RFR(XS): 8215044: C2 crash in loopTransform.cpp with assert(cl->trip_count() > 0) failed: peeling a fully unrolled loop

[Vladimir Kozlov]

Good.

Thanks,
Vladimir

On 12/17/18 1:39 AM, Roland Westrelin wrote:
> 
> http://cr.openjdk.java.net/~roland/8215044/webrev.00/
> 
> The trip count of the inner loop is first computed to be 4. The
> pre/main/post loops are then created and the main loop trip count is
> adjusted to be 3. The inner loop is unrolled once, trip count is set to
> 1 (3/2). Then peeling is attempted twice, the second one sees a zero
> trip count.
> 
> The fix I propose is to not attempt peeling on a loop with an expected
> trip count of 1.
> 
> Roland.
>