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 #include <sys/isa_defs.h>
  32 
  33 #define CSR_DEFAULT 0x1f80
  34 
  35 /* The following should be coded as inline expansion templates.  */
  36 
  37 /*
  38  * Multiplies two normal or subnormal doubles, returns result and exceptions.
  39  */
  40 double
  41 __mul_set(double x, double y, int *pe) {
  42         extern void _putmxcsr(), _getmxcsr();
  43         int csr;
  44         double z;
  45 
  46         _putmxcsr(CSR_DEFAULT);
  47         z = x * y;
  48         _getmxcsr(&csr);
  49         if ((csr & 0x3f) == 0) {
  50                 *pe = 0;
  51         } else {
  52                 /* Result may not be exact. */
  53                 *pe = 1;
  54         }
  55         return (z);
  56 }
  57 
  58 /*
  59  * Divides two normal or subnormal doubles x/y, returns result and exceptions.
  60  */
  61 double
  62 __div_set(double x, double y, int *pe) {
  63         extern void _putmxcsr(), _getmxcsr();
  64         int csr;
  65         double z;
  66 
  67         _putmxcsr(CSR_DEFAULT);
  68         z = x / y;
  69         _getmxcsr(&csr);
  70         if ((csr & 0x3f) == 0) {
  71                 *pe = 0;
  72         } else {
  73                 *pe = 1;
  74         }
  75         return (z);
  76 }
  77 
  78 double
  79 __dabs(double *d)
  80 {
  81         /* should use hardware fabs instruction */
  82         return ((*d < 0.0) ? -*d : *d);
  83 }
  84 
  85 /*
  86  * Returns IEEE mode/status and
  87  * sets up standard environment for base conversion.
  88  */
  89 void
  90 __get_ieee_flags(__ieee_flags_type *b) {
  91         extern void _getmxcsr(), _putmxcsr();
  92 
  93         _getmxcsr(&b->status);
  94 
  95         /* round-to-nearest, all exceptions masked, gradual underflow */
  96         _putmxcsr(CSR_DEFAULT);
  97 }
  98 
  99 /*
 100  * Restores previous IEEE mode/status
 101  */
 102 void
 103 __set_ieee_flags(__ieee_flags_type *b) {
 104         extern void _putmxcsr();
 105 
 106         _putmxcsr(b->status);
 107 }