RFR: 8217874: Shenandoah: AArch64: Clobbered register in ShenandoahBarrierSetAssembler::cmpxchg_oop()

[Roman Kennke]

> On 1/28/19 12:46 PM, Roman Kennke wrote:
>> Can I get a review please?
> 
> Isn't this a bug in the C2 pattern?

No. The declaration in C2 means that the result argument is supposed to
be live starting from the (end of) the instruction, and input arguments
are live up to the instruction. Overlap within an instruction need to be
taken care of by the implementation. (Doesn't usually happen, because
instructions are usually lowered to a single instruction.)

Roman