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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/104719] Use of `std::move` in libstdc++ leads to worsened debug performance
Date: Tue, 01 Mar 2022 20:12:41 +0000	[thread overview]
Message-ID: <bug-104719-4-kKO5Czc5de@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-104719-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104719

--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
There is a downside to always_inline, which might be similar to the stack usage
problem mentioned in the llvm ticket. If a function grows too large, the
optimiser can just give up and stop inlining. But for always_inline that gives
a fatal error with no way to fix it. The attribute tells the compiler kitty
isn't allowed to give up, the call must *always* be inline. If we liberally
sprinkle it all over the std::lib and it results in compiler errors, users
can't do anything about it. The code won't compile, period. Annotations that
usually improve performance, but then sometimes give unavoidable errors are not
a good idea.

  parent reply	other threads:[~2022-03-01 20:12 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-28 16:20 [Bug libstdc++/104719] New: " vittorio.romeo at outlook dot com
2022-02-28 16:46 ` [Bug libstdc++/104719] " redi at gcc dot gnu.org
2022-02-28 16:50 ` redi at gcc dot gnu.org
2022-02-28 16:56 ` egallager at gcc dot gnu.org
2022-02-28 17:00 ` vittorio.romeo at outlook dot com
2022-02-28 17:16 ` redi at gcc dot gnu.org
2022-02-28 17:20 ` vittorio.romeo at outlook dot com
2022-02-28 17:24 ` redi at gcc dot gnu.org
2022-02-28 17:37 ` redi at gcc dot gnu.org
2022-03-01  2:23 ` vittorio.romeo at outlook dot com
2022-03-01 20:12 ` redi at gcc dot gnu.org [this message]
2022-03-01 20:14 ` redi at gcc dot gnu.org
2022-03-10 23:04 ` jason at gcc dot gnu.org
2022-03-26 23:37 ` jason at gcc dot gnu.org
2022-03-27  7:35 ` redi at gcc dot gnu.org
2022-05-04 15:34 ` cvs-commit at gcc dot gnu.org
2022-05-04 15:34 ` cvs-commit at gcc dot gnu.org
2022-05-04 15:49 ` unlvsur at live dot com
2022-05-04 15:55 ` redi at gcc dot gnu.org

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