lib: zstd: Improve decode performance
[platform/kernel/linux-rpi.git] / lib / ashrdi3.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4
5 #include <linux/export.h>
6
7 #include <linux/libgcc.h>
8
9 long long notrace __ashrdi3(long long u, word_type b)
10 {
11         DWunion uu, w;
12         word_type bm;
13
14         if (b == 0)
15                 return u;
16
17         uu.ll = u;
18         bm = 32 - b;
19
20         if (bm <= 0) {
21                 /* w.s.high = 1..1 or 0..0 */
22                 w.s.high =
23                     uu.s.high >> 31;
24                 w.s.low = uu.s.high >> -bm;
25         } else {
26                 const unsigned int carries = (unsigned int) uu.s.high << bm;
27
28                 w.s.high = uu.s.high >> b;
29                 w.s.low = ((unsigned int) uu.s.low >> b) | carries;
30         }
31
32         return w.ll;
33 }
34 EXPORT_SYMBOL(__ashrdi3);