From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21631 invoked by alias); 22 Oct 2008 22:38:53 -0000 Received: (qmail 21133 invoked by uid 48); 22 Oct 2008 22:37:30 -0000 Date: Wed, 22 Oct 2008 22:38:00 -0000 Subject: [Bug other/37897] New: decNumber functions break strict-aliasing rules X-Bugzilla-Reason: CC Message-ID: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "janis at gcc dot gnu dot org" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2008-10/txt/msg01494.txt.bz2 The decNumber package in GCC provides support for decimal floating point arithmetic in the compiler and, for the DPD format, in libgcc's runtime support for decimal float. Some of the code in decNumber violates C's strict-aliasing rules and has resulted in warnings for quite some time. Some of that code has different results since the addition of patch r136695, leading to the failure of test gcc.dg/dfp/convert-int-max.c. The code in question has undefined behavior so I can't say that it is miscompiled, only that the results are different. I'm testing a patch that quiets all of the warnings about dereferencing type-punned pointers with very few changes to the decNumber code, mostly changes to data types and access macros. This PR is to keep track of the change because the decNumber code from GCC is also used by the GDB project and a branch in EGLIBC. -- Summary: decNumber functions break strict-aliasing rules Product: gcc Version: 4.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: janis at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37897