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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2008 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 "lint.h"
  30 #include "base_conversion.h"
  31 
  32 /* The following should be coded as inline expansion templates.  */
  33 
  34 /*
  35  * Multiplies two normal or subnormal doubles, returns result and exceptions.
  36  */
  37 double
  38 __mul_set(double x, double y, int *pe) {
  39         extern void _putsw(), _getsw();
  40         int sw;
  41         double z;
  42 
  43         _putsw(0);
  44         z = x * y;
  45         _getsw(&sw);
  46         if ((sw & 0x3f) == 0) {
  47                 *pe = 0;
  48         } else {
  49                 /* Result may not be exact. */
  50                 *pe = 1;
  51         }
  52         return (z);
  53 }
  54 
  55 /*
  56  * Divides two normal or subnormal doubles x/y, returns result and exceptions.
  57  */
  58 double
  59 __div_set(double x, double y, int *pe) {
  60         extern void _putsw(), _getsw();
  61         int sw;
  62         double z;
  63 
  64         _putsw(0);
  65         z = x / y;
  66         _getsw(&sw);
  67         if ((sw & 0x3f) == 0) {
  68                 *pe = 0;
  69         } else {
  70                 *pe = 1;
  71         }
  72         return (z);
  73 }
  74 
  75 double
  76 __dabs(double *d)
  77 {
  78         /* should use hardware fabs instruction */
  79         return ((*d < 0.0) ? -*d : *d);
  80 }
  81 
  82 /*
  83  * Returns IEEE mode/status and
  84  * sets up standard environment for base conversion.
  85  */
  86 void
  87 __get_ieee_flags(__ieee_flags_type *b) {
  88         extern void _getcw(), _getsw(), _putcw();
  89         int cw;
  90 
  91         _getcw(&cw);
  92         b->mode = cw;
  93         _getsw(&b->status);
  94         /*
  95          * set CW to...
  96          * RC (bits 10:11)      0 == round to nearest even
  97          * PC (bits 8:9)        2 == round to double
  98          * EM (bits 0:5)        0x3f == all exception trapping masked off
  99          */
 100         cw = (cw & ~0xf3f) | 0x23f;
 101         _putcw(cw);
 102 }
 103 
 104 /*
 105  * Restores previous IEEE mode/status
 106  */
 107 void
 108 __set_ieee_flags(__ieee_flags_type *b) {
 109         extern void _putcw(), _putsw();
 110 
 111         _putcw(b->mode);
 112         _putsw(b->status);
 113 }