workbench/libs/mathieeedoubbas/ieeedpabs.c

   1 /*
   2     Copyright © 1995-2003, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathieeedoubbas_intern.h"
   7
   8 /*
   9     FUNCTION
  10       Calculate the absolute value of the given IEEE double precision
  11       floating point number
  12
  13     RESULT
  14         absolute value of y
  15
  16         Flags:
  17           zero     : result is zero
  18           negative : 0
  19           overflow : 0
  20
  21     NOTES
  22
  23     EXAMPLE
  24
  25     BUGS
  26
  27     SEE ALSO
  28
  29     INTERNALS
  30       ALGORITHM:
  31         set the sign-bit to zero
  32
  33     HISTORY
  34 */
  35
  36 AROS_LHQUAD1(double, IEEEDPAbs,
  37     AROS_LHAQUAD(double, y, D0, D1),
  38     struct MathIeeeDoubBasBase *, MathIeeeDoubBasBase, 9, MathIeeeDoubBas
  39 )
  40 {
  41     AROS_LIBFUNC_INIT
  42
  43     QUAD * Qy = (QUAD *)&y;
  44
  45     /*if (0 == (*Qy)) */
  46     if (is_eqC((*Qy),0,0))
  47     {
  48         /* value is 0 -> set the Zero Flag */
  49         SetSR( Zero_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  50     }
  51     else
  52     {
  53         /* set the sign-bit to zero */
  54         /* (*Qy) &= (IEEEDPMantisse_Mask | IEEEDPExponent_Mask) */
  55         AND64QC
  56         (
  57             (*Qy),
  58             (IEEEDPMantisse_Mask_Hi | IEEEDPExponent_Mask_Hi),
  59             (IEEEDPMantisse_Mask_Lo | IEEEDPExponent_Mask_Lo)
  60         );
  61         SetSR(0, Zero_Bit | Overflow_Bit | Negative_Bit );
  62     }
  63
  64     return y;
  65
  66     AROS_LIBFUNC_EXIT
  67 }