-/* origin: OpenBSD /usr/src/lib/libm/src/ld80/s_tanhl.c */
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
-/* tanhl(x)
- * Return the Hyperbolic Tangent of x
- *
- * Method :
- * x -x
- * e - e
- * 0. tanhl(x) is defined to be -----------
- * x -x
- * e + e
- * 1. reduce x to non-negative by tanhl(-x) = -tanhl(x).
- * 2. 0 <= x <= 2**-55 : tanhl(x) := x*(one+x)
- * -t
- * 2**-55 < x <= 1 : tanhl(x) := -----; t = expm1l(-2x)
- * t + 2
- * 2
- * 1 <= x <= 23.0 : tanhl(x) := 1- ----- ; t=expm1l(2x)
- * t + 2
- * 23.0 < x <= INF : tanhl(x) := 1.
- *
- * Special cases:
- * tanhl(NaN) is NaN;
- * only tanhl(0)=0 is exact for finite argument.
- */
-