RFR: 8144067: Pass obj directly to G1ParScanThreadState::update_rs

[Thomas Schatzl]

Hi,

On Wed, 2015-11-25 at 18:53 +0100, Erik Helin wrote:
> Hi all,
> 
> this small patch is an optimization of the call to
> G1ParScanThreadState::update_rs, which is used during the object copy.
> All callers of update_rs (G1ParScanThreadState::do_oop_evac and
> G1ParScanClosure::do_oop_nv) have aleady decoded the field 'p', so instead of
> calling load_decode_heap_oop(p) again in update_rs, we can just pass the
> object 'obj' as parameter (update_rs will be inlined anyway, so the parameter
> won't actually be passed).
> 
> Thanks to Thomas for finding this optimization.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8144067
> 
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8144067/webrev.00/
> 
> Please note that the patch is based upon the patch for 8144052.
> 
> Testing:
> - GC test suite with full verification

  looks good.

Thomas