors.
!
! CREATION HISTORY:
!       Written by:     Paul van Delst, 12-Jun-2000
!                       paul.vandelst@noaa.gov
!

MODULE type_kinds

  ! ---------------------------
  ! Disable all implicit typing
  ! ---------------------------
  IMPLICIT NONE


  ! ------------
  ! Visibilities
  ! ------------
  ! Everything is private by default
  PRIVATE
  ! The integer types
  PUBLIC :: byte   , n_bytes_byte 
  PUBLIC :: short  , n_bytes_short
  PUBLIC :: long   , n_bytes_long 
  PUBLIC :: llong  , n_bytes_llong
  PUBLIC :: ip_kind, n_bytes_ip_kind  ! Default integer set by IIP
  PUBLIC :: ip     , n_bytes_ip       ! Aliases for IP_Kind
  ! The floating point types
  PUBLIC :: single , n_bytes_single
  PUBLIC :: double , n_bytes_double
  PUBLIC :: quad   , n_bytes_quad  
  PUBLIC :: fp_kind, n_bytes_fp_kind  ! Default integer set by IFP
  PUBLIC :: fp     , n_bytes_fp       ! Aliases for FP_Kind


  ! -------------------------------------------------------------------
  ! THE DEFAULT INTEGER INDEX. Change the value of IIP for the required
  ! integer kind. The following chart details the correspondence:
  !
  !    IIP        INTEGER(IP)
  !  ==============================
  !     1        Byte 
  !     2       Short (2 bytes)
  !     3        Long (4 bytes)
  !     4       LLong (8 bytes)  **IF AVAILABLE, Long OTHERWISE**
  !
  ! -------------------------------------------------------------------
  INTEGER, PARAMETER :: iip = 3  ! 1=Byte, 2=Short, 3=Long, 4=LLong


  ! -------------------------------------------------------------------
  ! THE DEFAULT FLOATING POINT INDEX. Change the value of IFP for the
  ! required floating point kind. The following chart details the
  ! correspondence:
  !
  !    IFP          REAL(FP)
  !  ==============================
  !     1       Single (4  bytes)
  !     2       Double (8  bytes)
  !     3       Quad   (16 bytes)  **IF AVAILABLE, Double OTHERWISE**
  !
  ! -------------------------------------------------------------------
  INTEGER, PARAMETER :: ifp = 2  ! 1=Single, 2=Double, 3=Quad


  ! -------------------
  ! Integer definitions
  ! -------------------
  ! Integer types
  INTEGER, PARAMETER :: byte    = selected_int_kind(1)   ! Byte  integer
  INTEGER, PARAMETER :: short   = selected_int_kind(4)   ! Short integer
  INTEGER, PARAMETER :: long    = selected_int_kind(8)   ! Long  integer
  INTEGER, PARAMETER :: llong   = selected_int_kind(16)  ! LLong integer

  ! Expected 8-bit byte sizes of the integer kinds
  INTEGER, PARAMETER :: n_bytes_byte  = 1
  INTEGER, PARAMETER :: n_bytes_short = 2
  INTEGER, PARAMETER :: n_bytes_long  = 4
  INTEGER, PARAMETER :: n_bytes_llong = 8
  ! Define arrays for default definition
  INTEGER, PARAMETER :: n_ip = 4
  INTEGER, PARAMETER, DIMENSION(N_IP) :: ip_kind_types = (/ byte,  &
                                                            short, &
                                                            long,  &
                                                            llong  /) 
  INTEGER, PARAMETER, DIMENSION(N_IP) :: ip_byte_sizes = (/ n_bytes_byte,  &
                                                            n_bytes_short, &
                                                            n_bytes_long,  &
                                                            n_bytes_llong  /)
  ! Default values
  INTEGER, PARAMETER :: ip_kind        =ip_kind_types(iip)
  INTEGER, PARAMETER :: n_bytes_ip_kind=ip_byte_sizes(iip)
  INTEGER, PARAMETER :: ip        =ip_kind
  INTEGER, PARAMETER :: n_bytes_ip=n_bytes_ip_kind


  ! --------------------------
  ! Floating point definitions
  ! --------------------------
  ! Floating point types
  INTEGER, PARAMETER :: single = selected_real_kind(6)  ! Single precision
  INTEGER, PARAMETER :: double = selected_real_kind(15) ! Double precision
  INTEGER, PARAMETER :: quad   = selected_real_kind(20) ! Quad precision

  ! Expected 8-bit byte sizes of the floating point kinds
  INTEGER, PARAMETER :: n_bytes_single = 4
  INTEGER, PARAMETER :: n_bytes_double = 8
  INTEGER, PARAMETER :: n_bytes_quad   = 16
  ! Define arrays for default definition
  INTEGER, PARAMETER :: n_fp = 3
  INTEGER, PARAMETER, DIMENSION(N_FP) :: fp_kind_types = (/ single, &
                                                            double, &
                                                            quad    /) 
  INTEGER, PARAMETER, DIMENSION(N_FP) :: fp_byte_sizes = (/ n_bytes_single, &
                                                            n_bytes_double, &
                                                            n_bytes_quad    /)
  ! Default values
  INTEGER, PARAMETER :: fp_kind         = fp_kind_types(ifp)
  INTEGER, PARAMETER :: n_bytes_fp_kind = fp_byte_sizes(ifp)
  INTEGER, PARAMETER :: fp        =fp_kind
  INTEGER, PARAMETER :: n_bytes_fp=n_bytes_fp_kind
  
END MODULE type_kinds