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From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/32667] block copy with exact overlap is expanded as
 memcpy
Date: Tue, 28 Nov 2023 10:58:14 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D32667

--- Comment #53 from rguenther at suse dot de <rguenther at suse dot de> ---
On Tue, 28 Nov 2023, post+gcc at ralfj dot de wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D32667
>=20
> --- Comment #51 from post+gcc at ralfj dot de ---
> Oh great, I love it when one part of the C standard just adds exceptions =
to
> statements made elsewhere. It's almost as if the authors want this to be =
as
> hard to understand as possible...
>=20
> That then raises the question which version of the signature is actually =
used
> for building (and optimizing) the function: the one in the declaration or=
 the
> one in the definition. Does the standard have an answer to that?

For avoidance of doubt the frontends should drop non-semantic qualifiers
from declarations then just in case the middle-end tries to apply
semantics there.  Like it does for const qualified reference arguments
(OK, that's not C but C++).  The middle-end also uses the qualifiers
for diagnostic purposes.=