From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 852E33858D33; Thu, 27 Apr 2023 06:42:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 852E33858D33 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1682577742; bh=WnSw0U6SFSW1daFRIfSJ4QlS0wdvmR80U/N42f2Lcmo=; h=From:To:Subject:Date:In-Reply-To:References:From; b=qqMNTgCD9epKr+wzYBVhxBzO7DmFWYFZJkj/kgkEtcy2j8FpDEi64IK8zg6FOCPAo uzjzyCXGhMCDkmhmwwXFf86PYDWvioHHEFIJJXfP89xAU4VnneQM9TWvmUI9DSeiCc itxbCbB9QhoqIceTFwVZ8oH18oWAlAwvTptWANOw= From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/109638] unsigned > 1 ? 0 : n is not optimized to n == 1 Date: Thu, 27 Apr 2023 06:42:22 +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: 13.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED 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 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109638 --- Comment #2 from Richard Biener --- Hmm, but more generally if (n !=3D x) n =3D 0; return n !=3D 0; could be handled as well. Or if (n !=3D x) n =3D 0; return n; -> return (n =3D=3D x) * x; -1 might be another special case that CPUs can efficiently handle.=