mirror of
https://github.com/torvalds/linux
synced 2024-07-08 20:29:39 +00:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
33 lines
514 B
C
33 lines
514 B
C
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.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 = 1 << 30;
|
|
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);
|