From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id EE94339AC86A; Wed, 10 Feb 2021 16:06:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org EE94339AC86A From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/38474] compile time explosion in dataflow_set_preserve_mem_locs at -O3 Date: Wed, 10 Feb 2021 16:06:19 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Version: 4.4.0 X-Bugzilla-Keywords: compile-time-hog, memory-hog, patch X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Feb 2021 16:06:20 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D38474 --- Comment #91 from Richard Biener --- So the other simple idea I have is to limit the number of active store grou= ps and force-terminate in either a LRU or FIFO manner. For the testcase at hand the decls we start the chain for are all only used in full but knowing that would require some pre-analysis of the IL similar to what SRA does for example (collecting all accesses). It's then also still easy to "break" such heuristic so limiting is in the end the only (and I guess best) option.=