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| author | James Morris <james.l.morris@oracle.com> | 2017-11-29 12:47:41 +1100 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2017-11-29 12:47:41 +1100 |
| commit | cf40a76e7d5874bb25f4404eecc58a2e033af885 (patch) | |
| tree | 8fd81cbea03c87b3d41d7ae5b1d11eadd35d6ef5 /lib/int_sqrt.c | |
| parent | ab5348c9c23cd253f5902980d2d8fe067dc24c82 (diff) | |
| parent | 4fbd8d194f06c8a3fd2af1ce560ddb31f7ec8323 (diff) | |
Merge tag 'v4.15-rc1' into next-seccomp
Linux 4.15-rc1
Diffstat (limited to 'lib/int_sqrt.c')
| -rw-r--r-- | lib/int_sqrt.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c index 1ef4cc344977..e2d329099bf7 100644 --- a/lib/int_sqrt.c +++ b/lib/int_sqrt.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2013 Davidlohr Bueso <davidlohr.bueso@hp.com> * @@ -7,12 +8,13 @@ #include <linux/kernel.h> #include <linux/export.h> +#include <linux/bitops.h> /** - * int_sqrt - rough approximation to sqrt + * int_sqrt - computes the integer square root * @x: integer of which to calculate the sqrt * - * A very rough approximation to the sqrt() function. + * Computes: floor(sqrt(x)) */ unsigned long int_sqrt(unsigned long x) { @@ -21,7 +23,7 @@ unsigned long int_sqrt(unsigned long x) if (x <= 1) return x; - m = 1UL << (BITS_PER_LONG - 2); + m = 1UL << (__fls(x) & ~1UL); while (m != 0) { b = y + m; y >>= 1; |