From: "sl" <junk AT bbs DOT darktech DOT org>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: GCC optimization
Date: Thu, 30 Dec 1999 20:09:46 -0500 (EST)
Organization: Posted via Supernews, http://www.supernews.com
Lines: 37
Message-ID: <fyoofqnexgrpubet.fnkz8a2.pminews@nntp.generation.net>
References: <fyoofqnexgrpubet DOT fniy770 DOT pminews AT nntp DOT generation DOT net> <4VLa4.70142$X47 DOT 388252 AT quark DOT idirect DOT com>
X-Complaints-To: newsabuse AT supernews DOT com
X-Newsreader: PMINews 2.00.1205 For OS/2
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

On Thu, 30 Dec 1999 16:39:28 GMT, Andrew Jones wrote:

>> Does GCC optimize "something*1024" into "something << 10"?
>
>Let's see.
>
>
>TEST.C
>~~~~
>int glob;
>
>int main(void)
>  {
>  return(glob * 1024);
>  }
>
>
>gcc -c -S test.c
>
>
>GLOB.S
>~~~~~
>[...]
>movl _glob,%eax
>movl %eax,%edx
>movl %edx,%ecx
>sall $10,%ecx
>movl %ecx,%eax
>[...]
>
>In a word: YES.

	Hehehe.. Thanks!

Gili