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 BBC4D3858012 for ; Mon, 15 Aug 2022 08:33:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BBC4D3858012 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27F86TMa028198; Mon, 15 Aug 2022 08:33:30 GMT Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3hyfer4sgs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 15 Aug 2022 08:33:29 +0000 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 27F8Ml7o010064; Mon, 15 Aug 2022 08:33:29 GMT Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3hyfer4sg6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 15 Aug 2022 08:33:28 +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 27F8KJgA017080; Mon, 15 Aug 2022 08:33:26 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 3hx3k99te3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 15 Aug 2022 08:33:26 +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 27F8XONd32244092 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 15 Aug 2022 08:33:24 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0FAA611C052; Mon, 15 Aug 2022 08:33:24 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5B53A11C058; Mon, 15 Aug 2022 08:33:22 +0000 (GMT) Received: from [9.197.235.82] (unknown [9.197.235.82]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 15 Aug 2022 08:33:22 +0000 (GMT) Message-ID: <0122f231-450a-1280-ba23-fb7127412aa9@linux.ibm.com> Date: Mon, 15 Aug 2022 16:33:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH] predict: Adjust optimize_function_for_size_p [PR105818] Content-Language: en-US From: "Kewen.Lin" To: Jan Hubicka Cc: GCC Patches , Richard Sandiford , Segher Boessenkool , Richard Biener References: <23b4998b-bbe6-b052-d7f5-5304ee0f46a3@linux.ibm.com> <77f90ce9-8c36-e442-03b6-82d5450da2a1@linux.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: ucNAtdHyCYVL3scfjGkVW4SJkAP3BfUD X-Proofpoint-ORIG-GUID: 8eyh497OFK3M46b7fRnElltm9KAiotOe X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-15_06,2022-08-11_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 impostorscore=0 bulkscore=0 priorityscore=1501 adultscore=0 spamscore=0 suspectscore=0 mlxscore=0 phishscore=0 malwarescore=0 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2208150029 X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, 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-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: Mon, 15 Aug 2022 08:33:36 -0000 on 2022/7/11 11:42, Kewen.Lin wrote: > on 2022/6/15 14:20, Kewen.Lin wrote: >> Hi Honza, >> >> Thanks for the comments! Some replies are inlined below. >> >> on 2022/6/14 19:37, Jan Hubicka wrote: >>>> Hi, >>>> >>>> Function optimize_function_for_size_p returns OPTIMIZE_SIZE_NO >>>> if func->decl is not null but no cgraph node is available for it. >>>> As PR105818 shows, this could give unexpected result. For the >>>> case in PR105818, when parsing bar decl in function foo, the cfun >>>> is a function structure for foo, for which there is none cgraph >>>> node, so it returns OPTIMIZE_SIZE_NO. But it's incorrect since >>>> the context is to optimize for size, the flag optimize_size is >>>> true. >>>> >>>> The patch is to make optimize_function_for_size_p to check >>>> optimize_size as what it does when func->decl is unavailable. >>>> >>>> One regression failure got exposed on aarch64-linux-gnu: >>>> >>>> PASS->FAIL: gcc.dg/guality/pr54693-2.c -Os \ >>>> -DPREVENT_OPTIMIZATION line 21 x == 10 - i >>>> >>>> The difference comes from the macro LOGICAL_OP_NON_SHORT_CIRCUIT >>>> used in function fold_range_test during c parsing, it uses >>>> optimize_function_for_speed_p which is equal to the invertion >>>> of optimize_function_for_size_p. At that time cfun->decl is valid >>>> but no cgraph node for it, w/o this patch function >>>> optimize_function_for_speed_p returns true eventually, while it >>>> returns false with this patch. Since the command line option -Os >>>> is specified, there is no reason to interpret it as "for speed". >>>> I think this failure is expected and adjust the test case >>>> accordingly. >>>> >>>> Is it ok for trunk? >>>> >>>> BR, >>>> Kewen >>>> ----- >>>> >>>> PR target/105818 >>>> >>>> gcc/ChangeLog: >>>> >>>> * predict.cc (optimize_function_for_size_p): Check optimize_size when >>>> func->decl is valid but its cgraph node is unavailable. >>>> >>>> gcc/testsuite/ChangeLog: >>>> >>>> * gcc.target/powerpc/pr105818.c: New test. >>>> * gcc.dg/guality/pr54693-2.c: Adjust for aarch64. >>>> --- >>>> gcc/predict.cc | 2 +- >>>> gcc/testsuite/gcc.dg/guality/pr54693-2.c | 2 +- >>>> gcc/testsuite/gcc.target/powerpc/pr105818.c | 9 +++++++++ >>>> 3 files changed, 11 insertions(+), 2 deletions(-) >>>> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr105818.c >>>> >>>> diff --git a/gcc/predict.cc b/gcc/predict.cc >>>> index 5734e4c8516..6c60a973236 100644 >>>> --- a/gcc/predict.cc >>>> +++ b/gcc/predict.cc >>>> @@ -268,7 +268,7 @@ optimize_function_for_size_p (struct function *fun) >>>> cgraph_node *n = cgraph_node::get (fun->decl); >>>> if (n) >>>> return n->optimize_for_size_p (); >>>> - return OPTIMIZE_SIZE_NO; >>>> + return optimize_size ? OPTIMIZE_SIZE_MAX : OPTIMIZE_SIZE_NO; >>> >>> We could also do (opt_for_fn (cfun->decl, optimize_size) that is >>> probably better since one can change optimize_size with optimization >>> attribute. >> >> Good point, agree! >> >>> However I think in most cases we check for optimize_size early I think >>> we are doing something wrong, since at that time htere is no profile >>> available. Why exactly PR105818 hits the flag change issue? >> >> For PR105818, the reason why the flag changs is that: >> >> Firstly, the inconsistent flag is OPTION_MASK_SAVE_TOC_INDIRECT bit >> of rs6000_isa_flags_explicit, it's set as below: >> >> /* If we can shrink-wrap the TOC register save separately, then use >> -msave-toc-indirect unless explicitly disabled. */ >> if ((rs6000_isa_flags_explicit & OPTION_MASK_SAVE_TOC_INDIRECT) == 0 >> && flag_shrink_wrap_separate >> && optimize_function_for_speed_p (cfun)) >> rs6000_isa_flags |= OPTION_MASK_SAVE_TOC_INDIRECT; >> >> Initially, rs6000 initialize target_option_default_node with >> OPTION_MASK_SAVE_TOC_INDIRECT unset, at that time cfun is NULL >> and optimize_size is true. >> >> Later, when c parser handling function foo, it builds target >> option node as target_option_default_node in function >> handle_optimize_attribute, it does global option saving and >> verifying there as well, at that time the cfun is NULL, no >> issue is found. And function store_parm_decls allocates >> struct_function for foo then, cfun becomes function struct >> for foo, when c parser continues to handle the decl bar in >> foo, function handle_optimize_attribute works as before, >> tries to restore the target options at the end, it calls >> targetm.target_option.restore (rs6000_function_specific_restore) >> which calls function rs6000_option_override_internal again, >> at this time the cfun is not NULL while there is no cgraph >> node for its decl, optimize_function_for_speed_p returns true >> and gets the OPTION_MASK_SAVE_TOC_INDIRECT bit of flag >> rs6000_isa_flags set unexpectedly. It becomes inconsistent >> as the one saved previously. >> >> IMHO, both contexts of global and function decl foo here hold >> optimize_size, function optimize_function_for_speed_p should >> not return true anyway. >> >> btw, the aarch64 failed case also gets the unexpected >> result for optimize_function_for_speed_p during c parsing >> (fold_range_test <- ... <- c_parser_condition). >> >> IIUC, in parsing time we don't have the profile information >> available. >> > > Hi Honza, > > Does the above explanation sound reasonable to you? > Hi Honza, Gentle ping ... BR, Kewen