From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 1D2BB385DC14; Fri, 3 Dec 2021 09:29:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1D2BB385DC14 From: "aoliva at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/103302] wrong code with -fharden-compares Date: Fri, 03 Dec 2021 09:29:23 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: aoliva at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: aoliva 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: Fri, 03 Dec 2021 09:29:24 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103302 --- Comment #9 from Alexandre Oliva --- Thanks, this alternate testcase confirms my suspicion that the original iss= ue was only going latent. It's clearly a preexisting register allocation issu= e on riscv, that was latent and that -fharden-compares exposed rather than introduced. If I understand correctly its pervasiveness, it may very well make -fharden-compares too risky to use on riscv, so I may be on the hook to fix= it regardless. ISTM that a post-reload insn_and_split would at least avoid the problem. Is there any reason why this approach is not in use on riscv?=