Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

atan2(3) Guardian Native C Library Calls Reference Manual
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:
• When used for IEEE floating-point values, errno is not set to [EDOM] when the value of
x or y is NaN.
• errno is not set to [ERANGE] when the return value would underflow.
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