From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id CCF3E385800B; Thu, 28 Jul 2022 12:53:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org CCF3E385800B Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 26SCntoZ025152; Thu, 28 Jul 2022 12:53:11 GMT Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3hkttc83bf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 28 Jul 2022 12:53:10 +0000 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 26SCodOV028733; Thu, 28 Jul 2022 12:53:10 GMT Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3hkttc83ax-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 28 Jul 2022 12:53:10 +0000 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 26SCnp0w025617; Thu, 28 Jul 2022 12:53:09 GMT Received: from b01cxnp22036.gho.pok.ibm.com (b01cxnp22036.gho.pok.ibm.com [9.57.198.26]) by ppma03dal.us.ibm.com with ESMTP id 3hg978yav7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 28 Jul 2022 12:53:09 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 26SCr83O15597824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 28 Jul 2022 12:53:08 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9CF67AC064; Thu, 28 Jul 2022 12:53:08 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 687D0AC05B; Thu, 28 Jul 2022 12:53:08 +0000 (GMT) Received: from pike (unknown [9.5.12.127]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTPS; Thu, 28 Jul 2022 12:53:08 +0000 (GMT) From: Jiufu Guo To: Segher Boessenkool Cc: gcc-patches@gcc.gnu.org, dje.gcc@gmail.com, linkw@gcc.gnu.org Subject: Re: [PATCH V1] HIGH part of symbol ref is invalid for constant pool References: <20220719143054.82832-1-guojiufu@linux.ibm.com> <20220726213621.GB25951@gate.crashing.org> Date: Thu, 28 Jul 2022 20:53:04 +0800 In-Reply-To: <20220726213621.GB25951@gate.crashing.org> (Segher Boessenkool's message of "Tue, 26 Jul 2022 16:36:22 -0500") Message-ID: <7emtctmma7.fsf@pike.rch.stglabs.ibm.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: af1RmBPO3Nd9nN68uUo_4LqykW6lvqov X-Proofpoint-GUID: NNISyExfSGDeYwnd7davjJXEUdCWd5rM X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 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=2022-07-28_05,2022-07-28_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 suspectscore=0 priorityscore=1501 mlxscore=0 malwarescore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 bulkscore=0 adultscore=0 clxscore=1015 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2207280055 X-Spam-Status: No, score=-6.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, KAM_SHORT, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP 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: Thu, 28 Jul 2022 12:53:13 -0000 Segher Boessenkool writes: Thanks a lot for your review! > Hi! > > On Tue, Jul 19, 2022 at 10:30:54PM +0800, Jiufu Guo wrote: >> In patch https://gcc.gnu.org/pipermail/gcc-patches/2022-July/597712.html, >> test case was not added. After more check, a testcase is added for it. >> >> The high part of the symbol address is invalid for the constant pool. > > Invalid, how so? Is there a PR related here? Thanks, I just opened PR106460 for this issue. > > But it is not particularly useful ever, either: we do not know two > different addresses will have the same HIGH unless we know the exact > address, and then we don't need HIGH anyway. > >> * config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem): >> Return true for HIGH code rtx. > > * config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem): Return true > for HIGH code rtx. > > Please don't wrap lines early: changelog lines are 80 positions long, > including the leading tab (which counts as eight positions). Thanks for your suggestion! > >> static bool >> rs6000_cannot_force_const_mem (machine_mode mode ATTRIBUTE_UNUSED, rtx x) >> { >> - if (GET_CODE (x) == HIGH >> - && GET_CODE (XEXP (x, 0)) == UNSPEC) >> + /* High part of a symbol ref/address can not be put into constant pool. e.g. >> + (high:DI (symbol_ref:DI ("var")..)) or >> + (high:DI (unspec:DI [(symbol_ref/u:DI ("*.LC0")..) >> + (high:DI (const:DI (plus:DI (symbol_ref:DI ("xx")) (const_int 12)))). */ >> + if (GET_CODE (x) == HIGH) >> return true; > > I'm not sure the new comment is helpful at all? Are these examples of > where the compiler (or assembler perhaps) will choke? I debugged this function with the source code from GCC bootstrap and regtest, and then figured out these examples. In the next version patch, I updated the comments a little, hope that is more meaningful. :-) > >> --- /dev/null >> +++ b/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c >> @@ -0,0 +1,11 @@ >> +/* { dg-do compile { target powerpc*-*-* } } */ > > Everything in gcc.target/powerpc is target powerpc* always. Thanks! I would remove this line. > >> +/* { dg-options "-O1 -mdejagnu-cpu=power10" } */ >> +/* (high:DI (symbol_ref:DI ("var_48")..))) should not cause ICE. */ > > Ah, so there is an ICE, I see. Please open a PR, and mention that in > the testcase as well as in the commit message and changelog. Thanks! I should open PR ealry :) In the updated patch, a testcase is named as pr106460.c, and memtioned in commit message and changelog. > > I agree with what the patch does, it just needs a little more work :-) I submitted a new version patch: https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598980.html Thanks in advance for any comments! BR, Jeff(Jiufu) > > > Segher