From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id E079F3857007; Wed, 1 Jul 2020 07:46:53 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E079F3857007 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1593589613; bh=YDhpFjrkFNuP2AY7DkF/urwAgBHRtSlUVnIp3qyjuo8=; h=From:To:Subject:Date:In-Reply-To:References:From; b=rtXL4yo8FOFAuM0V/EkX0hrPL706JbJQLZ8XK4lGXyIDPvVcQtL/J4R0abdBoArPr DbP4TbBCvT0VtpKzmrt9h7tikYkb7vi0ixtpPxlz4ceyd5GOmsFiFlaAYjGimjkJpy CBrBzhY2rYjLlWfQ8qPJbRd/dcMqPSvTO3YpQtX0= From: "ebotcazou at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug bootstrap/95940] [11 Regression] bootstrap broken by -Wmaybe-unintialized warnings Date: Wed, 01 Jul 2020 07:46:53 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: bootstrap X-Bugzilla-Version: 11.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: ebotcazou at gcc dot gnu.org 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: 11.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_status short_desc cc 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, 01 Jul 2020 07:46:54 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95940 Martin Sebor changed: What |Removed |Added ---------------------------------------------------------------------------- Status|WAITING |NEW Eric Botcazou changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[11 Regression] |[11 Regression] bootstrap |sparc64-linux bootstrap |broken by |with gcc-9.3 broken |-Wmaybe-unintialized | |warnings CC| |ebotcazou at gcc dot gnu.o= rg --- Comment #4 from Martin Sebor --- The first -Wmaybe-unintialized warning is issued for the read in this statement: SR.1076_294 =3D D.75512.D.16218.val[1]; in the following basic block: [local count: 130803720]: # SR.268_98 =3D PHI <_104(23), _75(39)> D.75553 =3D{v} {CLOBBER}; D.75512 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_294 =3D D.75512.D.16218.val[1]; <<< warning SR.1077_296 =3D D.75512.D.16218.val[2]; <<< warning D.75512 =3D{v} {CLOBBER}; D.75513 =3D{v} {CLOBBER}; goto ; [100.00%] Since D.75512 is clobbered just prior to the read from it I think the warni= ng is justified. Subsequent warnings follow a similar pattern: [local count: 349243402]: # SR.268_123 =3D PHI <_129(25), -1(41)> D.75575 =3D{v} {CLOBBER}; D.75514 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_230 =3D D.75514.D.16218.val[1]; <<< warning SR.1077_105 =3D D.75514.D.16218.val[2]; <<< warning D.75514 =3D{v} {CLOBBER}; D.75515 =3D{v} {CLOBBER}; goto ; [100.00%] ... [local count: 68586742]: # SR.268_148 =3D PHI <_154(30), -1(40)> D.75597 =3D{v} {CLOBBER}; D.75516 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_219 =3D D.75516.D.16218.val[1]; <<< warning SR.1077_220 =3D D.75516.D.16218.val[2]; <<< warning D.75516 =3D{v} {CLOBBER}; D.75517 =3D{v} {CLOBBER}; goto ; [100.00%] --- Comment #5 from Martin Sebor --- The first -Wmaybe-unintialized warning is issued for the read in this statement: SR.1076_294 =3D D.75512.D.16218.val[1]; in the following basic block: [local count: 130803720]: # SR.268_98 =3D PHI <_104(23), _75(39)> D.75553 =3D{v} {CLOBBER}; D.75512 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_294 =3D D.75512.D.16218.val[1]; <<< warning SR.1077_296 =3D D.75512.D.16218.val[2]; <<< warning D.75512 =3D{v} {CLOBBER}; D.75513 =3D{v} {CLOBBER}; goto ; [100.00%] Since D.75512 is clobbered just prior to the read from it I think the warni= ng is justified. Subsequent warnings follow a similar pattern: [local count: 349243402]: # SR.268_123 =3D PHI <_129(25), -1(41)> D.75575 =3D{v} {CLOBBER}; D.75514 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_230 =3D D.75514.D.16218.val[1]; <<< warning SR.1077_105 =3D D.75514.D.16218.val[2]; <<< warning D.75514 =3D{v} {CLOBBER}; D.75515 =3D{v} {CLOBBER}; goto ; [100.00%] ... [local count: 68586742]: # SR.268_148 =3D PHI <_154(30), -1(40)> D.75597 =3D{v} {CLOBBER}; D.75516 =3D{v} {CLOBBER}; xi =3D{v} {CLOBBER}; SR.1076_219 =3D D.75516.D.16218.val[1]; <<< warning SR.1077_220 =3D D.75516.D.16218.val[2]; <<< warning D.75516 =3D{v} {CLOBBER}; D.75517 =3D{v} {CLOBBER}; goto ; [100.00%] --- Comment #6 from Eric Botcazou --- > From the look of it, something is already miscompiled. No, not at all, it's just warnings turned into errors.=