From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id 40C85385742A for ; Tue, 17 May 2022 06:19:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 40C85385742A Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24H4rxqH003191; Tue, 17 May 2022 06:19:20 GMT Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3g45389edb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 May 2022 06:19:20 +0000 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 24H6I2cY022252; Tue, 17 May 2022 06:19:18 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma06ams.nl.ibm.com with ESMTP id 3g23pjbpxx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 May 2022 06:19:18 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 24H6JGP347382966 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 May 2022 06:19:16 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1DFBB11C04C; Tue, 17 May 2022 06:19:16 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ECC3511C054; Tue, 17 May 2022 06:19:15 +0000 (GMT) Received: from [9.171.94.135] (unknown [9.171.94.135]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 17 May 2022 06:19:15 +0000 (GMT) Message-ID: <7c969c7e-d397-f066-dad0-969825179231@linux.ibm.com> Date: Tue, 17 May 2022 08:19:15 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: CFI for saved argument registers Content-Language: en-US To: Andreas Schwab , Andreas Krebbel via Gcc References: <7d266787-9a64-07e6-bf7b-1bd01119517c@linux.ibm.com> <87k0ala6eh.fsf@igel.home> From: Andreas Krebbel In-Reply-To: <87k0ala6eh.fsf@igel.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: opsuAGHAK3V3OvcbCBKdj6SUwCOnNXeV X-Proofpoint-GUID: opsuAGHAK3V3OvcbCBKdj6SUwCOnNXeV X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-17_01,2022-05-16_02,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxscore=0 malwarescore=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 spamscore=0 adultscore=0 mlxlogscore=999 clxscore=1011 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2205170035 X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 May 2022 06:19:26 -0000 On 5/16/22 16:39, Andreas Schwab wrote: > On Mai 16 2022, Andreas Krebbel via Gcc wrote: > >> The only way I see right now is adding a new reg note to invalidate >> the save information in the reg_save array in dwarf2cfi. >> >> Would this be acceptable? Is there perhaps an easier way to achieve that? > > Doesn't it work to use .cfi_remember_state/.cfi_restore_state? > This might work but I think also for that I would have to implement means to trigger it explicitely with an RTX somehow. Also I rather would avoid emitting special CFI for that purpose. I think the CFI I currently have (with more .cfi_offset's than .cfi_restore's) is valid. I only have to convince the validation step in dwarf2cfi to accept this. Therefore the idea was to introduce a new regnote to say that at a certain point it is intentional that there is no .cfi_restore for a register. The action in dwarf2cfi should only be to remove the reg from reg_save and be done with it. Bye, Andreas