]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* lshrdi3.c extracted from gcc-2.7.2/libgcc2.c which is: */ |
2 | /* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #define BITS_PER_UNIT 8 | |
22 | ||
23 | typedef int SItype __attribute__ ((mode (SI))); | |
24 | typedef unsigned int USItype __attribute__ ((mode (SI))); | |
25 | typedef int DItype __attribute__ ((mode (DI))); | |
26 | typedef int word_type __attribute__ ((mode (__word__))); | |
27 | ||
28 | struct DIstruct {SItype high, low;}; | |
29 | ||
30 | typedef union | |
31 | { | |
32 | struct DIstruct s; | |
33 | DItype ll; | |
34 | } DIunion; | |
35 | ||
36 | DItype | |
37 | __lshrdi3 (DItype u, word_type b) | |
38 | { | |
39 | DIunion w; | |
40 | word_type bm; | |
41 | DIunion uu; | |
42 | ||
43 | if (b == 0) | |
44 | return u; | |
45 | ||
46 | uu.ll = u; | |
47 | ||
48 | bm = (sizeof (SItype) * BITS_PER_UNIT) - b; | |
49 | if (bm <= 0) | |
50 | { | |
51 | w.s.high = 0; | |
52 | w.s.low = (USItype)uu.s.high >> -bm; | |
53 | } | |
54 | else | |
55 | { | |
56 | USItype carries = (USItype)uu.s.high << bm; | |
57 | w.s.high = (USItype)uu.s.high >> b; | |
58 | w.s.low = ((USItype)uu.s.low >> b) | carries; | |
59 | } | |
60 | ||
61 | return w.ll; | |
62 | } |