IEEE_TEST(3) BSD Programmer's Manual IEEE_TEST(3)
logb, logbf, scalb, scalbf, significand, significandf - IEEE test func- tions
libm
#include <math.h> 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);
These functions allow users to test conformance to IEEE Std 754-1985. Their use is not otherwise recommended. logb(x) returns x's exponent n, a signed integer converted to double-precision floating-point. logb(+-Infinity) = +Infinity; logb(0) = -Infinity 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, +-Infinity, or NaN.
math(3)
IEEE Std 754-1985 MirBSD #10-current February 9, 2014 1