newlib-cygwin/newlib/libm/machine/amdgcn/v64df_tanh.c

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/*
* Copyright 2023 Siemens
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
/*
* Copyright (c) 1994-2009 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the BSD License. This program is distributed in the hope that
* it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
* including the implied warranties of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. A copy of this license is available at
* http://www.opensource.org/licenses. Any Red Hat trademarks that are
* incorporated in the source code or documentation are not subject to
* the BSD License and may only be used or replicated with the express
* permission of Red Hat, Inc.
*/
/*****************************************************************
* The following routines are coded directly from the algorithms
* and coefficients given in "Software Manual for the Elementary
* Functions" by William J. Cody, Jr. and William Waite, Prentice
* Hall, 1980.
*****************************************************************/
/* Based on newlib/libm/mathfp/s_tanh.c in Newlib. */
#include "amdgcnmach.h"
v64df v64df_exp_aux (v64df, v64di);
static const double LN3_OVER2 = 0.54930614433405484570;
static const double p[] = { -0.16134119023996228053e+4,
-0.99225929672236083313e+2,
-0.96437492777225469787 };
static const double q[] = { 0.48402357071988688686e+4,
0.22337720718962312926e+4,
0.11274474380534949335e+3 };
#if defined (__has_builtin) && __has_builtin (__builtin_gcn_fabsv)
DEF_VD_MATH_FUNC (v64df, tanh, v64df x)
{
FUNCTION_INIT (v64df);
v64df f = __builtin_gcn_fabsv (x);
v64df res;
/* Check if the input is too big. */
VECTOR_IF (f > BIGX, cond)
VECTOR_COND_MOVE (res, VECTOR_INIT (1.0), cond);
VECTOR_ELSEIF (f > LN3_OVER2, cond)
VECTOR_COND_MOVE (res, 1.0 - 2.0 / (v64df_exp_aux (2 * f, __mask) + 1.0),
cond);
/* Check if the input is too small. */
VECTOR_ELSEIF (f < z_rooteps, cond)
VECTOR_COND_MOVE (res, f, cond);
/* Calculate the Taylor series. */
VECTOR_ELSE (cond)
v64df g = f * f;
v64df P = (p[2] * g + p[1]) * g + p[0];
v64df Q = ((g + q[2]) * g + q[1]) * g + q[0];
v64df R = g * (P / Q);
VECTOR_COND_MOVE (res, f + f * R, cond);
VECTOR_ENDIF
VECTOR_COND_MOVE (res, -res, x < 0.0);
VECTOR_RETURN (res, NO_COND);
FUNCTION_RETURN;
}
DEF_VARIANTS (tanh, df, df)
#endif