RFR: fix loop unswitching with -XX:-ShenandoahWriteBarrierMemBar

[Aleksey Shipilev]

On 01/31/2018 04:34 PM, Roland Westrelin wrote:
> http://cr.openjdk.java.net/~roland/shenandoah/loop_unswitching%2b-ShenandoahWriteBarrierMemBar/webrev.00/

Looks good to me!

4059     Node* load = iff->in(1)->in(1)->in(1)->in(1);

Do we care anywhere else about deeper chain from that iff to the actual load? I.e. no other code is
broken due to the new graph shape?

> Part of the logic required for this to work (the code added by the
> patch) also got lost at some point.

That makes sense.

-Aleksey