workbench/libs/mathieeedoubtrans/intern_ieeedpld.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <aros/libcall.h>
  10 #include <proto/mathieeedoubbas.h>
  11 #include <proto/mathieeedoubtrans.h>
  12 #include <proto/exec.h>
  13 #include <exec/types.h>
  14 #include "mathieeedoubtrans_intern.h"
  15
  16
  17 QUAD intern_IEEEDPLd(struct MathIeeeDoubTransBase * MathIeeeDoubTransBase,
  18                      QUAD fnum)
  19 {
  20 QUAD tmp, Res, Mask = 0;
  21 ULONG i = 0;
  22
  23   /* argument = 0.5 -> return -1.0;*/
  24   if (is_eqC(fnum, 0x3fe00000, 0x0))
  25   {
  26     Set_Value64C(Res, 0xbff00000, 0x0);
  27     return Res;
  28   }
  29
  30   Set_Value64C(Res, 0x0, 0x0);
  31
  32   while (i <= 52)
  33   {
  34     Set_Value64(tmp, fnum);
  35     AND64QC(tmp, IEEEDPMantisse_Mask_Hi, IEEEDPMantisse_Mask_Lo);
  36     OR64QC(tmp, 0x00100000, 0x0);
  37     /* if (sqrtonehalf < fnum) */
  38     if ( is_greaterC(tmp, 0x0016a09e, 0x667f3bcc) )
  39     {
  40       i++;
  41       fnum = IEEEDPMul(fnum, fnum);
  42     }
  43     else
  44     {
  45       Set_Value64C(Mask, 0x40000000, 0x0);
  46       fnum = IEEEDPMul(fnum, fnum);
  47       ADD64QC(fnum, 0x00100000, 0x0);
  48       break;
  49     }
  50   }
  51
  52   while (is_neqC(Mask, 0x0, 0x200))
  53   {
  54     Set_Value64(tmp, fnum);
  55     AND64QC(tmp, IEEEDPMantisse_Mask_Hi, IEEEDPMantisse_Mask_Lo);
  56     OR64QC(tmp, 0x00100000, 0x0);
  57     if ( is_greaterC(tmp, 0x0016a09e, 0x667f3bcc) )
  58       /* fnum = fnum*fnum */
  59       fnum = IEEEDPMul(fnum, fnum);
  60     else
  61     {
  62       OR64Q(Res, Mask);
  63       /* fnum = fnum*fnum * 2 */
  64       fnum = IEEEDPMul(fnum, fnum);
  65       ADD64QC(fnum, 0x00100000, 0x0);
  66     }
  67     SHRU64(Mask, Mask, 1);
  68   }
  69
  70   /* for precision */
  71
  72   if ( (Get_Low32of64(Res) & 0x400) == 0x400)
  73     ADD64QC(Res, 0x0, 0x800);
  74
  75   SHRU64(Res, Res, 11);
  76   OR64QC(Res, IEEEDPSign_Mask_Hi, IEEEDPSign_Mask_Lo);
  77   SHL32(tmp, (0x3fe - i) , 52);
  78   OR64Q(Res, tmp);
  79   return Res;
  80 } /* intern_IEEEDPLd  */