cnvd2f.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 55 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
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  Double to float conversion helper routine.
*
****************************************************************************/


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

/* This routine is called from the C++ istream float extractor */

_WMRTLINK int __cnvd2f( double *src, float *tgt )
// return zero if ok, else non-zero
{
    double  value = *src;

    if( value == 0 ) {
        *tgt = (float)value;
        return( 0 );
    } else if( value > 0 && value <= FLT_MAX && value >= FLT_MIN ) {
        *tgt = (float)value;
        return( 0 );
    } else if( value >= -FLT_MAX && value <= -FLT_MIN ) {
        *tgt = (float)value;
        return( 0 );
    } else {
        return( 1 );
    }
}