logb(3M)logb(3M)NAMElogb(), logbf(), logbl(), logbw(), logbq() - radix-independent exponent
functions
SYNOPSIS
HP Integrity Server Only
DESCRIPTION
The function computes the exponent of the floating point value x. For‐
mally, the return value is the integral part of log base r of |x| as a
signed floating point value, for nonzero x, where r is the radix of the
machine's floating-point arithmetic. The radix r is 2 on HP-UX sys‐
tems.
If x is denormal, it is treated as though it were normalized, before
the exponent is determined.
Integrity Server Only
is a version of it takes a argument and returns a result.
is a version of it takes a argument and returns a result.
is an version of it takes an argument and returns an result.
is equivalent to on HP-UX systems.
USAGE
To use these functions, compile either with the default option or with
the and options.
To use (for Integrity servers) or compile also with
Make sure your program includes Link in the math library by specifying
on the compiler or linker command line. For more information, see the
at the following site:
RETURN VALUE
Upon successful completion, returns the exponent of x.
If x is NaN, returns NaN.
If x returns +INFINITY.
If x is zero, returns (equal to −INFINITY) and raises the divide-by-
zero floating-point exception.
ERRORS
If x is zero, sets to [EDOM].
Integrity Server Only
HP-UX functions on Integrity servers do not set by default. For set‐
ting, compile with the option.
SEE ALSOfrexp(3M), ilogb(3M), scalb(3M), scalbn(3M), scalbln(3M), math(5).
STANDARDS CONFORMANCE
: SVID3, XPG4.2, ANSI C, ISO/IEC C99 (including Annex F, ``IEC 60559
floating-point arithmetic'')
: ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arith‐
metic'')
logb(3M)