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linux-next/lib/int_sqrt.c
Paul Gortmaker 8bc3bcc93a lib: reduce the use of module.h wherever possible
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-07 15:04:04 -05:00

33 lines
533 B
C

#include <linux/kernel.h>
#include <linux/export.h>
/**
* int_sqrt - rough approximation to sqrt
* @x: integer of which to calculate the sqrt
*
* A very rough approximation to the sqrt() function.
*/
unsigned long int_sqrt(unsigned long x)
{
unsigned long op, res, one;
op = x;
res = 0;
one = 1UL << (BITS_PER_LONG - 2);
while (one > op)
one >>= 2;
while (one != 0) {
if (op >= res + one) {
op = op - (res + one);
res = res + 2 * one;
}
res /= 2;
one /= 4;
}
return res;
}
EXPORT_SYMBOL(int_sqrt);