Open System Services Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

OSS Library Calls (n - r) pow(3)
• If the value of x is positive or negative 0.0 (zero) and the value of y is an odd integral
value greater than 0.0 (zero), positive or negative 0.0 (zero) is returned.
• If the value of x is positive or negative 0.0 (zero) and the value of y is not an odd integral
value but is greater than 0.0 (zero), positive 0.0 (zero) is returned.
ERRORS
If any of the following conditions occurs, the pow( ) function sets errno to the corresponding
value:
[EDOM] One of the following conditions exists:
• The value of x is negative and the value of y is nonintegral.
• The value of x is 0.0 (zero) and the value of y is negative.
[ERANGE] The value to be returned would have caused an underflow or an overflow.
RELATED INFORMATION
Functions: exp(3), fp_class(3), isnan(3), log(3), log10(3), sinh(3).
STANDARDS CONFORMANCE
This function conforms to the XPG4 Version 2 specification with extensions when used for IEEE
floating-point format data. This function conforms to the XPG4 Version 2 specification without
extensions when used for Tandem floating-point data.
The XPG4 Version 2 specification leaves some features to the implementing vendor to define.
The following features are affected in the HP implementation:
• For IEEE floating-point data, this function does not set errno to [EDOM] if the value of
y is NaN.
• The errno value of [EDOM] is used instead of [ERANGE] when the value of x is 0.0
(zero) and the value of y is negative.
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