linux/lib/math/int_pow.c
Andy Shevchenko 9f61589469 lib/math: move int_pow() from pwm_bl.c for wider use
The integer exponentiation is used in few places and might be used in
the future by other call sites.  Move it to wider use.

Link: http://lkml.kernel.org/r/20190323172531.80025-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 19:52:49 -07:00

33 lines
631 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* An integer based power function
*
* Derived from drivers/video/backlight/pwm_bl.c
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/types.h>
/**
* int_pow - computes the exponentiation of the given base and exponent
* @base: base which will be raised to the given power
* @exp: power to be raised to
*
* Computes: pow(base, exp), i.e. @base raised to the @exp power
*/
u64 int_pow(u64 base, unsigned int exp)
{
u64 result = 1;
while (exp) {
if (exp & 1)
result *= base;
exp >>= 1;
base *= base;
}
return result;
}
EXPORT_SYMBOL_GPL(int_pow);