From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by sourceware.org (Postfix) with ESMTPS id 3F90F385BF92 for ; Wed, 1 Apr 2020 19:16:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 3F90F385BF92 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 031J3olI106096; Wed, 1 Apr 2020 15:16:58 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 304hjam8en-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Apr 2020 15:16:58 -0400 Received: from m0098394.ppops.net (m0098394.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 031J49R3107692; Wed, 1 Apr 2020 15:16:57 -0400 Received: from ppma01dal.us.ibm.com (83.d6.3fa9.ip4.static.sl-reverse.com [169.63.214.131]) by mx0a-001b2d01.pphosted.com with ESMTP id 304hjam8e5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Apr 2020 15:16:57 -0400 Received: from pps.filterd (ppma01dal.us.ibm.com [127.0.0.1]) by ppma01dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 031JF16C013460; Wed, 1 Apr 2020 19:16:56 GMT Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by ppma01dal.us.ibm.com with ESMTP id 301x77m1q3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Apr 2020 19:16:56 +0000 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 031JGt5V59965824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 1 Apr 2020 19:16:55 GMT Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 33D3F6E053; Wed, 1 Apr 2020 19:16:55 +0000 (GMT) Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A9CA36E04E; Wed, 1 Apr 2020 19:16:54 +0000 (GMT) Received: from ibm-tinman.the-meissners.org (unknown [9.80.207.254]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTPS; Wed, 1 Apr 2020 19:16:54 +0000 (GMT) Date: Wed, 1 Apr 2020 15:16:52 -0400 From: Michael Meissner To: Segher Boessenkool Cc: will schmidt , Michael Meissner , gcc-patches@gcc.gnu.org, David Edelsohn Subject: Re: [PATCH], Make PowerPC -mcpu=future enable -mpcrel on linux ELFv2 Message-ID: <20200401191652.GA12337@ibm-tinman.the-meissners.org> Mail-Followup-To: Michael Meissner , Segher Boessenkool , will schmidt , gcc-patches@gcc.gnu.org, David Edelsohn References: <20200328013146.GA26011@ibm-tinman.the-meissners.org> <20200330225149.GU22482@gate.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200330225149.GU22482@gate.crashing.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-04-01_04:2020-03-31, 2020-04-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 impostorscore=0 suspectscore=0 adultscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 clxscore=1015 spamscore=0 mlxlogscore=999 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004010151 X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Apr 2020 19:17:00 -0000 On Mon, Mar 30, 2020 at 05:51:49PM -0500, Segher Boessenkool wrote: > Hi! > > On Mon, Mar 30, 2020 at 12:50:43PM -0500, will schmidt wrote: > > On Fri, 2020-03-27 at 21:31 -0400, Michael Meissner via Gcc-patches > > > * config/rs6000/rs6000.c (PCREL_SUPPORTED_BY_OS): New macro. > > > (rs6000_option_override_internal): Set the -mprefixed and > > > -mpcrel > > > options for -mcpu=future if these options can be used. > > > > > s/can be used/are supported by the platform/ ? > > The code says > /* Enable -mprefixed by default on 64-bit 'future' systems. */ > /* If the OS has support for PC-relative relocations, enable it now. */ > and something like that should go in the changelog as well (two lines in > changelog is fine -- they are two hunks of patch as well, anyway!) Ok. > > > +/* Enable default support for PC-relative addressing on the 'future' > > > system if > > > + we can use the PC-relative instructions. Currently this support > > > only exits > > > > exists > > > > > + for the ELF v2 object file format using the medium code > > > model. */ > > > > should that be "s/object file format/ABI/" ? > > Yes. Ok. > > > -/* Support for a future processor's features. Do not enable -mpcrel > > > until it > > > - is fully functional. */ > > > +/* Support for a future processor's features. We do not set -mpcrel > > > or > > > + -mprefixed here. These bits are set in rs6000_option_override if > > > the system > > > + supports those options. */ > > > > I'm still not sure the comment here is actually necessary, there are > > many other places where we also do not set -mpcrel or -mprefixed. If > > history of the code here requires a hint to point at those options > > being set in rs6000_option_override, then it's fine. > > If you really need to say you do *not* do something, you should say why > not. Without that it only leaves more questions to the reader :-) > > Hopefully that then also explains why the reader should care about this. Given this comment is against Will's comment, and not the original code, is there anything I need to do to the code (other than the ChangeLog and adjusting object file format to ABI? -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meissner@linux.ibm.com, phone: +1 (978) 899-4797