workbench/libs/mathieeesingbas/ieeesptst.c

   1 /*
   2     Copyright © 1995-2004, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathieeesingbas_intern.h"
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11
  12         AROS_LH1(LONG, IEEESPTst,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHA(float, y, D0),
  16
  17 /*  LOCATION */
  18         struct LibHeader *, MathIeeeSingBasBase, 8, Mathieeesingbas)
  19
  20 /*  FUNCTION
  21         Compare a ieeesp-number against zero.
  22
  23     INPUTS
  24
  25     RESULT
  26         +1 : y > 0.0
  27          0 : y = 0.0
  28         -1 : y < 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         y == 0          : return 0
  41         Otherwise       : return 1
  42
  43 *****************************************************************************/
  44 {
  45     AROS_LIBFUNC_INIT
  46
  47     /* y is negative */
  48     if (y < 0)
  49     {
  50         SetSR(Negative_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  51         return -1;
  52     }
  53
  54     /* fnum1 is zero */
  55     if (0 == y)
  56     {
  57         SetSR(Zero_Bit, Zero_Bit | Overflow_Bit | Negative_Bit);
  58         return 0;
  59     }
  60
  61     /* fnum1 is positive */
  62     SetSR(0, Zero_Bit | Overflow_Bit | Negative_Bit );
  63
  64     return 1;
  65
  66     AROS_LIBFUNC_EXIT
  67 }