From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 108511 invoked by alias); 25 Aug 2017 10:33:26 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 106441 invoked by uid 89); 25 Aug 2017 10:33:24 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: smtp.polymtl.ca Received: from smtp.polymtl.ca (HELO smtp.polymtl.ca) (132.207.4.11) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 25 Aug 2017 10:33:23 +0000 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id v7PAXGVs001716 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 25 Aug 2017 06:33:21 -0400 Received: by simark.ca (Postfix, from userid 112) id 6BB231EA24; Fri, 25 Aug 2017 06:33:16 -0400 (EDT) Received: from simark.ca (localhost [127.0.0.1]) by simark.ca (Postfix) with ESMTP id 335321E043; Fri, 25 Aug 2017 06:33:15 -0400 (EDT) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 25 Aug 2017 10:33:00 -0000 From: Simon Marchi To: Pedro Alves Cc: Weimin Pan , gdb-patches@sourceware.org Subject: Re: [PATCH v2] break gdb build on 32-bit host with ADI support In-Reply-To: References: <1503624784-124602-1-git-send-email-weimin.pan@oracle.com> Message-ID: X-Sender: simon.marchi@polymtl.ca User-Agent: Roundcube Webmail/1.3.0 X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Fri, 25 Aug 2017 10:33:16 +0000 X-IsSubscribed: yes X-SW-Source: 2017-08/txt/msg00486.txt.bz2 On 2017-08-25 12:18, Pedro Alves wrote: > $subject should be "unbreak", I hope. :-) > > On 08/25/2017 02:33 AM, Weimin Pan wrote: > >> @@ -240,7 +242,7 @@ adi_normalize_address (CORE_ADDR addr) >> adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid)); >> >> if (ast.nbits) >> - return ((CORE_ADDR)(((long)addr << ast.nbits) >> ast.nbits)); >> + return (addr & ((1 << ast.nbits) - 1)) ^ (addr & (-1 >> >> ast.nbits)); > > How did you test this? Doesn't look right to me. > Also, "-1 >>" is still an implementation-defined signed > right shift. > > I _think_ this is what you want: > > /* Clear upper bits. */ > addr &= ((uint64_t) -1) >> ast.nbits; > > /* Sign extend. */ > CORE_ADDR signbit = (uint64_t) 1 << (64 - ast.nbits - 1); > return (addr ^ signbit) - signbit; > > I.e., with ast.nbits == 4: > > before: ffffffffffffffff > after: ffffffffffffffff > > before: f7ffffffffffffff > after: 07ffffffffffffff Since it's not trivial, I would suggest putting this operation in its own function and adding a unit-test for it. Simon