workbench/libs/mathieeedoubtrans/ieeedpsinh.c

   1 /*
   2     Copyright © 1995-2003, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathieeedoubtrans_intern.h"
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11
  12         AROS_LHQUAD1(double, IEEEDPSinh,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHAQUAD(double, y, D0, D1),
  16
  17 /*  LOCATION */
  18         struct MathIeeeDoubTransBase *, MathIeeeDoubTransBase, 10, MathIeeeDoubTrans)
  19
  20 /*  FUNCTION
  21         Calculate the hyperbolic sine of the IEEE double precision number
  22
  23     INPUTS
  24
  25     RESULT
  26         IEEE double precision floating point number
  27
  28         flags:
  29         zero     : result is zero
  30         negative : result is negative
  31         overflow : result is too big for IEEE double precsion format
  32
  33     BUGS
  34
  35     INTERNALS
  36         sinh(x) = (1/2)*( e^x- e^(-x) )
  37
  38         sinh( |x| >=  18 ) = (1/2) * (e^x);
  39
  40 *****************************************************************************/
  41 {
  42     AROS_LIBFUNC_INIT
  43
  44     QUAD Res;
  45     QUAD y2;
  46
  47     /* y2 = y & (IEEEDPMantisse_Mask + IEEEDPExponent_Mask); */
  48     Set_Value64(y2, y);
  49     AND64QC
  50     (
  51         y2,
  52         (IEEEDPMantisse_Mask_Hi + IEEEDPExponent_Mask_Hi),
  53         (IEEEDPMantisse_Mask_Lo + IEEEDPExponent_Mask_Lo)
  54     );
  55
  56     if ( is_eqC(y, IEEEDPPInfty_Hi, IEEEDPPInfty_Lo))
  57     {
  58         SetSR(Overflow_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  59         return y;
  60     }
  61
  62     /* sinh(-x) = -sinh(x) */
  63     Res = IEEEDPExp(y2);
  64
  65     if ( is_eqC(Res, IEEEDPPInfty_Hi, IEEEDPPInfty_Lo ))
  66     {
  67         SetSR(Overflow_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  68         if ( is_lessSC(y, 0x0, 0x0))
  69         {
  70             OR64QC(Res, IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo );
  71         }
  72         return Res;
  73     }
  74
  75     if ( is_lessC(y2, 0x40320000, 0x0) )
  76     {
  77         QUAD One, ResTmp;
  78         Set_Value64C(One, one_Hi, one_Lo);
  79         ResTmp = IEEEDPDiv(One, Res);
  80         OR64QC(ResTmp, IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo);
  81
  82         Res = IEEEDPAdd(Res, ResTmp);
  83     }
  84     /* Res = Res / 2 */
  85     ADD64QC(Res, 0xFFF00000, 0x0);
  86
  87     /* at this point Res has to be positive to be valid */
  88     if ( is_leqSC(Res, 0x0, 0x0))
  89     {
  90         SetSR(Zero_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  91         AND64QC(y, IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo);
  92         return y;
  93     }
  94
  95     if ( is_lessSC(y, 0x0, 0x0))
  96     {
  97         SetSR(Negative_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  98         OR64QC(Res, IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo );
  99
 100         return Res;
 101     }
 102
 103     return Res;
 104
 105     AROS_LIBFUNC_EXIT
 106 }