lib/fix-num.c


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# fix-num.c: conversions on ``fixnums'', which are a 32-bit
#            word with 20 bits of fraction.
#
# Copyright (C) 1992, 2011 Free Software Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#


#include "config.h"

#include "fix-num.h"


#define FIX_UNITY (1 << 20)


const real
fix_to_real (fix_word f)
{
  real r = f / FIX_UNITY + ((real) (f % FIX_UNITY) / (real) FIX_UNITY);

  return r;
}


const fix_word
real_to_fix (real r)
{
  fix_word f = floor (r) * FIX_UNITY + (r - floor (r)) * FIX_UNITY;

  return f;
}