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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/107676] Nonsensical docs for -mrelax-cmpxchg-loop
Date: Mon, 14 Nov 2022 17:26:46 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107676

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #4)
> I don't think __atomic_compare_exchange emits such a loop. This is about
> __atomic_fetch_xor and friends, which do emit cmpxchg loops. But there are
> four such functions to name.

Oh yes right.
Then this:
For compare and exchange loops that are emitted by some __atomic_* builtins
(e.g. ....), emit an atomic load before the loop and if the value was not t=
he
expected value, emit a pause instruction. This might reduce execussive cache
bouncing of the memory.


I think that is better wording than it was before. I hope the person who ad=
ded
this option can take over this to get it closer to what it should be.=