To: J3                                                     J3/18-276
From: Lorri Menard
Subject: IEEE pi trigonometric functions
Date: 2018-October-17

I  Introduction

At m217 J3 agreed to consider adding degree-argument versions of
some of the trigonometric intrinsic functions.

As part of the discussion it was suggested that we also add the
IEEE pi versions of the these same trigonometric intrinsic functions.


II  Use cases

This provides a portable mechanism for programs that need to use
the standard IEEE "pi" functions.


III What I have in mind

Only generic functions are to be added for these names, with
behavior to match that listed in IEEE 754 latest.

- ACOSPI     (*)
- ASINPI     (*)
- ATAN2PI
- ATANPI
- COSPI
- SINPI
- TANPI      (*)

The intrinsics marked with "(*)" weren't found in the IEEE 754-2008
version of the document, but we are assured that these are being
added to the next release of IEEE 754.