RFR: merge of 8203197

[Roman Kennke]

Hi Roland,

with your changes, I am still getting merge conflicts when pulling from
upstream. Could you do the following:

hg pull http://hg.openjdk.java.net/jdk/jdk -r 5209d8a6303e

This will pull in the conflicting change. Then:
hg merge

This will result in a bunch of conflicts:

$ hg resolve -l |grep ^U
U src/hotspot/share/opto/loopPredicate.cpp
U src/hotspot/share/opto/loopnode.cpp

Then please resolve those conflicts (I have no idea how), then:

hg resolve -ma       # mark conflicts as solved
hg commit -m"Merge"  # commit merge changeset
hg push              # pushes upstream changeset + merge


There's another C2 conflict waiting here:

changeset:   50632:fd430e352427
user:        thartmann
date:        Tue Jun 19 12:25:42 2018 +0200
files:       src/hotspot/share/opto/loopPredicate.cpp
src/hotspot/share/opto/loopTransform.cpp
src/hotspot/share/opto/loopnode.hpp
test/hotspot/jtreg/compiler/loopopts/IterationSplitPredicateInconsistency.java
test/hotspot/jtreg/compiler/loopopts/TestOverunrolling.java
description:
8205033: [REDO] Induction variable of over-unrolled loop conflicts with
range checks
Summary: Update skeleton predicates before main loop during unrolling to
remove dead code.
Reviewed-by: kvn, roland

Unfortunately, there's another changeset between the two C2 changesets
that will disturb a straight pull+merge on your side:

changeset:   50628:83b1a52f187c
user:        rkennke
date:        Tue Jun 19 11:27:05 2018 +0200
files:       src/hotspot/cpu/x86/templateTable_x86.cpp
description:
8204941: Refactor TemplateTable::_new to use MacroAssembler helpers for
tlab and eden
Reviewed-by: kvn, coleenp

I'll look into cherry-picking this, so that we can make progress faster.

Thanks, Roman




> The upstream change merged with the current shenandoah repo:
> 
> http://cr.openjdk.java.net/~roland/shenandoah/backport-8203197/webrev.00/
> 
> Some fixes to the upstream changes that I found are required for
> shenandoah:
> 
> http://cr.openjdk.java.net/~roland/shenandoah/fixes-8203197/webrev.00/
> 
> And a collection of small fixes unrelated to the upstream but I found
> while testing the change:
> 
> http://cr.openjdk.java.net/~roland/shenandoah/various-c2-fixes/webrev.00/
> 
> Roland.
>