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From: "vanyacpp at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/112480] optional<T>::reset emits inefficient code when T is trivially-destructible
Date: Mon, 13 Nov 2023 10:34:31 +0000	[thread overview]
Message-ID: <bug-112480-4-DixGbN8cKD@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-112480-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112480

--- Comment #7 from Ivan Sorokin <vanyacpp at gmail dot com> ---
(In reply to Jonathan Wakely from comment #6)

> +       // The following seems redundant but improves codegen, see PR 112480.
> +       if constexpr (is_trivially_destructible_v<_Tp>)
> +         this->_M_engaged = false;
>        }


In theory non-trivial destructors that are optimizible to no-op can also
benefit from the same optimization.

I don't know how often non-trivial no-op destructors occur in practice. Perhaps
we can ignore such case.

  parent reply	other threads:[~2023-11-13 10:34 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-10 19:42 [Bug libstdc++/112480] New: " gnu at kosak dot com
2023-11-10 21:00 ` [Bug libstdc++/112480] " redi at gcc dot gnu.org
2023-11-10 21:53 ` gnu at kosak dot com
2023-11-10 21:55 ` pinskia at gcc dot gnu.org
2023-11-10 23:03 ` redi at gcc dot gnu.org
2023-11-13  9:12 ` vanyacpp at gmail dot com
2023-11-13 10:11 ` redi at gcc dot gnu.org
2023-11-13 10:34 ` vanyacpp at gmail dot com [this message]
2023-11-13 12:22 ` redi at gcc dot gnu.org
2023-11-13 23:22 ` cvs-commit at gcc dot gnu.org
2023-12-06 14:44 ` cvs-commit at gcc dot gnu.org
2023-12-06 14:48 ` redi at gcc dot gnu.org

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