xref: /openbmc/linux/arch/m68k/lib/ashldi3.c (revision bc5aa3a0)
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 #define BITS_PER_UNIT 8
17 
18 typedef		 int SItype	__attribute__ ((mode (SI)));
19 typedef unsigned int USItype	__attribute__ ((mode (SI)));
20 typedef		 int DItype	__attribute__ ((mode (DI)));
21 typedef int word_type __attribute__ ((mode (__word__)));
22 
23 struct DIstruct {SItype high, low;};
24 
25 typedef union
26 {
27   struct DIstruct s;
28   DItype ll;
29 } DIunion;
30 
31 DItype
32 __ashldi3 (DItype u, word_type b)
33 {
34   DIunion w;
35   word_type bm;
36   DIunion uu;
37 
38   if (b == 0)
39     return u;
40 
41   uu.ll = u;
42 
43   bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
44   if (bm <= 0)
45     {
46       w.s.low = 0;
47       w.s.high = (USItype)uu.s.low << -bm;
48     }
49   else
50     {
51       USItype carries = (USItype)uu.s.low >> bm;
52       w.s.low = (USItype)uu.s.low << b;
53       w.s.high = ((USItype)uu.s.high << b) | carries;
54     }
55 
56   return w.ll;
57 }
58