RFR: 8252505: C1/C2 compiler support for blackholes

[Andrew Haley]

On 25/11/2020 12:45, Vladimir Ivanov wrote:
> Even if there are no instructions issued, some of the unfortunate effects of a call may be still there (e.g., spills around the place where the node is scheduled, memory state is effectively killed). Fixing that would involve overriding calling conventions, in_RegMask()/out_RegMask(), customize memory effects.

Is that even a downside? It does at least allow everything in flight to
become visible. It's certainly an improvement over what we have at the
moment.

But Aleksey, there is an alternative: a store that doesn't do anything.
Did you consider that instead? I guess the problem is that there'd be a lot
more nodes.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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