workbench/libs/mathffp/spcmp.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "mathffp_intern.h"
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11
  12         AROS_LH2(LONG, SPCmp,
  13
  14 /*  SYNOPSIS */
  15         AROS_LHA(float, fnum1, D1),
  16         AROS_LHA(float, fnum2, D0),
  17
  18 /*  LOCATION */
  19         struct LibHeader *, MathBase, 7, Mathffp)
  20
  21 /*  FUNCTION
  22         Compares two FFP numbers.
  23
  24     INPUTS
  25
  26     RESULT
  27        +1 : fnum1 > fnum2
  28         0 : fnum1 = fnum2
  29        -1 : fnum1 < fnum2
  30
  31
  32         Flags:
  33           zero     : fnum2 = fnum1
  34           negative : fnum2 < fnum1
  35           overflow : 0
  36
  37     BUGS
  38
  39     INTERNALS
  40
  41 *****************************************************************************/
  42 {
  43     AROS_LIBFUNC_INIT
  44
  45     LONG result;
  46     ULONG i1 = fnum1, i2 = fnum2, cc;
  47
  48     D(kprintf("SPCmp(%08x,%08x)=", fnum1, fnum2));
  49
  50     /* Convert numbers into a format that can be compared as if integers */
  51     fnum1 = i1 << 24 | i1 >> 8;
  52     if (fnum1 < 0)
  53         fnum1 ^= 0x7fffffff;
  54     fnum2 = i2 << 24 | i2 >> 8;
  55     if (fnum2 < 0)
  56         fnum2 ^= 0x7fffffff;
  57
  58     if (fnum1 > fnum2)
  59     {
  60         result = 1;
  61         cc = 0;
  62     }
  63     else if (fnum1 == fnum2)
  64     {
  65         result = 0;
  66         cc = Zero_Bit;
  67     }
  68     else
  69     {
  70         result = -1;
  71         cc = Negative_Bit;
  72     }
  73
  74     D(kprintf("%ld\n", result));
  75     SetSR(cc, Zero_Bit | Negative_Bit | Overflow_Bit);
  76     return result;
  77
  78     AROS_LIBFUNC_EXIT
  79 }