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/*
* Xytronic LF-1600
* Fixed point data type
*
* Copyright (c) 2015 Michael Buesch <m@bues.ch>
*
* 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 2 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "fixpt.h"
fixpt_t fixpt_deflate(fixpt_big_t a)
{
if (a >= FIXPT_MAX)
return FIXPT_MAX;
if (a <= FIXPT_MIN)
return FIXPT_MIN;
return (fixpt_t)a;
}
int32_t fixpt_big_to_int(fixpt_big_t p)
{
int32_t i;
if (p < 0) {
p = -p;
i = ((int32_t)p + (int32_t)(1L << (FIXPT_SHIFT - 1))) >> FIXPT_SHIFT;
i = -i;
} else {
i = ((int32_t)p + (int32_t)(1L << (FIXPT_SHIFT - 1))) >> FIXPT_SHIFT;
}
return i;
}
fixpt_big_t fixpt_big_mul(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
/* Multiply */
tmp = a * b;
/* Round */
tmp += (fixpt_big_t)1L << (FIXPT_SHIFT - 1);
/* Scale */
tmp >>= FIXPT_SHIFT;
return tmp;
}
fixpt_big_t fixpt_big_div(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
/* Scale */
tmp = a << FIXPT_SHIFT;
/* Round */
if ((tmp >= 0 && b >= 0) || (tmp < 0 && b < 0))
tmp += b / 2;
else
tmp -= b / 2;
/* Divide */
tmp /= b;
return tmp;
}
fixpt_big_t fixpt_big_mul_div(fixpt_big_t a, fixpt_big_t b, fixpt_big_t c)
{
fixpt_big_t tmp;
tmp = fixpt_big_mul(a, b);
tmp = fixpt_big_div(tmp, c);
return tmp;
}
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