rom/mathffp/spfix.c

   1 /*
   2     Copyright © 1995-2004, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathffp_intern.h"
   7
   8 /*
   9     FUNCTION
  10         Convert ffp-number to integer
  11
  12     RESULT
  13         absolute value of fnum1
  14
  15         Flags:
  16           zero     : result is zero
  17           negative : result is negative
  18           overflow : ffp out of integer-range
  19
  20     NOTES
  21
  22     EXAMPLE
  23
  24     BUGS
  25
  26     SEE ALSO
  27
  28
  29     INTERNALS
  30
  31     HISTORY
  32 */
  33
  34 AROS_LH1(LONG, SPFix,
  35     AROS_LHA(float, fnum, D0),
  36     struct LibHeader *, MathBase, 5, Mathffp
  37 )
  38 {
  39     AROS_LIBFUNC_INIT
  40
  41     LONG Res;
  42     BYTE Shift;
  43
  44     if ((fnum & FFPExponent_Mask) > 0x60 )
  45     {
  46         if(fnum < 0) /* don`t hurt the SR! */
  47         {
  48             SetSR(Overflow_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  49             return 0x80000000;
  50         }
  51         else
  52         {
  53             SetSR(Overflow_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  54             return 0x7fffffff;
  55         }
  56     }
  57
  58
  59     Shift = (fnum & FFPExponent_Mask) - 0x40;
  60     Res = ((ULONG)(fnum & FFPMantisse_Mask)) >> (32 - Shift);
  61
  62     if (0 == Res)
  63     {
  64         SetSR(Zero_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  65         return 0;
  66     }
  67
  68     if (0x80000000 == Res) return 0x7fffffff;
  69
  70
  71     /* Test for a negative sign */
  72     if ((char)fnum < 0)
  73     {
  74         Res = -Res;
  75         SetSR(Negative_Bit, Zero_Bit | Negative_Bit | Overflow_Bit);
  76     }
  77
  78     kprintf("SPFix(%x)=%d\n",fnum,Res);
  79
  80     return Res;
  81
  82     AROS_LIBFUNC_EXIT
  83 }