From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26937 invoked by alias); 26 Sep 2011 16:24:01 -0000 Received: (qmail 26873 invoked by uid 22791); 26 Sep 2011 16:23:57 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,TW_OV X-Spam-Check-By: sourceware.org Received: from mail-yi0-f47.google.com (HELO mail-yi0-f47.google.com) (209.85.218.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 26 Sep 2011 16:23:42 +0000 Received: by yia27 with SMTP id 27so4913403yia.20 for ; Mon, 26 Sep 2011 09:23:40 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.34.138 with SMTP id z10mr30576395pbi.105.1317054220587; Mon, 26 Sep 2011 09:23:40 -0700 (PDT) Received: by 10.68.55.101 with HTTP; Mon, 26 Sep 2011 09:23:40 -0700 (PDT) In-Reply-To: <201109261424.p8QEOtT1024571@d06av02.portsmouth.uk.ibm.com> References: <201109261424.p8QEOtT1024571@d06av02.portsmouth.uk.ibm.com> Date: Mon, 26 Sep 2011 18:02:00 -0000 Message-ID: Subject: Re: [patch, arm] Fix PR target/50305 (arm_legitimize_reload_address problem) From: Ramana Radhakrishnan To: Ulrich Weigand Cc: gcc-patches@gcc.gnu.org, rearnsha@arm.com, patches@linaro.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2011-09/txt/msg01627.txt.bz2 On 26 September 2011 15:24, Ulrich Weigand wrote: > Ramana Radhakrishnan wrote: >> On 9 September 2011 18:04, Ulrich Weigand wrote: >> > >> > In theory, LEGITIMIZE_RELOAD_ADDRESS could attempt to handle them by >> > substituting the equivalent constant and then reloading the result. >> > However, this might need additional steps (pushing to the constant poo= l, >> > reloading the constant pool address, ...) which would lead to signific= ant >> > duplication of code from core reload. =A0This doesn't seem worthwhile >> > at this point ... >> >> Thinking about it a bit more after our conversation, we do have the >> movw / movt instructions for armv7-a - why push this to the constant >> pool if we can rematerialize it ? =A0Finding a way to use them rather >> than pushing things out to the constant pool might be an interesting >> experiment for later .. > > Reload common code will already choose whatever the best option is > for reloading a constant, according to target hooks (legitimate_constant_p > and preferred_reload_class); it doesn't always push to the constant pool. > However, even on ARM there are currently certain cases where pushing to > the pool is necessary (floating point; some constants involving symbols). > I see your point. I parsed your last mail as it gets into the constant pool by default. If it does that's a separate problem. > > Is this sufficient, or should I test any other set of options as well? Could you run one set of tests with neon ? > >> Regarding the testcase - please add an -mfloat-abi=3Dsoft to the >> testcase so that it tests the specific case that failed in case the >> default configuration was with softfp. > > Just to clarify: in the presence of the other options that are already > in dg-options, the test case now fails (with the unpatched compiler) > for *any* setting of -mfloat-abi (hard, soft, or softfp). =A0Do you still > want me to add a specific setting to the test case? No the mfpu=3Dvfpv3 is fine. Instead of skipping I was wondering if we could prune the outputs to get this through all the testers we have. Otherwise this is OK. cheers Ramana > > Thanks, > Ulrich > > -- > =A0Dr. Ulrich Weigand > =A0GNU Toolchain for Linux on System z and Cell BE > =A0Ulrich.Weigand@de.ibm.com >