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 332483858D3C for ; Wed, 16 Feb 2022 08:28:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 332483858D3C Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 21G8Hjdr039196; Wed, 16 Feb 2022 08:28:18 GMT Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3e8wms052v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 16 Feb 2022 08:28:18 +0000 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 21G8Ie6g040318; Wed, 16 Feb 2022 08:28:17 GMT Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 3e8wms0528-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 16 Feb 2022 08:28:17 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 21G8ErFR003448; Wed, 16 Feb 2022 08:28:15 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma04ams.nl.ibm.com with ESMTP id 3e64ha65fe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 16 Feb 2022 08:28:14 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 21G8SCOF47579572 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 16 Feb 2022 08:28:12 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A610611C05C; Wed, 16 Feb 2022 08:28:12 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6A4ED11C058; Wed, 16 Feb 2022 08:28:11 +0000 (GMT) Received: from [9.200.101.176] (unknown [9.200.101.176]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 16 Feb 2022 08:28:11 +0000 (GMT) Message-ID: <6fa8a608-0437-7cc2-79e2-d113e7199048@linux.ibm.com> Date: Wed, 16 Feb 2022 16:28:09 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [PATCH, rs6000] Remove TImode from mode iterator BOOL_128 [PR100694] Content-Language: en-US To: Segher Boessenkool Cc: gcc-patches , David , Bill Schmidt References: <9fb9370d-52ef-e7f8-54cf-c245aba14e62@linux.ibm.com> <20220214213650.GA614@gate.crashing.org> <540516b7-e112-22e1-d839-d5191a241b6a@linux.ibm.com> <20220215145602.GB614@gate.crashing.org> From: HAO CHEN GUI In-Reply-To: <20220215145602.GB614@gate.crashing.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 6aCGvmn67plJnPhzp3Ud-MkJ2O8RP8fQ X-Proofpoint-GUID: -2GPRCpDpbHSByVMRhPE1UJ1K552gZZ6 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-16_03,2022-02-14_04,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 malwarescore=0 bulkscore=0 priorityscore=1501 phishscore=0 impostorscore=0 mlxlogscore=883 adultscore=0 spamscore=0 lowpriorityscore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202160045 X-Spam-Status: No, score=-6.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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, 16 Feb 2022 08:28:21 -0000 Hi, On 15/2/2022 下午 10:56, Segher Boessenkool wrote: > On Tue, Feb 15, 2022 at 11:01:03AM +0800, HAO CHEN GUI wrote: > Hi! > >> On 15/2/2022 上午 5:36, Segher Boessenkool wrote: >>> On Wed, Feb 09, 2022 at 10:43:17AM +0800, HAO CHEN GUI wrote: >>> All that are arguments for expanding to split form, not for removing >>> TImode from the iterator. And you leave PTImode, which *always* is in >>> GPRs! >> >From my understanding, PTImode has limitation that it needs to be assigned >> with an even/odd register pair. So it can't be split before the reload pass. > > TImode is put in an even/odd pair always as well. What is special about > PTImode here? TI is allowed in any GPRs. TI can be placed in r3/r4 or r4/r5 (both odd/even and even/odd) while PTI can only be placed in r4/r5 (even/odd). So if we split PTI before reload,the constraint is broken then PTI can be placed in any GPRs, I think. > >> Currently it is split after reload.> > > This prevents almost all optimisations. Splits after reload should be a > last resort thing. They almost always cause bigger problems than what > they are meant to solve. There aren't many splitters that *have* to run > after RA! > >>> (You'll also have to show it is *correct*, you need to prove (or show it >>> really likely :-) ) that after this change there are no TImode things >>> generated anywhere (anywhere!) that are no longer handled now). >>> >> Yes, the TI may be generated after expand pass and causes ICEs. So how about >> creating two mode iterators? One is for expand which doesn't include TImode, >> another is for the split which include TImode and make TImode to be split >> as early as possible? > > You can also have the expanders fail for TImode? That gives you a good > place to put in a code comment as well ;-) > Yes, I will take it. > > Segher