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
  10     NAME */
  11
  12         AROS_LHQUAD1(double, IEEEDPCeil,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHAQUAD(double, y, D0, D1),
  16
  17 /*  LOCATION */
  18         struct MathIeeeDoubBasBase *, MathIeeeDoubBasBase, 16, MathIeeeDoubBas)
  19
  20 /*  FUNCTION
  21         Calculates the ceil-value of a IEEE double precision number
  22
  23     INPUTS
  24
  25     RESULT
  26         Flags:
  27           zero     : result is zero
  28           negative : result is negative
  29           overflow : 0
  30
  31     BUGS
  32
  33     SEE ALSO
  34         IEEEDPFloor()
  35
  36     INTERNALS
  37         ALGORITHM:
  38         Ceil(y) = - Floor(-y)
  39
  40 *****************************************************************************/
  41 {
  42     AROS_LIBFUNC_INIT
  43
  44     QUAD * Qy = (QUAD *)&y;
  45
  46     if (is_eqC((*Qy),0,0))
  47     {
  48         SetSR(Zero_Bit, Negative_Bit|Overflow_Bit|Zero_Bit);
  49         return y;
  50     }
  51
  52     XOR64QC((*Qy), IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo);
  53     /* Ceil(y) = -Floor(-y); */
  54     y = IEEEDPFloor(y);
  55     if (is_eqC((*Qy), 0x0, 0x0))
  56     {
  57         Set_Value64C((*Qy), 0, 0);
  58         return y;
  59     }
  60     else
  61     {
  62         XOR64QC((*Qy), IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo );
  63         return y;
  64     }
  65
  66     AROS_LIBFUNC_EXIT
  67 }