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 839913858D1E for ; Thu, 18 Aug 2022 17:35:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 839913858D1E 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 27IHYZrg020576; Thu, 18 Aug 2022 12:34:35 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 27IHYZjc020575; Thu, 18 Aug 2022 12:34:35 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Thu, 18 Aug 2022 12:34:35 -0500 From: Segher Boessenkool To: "Kewen.Lin" Cc: GCC Patches , David Edelsohn , AlanM Subject: Re: [PATCH v3] rs6000: Rework ELFv2 support for -fpatchable-function-entry* [PR99888] Message-ID: <20220818173435.GN25951@gate.crashing.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, 18 Aug 2022 17:35:39 -0000 Hi! On Thu, Aug 18, 2022 at 10:12:48AM +0800, Kewen.Lin wrote: > As PR99888 and its related show, the current support for > -fpatchable-function-entry on powerpc ELFv2 doesn't work > well with global entry existence. > + /* Emit the NOPs after local entry. */ Please do not say "NOPs". It is not an acronym. I know some of our documentation has this bug already, but please do not spread it further. The machine instruction is "nop", lowercase. Please fix this. So, this patch overloads the meaning of the two parameters here to have more meaning than explained in the documentation for the option. There isn't much that can be done about this, so adding some new option would only be extra work for everyone. But, could you add a line or two in the documentation? "For PowerPC with the ELFv2 ABI, there will be M nops before the local entry point, and N-M after", something like that? Segher