nan.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
* 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 (c) 1988 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1996, by Sun Microsystems, Inc.
* All Rights Reserved
*/
#ifndef _NAN_H
#define _NAN_H
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Handling of Not_a_Number's (only in IEEE floating-point standard)
*/
#include <sys/isa_defs.h>
#include <values.h>
#ifdef __cplusplus
extern "C" {
#endif
#if defined(_IEEE_754)
/*
* Structure order is endian dependent. Only the common variants of
* big and little endian are supported.
*/
#if defined(_BIG_ENDIAN)
typedef union
{
struct
{
unsigned sign : 1;
unsigned exponent :11;
unsigned bits :20;
unsigned fraction_low :32;
} inf_parts;
struct
{
unsigned sign : 1;
unsigned exponent :11;
unsigned qnan_bit : 1;
unsigned bits :19;
unsigned fraction_low :32;
} nan_parts;
double d;
} dnan;
#else /* Must be _LITTLE_ENDIAN */
typedef union
{
struct {
unsigned fraction_low :32;
unsigned bits :20;
unsigned exponent :11;
unsigned sign : 1;
} inf_parts;
struct {
unsigned fraction_low :32;
unsigned bits :19;
unsigned qnan_bit : 1;
unsigned exponent :11;
unsigned sign : 1;
} nan_parts;
double d;
} dnan;
#endif /* Endian based selection */
/*
* IsNANorINF checks that exponent of double == 2047
* i.e. that number is a NaN or an infinity
*/
/*
* IsINF must be used after IsNANorINF has checked the exponent
*/
/*
* IsPosNAN and IsNegNAN can be used to check the sign of infinities too
*/
/*
* GETNaNPC gets the leftmost 32 bits of the fraction part
*/
#if defined(__STDC__)
#else
#endif
#else /* defined(_IEEE_754) */
/* #error is strictly ansi-C, but works as well as anything for K&R systems. */
#endif /* defined(_IEEE_754) */
#ifdef __cplusplus
}
#endif
#endif /* _NAN_H */