From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 19EF33857006; Fri, 1 Oct 2021 20:23:35 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 19EF33857006 From: "qinzhao at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/102285] New flag -ftrivial-auto-var-init=zero causes crash in pr82421.c Date: Fri, 01 Oct 2021 20:23:35 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: ice-on-valid-code X-Bugzilla-Severity: normal X-Bugzilla-Who: qinzhao at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: qinzhao 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, 01 Oct 2021 20:23:36 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102285 --- Comment #18 from qinzhao at gcc dot gnu.org --- (In reply to Richard Biener from comment #13) > We could try sth like the following which should cover this testcase and > also hopefully doesn't break anything else. >=20 > diff --git a/gcc/expr.c b/gcc/expr.c > index e0bcbccd905..ab3b5b26c20 100644 > --- a/gcc/expr.c > +++ b/gcc/expr.c > @@ -5322,7 +5322,7 @@ non_mem_decl_p (tree base) > /* Returns true if REF refers to an object that does not > reside in memory and has non-BLKmode. */ >=20=20 > -static inline bool > +bool > mem_ref_refers_to_non_mem_p (tree ref) > { > tree base; > diff --git a/gcc/expr.h b/gcc/expr.h > index 94a85b40dca..85650e96834 100644 > --- a/gcc/expr.h > +++ b/gcc/expr.h > @@ -346,4 +346,6 @@ extern void expand_operands (tree, tree, rtx, rtx*, r= tx*, > /* Return an rtx for the size in bytes of the value of an expr. */ > extern rtx expr_size (tree); >=20=20 > +extern bool mem_ref_refers_to_non_mem_p (tree ref); > + > #endif /* GCC_EXPR_H */ > diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c > index 8312d08aab2..c1d23dfd21e 100644 > --- a/gcc/internal-fn.c > +++ b/gcc/internal-fn.c > @@ -3015,8 +3015,10 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt) > reg_lhs =3D true; > else > { > - rtx tem =3D expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE); > - reg_lhs =3D !MEM_P (tem); > + tree lhs_base =3D lhs; > + while (handled_component_p (lhs_base)) > + lhs_base =3D TREE_OPERAND (lhs_base, 0); > + reg_lhs =3D mem_refers_to_non_mem_p (lhs_base); > } >=20=20 > if (!reg_lhs) I tried the above patch, it even doesn't work for this testing case.=20 After the patch, this call to .DEFERRED_INIT will be expanded through REG p= ath, however, the existing problem in the LHS IR broke the "expand_assignment" t= oo.=20 so, I still think that the root cause is the IR for LHS of the following ca= ll to .DEFERRED_INIT is not correct: MEM[(int[0:D.1993] *)&fb.3] =3D .DEFERRED_INIT (16, 2, 1); the LHS is: MEM[(int[0:D.1993] *)&fb.3] this is the MEM_REF, whose base address is a ADDR_EXPR of a VAR_DECL, howev= er, this VAR_DECL is not addressable, will be in REG. this is conflicting: how = can a variable that in a REG be address taken?=