finite.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 42 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
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* Description:  Determine if floating-point value is finite (not NaN/Inf).
*
****************************************************************************/


#include "variety.h"
#include <math.h>
#include <float.h>


_WMRTLINK int _finite( double value )
/***********************************/
{
    return( (*(((unsigned short *)(&value)) + 3) & 0x7FF0 ) != 0x7FF0 );
}