workbench/libs/mathieeedoubbas/ieeedpabs.c

   1 /*
   2     Copyright © 1995-2017, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathieeedoubbas_intern.h"
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11
  12         AROS_LHQUAD1(double, IEEEDPAbs,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHAQUAD(double, y, D0, D1),
  16
  17 /*  LOCATION */
  18         struct MathIeeeDoubBasBase *, MathIeeeDoubBasBase, 9, MathIeeeDoubBas)
  19
  20 /*  FUNCTION
  21         Calculate the absolute value of the given IEEE double precision
  22         floating point number.
  23
  24     INPUTS
  25         y - IEEE double precision floating point number.
  26
  27     RESULT
  28         x - absolute value of y.
  29
  30         Flags:
  31           zero     : result is zero
  32           negative : 0
  33           overflow : 0
  34
  35     NOTES
  36
  37     EXAMPLE
  38
  39     BUGS
  40
  41     SEE ALSO
  42         IEEEDPNeg()
  43
  44     INTERNALS
  45         Algorithm:
  46         Set the sign-bit to zero.
  47
  48 *****************************************************************************/
  49 {
  50     AROS_LIBFUNC_INIT
  51
  52     QUAD * Qy = (QUAD *)&y;
  53
  54     /*if (0 == (*Qy)) */
  55     if (is_eqC((*Qy),0,0))
  56     {
  57         /* value is 0 -> set the Zero Flag */
  58         SetSR( Zero_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  59     }
  60     else
  61     {
  62         /* set the sign-bit to zero */
  63         /* (*Qy) &= (IEEEDPMantisse_Mask | IEEEDPExponent_Mask) */
  64         AND64QC
  65         (
  66             (*Qy),
  67             (IEEEDPMantisse_Mask_Hi | IEEEDPExponent_Mask_Hi),
  68             (IEEEDPMantisse_Mask_Lo | IEEEDPExponent_Mask_Lo)
  69         );
  70         SetSR(0, Zero_Bit | Overflow_Bit | Negative_Bit );
  71     }
  72
  73     return y;
  74
  75     AROS_LIBFUNC_EXIT
  76 }