From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 89899 invoked by alias); 21 Apr 2015 15:24:04 -0000 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 Received: (qmail 89888 invoked by uid 89); 21 Apr 2015 15:24:03 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.7 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: paperclip.tbsaunde.org Received: from tbsaunde.org (HELO paperclip.tbsaunde.org) (66.228.47.254) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 21 Apr 2015 15:24:02 +0000 Received: from tsaunders-iceball.corp.tor1.mozilla.com (unknown [66.207.208.102]) by paperclip.tbsaunde.org (Postfix) with ESMTPSA id F1E8FC0A2; Tue, 21 Apr 2015 15:23:59 +0000 (UTC) Date: Tue, 21 Apr 2015 15:24:00 -0000 From: Trevor Saunders To: Jeff Law Cc: tbsaunde+gcc@tbsaunde.org, gcc-patches@gcc.gnu.org Subject: Re: [PATCH 03/12] more removal of ifdef HAVE_cc0 Message-ID: <20150421152357.GC9945@tsaunders-iceball.corp.tor1.mozilla.com> References: <1429622658-9034-1-git-send-email-tbsaunde+gcc@tbsaunde.org> <1429622658-9034-4-git-send-email-tbsaunde+gcc@tbsaunde.org> <553655D2.40200@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <553655D2.40200@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-SW-Source: 2015-04/txt/msg01206.txt.bz2 On Tue, Apr 21, 2015 at 07:51:14AM -0600, Jeff Law wrote: > On 04/21/2015 07:24 AM, tbsaunde+gcc@tbsaunde.org wrote: > >From: Trevor Saunders > > > >gcc/ChangeLog: > > > >2015-04-21 Trevor Saunders > > > > * combine.c (find_single_use): Remove HAVE_cc0 ifdef for code > > that is trivially ded on non cc0 targets. > > (simplify_set): Likewise. > > (mark_used_regs_combine): Likewise. > > * cse.c (new_basic_block): Likewise. > > (fold_rtx): Likewise. > > (cse_insn): Likewise. > > (cse_extended_basic_block): Likewise. > > (set_live_p): Likewise. > > * rtlanal.c (canonicalize_condition): Likewise. > > * simplify-rtx.c (simplify_binary_operation_1): Likewise. > OK. I find myself wondering if the conditionals should look like > if (HAVE_cc0 > && (whatever)) > > But I doubt it makes any measurable difference. It's something we can > always add in the future if we feel the need to avoid the runtime checks for > things that aren't ever going to happen on most modern targets. yeah, it seems reasonably likely the branch predictor can deal with this for us (I tried to ensure things handled this way didn't do much other than a compare). If not well that's what profiling is for :-) Trev > > jeff >