From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9541 invoked by alias); 5 Mar 2011 00:18:59 -0000 Received: (qmail 9527 invoked by uid 22791); 5 Mar 2011 00:18:55 -0000 X-SWARE-Spam-Status: No, hits=-2.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 05 Mar 2011 00:18:49 +0000 From: "steven at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/37916] [4.3/4.4/4.5/4.6 Regression] SSA names causing register pressure; unnecessarily many simultaneously "live" names. X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: steven at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P5 X-Bugzilla-Assigned-To: hp at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.3.6 X-Bugzilla-Changed-Fields: CC Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Sat, 05 Mar 2011 00:18:00 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-03/txt/msg00471.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37916 Steven Bosscher changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |steven at gcc dot gnu.org --- Comment #19 from Steven Bosscher 2011-03-05 00:18:29 UTC --- (In reply to comment #11) > (In reply to comment #10) > > Is scheduling before reload enabled for your target? If not can you try > > -fschedule-insns1? > > No such option, I presume you mean -fschedule-insns. But, as there's no > scheduler description defined for the architecture, all I get is of course: > warning: instruction scheduling not supported on this target machine > with no difference in the output with -O2 -march=v10 -mno-mul-bug-workaround > -fno-ivopts -fno-reorder-blocks -fno-gcse. > > Besides, scheduling would move uses away from definitions, not closer to them. > :) Also, if this is meant as a permanent solution, that pass seems a bit late. Random thought on this PR: With a scheduler description, -fschedule-insns -fsched-pressure may help. Is there a reason why there is no scheduler description?