From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3592 invoked by alias); 19 Nov 2002 15:26:08 -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 3562 invoked by uid 71); 19 Nov 2002 15:26:05 -0000 Date: Mon, 25 Nov 2002 15:36:00 -0000 Message-ID: <20021119152605.3558.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Wolfgang Bangerth Subject: RE: c++/8543: bus error with 2 word alignments Reply-To: Wolfgang Bangerth X-SW-Source: 2002-11/txt/msg00957.txt.bz2 List-Id: The following reply was made to PR c++/8543; it has been noted by GNATS. From: Wolfgang Bangerth To: Massimo Ravasi Cc: gcc-gnats@gcc.gnu.org Subject: RE: c++/8543: bus error with 2 word alignments Date: Tue, 19 Nov 2002 09:25:53 -0600 (CST) Massimo, alignment issues are generally something that differs between processors and operating systems. Some processors cannot load doubles that are not aligned, some can. The same may apply to long long data types, but the alignment requirements of types of the same length are not necessarily the same. If a processor is told to load data from an address that is not properly aligned, it will generate a bus error. This is what you are seeing. Since alignment issues are platform dependent, it is only sensible to have the flag you describe on certain platforms only. This being said, since I don't know the requirements SunOS/SPARC has on long long data types, I cannot help you more on this. Some Sparc maintainer would have to help out here. Accessing data at a lower alignment is certainly suspicious. Regards Wolfgang ------------------------------------------------------------------------- Wolfgang Bangerth email: bangerth@ticam.utexas.edu www: http://www.ticam.utexas.edu/~bangerth