aboutsummaryrefslogtreecommitdiffstats
path: root/tools/testing/radix-tree/linux/bitops/fls.h
diff options
context:
space:
mode:
authorMatthew Wilcox <willy@linux.intel.com>2016-03-17 17:21:45 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 18:09:34 -0400
commit1366c37ed84b166a0fffe201154b0d3b78a3976b (patch)
tree3a688edaf09069694db90421f200568b886a4295 /tools/testing/radix-tree/linux/bitops/fls.h
parentf67c07f07fca95a7f330b8bb928eabaf9fcce75d (diff)
radix tree test harness
This code is mostly from Andrew Morton and Nick Piggin; tarball downloaded from http://ozlabs.org/~akpm/rtth.tar.gz with sha1sum 0ce679db9ec047296b5d1ff7a1dfaa03a7bef1bd Some small modifications were necessary to the test harness to fix the build with the current Linux source code. I also made minor modifications to automatically test the radix-tree.c and radix-tree.h files that are in the current source tree, as opposed to a copied and slightly modified version. I am sure more could be done to tidy up the harness, as well as adding more tests. [koct9i@gmail.com: fix compilation] Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/testing/radix-tree/linux/bitops/fls.h')
-rw-r--r--tools/testing/radix-tree/linux/bitops/fls.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/linux/bitops/fls.h b/tools/testing/radix-tree/linux/bitops/fls.h
new file mode 100644
index 000000000000..850859bc5069
--- /dev/null
+++ b/tools/testing/radix-tree/linux/bitops/fls.h
@@ -0,0 +1,41 @@
1#ifndef _ASM_GENERIC_BITOPS_FLS_H_
2#define _ASM_GENERIC_BITOPS_FLS_H_
3
4/**
5 * fls - find last (most-significant) bit set
6 * @x: the word to search
7 *
8 * This is defined the same way as ffs.
9 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
10 */
11
12static inline int fls(int x)
13{
14 int r = 32;
15
16 if (!x)
17 return 0;
18 if (!(x & 0xffff0000u)) {
19 x <<= 16;
20 r -= 16;
21 }
22 if (!(x & 0xff000000u)) {
23 x <<= 8;
24 r -= 8;
25 }
26 if (!(x & 0xf0000000u)) {
27 x <<= 4;
28 r -= 4;
29 }
30 if (!(x & 0xc0000000u)) {
31 x <<= 2;
32 r -= 2;
33 }
34 if (!(x & 0x80000000u)) {
35 x <<= 1;
36 r -= 1;
37 }
38 return r;
39}
40
41#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */