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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 Licence 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 Licence for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public Licence | |
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 { | |
29 | SItype low; | |
30 | SItype high; | |
31 | }; | |
32 | ||
33 | union DIunion { | |
34 | struct DIstruct s; | |
35 | DItype ll; | |
36 | }; | |
37 | ||
38 | DItype __lshrdi3(DItype u, word_type b) | |
39 | { | |
40 | union DIunion w; | |
41 | word_type bm; | |
42 | union DIunion uu; | |
43 | ||
44 | if (b == 0) | |
45 | return u; | |
46 | ||
47 | uu.ll = u; | |
48 | ||
49 | bm = (sizeof(SItype) * BITS_PER_UNIT) - b; | |
50 | if (bm <= 0) { | |
51 | w.s.high = 0; | |
52 | w.s.low = (USItype) uu.s.high >> -bm; | |
53 | } else { | |
54 | USItype carries = (USItype) uu.s.high << bm; | |
55 | w.s.high = (USItype) uu.s.high >> b; | |
56 | w.s.low = ((USItype) uu.s.low >> b) | carries; | |
57 | } | |
58 | ||
59 | return w.ll; | |
60 | } |