RFR: 8223454: Reduce String concatenation shapes by folding initialLengthCoder into last mixer

[Jim Laskey]

+1


> On May 8, 2019, at 11:49 AM, Claes Redestad <claes.redestad at oracle.com> wrote:
> 
> Hi,
> 
> yet another String concat startup/footprint optimization.
> 
> As the subject implies, we could fold the initialLengthCoder it into the
> final mixer. This way we end up with one less bound argument into the
> larger method handle combinator tree, with fewer species classes and
> lambda forms generated as a result. This means a significant speed-up on
> several startup and footprint tests, and especially noticeable on
> realistic workloads that just have a few different small concat shapes.
> 
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8223454
> Webrev: http://cr.openjdk.java.net/~redestad/8223454/open.00/
> 
> Thanks!
> 
> /Claes