From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 127115 invoked by alias); 20 Mar 2015 14:02:35 -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 125949 invoked by uid 48); 20 Mar 2015 14:02:26 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/65492] Bad optimization in -O3 on SSE intrinsics Date: Fri, 20 Mar 2015 14:59:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 5.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth 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: --- 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: 2015-03/txt/msg02118.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65492 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |hubicka at gcc dot gnu.org --- Comment #6 from Richard Biener --- --param max-peel-branches default of 32 seems to be quite high. For this loop we have two branches on the hot path and 4 times unrolling. Honza - how did you arrive at the default of 32? Shouldn't that depend on the number of other stmts thus rather look at branch density? Similarly late unrolling should take conditional stmts (COND_EXPR rhs_code) into account? Especially as we don't really estimate anything to become constant after unrolling.