selected_real_kind.f90 [plain text]
! Copyright 2003, 2004 Free Software Foundation, Inc.
! Contributed by Kejia Zhao <email@example.com>
!This file is part of the GNU Fortran 95 runtime library (libgfor).
!GNU libgfor is free software; you can redistribute it and/or
!modify it under the terms of the GNU Lesser General Public
!License as published by the Free Software Foundation; either
!version 2.1 of the License, or (at your option) any later version.
!GNU libgfor is distributed in the hope that it will be useful,
!but WITHOUT ANY WARRANTY; without even the implied warranty of
!MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
!GNU Lesser General Public License for more details.
!You should have received a copy of the GNU Lesser General Public
!License along with libgfor; see the file COPYING. If not,
!write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
!Boston, MA 02110-1301, USA.
function selected_real_kind (p, r)
integer, optional, intent (in) :: p, r
integer :: selected_real_kind
integer :: i, p2, r2
logical :: found_p, found_r
! Real kind_precision_range table
type :: real_info
integer :: kind
integer :: precision
integer :: range
end type real_info
selected_real_kind = 0
p2 = 0
r2 = 0
found_p = .false.
found_r = .false.
if (present (p)) p2 = p
if (present (r)) r2 = r
! Assumes each type has a greater precision and range than previous one.
do i = 1, c
if (p2 <= real_infos (i) % precision) found_p = .true.
if (r2 <= real_infos (i) % range) found_r = .true.
if (found_p .and. found_r) then
selected_real_kind = real_infos (i) % kind
if (.not. (found_p)) selected_real_kind = selected_real_kind - 1
if (.not. (found_r)) selected_real_kind = selected_real_kind - 2