RFR 8203628: Optimize (masked) byte memory comparisons on x86

Aleksey Shipilev shade at redhat.com
Wed May 23 08:19:26 UTC 2018


On 05/22/2018 08:01 PM, John Rose wrote:
> On May 22, 2018, at 8:53 AM, Aleksey Shipilev <shade at redhat.com <mailto:shade at redhat.com>> wrote:
> Bottom line:  While you are in this code, please check for remaining holes
> for in-memory tests against constants and against bitmasks. I think they might
> be listed completely in this mail.  And then please file a tracking bug with your
> findings.

I appreciate the sentiment, but in the grand scheme of things, it seems unwise to spend time doing
the improvements that do not have a testable use case yet, when there are improvements in other
areas that require our attention. Perfect is the enemy of good.

Submitted this RFE that whoever is doing Valhalla performance work, where the new use cases appear,
might address:
  https://bugs.openjdk.java.net/browse/JDK-8203696

-Aleksey

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