Guardian Native C Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

atanhl(3) Guardian Native C Library Calls Reference Manual
NAME
atanhl - Computes the inverse hyperbolic tangent function for a long double value
LIBRARY
H-series and J-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
32-bit H-series and J-series OSS processes: /G/system/zdllnnn/zcredll
64-bit H-series and J-series OSS processes: /G/system/zdllnnn/ycredll
SYNOPSIS
#include <math.h>
long double atanhl(
long double x);
PARAMETERS
x Is the long double value for which the inverse hyperbolic tangent function is to
be computed.
DESCRIPTION
The atanhl() function is a long double version of the atanh() function; it takes a long double
argument and returns a long double result.
The atanhl() function computes the inverse hyperbolic tangent of x.
The atanhl() function can be called only by native processes.
NOTES
This function supports both IEEE Std 754-1985 floating-point and Tandem floating-point values.
IEEE values can include NaN and infinity, and the sign of 0.0 (zero) can be either positive or
negative. Refer to the fp_class(3) reference page for a description of IEEE value classes.
Guardian functions are available to convert between floating-point formats. Refer to the Guar-
dian Programmer’s Guide for a discussion of floating-point conversions.
RETURN VALUES
The atanhl() function returns the inverse hyperbolic tangent of the x parameter.
For IEEE floating-point values, when the value of x is NaN, the atanhl() function returns NaN.
When the absolute value of x is 1.0, the atanhl() function returns +HUGE_VALL or
-HUGE_VALL as appropriate and sets errno to [ERANGE]. When the absolute value of x is
greater than 1.0, the atanhl() function returns NaN and sets errno to [EDOM].
For Tandem floating-point values, when the absolute value of x is 1.0, the atanhl() function
returns +HUGE_VALL or -HUGE_VALL as appropriate and sets errno to [ERANGE]. When
the absolute value of x is greater than 1.0, the atanhl() function returns HUGE_VALL and sets
errno to [EDOM].
ERRORS
If any of the following conditions occur, the atanhl() function sets errno to the corresponding
value:
[EDOM] The absolute value of the x parameter is greater than 1.0.
[ERANGE] The absolute value of the x parameter is equal to 1.0.
RELATED INFORMATION
Functions: acos(3), acosh(3), asin(3), asinh(3), atan(3), atanh(3), atanhf(3), atan2(3), catan(3),
catanh(3), fp_class(3), isnan(3), tan(3), tanh(3).
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