RFR: SFX AddP cloning should check for dependent AddP explicitly

[Aleksey Shipilev]

On 7/15/19 2:35 PM, Roman Kennke wrote:
>>> CTW tests fail with sh/jdk with the assert here:
>>>  1545         assert(addr2->Opcode() == Op_AddP, "expected");
>>>
>>> I believe we should instead check for the shape of the graph explicitly here:
>>>   http://cr.openjdk.java.net/~shade/shenandoah/sfx-hard-arr/webrev.01/
>>
>> This also apparently fixes a lot of x86_32 CTW tests.
> 
> It looks ok to me.
> I assume the failure case is rare enough that we can accept the register
> mess-up there?

Where is the register mess-up? I see there is a dangling CheckCastPP, but that node would be dead in
that corner case.

-- 
Thanks,
-Aleksey