fpparts.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Macros to pull apart parts of single and double precision
* floating point numbers in IEEE format
* Be sure to include /usr/include/values.h before including
* this file to get the required definition of _IEEE
*/
#if _IEEE
#if defined(__sparc)
/* byte order with high order bits at lowest address */
/* double precision */
typedef union {
struct {
unsigned sign :1;
unsigned exp :11;
unsigned hi :20;
unsigned lo :32;
} fparts;
struct {
unsigned sign :1;
unsigned exp :11;
unsigned qnan_bit :1;
unsigned hi :19;
unsigned lo :32;
} nparts;
struct {
unsigned hi;
unsigned lo;
} fwords;
double d;
} _dval;
/* single precision */
typedef union {
struct {
unsigned sign :1;
unsigned exp :8;
unsigned fract :23;
} fparts;
struct {
unsigned sign :1;
unsigned exp :8;
unsigned qnan_bit :1;
unsigned fract :22;
} nparts;
unsigned long fword;
float f;
} _fval;
#elif defined(__i386) || defined(__amd64)
/* byte order with low order bits at lowest address */
/* double precision */
typedef union {
struct {
unsigned lo :32;
unsigned hi :20;
unsigned exp :11;
unsigned sign :1;
} fparts;
struct {
unsigned lo :32;
unsigned hi :19;
unsigned qnan_bit :1;
unsigned exp :11;
unsigned sign :1;
} nparts;
struct {
unsigned lo :32;
unsigned hi :32;
} fwords;
double d;
} _dval;
/* single precision */
typedef union {
struct {
unsigned fract :23;
unsigned exp :8;
unsigned sign :1;
} fparts;
struct {
unsigned fract :22;
unsigned qnan_bit :1;
unsigned exp :8;
unsigned sign :1;
} nparts;
unsigned long fword;
float f;
} _fval;
#endif
/* parts of a double precision floating point number */
#define SIGNBIT(X) (((_dval *)&(X))->fparts.sign)
#define EXPONENT(X) (((_dval *)&(X))->fparts.exp)
#define HIFRACTION(X) (((_dval *)&(X))->fparts.hi)
#define LOFRACTION(X) (((_dval *)&(X))->fparts.lo)
#define QNANBIT(X) (((_dval *)&(X))->nparts.qnan_bit)
#define HIWORD(X) (((_dval *)&(X))->fwords.hi)
#define LOWORD(X) (((_dval *)&(X))->fwords.lo)
#define MAXEXP 0x7ff /* maximum exponent of double */
#define ISMAXEXP(X) ((EXPONENT(X)) == MAXEXP)
/* macros used to create quiet NaNs as return values */
#define SETQNAN(X) ((((_dval *)&(X))->nparts.qnan_bit) = 0x1)
#define HIQNAN(X) ((HIWORD(X)) = 0x7ff80000)
#define LOQNAN(X) ((((_dval *)&(X))->fwords.lo) = 0x0)
/* macros used to extract parts of single precision values */
#define FSIGNBIT(X) (((_fval *)&(X))->fparts.sign)
#define FEXPONENT(X) (((_fval *)&(X))->fparts.exp)
#define FFRACTION(X) (((_fval *)&(X))->fparts.fract)
#define FWORD(X) (((_fval *)&(X))->fword)
#define FQNANBIT(X) (((_fval *)&(X))->nparts.qnan_bit)
#define MAXEXPF 255 /* maximum exponent of single */
#define FISMAXEXP(X) ((FEXPONENT(X)) == MAXEXPF)
#endif /* _IEEE */