From d809884f14570bc7f2e9a4a7b43c2ea15eb15aba Mon Sep 17 00:00:00 2001 From: Jacob Lifshay Date: Thu, 7 Jul 2022 23:15:19 -0700 Subject: [PATCH] add input/output register comments --- openpower/atomics.mdwn | 2 ++ 1 file changed, 2 insertions(+) diff --git a/openpower/atomics.mdwn b/openpower/atomics.mdwn index 79ee04f26..0ac92a556 100644 --- a/openpower/atomics.mdwn +++ b/openpower/atomics.mdwn @@ -57,11 +57,13 @@ not_eq: `atomic_load_acquire` is 4 instructions, including a branch and an unnecessarily-strong memory fence: ``` +# address in r3 ld 3, 0(3) cmpw 0, 3, 3 bne- skip isync skip: +# output in r3 ``` Having single atomic operations is useful for implementations that want to send atomic operations to a shared cache since they can be more efficient to execute there, rather than having to move a whole cache block. Relying exclusively on -- 2.30.2