float frexpf(float x, int *exp);

**frexpf** breaks a floating-point number into a normalized fraction
and an integral power of 2.

**frexpf** stores power of two in the **int** object
pointed to by **frexpf** and returns the value **x**,
such that **x** has a magnitude in the interval [½, 1) or zero,
and value equals **x** * 2^**exp**.

If **x** is zero, both parts of the result are zero.

If **x** is ∞ or NaN, **frexpf** **returns** **x** and stores zero
into the int object pointed to by **exp**.