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/* scaled-num.c: conversions on ``scaled'' numbers, which are a 32-bit
word with 16 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "config.h"
#include "scaled-num.h"
#define SCALED_UNITY (1 << 16) /* 2^16, represents 1.00000. */
/* This prints a scaled number, rounded to five digits. */
void
print_scaled (scaled s)
{
scaled delta;
if (s < 0)
{ /* Print sign, if negative. */
putchar ('-');
s = -s;
}
printf ("%u", s / SCALED_UNITY); /* Print integer part. */
putchar ('.');
s = 10 * (s % SCALED_UNITY) + 5;
delta = 10;
do
{
if (delta > SCALED_UNITY)
s += 0100000 - (delta / 2); /* Round the last digit. */
printf ("%c", '0' + (s / SCALED_UNITY));
s = 10 * (s % SCALED_UNITY);
delta *= 10;
}
while (s > delta);
}
const real
scaled_to_real (scaled s)
{
real r = (real) s / SCALED_UNITY;
return r;
}
const scaled
real_to_scaled (real r)
{
scaled s = r * SCALED_UNITY;
return s;
}
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