workbench/libs/mathffp/sptst.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
  10     NAME */
  11
  12         AROS_LH1(LONG, SPTst,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHA(float, fnum, D1),
  16
  17 /*  LOCATION */
  18         struct LibHeader *, MathBase, 8, Mathffp)
  19
  20 /*  FUNCTION
  21         Compare a ffp-number against zero.
  22
  23     INPUTS
  24
  25     RESULT
  26         +1 : fnum > 0.0
  27          0 : fnum = 0.0
  28         -1 : fnum < 0.0
  29
  30         Flags:
  31           zero     : result is zero
  32           negative : result is negative
  33           overflow : 0
  34
  35     BUGS
  36
  37     INTERNALS
  38         ALGORITHM:
  39         Sign is negative: return -1
  40         fnum == 0       : return 0
  41         Otherwise       : return 1
  42
  43 *****************************************************************************/
  44 {
  45     AROS_LIBFUNC_INIT
  46
  47     D(kprintf("SPTst(%08x)\n", fnum));
  48     /* fnum1 is negative */
  49     if ((char) fnum < 0)
  50     {
  51         SetSR(Negative_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  52         return -1;
  53     }
  54
  55     /* fnum1 is zero */
  56     if (0 == fnum)
  57     {
  58         SetSR(Zero_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  59         return 0;
  60     }
  61
  62     /* fnum1 is positive */
  63     SetSR(0, Zero_Bit | Overflow_Bit | Negative_Bit );
  64
  65     return 1;
  66
  67     AROS_LIBFUNC_EXIT
  68 }