From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29750 invoked by alias); 22 Jan 2014 15:01:19 -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 29702 invoked by uid 48); 22 Jan 2014 15:01:14 -0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/59811] [4.8/4.9 Regression] Huge increase in memory usage and compile time in combine Date: Wed, 22 Jan 2014 15:01:00 -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: 4.8.2 X-Bugzilla-Keywords: compile-time-hog, memory-hog X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.8.3 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc 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: 2014-01/txt/msg02351.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59811 Jakub Jelinek changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #3 from Jakub Jelinek --- Started with r190594 which apparently made big changes in some of the GIMPLE passes, e.g. the optimized dump linecount went down from 65782 lines (r190593) to 52107 lines (r190594). But, for some reason that change results in uncomparably more log links and combiner opportunities. In -fdump-rtl-combine-details dump, 'Successfully match' matches went up from 9742 up to 3921927, and 'Failed to match' matches went up from 53193 to 22538586. So, the combiner success rate is approximately the same, around 17.5%, just on 400 times more opportunities. For GIMPLE passes, looking just at the sizes of the gimple dumps, until esra the sizes are the same, from fre1 the dump with r190594 is slightly to significantly larger than corresponding r190593 dump until crited, and then surprisingly the pre dump is on the other side half the size of r190593 dump and from sink till optimized the dump sizes roughly match the 65782 to 52107 lines.