blob: 8dffd36ec4f2411f867629111844c907ac47f7bf [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* ashrdi3.c extracted from gcc-2.95.2/libgcc2.c which is: */
2/* Copyright (C) 1989, 92-98, 1999 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 License 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
Geert Uytterhoevend6410ef2014-11-08 19:19:07 +010014GNU General Public License for more details. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Al Virod13ffb52016-01-11 13:04:04 -050016#include <linux/compiler.h>
17#include <linux/export.h>
18
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#define BITS_PER_UNIT 8
20
21typedef int SItype __attribute__ ((mode (SI)));
22typedef unsigned int USItype __attribute__ ((mode (SI)));
23typedef int DItype __attribute__ ((mode (DI)));
24typedef int word_type __attribute__ ((mode (__word__)));
25
26struct DIstruct {SItype high, low;};
27
28typedef union
29{
30 struct DIstruct s;
31 DItype ll;
32} DIunion;
33
34DItype
35__ashldi3 (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.low = 0;
50 w.s.high = (USItype)uu.s.low << -bm;
51 }
52 else
53 {
54 USItype carries = (USItype)uu.s.low >> bm;
55 w.s.low = (USItype)uu.s.low << b;
56 w.s.high = ((USItype)uu.s.high << b) | carries;
57 }
58
59 return w.ll;
60}
Al Virod13ffb52016-01-11 13:04:04 -050061EXPORT_SYMBOL(__ashldi3);