mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-24 21:45:12 +00:00
79 lines
2.9 KiB
Fortran
79 lines
2.9 KiB
Fortran
c Copyright (c) 2003, 2007-14 Matteo Frigo
|
|
c Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
|
|
c
|
|
c This program is free software; you can redistribute it and/or modify
|
|
c it under the terms of the GNU General Public License as published by
|
|
c the Free Software Foundation; either version 2 of the License, or
|
|
c (at your option) any later version.
|
|
c
|
|
c This program is distributed in the hope that it will be useful,
|
|
c but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
c MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
c GNU General Public License for more details.
|
|
c
|
|
c You should have received a copy of the GNU General Public License
|
|
c along with this program; if not, write to the Free Software
|
|
c Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
c
|
|
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
|
|
c
|
|
c This is an example implementation of Fortran wisdom export/import
|
|
c to/from a Fortran unit (file), exploiting the generic
|
|
c dfftw_export_wisdom/dfftw_import_wisdom functions.
|
|
c
|
|
c We cannot compile this file into the FFTW library itself, lest all
|
|
c FFTW-calling programs be required to link to the Fortran I/O
|
|
c libraries.
|
|
c
|
|
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
|
|
|
|
c Strictly speaking, the '$' format specifier, which allows us to
|
|
c write a character without a trailing newline, is not standard F77.
|
|
c However, it seems to be a nearly universal extension.
|
|
subroutine write_char(c, iunit)
|
|
character c
|
|
integer iunit
|
|
write(iunit,321) c
|
|
321 format(a,$)
|
|
end
|
|
|
|
subroutine export_wisdom_to_file(iunit)
|
|
integer iunit
|
|
external write_char
|
|
call dfftw_export_wisdom(write_char, iunit)
|
|
end
|
|
|
|
c Fortran 77 does not have any portable way to read an arbitrary
|
|
c file one character at a time. The best alternative seems to be to
|
|
c read a whole line into a buffer, since for fftw-exported wisdom we
|
|
c can bound the line length. (If the file contains longer lines,
|
|
c then the lines will be truncated and the wisdom import should
|
|
c simply fail.) Ugh.
|
|
subroutine read_char(ic, iunit)
|
|
integer ic
|
|
integer iunit
|
|
character*256 buf
|
|
save buf
|
|
integer ibuf
|
|
data ibuf/257/
|
|
save ibuf
|
|
if (ibuf .lt. 257) then
|
|
ic = ichar(buf(ibuf:ibuf))
|
|
ibuf = ibuf + 1
|
|
return
|
|
endif
|
|
read(iunit,123,end=666) buf
|
|
ic = ichar(buf(1:1))
|
|
ibuf = 2
|
|
return
|
|
666 ic = -1
|
|
ibuf = 257
|
|
123 format(a256)
|
|
end
|
|
|
|
subroutine import_wisdom_from_file(isuccess, iunit)
|
|
integer isuccess
|
|
integer iunit
|
|
external read_char
|
|
call dfftw_import_wisdom(isuccess, read_char, iunit)
|
|
end
|