blob: e05e64e9ce969e306515c43eeb7643d77c04a930 [file] [log] [blame]
David Howellsb920de12008-02-08 04:19:31 -08001/* 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
4This file is part of GNU CC.
5
6GNU CC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public Licence as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU CC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public Licence for more details.
15
16You should have received a copy of the GNU General Public Licence
17along with GNU CC; see the file COPYING. If not, write to
18the Free Software Foundation, 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA. */
20
21#define BITS_PER_UNIT 8
22
23typedef int SItype __attribute__((mode(SI)));
24typedef unsigned int USItype __attribute__((mode(SI)));
25typedef int DItype __attribute__((mode(DI)));
26typedef int word_type __attribute__((mode(__word__)));
27
28struct DIstruct {
29 SItype low;
30 SItype high;
31};
32
33union DIunion {
34 struct DIstruct s;
35 DItype ll;
36};
37
38DItype __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}