delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2005/06/12/18:57:36

Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Date: Sun, 12 Jun 2005 18:57:28 -0400
From: Christopher Faylor <cgf-no-personal-reply-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: gcc 3.4.4 optimization problem (was Re: Negative stats from rsync with 20050610 snapshot)
Message-ID: <20050612225728.GB31595@trixie.casa.cgf.cx>
Reply-To: cygwin AT cygwin DOT com
References: <42AA611A DOT 2050605 AT acm DOT org> <20050611145713 DOT GA11065 AT calimero DOT vinschen DOT de> <42AB16FA DOT 4000701 AT familiehaase DOT de> <20050612082206 DOT GB6568 AT calimero DOT vinschen DOT de> <42ABFED3 DOT 5030009 AT familiehaase DOT de> <20050612093308 DOT GF6568 AT calimero DOT vinschen DOT de>
Mime-Version: 1.0
In-Reply-To: <20050612093308.GF6568@calimero.vinschen.de>
User-Agent: Mutt/1.5.8i

On Sun, Jun 12, 2005 at 11:33:08AM +0200, Corinna Vinschen wrote:
>I see.  It seems the 3.4.x code is just assuming a bit too much when
>examining functions, whereas the 4.x implementation is a bit more careful.

AFAICT, the code was just plain wrong with gcc 3.4.4.  However, I found a bug
report where someone was reporting a similar problem and the reply was "Well,
you had aliasing problems.  What woudl you expect?" and, indeed, fixing the
aliasing problems seemed to fix the code generation problem.

It still is troubling that gcc 3.4.4 ended up using a completely wrong
place on the stack for a variable (after changing a static function to
an inline function).

cgf

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019