From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20564 invoked by alias); 7 Apr 2003 20:06:01 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 20527 invoked by uid 71); 7 Apr 2003 20:06:01 -0000 Date: Mon, 07 Apr 2003 20:06:00 -0000 Message-ID: <20030407200601.20526.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Andreas Schwab Subject: Re: c/10339: strncmp generates imPure code Reply-To: Andreas Schwab X-SW-Source: 2003-04/txt/msg00304.txt.bz2 List-Id: The following reply was made to PR optimization/10339; it has been noted by GNATS. From: Andreas Schwab To: Michael Ubell Cc: Falk Hueffner , Wolfgang Bangerth , gcc-bugs@gcc.gnu.org, gcc-gnats@gcc.gnu.org Subject: Re: c/10339: strncmp generates imPure code Date: Mon, 07 Apr 2003 22:04:08 +0200 Michael Ubell writes: |> Do you mean you want me to set up a case where it runs off the |> end of memory? Yes. |> I think it is sufficient that it is reading memory |> that is not allocated, no? No, it is not. |> If you change the length of the string |> in the example you can see that it will read more unallocated |> memory. You haven't provided any evidence yet. The provided test case is correctly translated for the given platform. |> Do you have some reason why reading arbirary unallocated |> memory is acceptable? I don't see how the alignment is an issue. It is. Memory returned by malloc is required to be correctly aligned for any type. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."