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From: "unlvsur at live dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug middle-end/101197] __builtin_memmove does not perform constant
 optimizations
Date: Mon, 16 Aug 2021 10:37:46 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101197

--- Comment #9 from cqwrteur <unlvsur at live dot com> ---
(In reply to Tamar Christina from comment #8)
> (In reply to Jakub Jelinek from comment #6)
> > Shouldn't that be a different PR with details?  I mean, this PR is that=
 we
> > should expand shorter memmove inline even if the regions do overlap.
>=20
> Sure, I'm still trying to create a minimal representative example (it's C=
++
> and templated) unless just pointing at the github is enough.=20
>=20
> To be clear though, just inlining memmove at all will cover most of the
> distance, it's just that you require less registers.

inline things like memcpy and memmove will lead to serious binary bloat. The
compiler usually picks to emit call to libc's memcpy and memmove that is
usually highly optimized with assembly code.=