From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=0.6 required=5.0 tests=BAYES_50,FREEMAIL_FROM,
	HELO_NO_DOMAIN,MAILING_LIST_MULTI,RDNS_NONE,SPOOFED_FREEMAIL_NO_RDNS
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,25aa3c7e1b59f7b5
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-01-05 04:48:05 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!xmission!isdnet!enst!enst.fr!not-for-mail
From: "Gautier Write-only-address" <gautier_niouzes@hotmail.com>
Newsgroups: comp.lang.ada
Subject: Re: A case where Ada defaults to unsafe?
Date: Sat, 05 Jan 2002 12:47:17 +0000
Organization: ENST, France
Sender: comp.lang.ada-admin@ada.eu.org
Message-ID: <mailman.1010234881.12215.comp.lang.ada@ada.eu.org>
Reply-To: comp.lang.ada@ada.eu.org
NNTP-Posting-Host: marvin.enst.fr
Mime-Version: 1.0
Content-Type: text/plain; format=flowed
X-Trace: avanie.enst.fr 1010234882 40817 137.194.161.2 (5 Jan 2002 12:48:02
 GMT)
X-Complaints-To: usenet@enst.fr
NNTP-Posting-Date: Sat, 5 Jan 2002 12:48:02 +0000 (UTC)
To: comp.lang.ada@ada.eu.org
Return-Path: <gautier_niouzes@hotmail.com>
X-Originating-IP: [217.162.132.193]
X-OriginalArrivalTime: 05 Jan 2002 12:47:18.0077 (UTC)
 FILETIME=[1BE08ED0:01C195E7]
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
X-Mailman-Version: 2.0.6
Precedence: bulk
List-Help: <mailto:comp.lang.ada-request@ada.eu.org?subject=help>
List-Post: <mailto:comp.lang.ada@ada.eu.org>
List-Subscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto:comp.lang.ada-request@ada.eu.org?subject=subscribe>
List-Id: comp.lang.ada mail<->news gateway <comp.lang.ada.ada.eu.org>
List-Unsubscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto:comp.lang.ada-request@ada.eu.org?subject=unsubscribe>
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
Xref: archiver1.google.com comp.lang.ada:18579
Date: 2002-01-05T12:47:17+00:00

>If I use "and" and I'm wrong in assuming that the order doesn't matter,
>then I have introduced a subtle bug. If I'm right, then I haven't gained
>anything. So why not always use "and then"?

The short circuit is not always the faster. A good compiler
can much more aggressively optimize an "x>=0 and x<=xmax" than
"x>=0 and then x<=xmax"; in addition "and then" introduces
branch(es) in the machine code, this is a performance
penalty on processors like the Pentiums.

____________________________________________________________
Gautier  --  http://www.mysunrise.ch/users/gdm/index.htm#Ada

NB: For a direct answer, address on the Web site!


_________________________________________________________________
MSN Photos is the easiest way to share and print your photos: 
http://photos.msn.com/support/worldwide.aspx