libgfortran/intrinsics/selected_real_kind.f90

   1 !   Copyright 2003, 2004, 2009 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 (libgfortran).
   5 !
   6 !Libgfortran is free software; you can redistribute it and/or
   7 !modify it under the terms of the GNU General Public
   8 !License as published by the Free Software Foundation; either
   9 !version 3 of the License, or (at your option) any later version.
  10 !
  11 !Libgfortran 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 General Public License for more details.
  15 !
  16 !Under Section 7 of GPL version 3, you are granted additional
  17 !permissions described in the GCC Runtime Library Exception, version
  18 !3.1, as published by the Free Software Foundation.
  19 !
  20 !You should have received a copy of the GNU General Public License and
  21 !a copy of the GCC Runtime Library Exception along with this program;
  22 !see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 !<http://www.gnu.org/licenses/>.
  24
  25 function _gfortran_selected_real_kind (p, r)
  26   implicit none
  27   integer, optional, intent (in) :: p, r
  28   integer :: _gfortran_selected_real_kind
  29   integer :: i, p2, r2
  30   logical :: found_p, found_r
  31   ! Real kind_precision_range table
  32   type :: real_info
  33     integer :: kind
  34     integer :: precision
  35     integer :: range
  36   end type real_info
  37
  38   include "selected_real_kind.inc"
  39
  40   _gfortran_selected_real_kind = 0
  41   p2 = 0
  42   r2 = 0
  43   found_p = .false.
  44   found_r = .false.
  45
  46   if (present (p)) p2 = p
  47   if (present (r)) r2 = r
  48
  49   ! Assumes each type has a greater precision and range than previous one.
  50
  51   do i = 1, c
  52     if (p2 <= real_infos (i) % precision) found_p = .true.
  53     if (r2 <= real_infos (i) % range) found_r = .true.
  54     if (found_p .and. found_r) then
  55       _gfortran_selected_real_kind = real_infos (i) % kind
  56       return
  57     end if
  58   end do
  59
  60   if (.not. (found_p)) _gfortran_selected_real_kind = _gfortran_selected_real_kind - 1
  61   if (.not. (found_r)) _gfortran_selected_real_kind = _gfortran_selected_real_kind - 2
  62
  63   return
  64 end function