usr/src/lib/libc/port/fp/fpparts.h

   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 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 /*
  34  * Macros to pull apart parts of single and  double precision
  35  * floating point numbers in IEEE format
  36  * Be sure to include /usr/include/values.h before including
  37  * this file to get the required definition of _IEEE
  38  */
  39
  40 #if _IEEE
  41 #if defined(__sparc)
  42 /* byte order with high order bits at lowest address */
  43
  44 /* double precision */
  45 typedef  union {
  46         struct {
  47                 unsigned  sign  :1;
  48                 unsigned  exp   :11;
  49                 unsigned  hi    :20;
  50                 unsigned  lo    :32;
  51         } fparts;
  52         struct {
  53                 unsigned  sign  :1;
  54                 unsigned  exp   :11;
  55                 unsigned  qnan_bit      :1;
  56                 unsigned  hi    :19;
  57                 unsigned  lo    :32;
  58         } nparts;
  59         struct {
  60                 unsigned hi;
  61                 unsigned lo;
  62         } fwords;
  63         double  d;
  64 } _dval;
  65
  66 /* single precision */
  67 typedef  union {
  68         struct {
  69                 unsigned sign   :1;
  70                 unsigned exp    :8;
  71                 unsigned fract  :23;
  72         } fparts;
  73         struct {
  74                 unsigned sign   :1;
  75                 unsigned exp    :8;
  76                 unsigned qnan_bit       :1;
  77                 unsigned fract  :22;
  78         } nparts;
  79         unsigned long   fword;
  80         float   f;
  81 } _fval;
  82
  83
  84 #elif defined(__i386) || defined(__amd64)
  85 /* byte order with low order bits at lowest address */
  86
  87 /* double precision */
  88 typedef  union {
  89         struct {
  90                 unsigned  lo    :32;
  91                 unsigned  hi    :20;
  92                 unsigned  exp   :11;
  93                 unsigned  sign  :1;
  94         } fparts;
  95         struct {
  96                 unsigned  lo    :32;
  97                 unsigned  hi    :19;
  98                 unsigned  qnan_bit      :1;
  99                 unsigned  exp   :11;
 100                 unsigned  sign  :1;
 101         } nparts;
 102         struct {
 103                 unsigned  lo    :32;
 104                 unsigned  hi    :32;
 105         } fwords;
 106         double  d;
 107 } _dval;
 108
 109 /* single precision */
 110 typedef  union {
 111         struct {
 112                 unsigned fract  :23;
 113                 unsigned exp    :8;
 114                 unsigned sign   :1;
 115         } fparts;
 116         struct {
 117                 unsigned fract  :22;
 118                 unsigned qnan_bit       :1;
 119                 unsigned exp    :8;
 120                 unsigned sign   :1;
 121         } nparts;
 122         unsigned long   fword;
 123         float   f;
 124 } _fval;
 125 #endif
 126
 127 /* parts of a double precision floating point number */
 128 #define SIGNBIT(X)      (((_dval *)&(X))->fparts.sign)
 129 #define EXPONENT(X)     (((_dval *)&(X))->fparts.exp)
 130
 131 #define HIFRACTION(X)   (((_dval *)&(X))->fparts.hi)
 132 #define LOFRACTION(X)   (((_dval *)&(X))->fparts.lo)
 133 #define QNANBIT(X)      (((_dval *)&(X))->nparts.qnan_bit)
 134 #define HIWORD(X)       (((_dval *)&(X))->fwords.hi)
 135 #define LOWORD(X)       (((_dval *)&(X))->fwords.lo)
 136
 137 #define MAXEXP  0x7ff /* maximum exponent of double */
 138 #define ISMAXEXP(X)     ((EXPONENT(X)) == MAXEXP)
 139
 140 /* macros used to create quiet NaNs as return values */
 141 #define SETQNAN(X)      ((((_dval *)&(X))->nparts.qnan_bit) = 0x1)
 142 #define HIQNAN(X)       ((HIWORD(X)) = 0x7ff80000)
 143 #define LOQNAN(X)       ((((_dval *)&(X))->fwords.lo) = 0x0)
 144
 145 /* macros used to extract parts of single precision values */
 146 #define FSIGNBIT(X)     (((_fval *)&(X))->fparts.sign)
 147 #define FEXPONENT(X)    (((_fval *)&(X))->fparts.exp)
 148 #define FFRACTION(X)    (((_fval *)&(X))->fparts.fract)
 149
 150 #define FWORD(X)        (((_fval *)&(X))->fword)
 151 #define FQNANBIT(X)     (((_fval *)&(X))->nparts.qnan_bit)
 152 #define MAXEXPF 255 /* maximum exponent of single */
 153 #define FISMAXEXP(X)    ((FEXPONENT(X)) == MAXEXPF)
 154
 155 #endif  /* _IEEE */