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1394f032 BW |
1 | /* |
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 | ||
32 | typedef int SItype __attribute__ ((mode(SI))); | |
33 | typedef unsigned int USItype __attribute__ ((mode(SI))); | |
34 | typedef int DItype __attribute__ ((mode(DI))); | |
35 | typedef int word_type __attribute__ ((mode(__word__))); | |
36 | ||
37 | struct DIstruct { | |
38 | SItype high, low; | |
39 | }; | |
40 | ||
41 | typedef union { | |
42 | struct DIstruct s; | |
43 | DItype ll; | |
44 | } DIunion; | |
45 | ||
46 | #ifdef CONFIG_ARITHMETIC_OPS_L1 | |
47 | DItype __lshrdi3(DItype u, word_type b)__attribute__((l1_text)); | |
48 | #endif | |
49 | ||
50 | DItype __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 | } |