newlib-cygwin/newlib/libm/machine/amdgcn/v64df_acosh.c

82 lines
2.4 KiB
C

/*
* 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) 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.
* ====================================================
*
*/
/* Based on newlib/libm/mathfp/e_acosh.c in Newlib. */
#include "amdgcnmach.h"
v64df v64df_log_aux (v64df, v64di);
v64df v64df_log1p_aux (v64df, v64di);
v64df v64df_sqrt_aux (v64df, v64di);
DEF_VD_MATH_FUNC (v64df, acosh, v64df x)
{
static const double one = 1.0;
static const double ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */
FUNCTION_INIT (v64df);
v64si hx, lx;
EXTRACT_WORDS (hx, lx, x);
VECTOR_IF (hx < 0x3ff00000, cond) // x < 1 */
VECTOR_RETURN ((x-x) / (x-x), cond);
VECTOR_ENDIF
VECTOR_IF (hx >=0x41b00000, cond) // x > 2**28 */
VECTOR_IF2 (hx >=0x7ff00000, cond2, cond) // x is inf of NaN */
VECTOR_RETURN (x+x, cond2);
VECTOR_ELSE (cond2)
/* acosh(huge)=log(2x) */
VECTOR_RETURN (v64df_log_aux (x, __mask) + ln2, cond2);
VECTOR_ENDIF
VECTOR_ENDIF
VECTOR_IF (((hx - 0x3ff00000) | lx) == 0, cond)
/* acosh(1) = 0 */
VECTOR_RETURN (VECTOR_INIT (0.0), cond);
VECTOR_ENDIF
VECTOR_IF (hx > 0x40000000, cond) /* 2**28 > x > 2 */
{
v64df t = x * x;
VECTOR_RETURN (v64df_log_aux (2.0*x - one /
(x + v64df_sqrt_aux (t - one, __mask)),
__mask),
cond);
}
VECTOR_ELSE (cond) /* 1<x<2 */
{
v64df t = x - one;
VECTOR_RETURN (v64df_log1p_aux (t + v64df_sqrt_aux(2.0*t + t*t, __mask),
__mask),
cond);
}
VECTOR_ENDIF
FUNCTION_RETURN;
}
DEF_VARIANTS (acosh, df, df)