libgfortran/intrinsics/selected_kind.f90

   1 !   Copyright 2003 Free Software Foundation, Inc.
   2 !   Contributed by Kejia Zhao <kejia_zh@yahoo.com.cn>
   3 !
   4 !This file is part of the GNU Fortran 95 runtime library (libgfor).
   5 !
   6 !GNU libgfor is free software; you can redistribute it and/or
   7 !modify it under the terms of the GNU Lesser General Public
   8 !License as published by the Free Software Foundation; either
   9 !version 2.1 of the License, or (at your option) any later version.
  10 !
  11 !GNU libgfor is distributed in the hope that it will be useful,
  12 !but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 !MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 !GNU Lesser General Public License for more details.
  15 !
  16 !You should have received a copy of the GNU Lesser General Public
  17 !License along with libgfor; see the file COPYING.  If not,
  18 !write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 !Boston, MA 02111-1307, USA.
  20 !
  21
  22 function selected_int_kind (r)
  23   implicit none
  24   integer, intent (in) :: r
  25   integer :: selected_int_kind
  26   integer :: i
  27   ! Integer kind_range table
  28   integer, parameter :: c = 4
  29   type :: int_info
  30     integer :: kind
  31     integer :: range
  32   end type int_info
  33   type (int_info), parameter :: int_infos (c) = &
  34       (/int_info (1, range (0_1)), &
  35         int_info (2, range (0_2)), &
  36         int_info (4, range (0_4)), &
  37         int_info (8, range (0_8))/)
  38
  39   do i = 1, c
  40     if (r <= int_infos (i) % range) then
  41       selected_int_kind = int_infos (i) % kind
  42       return
  43     end if
  44   end do
  45   selected_int_kind = -1
  46   return
  47 end function
  48
  49 function selected_real_kind (p, r)
  50   implicit none
  51   integer, optional, intent (in) :: p, r
  52   integer :: selected_real_kind
  53   integer :: i, p2, r2
  54   logical :: found_p, found_r
  55   ! Real kind_precision_range table
  56   integer, parameter :: c = 2
  57   type :: real_info
  58     integer :: kind
  59     integer :: precision
  60     integer :: range
  61   end type real_info
  62   type (real_info) :: real_infos (c) = &
  63       (/real_info (4, precision (0.0_4), range (0.0_4)), &
  64         real_info (8, precision (0.0_8), range (0.0_8))/)
  65
  66   selected_real_kind = 0
  67   p2 = 0
  68   r2 = 0
  69   found_p = .false.
  70   found_r = .false.
  71
  72   if (present (p)) p2 = p
  73   if (present (r)) r2 = r
  74
  75   ! Assumes each type has a greater precision and range than previous one.
  76
  77   do i = 1, c
  78     if (p2 <= real_infos (i) % precision) found_p = .true.
  79     if (r2 <= real_infos (i) % range) found_r = .true.
  80     if (found_p .and. found_r) then
  81       selected_real_kind = real_infos (i) % kind
  82       return
  83     end if
  84   end do
  85
  86   if (.not. (found_p)) selected_real_kind = selected_real_kind - 1
  87   if (.not. (found_r)) selected_real_kind = selected_real_kind - 2
  88
  89   return
  90 end function