ieee_test(3)

NAME

logb, logbf, scalb, scalbf, significand, significandf - IEEE

test functions

LIBRARY

Math Library (libm, -lm)

SYNOPSIS

#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);

DESCRIPTION

These functions allow users to test conformance to IEEE Std

754-1985.
Their use is not otherwise recommended.

logb(x) and logbf(x) return x's exponent n, a signed integer

converted to
double-precision floating-point. logb(+-infinity) = +infin

ity; logb(0) =
-infinity with a division by zero exception.

scalb(x, n) and scalbf(x, n) return x*(2**n) computed by ex

ponent manipulation. If n is not an integer, +-infinity, or an NaN, the

result is
unspecified.

significand(x) and significandf(x) return sig, where x :=

sig * 2**n with
1 <= sig < 2. significand(x) and significandf(x) are not

defined when x
is 0, +-infinity, or NaN.

SEE ALSO

ieee(3), math(3)

STANDARDS

IEEE Std 754-1985

BSD March 10, 1994

BSD