From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29023 invoked by alias); 31 Jan 2015 20:19:36 -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 Received: (qmail 28876 invoked by uid 48); 31 Jan 2015 20:19:31 -0000 From: "segher at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/63577] [4.8/4.9/5 Regression]: Huge compile time and memory usage with -O and not -fPIC Date: Sat, 31 Jan 2015 20:19:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 4.9.1 X-Bugzilla-Keywords: compile-time-hog, memory-hog X-Bugzilla-Severity: normal X-Bugzilla-Who: segher at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 6.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-01/txt/msg03649.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63577 --- Comment #10 from Segher Boessenkool --- Also note that doing GC during the pass will not reduce the compile time or the amount of garbage created at all, so won't fix the actual problem; it does of course make it more bearable on smaller machines. I'll have another look at what causes this; from what I remember last time I looked there simply *are* very many opportunities to combine some insns (most of which fail, maybe we could short-circuit some).