workbench/libs/mathieeedoubbas/ieeedpceil.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         Calculates the ceil-value of a IEEE double precision number
  11
  12     RESULT
  13         Flags:
  14           zero     : result is zero
  15           negative : result is negative
  16           overflow : 0
  17
  18     NOTES
  19
  20     EXAMPLE
  21
  22     BUGS
  23
  24     SEE ALSO
  25         IEEEDPFloor()
  26
  27     INTERNALS
  28       ALGORITHM:
  29          Ceil(y) = - Floor(-y)
  30
  31     HISTORY
  32 */
  33
  34 AROS_LHQUAD1(double, IEEEDPCeil,
  35     AROS_LHAQUAD(double, y, D0, D1),
  36     struct MathIeeeDoubBasBase *, MathIeeeDoubBasBase, 16, MathIeeeDoubBas
  37 )
  38 {
  39     AROS_LIBFUNC_INIT
  40
  41     QUAD * Qy = (QUAD *)&y;
  42
  43     if (is_eqC((*Qy),0,0))
  44     {
  45         SetSR(Zero_Bit, Negative_Bit|Overflow_Bit|Zero_Bit);
  46         return y;
  47     }
  48
  49     XOR64QC((*Qy), IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo);
  50     /* Ceil(y) = -Floor(-y); */
  51     y = IEEEDPFloor(y);
  52     if (is_eqC((*Qy), 0x0, 0x0))
  53     {
  54         Set_Value64C((*Qy), 0, 0);
  55         return y;
  56     }
  57     else
  58     {
  59         XOR64QC((*Qy), IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo );
  60         return y;
  61     }
  62
  63     AROS_LIBFUNC_EXIT
  64 }