1/* Copyright (C) 2004-2020 Free Software Foundation, Inc.
2
3This file is free software; you can redistribute it and/or modify it
4under the terms of the GNU General Public License as published by the
5Free Software Foundation; either version 3, or (at your option) any
6later version.
7
8This file is distributed in the hope that it will be useful, but
9WITHOUT ANY WARRANTY; without even the implied warranty of
10MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11General Public License for more details.
12
13Under Section 7 of GPL version 3, you are granted additional
14permissions described in the GCC Runtime Library Exception, version
153.1, as published by the Free Software Foundation.
16
17You should have received a copy of the GNU General Public License and
18a copy of the GCC Runtime Library Exception along with this program;
19see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
20<http://www.gnu.org/licenses/>.  */
21
22
23/* Calculate division table for ST40-300 integer division
24   Contributed by Joern Rennecke
25   joern.rennecke@st.com  */
26
27#include <stdio.h>
28#include <math.h>
29
30int
31main ()
32{
33  int i, j;
34  double q, r, err, max_err = 0, max_s_err = 0;
35
36  puts("/* This table has been generated by divtab-sh4.c.  */");
37  puts ("\t.balign 4");
38  for (i = -128; i < 128; i++)
39    {
40      int n = 0;
41      if (i == 0)
42	{
43	  /* output some dummy number for 1/0.  */
44	  puts ("LOCAL(div_table_clz):\n\t.byte\t0");
45	  continue;
46	}
47      for (j = i < 0 ? -i : i; j < 128; j += j)
48	n++;
49      printf ("\t.byte\t%d\n", n - 7);
50    }
51  puts("\
52/* 1/-128 .. 1/127, normalized.  There is an implicit leading 1 in bit 32,\n\
53   or in bit 33 for powers of two.  */\n\
54	.balign 4");
55  for (i = -128; i < 128; i++)
56    {
57      if (i == 0)
58	{
59	  puts ("LOCAL(div_table_inv):\n\t.long\t0x0");
60	  continue;
61	}
62      j = i < 0 ? -i : i;
63      while (j < 64)
64	j += j;
65      q = 4.*(1<<30)*128/j;
66      r = ceil (q);
67      printf ("\t.long\t0x%X\n", (unsigned) r);
68      err = r - q;
69      if (err > max_err)
70	max_err = err;
71      err = err * j / 128;
72      if (err > max_s_err)
73	max_s_err = err;
74    }
75  printf ("\t/* maximum error: %f scaled: %f*/\n", max_err, max_s_err);
76  exit (0);
77}
78