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 ABEAC3858C3A for ; Tue, 31 Aug 2021 03:11:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org ABEAC3858C3A Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 17V33afG123960; Mon, 30 Aug 2021 23:10:56 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3asac72k2m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 30 Aug 2021 23:10:56 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 17V33t4k126347; Mon, 30 Aug 2021 23:10:55 -0400 Received: from ppma01fra.de.ibm.com (46.49.7a9f.ip4.static.sl-reverse.com [159.122.73.70]) by mx0a-001b2d01.pphosted.com with ESMTP id 3asac72k24-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 30 Aug 2021 23:10:55 -0400 Received: from pps.filterd (ppma01fra.de.ibm.com [127.0.0.1]) by ppma01fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 17V31Zl1015146; Tue, 31 Aug 2021 03:10:53 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma01fra.de.ibm.com with ESMTP id 3aqcs8snc5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 31 Aug 2021 03:10:52 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 17V3AoDH50921846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 31 Aug 2021 03:10:50 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1FB2611C058; Tue, 31 Aug 2021 03:10:50 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3FB7711C01F; Tue, 31 Aug 2021 03:10:46 +0000 (GMT) Received: from KewenLins-MacBook-Pro.local (unknown [9.200.44.204]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 31 Aug 2021 03:10:45 +0000 (GMT) Subject: Re: Enable the vectorizer at -O2 for GCC 12 To: wschmidt@linux.ibm.com, Florian Weimer Cc: Jeff Law , "H.J. Lu" , Hongtao Liu , Segher Boessenkool , jakub@redhat.com, rearnsha@arm.com, richard.sandiford@arm.com, Premachandra.Mallappa@amd.com, gcc@gcc.gnu.org References: <87v93nozh7.fsf@oldenburg.str.redhat.com> <0e35169d-b9df-f665-dbc1-a3e76a3e7d8e@linux.ibm.com> From: "Kewen.Lin" Message-ID: <2ab5dd7f-3170-a0fc-e3e4-6376510f89ea@linux.ibm.com> Date: Tue, 31 Aug 2021 11:10:44 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <0e35169d-b9df-f665-dbc1-a3e76a3e7d8e@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: yLlOutCbmAS_Lddko478zC-bmqAGM20x X-Proofpoint-GUID: vvdNRKxCNRMurjXNyA8rL7tKjQNPA9b2 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.790 definitions=2021-08-30_06:2021-08-30, 2021-08-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 phishscore=0 mlxscore=0 malwarescore=0 adultscore=0 mlxlogscore=999 priorityscore=1501 spamscore=0 lowpriorityscore=0 bulkscore=0 impostorscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108310015 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, KAM_NUMSUBJECT, NICE_REPLY_A, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP 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@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, 31 Aug 2021 03:11:06 -0000 on 2021/8/30 下午10:11, Bill Schmidt wrote: > On 8/30/21 8:04 AM, Florian Weimer wrote: >> There has been a discussion, both off-list and on the gcc-help mailing >> list (“Why vectorization didn't turn on by -O2”, spread across several >> months), about enabling the auto-vectorizer at -O2, similar to what >> Clang does. >> >> I think the review concluded that the very cheap cost model should be >> used for that. >> >> Are there any remaining blockers? > > Hi Florian, > > I don't think I'd characterize it as having blockers, but we are continuing to investigate small performance issues that arise with very-cheap, including some things that regressed in GCC 12.  Kewen Lin is leading that effort.  Kewen, do you feel we have any major remaining concerns with this plan? > Hi Florian & Bill, There are some small performance issues like PR101944 and PR102054, and still two degraded bmks (P9 520.omnetpp_r -2.41% and P8 526.blender_r -1.31%) to be investigated/clarified, but since their performance numbers with separated loop and slp vectorization options look neutral, they are very likely noises. IMHO I don't think they are/will be blockers. So I think it's good to turn this on by default for Power. BR, Kewen