usr/src/lib/libbc/libc/gen/common/_Qfcompare.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 #pragma ident   "%Z%%M% %I%     %E% SMI"
  23
  24 /*
  25  * Copyright (c) 1988 by Sun Microsystems, Inc.
  26  */
  27
  28 #include "_Qquad.h"
  29 #include "_Qglobals.h"
  30
  31 enum fcc_type
  32 _fp_compare(px, py, strict)
  33         unpacked       *px, *py;
  34         int             strict; /* 0 if quiet NaN unexceptional, 1 if
  35                                  * exceptional */
  36
  37 {
  38         enum fcc_type   cc;
  39         int  k,n;
  40
  41         if ((px->fpclass == fp_quiet) || (py->fpclass == fp_quiet) ||
  42             (px->fpclass == fp_signaling) || (py->fpclass == fp_signaling)) {
  43                 if (strict)                             /* NaN */
  44                         fpu_set_exception(fp_invalid);
  45                 cc = fcc_unordered;
  46         } else if ((px->fpclass == fp_zero) && (py->fpclass == fp_zero))
  47                 cc = fcc_equal;
  48         /* both zeros */
  49         else if (px->sign < py->sign)
  50                 cc = fcc_greater;
  51         else if (px->sign > py->sign)
  52                 cc = fcc_less;
  53         else {                  /* signs the same, compute magnitude cc */
  54                 if ((int) px->fpclass > (int) py->fpclass)
  55                         cc = fcc_greater;
  56                 else if ((int) px->fpclass < (int) py->fpclass)
  57                         cc = fcc_less;
  58                 else
  59                  /* same classes */ if (px->fpclass == fp_infinity)
  60                         cc = fcc_equal; /* same infinity */
  61                 else if (px->exponent > py->exponent)
  62                         cc = fcc_greater;
  63                 else if (px->exponent < py->exponent)
  64                         cc = fcc_less;
  65                 else {  /* equal exponents */
  66                         n = fpu_cmpli(px->significand,py->significand,4);
  67                         if(n>0) cc = fcc_greater;
  68                         else if(n<0) cc = fcc_less;
  69                         else cc = fcc_equal;
  70                 }
  71                 if (px->sign)
  72                         switch (cc) {   /* negative numbers */
  73                         case fcc_less:
  74                                 cc = fcc_greater;
  75                                 break;
  76                         case fcc_greater:
  77                                 cc = fcc_less;
  78                                 break;
  79                         }
  80         }
  81         return (cc);
  82 }