ashldi3.c
1.57 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
/* ashrdi3.c extracted from gcc-2.95.2/libgcc2.c which is: */
/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#define BITS_PER_UNIT 8
typedef int SItype __attribute__ ((mode (SI)));
typedef unsigned int USItype __attribute__ ((mode (SI)));
typedef int DItype __attribute__ ((mode (DI)));
typedef int word_type __attribute__ ((mode (__word__)));
struct DIstruct {SItype high, low;};
typedef union
{
struct DIstruct s;
DItype ll;
} DIunion;
DItype
__ashldi3 (DItype u, word_type b)
{
DIunion w;
word_type bm;
DIunion uu;
if (b == 0)
return u;
uu.ll = u;
bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
if (bm <= 0)
{
w.s.low = 0;
w.s.high = (USItype)uu.s.low << -bm;
}
else
{
USItype carries = (USItype)uu.s.low >> bm;
w.s.low = (USItype)uu.s.low << b;
w.s.high = ((USItype)uu.s.high << b) | carries;
}
return w.ll;
}