libgfortran/intrinsics/selected_real_kind.f90

   1 !   Copyright 2003, 2004 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., 51 Franklin Street, Fifth Floor,
  19 !Boston, MA 02110-1301, USA.
  20 !
  21
  22 function selected_real_kind (p, r)
  23   implicit none
  24   integer, optional, intent (in) :: p, r
  25   integer :: selected_real_kind
  26   integer :: i, p2, r2
  27   logical :: found_p, found_r
  28   ! Real kind_precision_range table
  29   type :: real_info
  30     integer :: kind
  31     integer :: precision
  32     integer :: range
  33   end type real_info
  34
  35   include "selected_real_kind.inc"
  36
  37   selected_real_kind = 0
  38   p2 = 0
  39   r2 = 0
  40   found_p = .false.
  41   found_r = .false.
  42
  43   if (present (p)) p2 = p
  44   if (present (r)) r2 = r
  45
  46   ! Assumes each type has a greater precision and range than previous one.
  47
  48   do i = 1, c
  49     if (p2 <= real_infos (i) % precision) found_p = .true.
  50     if (r2 <= real_infos (i) % range) found_r = .true.
  51     if (found_p .and. found_r) then
  52       selected_real_kind = real_infos (i) % kind
  53       return
  54     end if
  55   end do
  56
  57   if (.not. (found_p)) selected_real_kind = selected_real_kind - 1
  58   if (.not. (found_r)) selected_real_kind = selected_real_kind - 2
  59
  60   return
  61 end function