RFR(S): 8217042: Shenandoah: write barrier on backedge of strip mined loop causes c2 crash at expansion time

[Tobias Hartmann]

Hi Roland,

looks reasonable to me.

Best regards,
Tobias

On 15.01.19 10:03, Roland Westrelin wrote:
> 
> http://cr.openjdk.java.net/~roland/8217042/webrev.00/
> 
> If a write barrier is in the body of the outer strip mined loop,
> expanding it causes loop strip mining verification code to fail. This is
> worked around by turning the strip mined loop nest into a regular
> counted loop nest so verification code doesn't trigger. The logic that
> takes care of that breaks when the write barrier is on the backedge of
> the strip mined loop because it is applied after the barrier is
> expanded. The fix I propose is to move that logic before barrier
> expansion.
> 
> Roland.
>