var/da/da_radiance/gsi_kinds.f90

   1 module gsi_kinds
   2 !$$$  module documentation block
   3 !                .      .    .                                       .
   4 ! module:   kinds
   5 !   prgmmr: treadon          org: np23                date: 2004-08-15
   6 !
   7 ! abstract:  Module to hold specification kinds for variable declaration.
   8 !            This module is based on (copied from) Paul vanDelst's
   9 !            type_kinds module found in the community radiative transfer
  10 !            model
  11 !
  12 ! module history log:
  13 !   2004-08-15  treadon
  14 !
  15 ! Subroutines Included:
  16 !
  17 ! Functions Included:
  18 !
  19 ! remarks:
  20 !   The numerical data types defined in this module are:
  21 !      i_byte    - specification kind for byte (1-byte) integer variable
  22 !      i_short   - specification kind for short (2-byte) integer variable
  23 !      i_long    - specification kind for long (4-byte) integer variable
  24 !      i_llong   - specification kind for double long (8-byte) integer variable
  25 !      r_single  - specification kind for single precision (4-byte) real variable
  26 !      r_double  - specification kind for double precision (8-byte) real variable
  27 !      r_quad    - specification kind for quad precision (16-byte) real variable
  28 !
  29 !      i_kind    - generic specification kind for default integer
  30 !      r_kind    - generic specification kind for default floating point
  31 !
  32 !
  33 ! attributes:
  34 !   language: f90
  35 !   machine:  ibm RS/6000 SP
  36 !
  37 !$$$ end documentation block
  38   implicit none
  39   private
  40
  41 ! Integer type definitions below
  42
  43 ! Integer types
  44   integer, parameter, public  :: i_byte  = selected_int_kind(1)      ! byte  integer
  45   integer, parameter, public  :: i_short = selected_int_kind(4)      ! short integer
  46   integer, parameter, public  :: i_long  = selected_int_kind(8)      ! long  integer
  47   integer, parameter, private :: llong_t = selected_int_kind(16)     ! llong integer
  48   integer, parameter, public  :: i_llong = max( llong_t, i_long )
  49
  50 ! Expected 8-bit byte sizes of the integer kinds
  51   integer, parameter, public :: num_bytes_for_i_byte  = 1
  52   integer, parameter, public :: num_bytes_for_i_short = 2
  53   integer, parameter, public :: num_bytes_for_i_long  = 4
  54   integer, parameter, public :: num_bytes_for_i_llong = 8
  55
  56 ! Define arrays for default definition
  57   integer, parameter, private :: num_i_kinds = 4
  58   integer, parameter, dimension( num_i_kinds ), private :: integer_types = (/ &
  59        i_byte, i_short, i_long,  i_llong  /)
  60   integer, parameter, dimension( num_i_kinds ), private :: integer_byte_sizes = (/ &
  61        num_bytes_for_i_byte, num_bytes_for_i_short, &
  62        num_bytes_for_i_long, num_bytes_for_i_llong  /)
  63
  64 ! Default values
  65 ! **** CHANGE THE FOLLOWING TO CHANGE THE DEFAULT INTEGER TYPE KIND ***
  66   integer, parameter, private :: default_integer = 3  ! 1=byte,
  67                                                       ! 2=short,
  68                                                       ! 3=long,
  69                                                       ! 4=llong
  70   integer, parameter, public  :: i_kind = integer_types( default_integer )
  71   integer, parameter, public  :: num_bytes_for_i_kind = &
  72        integer_byte_sizes( default_integer )
  73
  74
  75 ! Real definitions below
  76
  77 ! Real types
  78   integer, parameter, public  :: r_single = selected_real_kind(6)  ! single precision
  79   integer, parameter, public  :: r_double = selected_real_kind(15) ! double precision
  80   integer, parameter, private :: quad_t   = selected_real_kind(20) ! quad precision
  81   integer, parameter, public  :: r_quad   = max( quad_t, r_double )
  82
  83 ! Expected 8-bit byte sizes of the real kinds
  84   integer, parameter, public :: num_bytes_for_r_single = 4
  85   integer, parameter, public :: num_bytes_for_r_double = 8
  86   integer, parameter, public :: num_bytes_for_r_quad   = 16
  87
  88 ! Define arrays for default definition
  89   integer, parameter, private :: num_r_kinds = 3
  90   integer, parameter, dimension( num_r_kinds ), private :: real_kinds = (/ &
  91        r_single, r_double, r_quad    /)
  92   integer, parameter, dimension( num_r_kinds ), private :: real_byte_sizes = (/ &
  93        num_bytes_for_r_single, num_bytes_for_r_double, &
  94        num_bytes_for_r_quad    /)
  95
  96 ! Default values
  97 ! **** CHANGE THE FOLLOWING TO CHANGE THE DEFAULT REAL TYPE KIND ***
  98 ! 1=single, 2=double, 3=quad
  99 #if ( RWORDSIZE == 4 )
 100   integer, parameter, private :: default_real = 1
 101 #else
 102   integer, parameter, private :: default_real = 2
 103 #endif
 104
 105   integer, parameter, public  :: r_kind = real_kinds( default_real )
 106   integer, parameter, public  :: num_bytes_for_r_kind = &
 107        real_byte_sizes( default_real )
 108
 109 end module gsi_kinds