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5624e564 | 1 | /* Copyright (C) 2004-2015 Free Software Foundation, Inc. |
b368d6b8 R |
2 | |
3 | This file is free software; you can redistribute it and/or modify it | |
4 | under the terms of the GNU General Public License as published by the | |
748086b7 | 5 | Free Software Foundation; either version 3, or (at your option) any |
b368d6b8 R |
6 | later version. |
7 | ||
b368d6b8 R |
8 | This file is distributed in the hope that it will be useful, but |
9 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | General Public License for more details. | |
12 | ||
748086b7 JJ |
13 | Under Section 7 of GPL version 3, you are granted additional |
14 | permissions described in the GCC Runtime Library Exception, version | |
15 | 3.1, as published by the Free Software Foundation. | |
16 | ||
17 | You should have received a copy of the GNU General Public License and | |
18 | a copy of the GCC Runtime Library Exception along with this program; | |
19 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
20 | <http://www.gnu.org/licenses/>. */ | |
b368d6b8 R |
21 | |
22 | /* Calculate division table for SH2..4 integer division | |
23 | Contributed by Joern Rernnecke | |
24 | joern.rennecke@superh.com */ | |
25 | ||
26 | #include <stdio.h> | |
27 | #include <math.h> | |
28 | ||
29 | int | |
30 | main () | |
31 | { | |
32 | int i, j; | |
33 | double q, r, err, max_err = 0, max_s_err = 0; | |
34 | ||
35 | puts("/* This table has been generated by divtab-sh4.c. */"); | |
36 | puts ("\t.balign 4"); | |
37 | puts ("LOCAL(div_table_clz):"); | |
38 | /* output some dummy number for 1/0. */ | |
39 | printf ("\t.byte\t%d\n", 0); | |
40 | for (i = 1; i <= 128; i++) | |
41 | { | |
42 | int n = 0; | |
43 | if (i == 128) | |
44 | puts ("\ | |
45 | /* Lookup table translating positive divisor to index into table of\n\ | |
46 | normalized inverse. N.B. the '0' entry is also the last entry of the\n\ | |
47 | previous table, and causes an unaligned access for division by zero. */\n\ | |
48 | LOCAL(div_table_ix):"); | |
49 | for (j = i; j <= 128; j += j) | |
50 | n++; | |
51 | printf ("\t.byte\t%d\n", n - 7); | |
52 | } | |
53 | for (i = 1; i <= 128; i++) | |
54 | { | |
55 | j = i < 0 ? -i : i; | |
56 | while (j < 128) | |
57 | j += j; | |
58 | printf ("\t.byte\t%d\n", j * 2 - 96*4); | |
59 | } | |
60 | puts("\ | |
61 | /* 1/64 .. 1/127, normalized. There is an implicit leading 1 in bit 32. */\n\ | |
62 | .balign 4\n\ | |
63 | LOCAL(zero_l):"); | |
64 | for (i = 64; i < 128; i++) | |
65 | { | |
66 | if (i == 96) | |
67 | puts ("LOCAL(div_table):"); | |
68 | q = 4.*(1<<30)*128/i; | |
69 | r = ceil (q); | |
70 | /* The value for 64 is actually differently scaled that it would | |
71 | appear from this calculation. The implicit part is %01, not 10. | |
72 | Still, since the value in the table is 0 either way, this | |
73 | doesn't matter here. Still, the 1/64 entry is effectively a 1/128 | |
74 | entry. */ | |
75 | printf ("\t.long\t0x%X\n", (unsigned) r); | |
76 | err = r - q; | |
77 | if (err > max_err) | |
78 | max_err = err; | |
79 | err = err * i / 128; | |
80 | if (err > max_s_err) | |
81 | max_s_err = err; | |
82 | } | |
83 | printf ("\t/* maximum error: %f scaled: %f*/\n", max_err, max_s_err); | |
84 | exit (0); | |
85 | } |