blob: 84b9c5592220eac8648306a57295047b21456671 [file] [log] [blame]
Bryan Wu1394f032007-05-06 14:50:22 -07001/*
2 * File: arch/blackfin/lib/lshrdi3.c
3 * Based on:
4 * Author:
5 *
6 * Created:
7 * Description:
8 *
9 * Modified:
10 * Copyright 2004-2006 Analog Devices Inc.
11 *
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#define BITS_PER_UNIT 8
31
32typedef int SItype __attribute__ ((mode(SI)));
33typedef unsigned int USItype __attribute__ ((mode(SI)));
34typedef int DItype __attribute__ ((mode(DI)));
35typedef int word_type __attribute__ ((mode(__word__)));
36
37struct DIstruct {
38 SItype high, low;
39};
40
41typedef union {
42 struct DIstruct s;
43 DItype ll;
44} DIunion;
45
46#ifdef CONFIG_ARITHMETIC_OPS_L1
47DItype __lshrdi3(DItype u, word_type b)__attribute__((l1_text));
48#endif
49
50DItype __lshrdi3(DItype u, word_type b)
51{
52 DIunion w;
53 word_type bm;
54 DIunion uu;
55
56 if (b == 0)
57 return u;
58
59 uu.ll = u;
60
61 bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
62 if (bm <= 0) {
63 w.s.high = 0;
64 w.s.low = (USItype) uu.s.high >> -bm;
65 } else {
66 USItype carries = (USItype) uu.s.high << bm;
67 w.s.high = (USItype) uu.s.high >> b;
68 w.s.low = ((USItype) uu.s.low >> b) | carries;
69 }
70
71 return w.ll;
72}