Message-ID: <330CEF04.189D@post.comstar.ru>
Date: Thu, 20 Feb 1997 16:40:36 -0800
From: Dim Zegebart <zager AT post DOT comstar DOT ru>
Reply-To: zager AT post DOT comstar DOT ru
Organization: zager AT post DOT comstar DOT ru
MIME-Version: 1.0
To: DJGPP Mail List <djgpp AT delorie DOT com>
Subject: Re: fixed point math: SOLUTION!!!
References: <5egfq4$3pk AT nr1 DOT toronto DOT istar DOT net> <5eh67b$m3i AT news DOT ox DOT ac DOT uk>
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George Foot wrote:
> 
> #define subtract1(a,b) a-b           /* very bad */
> #define subtract2(a,b) (a)-(b)       /* better   */
> #define subtract3(a,b) ((a)-(b))     /* best     */

I read in GCC info (C Extensions chapter) what the best way to do such
things is :

#define substruct(a,b) ({int _a=a,_b=b,x;x=_a-_b;})

The value of whole expression will eq. to last statment, x - in our
case.
 
-- 
Regards,
Dim Zegebart,
Moscow Russia.