[aarch64-port-dev ] RFR: 8129426: aarch64: add support for PopCount in C2

[Edward Nevill]

On Wed, 2015-06-24 at 12:54 -0600, Alejandro E Murillo wrote:
> 
> On 6/24/2015 7:36 AM, Edward Nevill wrote:
> > On Tue, 2015-06-23 at 15:11 -0600, Alejandro E Murillo wrote:
> >> On 6/23/2015 7:51 AM, Edward Nevill wrote:
> >>> On Tue, 2015-06-23 at 11:32 +0100, Andrew Dinn wrote:
> >>>> On 23/06/15 11:10, Andrew Haley wrote:
> >>>>> On 22/06/15 17:14, Andrew Dinn wrote:
> >>>>>> . . .
> >>>>>> Well, you might not want to take this risk and instead add an explicit
> >>>>>> zero of the upper half. But I think we need to be clear what risk we are
> >>>>>> taking.
> >>>>> It's this: if we don't explicitly zero the upper half we'll have to
> >>>>> audit all the code which might present a sign-extended value (instead
> >>>>> of a zero-extended one) in a register that's supposed to contain a
> >>>>> jint.
> >>>> Ok, let's play safe. If Ed tweaks the patch to zero the upper word we
> >>>> can always revise that later if/when we decide we are feeling lucky.
> >>>>
> >>> OK. New webrev at
> >>>
> >>> http://cr.openjdk.java.net/~enevill/8129426/webrev.02/
> >>>
> >>> All the best,
> >>> Ed.
> >>>
> >>>
> >> Hi,
> >> to be consistent with similar integrations and to avoid potential
> >> merging problems,
> >> going forward please work with  the hs-rt repo for this kind of changes,
> >> as Volker has been doing.
> > Hi Alejandro,
> >
> > I have rebased the patch on hs-rt. New webrev
> >
> > http://cr.openjdk.java.net/~enevill/8129426/webrev.03/
> >
> > Does it look OK to push?
> >
> > Thanks,
> > Ed.
> >
> Apologies, I thought you had already pushed that to jdk9/dev,
> but it turns out you had pushed 8129551 , no this one.
> 
> If this is a follow up to the previous push into jdk9/dev (8129551)
> or somewhat related, then it's probably better if you pushed
> this one  to jdk9/dev as well, as to avoid any possible conflict
> when we merge jdk9/dev with jdk9/hs. If they are completely
> independent then go ahead and push it to hs-rt, after review of course.

OK, I was confused when you suggested it should be pushed to hs-rt, since the change is adding PopCount to C2.

Should I base it on hs-comp and move the review over to hotspot-compiler-dev?

All the best,
Ed.