1 /* ashrdi3.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 #include <linux/compiler.h>
17 #include <linux/export.h>
18
19 #define BITS_PER_UNIT 8
20
21 typedef int SItype __mode(SI);
22 typedef unsigned int USItype __mode(SI);
23 typedef int DItype __mode(DI);
24 typedef int word_type __mode(__word__);
25
26 struct DIstruct {SItype high, low;};
27
28 typedef union
29 {
30 struct DIstruct s;
31 DItype ll;
32 } DIunion;
33
34 DItype
__ashrdi3(DItype u,word_type b)35 __ashrdi3 (DItype u, word_type b)
36 {
37 DIunion w;
38 word_type bm;
39 DIunion uu;
40
41 if (b == 0)
42 return u;
43
44 uu.ll = u;
45
46 bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
47 if (bm <= 0)
48 {
49 /* w.s.high = 1..1 or 0..0 */
50 w.s.high = uu.s.high >> (sizeof (SItype) * BITS_PER_UNIT - 1);
51 w.s.low = uu.s.high >> -bm;
52 }
53 else
54 {
55 USItype carries = (USItype)uu.s.high << bm;
56 w.s.high = uu.s.high >> b;
57 w.s.low = ((USItype)uu.s.low >> b) | carries;
58 }
59
60 return w.ll;
61 }
62 EXPORT_SYMBOL(__ashrdi3);
63