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| author | David S. Miller <davem@davemloft.net> | 2016-03-19 21:05:24 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-03-19 21:05:24 -0400 |
| commit | c78a85a8430e35aecd53e190a2f6b999062b1037 (patch) | |
| tree | fbd69827579db437492fb77b5faa53814114bed3 /tools/testing/radix-tree/linux/bitops/fls.h | |
| parent | 133800d1f0288b9ddfc0d0aded10d9efa82d5b8c (diff) | |
| parent | de06dbfa7861c9019eedefc0c356ba86e5098f1b (diff) | |
| download | linux-stable-c78a85a8430e35aecd53e190a2f6b999062b1037.tar.gz linux-stable-c78a85a8430e35aecd53e190a2f6b999062b1037.tar.bz2 linux-stable-c78a85a8430e35aecd53e190a2f6b999062b1037.zip | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
Diffstat (limited to 'tools/testing/radix-tree/linux/bitops/fls.h')
| -rw-r--r-- | tools/testing/radix-tree/linux/bitops/fls.h | 41 |
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 @@ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static inline int fls(int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ |