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 8F74C385700D for ; Mon, 2 Aug 2021 23:44:52 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 8F74C385700D Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=fail 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 172NhpcS018525; Mon, 2 Aug 2021 18:43:52 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 172NhpLE018524; Mon, 2 Aug 2021 18:43:51 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 2 Aug 2021 18:43:51 -0500 From: Segher Boessenkool To: Bill Schmidt Cc: will schmidt , gcc-patches@gcc.gnu.org Subject: Re: [PATCH 42/55] rs6000: Handle gimple folding of target built-ins Message-ID: <20210802234351.GS1583@gate.crashing.org> References: <91c28178ab7912df2a6b8f8299ef6563a69781b5.1623941442.git.wschmidt@linux.ibm.com> <60e83e75-6c86-2c78-492b-1d56ac1857a6@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, TXREP, T_SPF_HELO_PERMERROR, T_SPF_PERMERROR autolearn=no 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: Mon, 02 Aug 2021 23:44:53 -0000 On Mon, Aug 02, 2021 at 08:31:43AM -0500, Bill Schmidt wrote: > Interestingly, when the quadword compares are expanded at GIMPLE time, > we generate worse code involving individual 64-bit compares.  For the > time being, I will not expand these at GIMPLE time; independently, this > bears looking at to see why expressions like (uint128_1 < uint128_2) > will generate poor code. Details like this should probably not be exposed before RTL anyway? Everything else is at a more abstracted level as well before expand? It will be interesting to see what causes the worse code though :-) Segher