From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id E8FB83858C27; Sat, 1 Jan 2022 16:37:30 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E8FB83858C27 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/103882] Register corruption in ASM only functions when optization is -O2/-Os/-O3 Date: Sat, 01 Jan 2022 16:37:30 +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: 10.3.0 X-Bugzilla-Keywords: inline-asm X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: INVALID 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: Sat, 01 Jan 2022 16:37:31 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103882 --- Comment #10 from Jakub Jelinek --- That is just a total misunderstanding why the compiler needs to know (be to= ld) the observable side-effects of the inline asm. Interprocedural optimizatio= ns are just one of the many reasons, much more important is that it needs to k= now what the inline asm does for code generation within the function, it needs = to know in which registers or memory it can spill values live across the inline asm etc. Don't use inline asm if you are unable or not willing to tell the compiler = how it behaves.=