From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id DC35D3858C1F; Mon, 21 Feb 2022 13:10:52 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org DC35D3858C1F From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/104530] [12 Regression] Dead Code Elimination Regression at -O3 (trunk vs. 11.2.0) Date: Mon, 21 Feb 2022 13:10:52 +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: 12.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 12.0 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, 21 Feb 2022 13:10:53 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104530 --- Comment #3 from Jakub Jelinek --- What could be done in passes like evrp or vrp* but not in unrelated other passes that use the range infrastructure would be to set uids on stmts depending on presence of calls that might not always return in the middle of basic blocks (and perhaps other stmts, wonder about e.g. inline asm), and optimize whenever the comparison and dereference have the same uid (aka there is nothing in between that would make the optimization problematic).=