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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug libstdc++/104719] Use of `std::move` in libstdc++ leads to
 worsened debug performance
Date: Tue, 01 Mar 2022 20:12:41 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104719

--- 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 u=
sage
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 gi=
ves
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.=