blob: ff4581a2dbc3ea0704b1a5bc3d138fcfc32d3749 [file] [log] [blame]
/* Copyright (C) 2004-2020 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);
}