RFR: 8245677: Optimize lookups in empty HashMap

[Jim Laskey]

+1

(Copyright date)

> On May 25, 2020, at 7:02 AM, Claes Redestad <claes.redestad at oracle.com> wrote:
> 
> Hi,
> 
> sponsoring this patch from Christoph Dreis.
> 
> By pushing down the hash calculation we can optimize lookups
> in empty HashMaps (also helps LinkedHashMap).
> 
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8245677
> Webrev: http://cr.openjdk.java.net/~redestad/8245677/open.00/
> 
> Testing: tier1+2
> 
> Original report: https://mail.openjdk.java.net/pipermail/core-libs-dev/2020-May/066530.html
> 
> /Claes