Divide floating-point number into mantissa and power
float frexpf(float val, int *exp);
frexpf sets 0 to *exp and returns 0 if val is 0.
frexpf sets 0 to *exp, returns a NaN and sets macro EDOM to global variable errno if val is ±∞.
If val is NaN, frexpf sets 0 to *exp and returns a NaN.
This function expresses val of float type as mantissa m and the pth power of 2. The resulting mantissa m is 0.5 <= | x | < 1.0, unless val is zero. p is stored in *exp. m and p are calculated so that val = m * 2 p.
#include <mathf.h> void func(void) { float ret, x; int exp; x = 5.28; ret = frexpf(x, &exp); /*Resultant mantissa 0.66 is returned to ret, and 3 is stored in exp.*/ : } |