usr/src/lib/libbc/libc/gen/common/_Q_add.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 /*
  23  * Copyright 1988 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "_Qquad.h"
  30 #include "_Qglobals.h"
  31
  32 static double zero = 0.0, tiny = 1.0e-300, huge = 1.0e300;
  33 static void     dummy(double);
  34
  35 QUAD
  36 _Q_add(QUAD x, QUAD y)
  37 {
  38         unpacked        px,py,pz;
  39         QUAD            z;
  40         _fp_current_exceptions = 0;
  41         _Q_get_rp_rd();         /* get fp_precision, fp_direction */
  42         _fp_unpack(&px,(int *)&x,fp_op_extended);
  43         _fp_unpack(&py,(int *)&y,fp_op_extended);
  44         _fp_add(&px,&py,&pz);
  45         _fp_pack(&pz,(int *)&z,fp_op_extended);
  46         _Q_set_exception(_fp_current_exceptions);
  47         return (z);
  48 }
  49
  50 void
  51 _Q_set_exception(unsigned ex)
  52 {
  53     /* simulate exceptions using double arithmetic */
  54         double t;
  55         if((ex&(1<<fp_invalid))!=0)     t = (zero/zero);
  56         if((ex&(1<<fp_overflow))!=0)    t = (huge*huge);
  57         if((ex&(1<<fp_underflow))!=0)   t = (tiny*tiny);
  58         if((ex&(1<<fp_division))!=0)    t = (tiny/zero);
  59         if((ex&(1<<fp_inexact))!=0)     t = (huge+tiny);
  60         dummy(t);  /* prevent optimizer eliminating previous expression */
  61 }
  62
  63 static void
  64 dummy(double x)
  65 {
  66 }