newlib-cygwin/newlib/libm/machine/amdgcn/v64df_exp.c

104 lines
3.7 KiB
C
Raw Normal View History

/*
* 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_exp.c in Newlib. */
#include "amdgcnmach.h"
v64si v64df_ispos (v64df);
v64si v64df_numtest (v64df);
static const double INV_LN2 = 1.4426950408889634074;
static const double LN2 = 0.6931471805599453094172321;
static const double p[] = { 0.25, 0.75753180159422776666e-2,
0.31555192765684646356e-4 };
static const double q[] = { 0.5, 0.56817302698551221787e-1,
0.63121894374398504557e-3,
0.75104028399870046114e-6 };
#if defined (__has_builtin) && __has_builtin (__builtin_gcn_ldexpv)
DEF_VD_MATH_FUNC (v64df, exp, v64df x)
{
FUNCTION_INIT (v64df);
v64si num_type = v64df_numtest (x);
VECTOR_IF (num_type == NAN, cond)
errno = EDOM;
VECTOR_RETURN (x, cond);
VECTOR_ELSEIF (num_type == INF, cond)
errno = ERANGE;
VECTOR_RETURN (VECTOR_MERGE (VECTOR_INIT (z_infinity.d),
VECTOR_INIT (0.0),
v64df_ispos (x)),
cond);
VECTOR_ELSEIF (num_type == 0, cond)
VECTOR_RETURN (VECTOR_INIT (1.0), cond);
VECTOR_ENDIF
/* Check for out of bounds. */
VECTOR_IF ((x > BIGX) | (x < SMALLX), cond)
errno = ERANGE;
VECTOR_RETURN (x, cond);
VECTOR_ENDIF
/* Check for a value too small to calculate. */
VECTOR_RETURN (VECTOR_INIT (1.0),
(-z_rooteps_f < x) & (x < z_rooteps_f));
/* Calculate the exponent. */
v64si Nneg = __builtin_convertvector (x * INV_LN2 - 0.5, v64si);
v64si Npos = __builtin_convertvector (x * INV_LN2 + 0.5, v64si);
v64si N = VECTOR_MERGE (Nneg, Npos, x < 0.0);
/* Construct the mantissa. */
v64df g = x - __builtin_convertvector (N, v64df) * LN2;
v64df z = g * g;
v64df P = g * ((p[2] * z + p[1]) * z + p[0]);
v64df Q = ((q[3] * z + q[2]) * z + q[1]) * z + q[0];
v64df R = 0.5 + P / (Q - P);
/* Return the floating point value. */
N++;
VECTOR_RETURN (__builtin_gcn_ldexpv (R, N), NO_COND);
FUNCTION_RETURN;
}
DEF_VARIANTS (exp, df, df)
#endif