logb(3) - NetBSD Manual Pages

IEEE_TEST(3)            NetBSD Library Functions Manual           IEEE_TEST(3)


NAME

     logb, logbf, logbl, scalb, scalbf, significand, significandf -- IEEE test
     functions


LIBRARY

     Math Library (libm, -lm)


SYNOPSIS

     #include <math.h>

     double
     logb(double x);

     float
     logbf(float x);

     long double
     logbl(long double x);

     double
     scalb(double x, double n);

     float
     scalbf(float x, float n);

     double
     significand(double x);

     float
     significandf(float x);


DESCRIPTION

     These functions allow users to test conformance to IEEE Std 754-1985.
     Their use is otherwise not recommended.

     logb(x) returns x's exponent n, a signed integer converted to double-pre-
     cision floating-point.  logb(±infinity) = +infinity; logb(0) = -infinity
     with a division by zero exception.

     scalb(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.


SEE ALSO

     math(3)


STANDARDS

     IEEE Std 754-1985

NetBSD 10.99                    August 3, 2011                    NetBSD 10.99