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From: "eyalroz at technion dot ac.il" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/97553] [missed optimization] constexprness not noticed when
 UBsan enabled
Date: Mon, 26 Oct 2020 20:46:29 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97553

--- Comment #5 from Eyal Rozenberg <eyalroz at technion dot ac.il> ---
(In reply to Jakub Jelinek from comment #4)
> Depends on what you mean by properly.  -O3 can be used with sanitization,
> but expecting the code to be optimized the same way as without sanitizati=
on
> is wrong, it is more important to catch as many bugs as possible, and the
> runtime instrumentation slows things down anyway.  The sanitization is not
> meant to be used for production code, only when debugging it.

I wonder, then, if some kind of notice isn't called for when -O3 and UBsan =
are
used together.=