From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A4A5F385840F; Wed, 6 Apr 2022 08:45:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A4A5F385840F From: "vincent-gcc at vinc17 dot net" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/31178] VRP can infer a range for b in a >> b and a << b Date: Wed, 06 Apr 2022 08:45:19 +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: 4.3.0 X-Bugzilla-Keywords: easyhack, missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: vincent-gcc at vinc17 dot net 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: Wed, 06 Apr 2022 08:45:19 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D31178 --- Comment #19 from Vincent Lef=C3=A8vre -= -- (In reply to rguenther@suse.de from comment #18) > Sure, if that's what the precision is used for. The message from Andrew > sounded like 'I want the precision for the shift operand but let me > just use that of the shifted anyway' Andrew should clarify. From what I understand, he does not want the precisi= on for the shift operand (right operand), but an upper bound (this is what this bug is about). And this upper bound is deduced from the precision of the shifted element (promoted left operand).=