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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114647] missing DSE when looping over a VLA
Date: Tue, 09 Apr 2024 07:12:50 +0000	[thread overview]
Message-ID: <bug-114647-4-mT318UnZab@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-114647-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114647

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
                      /* If we visit this PHI by following a backedge then we
                         have to make sure ref->ref only refers to SSA names
                         that are invariant with respect to the loop
                         represented by this PHI node.  */
                      if (dominated_by_p (CDI_DOMINATORS, gimple_bb (stmt),
                                          gimple_bb (use_stmt))
                          && !for_each_index (ref->ref ? &ref->ref :
&ref->base,
                                              check_name, gimple_bb
(use_stmt)))
                        return DSE_STORE_LIVE;

we could make this bail-out "delayed" until we hit the next possible use in
the loop (of which there is none).

      parent reply	other threads:[~2024-04-09  7:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-08 21:37 [Bug middle-end/114647] New: missing DCE " franckbehaghel_gcc at protonmail dot com
2024-04-08 21:40 ` [Bug tree-optimization/114647] missing DSE " pinskia at gcc dot gnu.org
2024-04-08 21:46 ` pinskia at gcc dot gnu.org
2024-04-09  7:12 ` rguenth at gcc dot gnu.org [this message]

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