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 3CA823858C60; Wed, 8 Dec 2021 05:54:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3CA823858C60 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1B82Ng7j011033; Wed, 8 Dec 2021 05:54:50 GMT Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3ctkvq3108-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Dec 2021 05:54:50 +0000 Received: from m0127361.ppops.net (m0127361.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 1B85S9AL002671; Wed, 8 Dec 2021 05:54:50 GMT Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com with ESMTP id 3ctkvq30yy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Dec 2021 05:54:49 +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 1B85qroT003706; Wed, 8 Dec 2021 05:54:48 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma06ams.nl.ibm.com with ESMTP id 3cqykjc7f7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Dec 2021 05:54:48 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1B85sisf29884824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 Dec 2021 05:54:45 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DD37A52050; Wed, 8 Dec 2021 05:54:44 +0000 (GMT) Received: from genoa.aus.stglabs.ibm.com (unknown [9.40.192.157]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 7D7945204F; Wed, 8 Dec 2021 05:54:43 +0000 (GMT) From: Xionghu Luo To: gcc-patches@gcc.gnu.org Cc: segher@kernel.crashing.org, dje.gcc@gmail.com, wschmidt@linux.ibm.com, guojiufu@linux.ibm.com, linkw@gcc.gnu.org, hubicka@kam.mff.cuni.cz, richard.guenther@gmail.com, Xionghu Luo Subject: [PATCH 2/3] Fix incorrect loop exit edge probability [PR103270] Date: Tue, 7 Dec 2021 23:54:15 -0600 Message-Id: <20211208055416.1415283-3-luoxhu@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211208055416.1415283-1-luoxhu@linux.ibm.com> References: <20211208055416.1415283-1-luoxhu@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: Xp2As9Q4dUjwgWL2NNiMZLbyznwgfr18 X-Proofpoint-ORIG-GUID: GNafevTR1IeFYF2M1J6ZyDwGeE3KFNFT X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2021-12-08_01,2021-12-06_02,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 mlxlogscore=926 phishscore=0 impostorscore=0 adultscore=0 spamscore=0 mlxscore=0 clxscore=1015 bulkscore=0 suspectscore=0 priorityscore=1501 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2112080038 X-Spam-Status: No, score=-11.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_MSPIKE_H4, 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-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, 08 Dec 2021 05:54:52 -0000 r12-4526 cancelled jump thread path rotates loop. It exposes a issue in profile-estimate when predict_extra_loop_exits, outer loop's exit edge is marked as inner loop's extra loop exit and set with incorrect prediction, then a hot inner loop will become cold loop finally through optimizations, this patch add loop check when searching extra exit edges to avoid unexpected predict_edge from predict_paths_for_bb. Regression tested on P8LE, OK for master? gcc/ChangeLog: PR middle-end/103270 * predict.c (predict_extra_loop_exits): Add loop parameter. (predict_loops): Call with loop argument. gcc/testsuite/ChangeLog: PR middle-end/103270 * gcc.dg/pr103270.c: New test. --- gcc/predict.c | 10 ++++++---- gcc/testsuite/gcc.dg/pr103270.c | 19 +++++++++++++++++++ 2 files changed, 25 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr103270.c diff --git a/gcc/predict.c b/gcc/predict.c index 3cb4e3c0eb5..5b6e0cf722b 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -1859,7 +1859,7 @@ predict_iv_comparison (class loop *loop, basic_block bb, exits to predict them using PRED_LOOP_EXTRA_EXIT. */ static void -predict_extra_loop_exits (edge exit_edge) +predict_extra_loop_exits (class loop *loop, edge exit_edge) { unsigned i; bool check_value_one; @@ -1912,12 +1912,14 @@ predict_extra_loop_exits (edge exit_edge) continue; if (EDGE_COUNT (e->src->succs) != 1) { - predict_paths_leading_to_edge (e, PRED_LOOP_EXTRA_EXIT, NOT_TAKEN); + predict_paths_leading_to_edge (e, PRED_LOOP_EXTRA_EXIT, NOT_TAKEN, + loop); continue; } FOR_EACH_EDGE (e1, ei, e->src->preds) - predict_paths_leading_to_edge (e1, PRED_LOOP_EXTRA_EXIT, NOT_TAKEN); + predict_paths_leading_to_edge (e1, PRED_LOOP_EXTRA_EXIT, NOT_TAKEN, + loop); } } @@ -2008,7 +2010,7 @@ predict_loops (void) ex->src->index, ex->dest->index); continue; } - predict_extra_loop_exits (ex); + predict_extra_loop_exits (loop, ex); if (number_of_iterations_exit (loop, ex, &niter_desc, false, false)) niter = niter_desc.niter; diff --git a/gcc/testsuite/gcc.dg/pr103270.c b/gcc/testsuite/gcc.dg/pr103270.c new file mode 100644 index 00000000000..819310e360e --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr103270.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-profile_estimate" } */ + +void test(int a, int* i) +{ + for (; a < 5; ++a) + { + int b = 0; + int c = 0; + for (; b != -11; b--) + for (int d = 0; d ==0; d++) + { + *i += c & a; + c = b; + } + } +} + +/* { dg-final { scan-tree-dump-not "extra loop exit heuristics of edge\[^:\]*:" "profile_estimate"} } */ -- 2.25.1