78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
/* Copyright (C) 2004, 2006, 2009 Free Software Foundation, Inc.
|
|
|
|
This file 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 file 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.
|
|
|
|
Under Section 7 of GPL version 3, you are granted additional
|
|
permissions described in the GCC Runtime Library Exception, version
|
|
3.1, as published by the Free Software Foundation.
|
|
|
|
You should have received a copy of the GNU General Public License and
|
|
a copy of the GCC Runtime Library Exception along with this program;
|
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
|
|
/* Calculate division table for ST40-300 integer division
|
|
Contributed by Joern Rennecke
|
|
joern.rennecke@st.com */
|
|
|
|
#include <stdio.h>
|
|
#include <math.h>
|
|
|
|
int
|
|
main ()
|
|
{
|
|
int i, j;
|
|
double q, r, err, max_err = 0, max_s_err = 0;
|
|
|
|
puts("/* This table has been generated by divtab-sh4.c. */");
|
|
puts ("\t.balign 4");
|
|
for (i = -128; i < 128; i++)
|
|
{
|
|
int n = 0;
|
|
if (i == 0)
|
|
{
|
|
/* output some dummy number for 1/0. */
|
|
puts ("LOCAL(div_table_clz):\n\t.byte\t0");
|
|
continue;
|
|
}
|
|
for (j = i < 0 ? -i : i; j < 128; j += j)
|
|
n++;
|
|
printf ("\t.byte\t%d\n", n - 7);
|
|
}
|
|
puts("\
|
|
/* 1/-128 .. 1/127, normalized. There is an implicit leading 1 in bit 32,\n\
|
|
or in bit 33 for powers of two. */\n\
|
|
.balign 4");
|
|
for (i = -128; i < 128; i++)
|
|
{
|
|
if (i == 0)
|
|
{
|
|
puts ("LOCAL(div_table_inv):\n\t.long\t0x0");
|
|
continue;
|
|
}
|
|
j = i < 0 ? -i : i;
|
|
while (j < 64)
|
|
j += j;
|
|
q = 4.*(1<<30)*128/j;
|
|
r = ceil (q);
|
|
printf ("\t.long\t0x%X\n", (unsigned) r);
|
|
err = r - q;
|
|
if (err > max_err)
|
|
max_err = err;
|
|
err = err * j / 128;
|
|
if (err > max_s_err)
|
|
max_s_err = err;
|
|
}
|
|
printf ("\t/* maximum error: %f scaled: %f*/\n", max_err, max_s_err);
|
|
exit (0);
|
|
}
|