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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 10:52:07 +0000	[thread overview]
Message-ID: <bug-103416-4-NtKNmmwab6@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-103416-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103416

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Okay, the
  map(to:D.4217 [len: 4][implicit]) map(tofrom:n [len: 4][implicit])
issue is not new – only the '[implicit]' + the misaligned address one (fixed by
the patch from comment 1).

 * * *

Thus regression → comment 1

***

And extra map(to:D.4217) – this occurs already with GCC 11 and is, thus, not a
regression.
(Only '[implicit]' is new.)

This seems to be due to a scope issue. In gimplify_omp_for

(gdb) p debug(for_stmt)
#pragma omp for nowait
for (i0 = 1; i0 <= D.4217; i0 = i0 + 1)
      REALPART_EXPR <scalar> = (real(kind=8)) n;

which then calls at some point
  omp_notice_variable (
debug_tree(decl) which ends up with
7698                            nflags |= GOVD_MAP | GOVD_MAP_TO_ONLY;

The problem is that here
        integer(kind=4) D.3933;
is generated in the parent scope of '#omp target' instead of in the parent
scope of '#omp parallel do'.

Thus, there are two questions:
* Why is 'map(to:' and not 'firstprivate' used?
* Why is the var generated in the parent scope of 'omp target' instead of
inside 'omp target'?

  parent reply	other threads:[~2021-11-25 10:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-24 18:41 [Bug middle-end/103416] New: " burnus at gcc dot gnu.org
2021-11-24 19:05 ` [Bug middle-end/103416] " cltang at gcc dot gnu.org
2021-11-25  7:18 ` rguenth at gcc dot gnu.org
2021-11-25 10:07 ` burnus at gcc dot gnu.org
2021-11-25 10:52 ` burnus at gcc dot gnu.org [this message]
2021-11-25 11:21 ` burnus at gcc dot gnu.org
2021-11-25 11:24 ` burnus at gcc dot gnu.org
2021-12-02 11:07 ` [Bug middle-end/103416] [OpenMP] Double mapping via " burnus at gcc dot gnu.org
2022-05-06  8:32 ` [Bug fortran/103416] [OpenMP] Double mapping via firstprivate(n) map(to:n [len: 4][implicit]) of loop bounds jakub at gcc dot gnu.org
2023-05-08 12:23 ` rguenth at gcc dot gnu.org

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