log2 ( x -- n )
Factor handbook » The language » Numbers » Mathematical functions » Integer functions

Prev:	gcd ( x y -- a d )
Next:	next-power-of-2 ( m -- n )

Vocabulary
math

Inputs

x	a positive integer

Outputs

n	an integer

Word description
Outputs the largest integer n such that 2^n is less than or equal to x.

Errors
Throws an error if x is zero or negative.

Definition

USING: math.private ;

IN: math

: log2 ( x -- n ) assert-positive (log2) ; inline