JEP 280 (Indify String Concat) integration

[Remi Forax]

Yes, 
it's time to integrate that code,
thumb up !

BTW, once the second part will be done, varargs calls should be the next target, 
see https://bugs.openjdk.java.net/browse/JDK-8013269.

Rémi

----- Mail original -----
> De: "Paul Sandoz" <paul.sandoz at oracle.com>
> Cc: compiler-dev at openjdk.java.net, "Java Core Libs" <core-libs-dev at openjdk.java.net>
> Envoyé: Vendredi 22 Janvier 2016 10:46:14
> Objet: Re: JEP 280 (Indify String Concat) integration
> 
> Looks a fine approach to me.
> 
> Getting code in earlier and tested, even initially under the less optimal
> strategy, is good in terms of exposure.
> 
> Paul.
> 
> > On 22 Jan 2016, at 10:31, Aleksey Shipilev <aleksey.shipilev at oracle.com>
> > wrote:
> > 
> > Hi,
> > 
> > I think it is time to integrate JEP 280 ("Indify String Concat") into JDK
> > 9:
> > http://openjdk.java.net/jeps/280
> > 
> > The JEP is Targeted, the CCC is approved, the code reviews and
> > pre-integration checks come clean. In theory, we would like to integrate
> > with some "optimal" concat strategy switched by default, but we have to
> > wait for some Hotspot compiler changes to settle before we can make that
> > call. (Notably, https://bugs.openjdk.java.net/browse/JDK-8136469).
> > 
> > So, I would like to proceed in two parts:
> > 
> > Part 1: Integrate all code changes, but keep the concatenation strategy
> > to be the same "naive" StringBuilder.append chains. In other words, we
> > are emitting string concat indy, but always link in the naive
> > StringBuilder.append code.
> > 
> > Part 2: (After HS changes settle in) Re-run performance tests, and
> > switch to a more optimal concatenation strategy. This amounts to
> > one-liner change in a default value for Java property.
> > 
> > Thoughts? I would like relevant Project Leads / Reviewers (langtools and
> > jdk) to OKay the integration.
> > 
> > FTR, the webrevs:
> >  http://cr.openjdk.java.net/~shade/8085796/webrev.root.00/
> >  http://cr.openjdk.java.net/~shade/8085796/webrev.langtools.05/
> >  http://cr.openjdk.java.net/~shade/8085796/webrev.jdk.08/
> > 
> > Thanks,
> > -Aleksey
> > 
> 
>