From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 2C5B438515E6; Tue, 11 May 2021 08:31:51 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2C5B438515E6
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/100508] ICE with '-g -O3': in
 expand_debug_locations, at cfgexpand.c:5618
Date: Tue, 11 May 2021 08:31:50 +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, openmp
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub 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: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-100508-4-l2ar0kQ6sZ@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-100508-4@http.gcc.gnu.org/bugzilla/>
References: <bug-100508-4@http.gcc.gnu.org/bugzilla/>
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 <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 11 May 2021 08:31:51 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100508

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
If you change it to #pragma omp declare simd it will start certainly earlie=
r.
I think the bug is in the inliner.
Before dse1 we have:
  V m;

  <bb 2> :
  m_2 =3D j;
  # DEBUG m =3D> m_2
and dse1 turns that into:
  # DEBUG D#1 =3D> j
  # DEBUG m =3D> D#1
But it seems the inliner doesn't remap the DEBUG_EXPR_DECLs, which means th=
ey
are shared between different functions, and during expansion the correspond=
ing
DEBUG_EXPRs are shared between the functions too:
    case DEBUG_EXPR_DECL:
      op0 =3D DECL_RTL_IF_SET (exp);

      if (op0)
        return op0;

      op0 =3D gen_rtx_DEBUG_EXPR (mode);
      DEBUG_EXPR_TREE_DECL (op0) =3D exp;
      SET_DECL_RTL (exp, op0);

      return op0;
because DECL_RTL will be set after expanding first function referencing tha=
t.

So, I guess one option is to remap DEBUG_EXPR_DECLs during inlining (and
function versioning etc.), but guess that would need to be done very carefu=
lly
for the DW_OP_GNU_parameter_ref case of optimized away arguments, another o=
ne
would be to clear DECL_RTL of DEBUG_EXPR_DECLs at the end of expansion (say
push DEBUG_EXPR_DECLs for which we SET_DECL_RTL into a vector and then walk=
 the
vector and clear DECL_RTLs), or do this only for the vector type mode misma=
tch
case (ignore DECL_RTL in that case and therefore force a different DEBUG_EX=
PR).=