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 69E653858D28; Thu, 25 Nov 2021 11:21:22 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 69E653858D28
From: "burnus at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/103416] [12 Regression][OpenMP] Bogus
 firstprivate(n) map(to:n [len: 4][implicit])
Date: Thu, 25 Nov 2021 11:21:22 +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: openmp, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: burnus at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: attachments.created
Message-ID: <bug-103416-4-sC7FWWDKbK@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-103416-4@http.gcc.gnu.org/bugzilla/>
References: <bug-103416-4@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: Thu, 25 Nov 2021 11:21:22 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103416

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Created attachment 51872
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D51872&action=3Dedit
RFC Patch to avoid the pointless evaluation, see comment 4

(In reply to Tobias Burnus from comment #3)

> * Why is the var generated in the parent scope of 'omp target' instead of
> inside 'omp target'?

The problem is a forced evaluation of the array bounds, which I regard as
pointless if the variable is just a plain variable - no array ref, not stru=
ct
ref no ...

Cf. attachment. (The question is when 'force=3Dtrue' is needed and whether =
the
DECL_P check is the right one or whether more or less should be permitted.)

This is indeed the same as issue as PR80330 (8...)

 * * *

The
  libgomp: cuCtxSynchronize error: misaligned address
is a regression =E2=80=93 see comment 1 for a patch which fixes it. This is=
 PR90030
(9...)


 * * *

> * Why is 'map(to:' and not 'firstprivate' used?

Because of:

gfc_omp_predetermined_mapping (tree decl)
{
  if (DECL_ARTIFICIAL (decl)
      && ! GFC_DECL_RESULT (decl)
      && ! (DECL_LANG_SPECIFIC (decl)
            && GFC_DECL_SAVED_DESCRIPTOR (decl)))
    return OMP_CLAUSE_DEFAULTMAP_TO;

I wonder whether OMP_DEFAULTMAP_FIRSTPRIVATE  wouldn't make more sense in t=
his
case =E2=80=93 at least for gfc_omp_scalar_target_p ?

Which is also related to PR80330 (8...)=