From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26340 invoked by alias); 23 Apr 2002 23:16:12 -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 26311 invoked by uid 71); 23 Apr 2002 23:16:07 -0000 Date: Tue, 23 Apr 2002 16:16:00 -0000 Message-ID: <20020423231607.26299.qmail@sources.redhat.com> To: echristo@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: cgd@broadcom.com Subject: Re: libstdc++/5625: exception unwinding creates invalid pointer o n mips Reply-To: cgd@broadcom.com X-SW-Source: 2002-04/txt/msg01229.txt.bz2 List-Id: The following reply was made to PR libstdc++/5625; it has been noted by GNATS. From: cgd@broadcom.com To: echristo@redhat.com Cc: "Ed Maste" , "'echristo@gcc.gnu.org'" , "'gcc-bugs@gcc.gnu.org'" , "'gcc-prs@gcc.gnu.org'" , "'gcc-gnats@gcc.gnu.org'" Subject: Re: libstdc++/5625: exception unwinding creates invalid pointer o n mips Date: 23 Apr 2002 16:07:19 -0700 Eric asked me a further question off-list, and I responded: > [I believe] The problem is that: > > typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__))); > > So the cast to _Unwind_Ptr makes the 32-bit result unsigned, and the > promotion to the 64-bit _Unwind_Word happens therefore to zero extend, > rather than sign extend. > > If _Unwind_Ptr were signed, the right thing should happen. (iirc; i > seem to recall having discussed this with Ed previously [and him > having confirmed that result, but I may be mistaken].) chris