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 1C3ED3858405 for ; Fri, 22 Jul 2022 18:18:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1C3ED3858405 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 26MIHD8E016882; Fri, 22 Jul 2022 13:17:13 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 26MIHDmc016881; Fri, 22 Jul 2022 13:17:13 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Fri, 22 Jul 2022 13:17:13 -0500 From: Segher Boessenkool To: "Kewen.Lin" Cc: GCC Patches , David Edelsohn , Peter Bergner Subject: Re: [PATCH] rs6000/test: Update some cases with -mdejagnu-tune Message-ID: <20220722181712.GO25951@gate.crashing.org> References: <4847b51d-dde2-916b-27aa-8e63518d66d2@linux.ibm.com> <20220721184806.GK25951@gate.crashing.org> <11061a26-e6db-2f61-065e-b1c9a32d3181@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <11061a26-e6db-2f61-065e-b1c9a32d3181@linux.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 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: Fri, 22 Jul 2022 18:18:15 -0000 On Fri, Jul 22, 2022 at 10:22:51AM +0800, Kewen.Lin wrote: > on 2022/7/22 02:48, Segher Boessenkool wrote: > > On Wed, Jul 20, 2022 at 05:31:11PM +0800, Kewen.Lin wrote: > >> As PR106345 shows, some test cases should be updated with > >> -mdejagnu-tune, since their test points are sensitive to > >> rs6000_tune, such as: group_ending_nop, loop align (ic), > >> float conversion cost etc. > > > > It does not make sense to require -mdejagnu-tune= if -mdejagnu-cpu= is > > already given? What is the failure case? > > > > I think cpu setting only sets tune setting when tune setting isn't > explicitly provided as: > > if (rs6000_tune_index >= 0) > tune_index = rs6000_tune_index; > else if (cpu_index >= 0) > rs6000_tune_index = tune_index = cpu_index; > > As PR106345 shows, GCC can use an explicit tune setting when it's > configured, even if there is one "-mdejagnu-cpu=", it doesn't > override the explicit given one, so we need one explicit > "-mdejagnu-tune=". And that is the problem. GCC's automatic setting is *not* an explicit option, not given by the user. --with-tune= should not result in adding an -mtune= option in the resulting compiler, it should not set command- line options. > Although the test case has adopted option "-mdejagnu-cpu=power7", but > the configured "--with-tune-64=power9" takes effect and make it > return align_loops instead of align_flags (5). And it should not do that. > >> This patch is to replace -mdejagnu-cpu with -mdejagnu-tune > >> or append -mdejagnu-tune (keep the original -mdejagnu-cpu > >> when it's required) accordingly. > > > > It is *always* required. Testcases with -mtune= but unspecified -mcpu= > > make no sense. > > The loop_align.c testings made me think if we know the insn count for > the loop on all cpus is in range (4,8] then the cpu setting doesn't matter. Sure, it probably works without -mcpu=, but it does not make sense :-) Only using -mtune= while not having -mcpu= serves no purpose in any "normal" use, so we shouldn't do that in the testsuite either. > > This should only make a difference if you have -mtune= in your > > RUNTEST_FLAGS, and you shouldn't do silly things like that. I suspect > > you see it in other cases, and those are actual bugs then, that need > > actual fixing instead of sweeping under the carper. > > Unfortunately it's due to the explicit tune setting in configuration. So that needs some actual fixes. Something in how --with-tune= works is suboptimal? > > The testcase suggests this is with a compiler configured with > > --with-cpu= --with-tune=, which should just work, and -mcpu= should > > override both of those! > > Unfortunately -mcpu= (-mdejagnu-cpu=) doesn't actually override here. ... or that. Segher