newlib/libm/machine/amdgcn/v64df_acosh.c

   1 /*
   2  * Copyright 2023 Siemens
   3  *
   4  * The authors hereby grant permission to use, copy, modify, distribute,
   5  * and license this software and its documentation for any purpose, provided
   6  * that existing copyright notices are retained in all copies and that this
   7  * notice is included verbatim in any distributions.  No written agreement,
   8  * license, or royalty fee is required for any of the authorized uses.
   9  * Modifications to this software may be copyrighted by their authors
  10  * and need not follow the licensing terms described here, provided that
  11  * the new terms are clearly indicated on the first page of each file where
  12  * they apply.
  13  */
  14
  15 /*
  16  * ====================================================
  17  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  18  *
  19  * Developed at SunPro, a Sun Microsystems, Inc. business.
  20  * Permission to use, copy, modify, and distribute this
  21  * software is freely granted, provided that this notice
  22  * is preserved.
  23  * ====================================================
  24  *
  25  */
  26
  27 /* Based on newlib/libm/mathfp/e_acosh.c in Newlib.  */
  28
  29 #include "amdgcnmach.h"
  30
  31 v64df v64df_log_aux (v64df, v64di);
  32 v64df v64df_log1p_aux (v64df, v64di);
  33 v64df v64df_sqrt_aux (v64df, v64di);
  34
  35 DEF_VD_MATH_FUNC (v64df, acosh, v64df x)
  36 {
  37   static const double one = 1.0;
  38   static const double ln2 = 6.93147180559945286227e-01;  /* 0x3FE62E42, 0xFEFA39EF */
  39
  40   FUNCTION_INIT (v64df);
  41
  42   v64si hx, lx;
  43   EXTRACT_WORDS (hx, lx, x);
  44
  45   VECTOR_IF (hx < 0x3ff00000, cond)             // x < 1 */
  46     VECTOR_RETURN ((x-x) / (x-x), cond);
  47   VECTOR_ENDIF
  48   VECTOR_IF (hx >=0x41b00000, cond)     // x > 2**28 */
  49     VECTOR_IF2 (hx >=0x7ff00000, cond2, cond)   // x is inf of NaN */
  50       VECTOR_RETURN (x+x, cond2);
  51     VECTOR_ELSE (cond2)
  52       /* acosh(huge)=log(2x) */
  53       VECTOR_RETURN (v64df_log_aux (x, __mask) + ln2, cond2);
  54     VECTOR_ENDIF
  55   VECTOR_ENDIF
  56   VECTOR_IF (((hx - 0x3ff00000) | lx) == 0, cond)
  57     /* acosh(1) = 0 */
  58     VECTOR_RETURN (VECTOR_INIT (0.0), cond);
  59   VECTOR_ENDIF
  60   VECTOR_IF (hx > 0x40000000, cond)     /* 2**28 > x > 2 */
  61   {
  62     v64df t = x * x;
  63     VECTOR_RETURN (v64df_log_aux (2.0*x - one /
  64                                   (x + v64df_sqrt_aux (t - one, __mask)),
  65                                   __mask),
  66                    cond);
  67   }
  68   VECTOR_ELSE (cond)    /* 1<x<2 */
  69   {
  70     v64df t = x - one;
  71     VECTOR_RETURN (v64df_log1p_aux (t + v64df_sqrt_aux(2.0*t + t*t, __mask),
  72                                     __mask),
  73                    cond);
  74   }
  75   VECTOR_ENDIF
  76
  77   FUNCTION_RETURN;
  78 }
  79
  80 DEF_VARIANTS (acosh, df, df)
  81