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/arch/mn10300/lib/ashrdi3.c

http://github.com/mirrors/linux
C | 61 lines | 32 code | 9 blank | 20 comment | 4 complexity | 5e2ee78d17e305790e7f6091b67d7e72 MD5 | raw file
 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 Licence 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 Licence for more details.
15
16You should have received a copy of the GNU General Public Licence
17along with GNU CC; see the file COPYING.  If not, write to
18the Free Software Foundation, 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21#define BITS_PER_UNIT 8
22
23typedef 	 int SItype	__attribute__((mode(SI)));
24typedef unsigned int USItype	__attribute__((mode(SI)));
25typedef		 int DItype	__attribute__((mode(DI)));
26typedef		 int word_type	__attribute__((mode(__word__)));
27
28struct DIstruct {
29	SItype low;
30	SItype high;
31};
32
33union DIunion {
34	struct DIstruct	s;
35	DItype		ll;
36};
37
38DItype __ashrdi3(DItype u, word_type b)
39{
40	union DIunion w;
41	union DIunion uu;
42	word_type bm;
43
44	if (b == 0)
45		return u;
46
47	uu.ll = u;
48
49	bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
50	if (bm <= 0) {
51		/* w.s.high = 1..1 or 0..0 */
52		w.s.high = uu.s.high >> (sizeof(SItype) * BITS_PER_UNIT - 1);
53		w.s.low = uu.s.high >> -bm;
54	} else {
55		USItype carries = (USItype)uu.s.high << bm;
56		w.s.high = uu.s.high >> b;
57		w.s.low = ((USItype)uu.s.low >> b) | carries;
58	}
59
60	return w.ll;
61}