From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by sourceware.org (Postfix) with ESMTP id E03763858429; Thu, 11 Aug 2022 13:49:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E03763858429 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=kernel.crashing.org Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 27BDmTDu028083; Thu, 11 Aug 2022 08:48:29 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 27BDmS5O028080; Thu, 11 Aug 2022 08:48:28 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Thu, 11 Aug 2022 08:48:28 -0500 From: Segher Boessenkool To: Jiufu Guo Cc: gcc-patches@gcc.gnu.org, dje.gcc@gmail.com, linkw@gcc.gnu.org Subject: Re: [PATCH] rs6000: Enable generate const through pli+pli+rldimi Message-ID: <20220811134828.GE25951@gate.crashing.org> References: <20220810071123.165157-1-guojiufu@linux.ibm.com> <20220810164306.GY25951@gate.crashing.org> <7ev8qzkkm6.fsf@pike.rch.stglabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7ev8qzkkm6.fsf@pike.rch.stglabs.ibm.com> User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-3.1 required=5.0 tests=BAYES_00, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=no 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, 11 Aug 2022 13:49:40 -0000 Hi! On Thu, Aug 11, 2022 at 08:52:49PM +0800, Jiufu Guo wrote: > Segher Boessenkool writes: > > On Wed, Aug 10, 2022 at 03:11:23PM +0800, Jiufu Guo wrote: > >> @@ -9659,7 +9659,7 @@ (define_split > >> ;; When non-easy constants can go in the TOC, this should use > >> ;; easy_fp_constant predicate. > >> (define_split > >> - [(set (match_operand:DI 0 "int_reg_operand_not_pseudo") > >> + [(set (match_operand:DI 0 "gpc_reg_operand") > >> (match_operand:DI 1 "const_int_operand"))] > >> "TARGET_POWERPC64 && num_insns_constant (operands[1], DImode) > 1" > >> [(set (match_dup 0) (match_dup 2)) > > > > This is a huge change. Do you have some indication that it helps / > > hurts / is neutral? Some reasoning why it is a good idea? > Thanks for this concern! I would do more check/test for this. > > The 'int_reg_operand_not_pseudo' cause this splitter only work after RA. > Using 'int_reg_operand_not_pseudo', the code sequence "pli+sldi+paddi" > can be used. Yes. Splitting early and to allowing pseudos is all good -- but this was disallowed for a reason, supposedly. Changing this now and then changing it back in a few weeks or months isn't progress :-/ Segher