From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6BD5D385BF86; Mon, 6 Sep 2021 18:43:43 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6BD5D385BF86 From: "gabravier at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/96563] Failure to optimize loop with condition to simple arithmetic Date: Mon, 06 Sep 2021 18:43:43 +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: 11.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: gabravier at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: 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: 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: Mon, 06 Sep 2021 18:43:43 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96563 --- Comment #3 from Gabriel Ravier --- It seems like GCC does better for the unrolled case as of now on trunk and seemingly since GCC 11, though the operation is done in a different way due= to `((unsigned)x <=3D 9) ? 8 : 4;` being expanded differently, which does seem interesting w.r.t. perhaps optimizing `(((unsigned)x <=3D 9) * 4) + 4` to i= t or the other way around.=