double
logb(double x)
float
logbf(float x)
double
scalb(double x, double n)
float
scalbf(float x, float n)
double
significand(double x)
float
significandf(float x)
logb(x)
returns
x's exponent
n,
a signed integer converted to double-precision floating-point.
logb()
= +;
logb(0)
= - with a division by zero exception.
scalbn(x, n)
returns
x*(2**n)
computed by exponent manipulation.
significand(x)
returns
sig,
where
x
:=
sig * 2**n
with 1
sig
< 2.
significand(x)
is not defined when
x
is 0, , or .