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
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
14GNU General Public License for more details. */
15
16#define BITS_PER_UNIT 8
17
18typedef		 int SItype	__attribute__ ((mode (SI)));
19typedef unsigned int USItype	__attribute__ ((mode (SI)));
20typedef		 int DItype	__attribute__ ((mode (DI)));
21typedef int word_type __attribute__ ((mode (__word__)));
22
23struct DIstruct {SItype high, low;};
24
25typedef union
26{
27  struct DIstruct s;
28  DItype ll;
29} DIunion;
30
31DItype
32__ashrdi3 (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.high = 1..1 or 0..0 */
47      w.s.high = uu.s.high >> (sizeof (SItype) * BITS_PER_UNIT - 1);
48      w.s.low = uu.s.high >> -bm;
49    }
50  else
51    {
52      USItype carries = (USItype)uu.s.high << bm;
53      w.s.high = uu.s.high >> b;
54      w.s.low = ((USItype)uu.s.low >> b) | carries;
55    }
56
57  return w.ll;
58}
59