xref: /openbmc/linux/lib/lshrdi3.c (revision 82e6fdd6)
1 /*
2  * lib/lshrdi3.c
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see the file COPYING, or write
16  * to the Free Software Foundation, Inc.
17  */
18 
19 #include <linux/module.h>
20 #include <linux/libgcc.h>
21 
22 long long notrace __lshrdi3(long long u, word_type b)
23 {
24 	DWunion uu, w;
25 	word_type bm;
26 
27 	if (b == 0)
28 		return u;
29 
30 	uu.ll = u;
31 	bm = 32 - b;
32 
33 	if (bm <= 0) {
34 		w.s.high = 0;
35 		w.s.low = (unsigned int) uu.s.high >> -bm;
36 	} else {
37 		const unsigned int carries = (unsigned int) uu.s.high << bm;
38 
39 		w.s.high = (unsigned int) uu.s.high >> b;
40 		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
41 	}
42 
43 	return w.ll;
44 }
45 EXPORT_SYMBOL(__lshrdi3);
46