xref: /openbmc/linux/arch/m68k/lib/ashldi3.c (revision 275876e2)
1 /* ashrdi3.c extracted from gcc-2.95.2/libgcc2.c which is: */
2 /* Copyright (C) 1989, 92-98, 1999 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 You should have received a copy of the GNU General Public License
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 {SItype high, low;};
29 
30 typedef union
31 {
32   struct DIstruct s;
33   DItype ll;
34 } DIunion;
35 
36 DItype
37 __ashldi3 (DItype u, word_type b)
38 {
39   DIunion w;
40   word_type bm;
41   DIunion uu;
42 
43   if (b == 0)
44     return u;
45 
46   uu.ll = u;
47 
48   bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
49   if (bm <= 0)
50     {
51       w.s.low = 0;
52       w.s.high = (USItype)uu.s.low << -bm;
53     }
54   else
55     {
56       USItype carries = (USItype)uu.s.low >> bm;
57       w.s.low = (USItype)uu.s.low << b;
58       w.s.high = ((USItype)uu.s.high << b) | carries;
59     }
60 
61   return w.ll;
62 }
63