RFR(L): 8203197: C2: consider all paths in loop body for loop predication

[Nils Eliasson]

Looks good!

The split of the webrev made it much easier to digest.

Thanks!

// Nils


On 2018-06-18 11:00, Roland Westrelin wrote:
> http://cr.openjdk.java.net/~roland/8203197/webrev.01/
>
> Incremental change:
>
> http://cr.openjdk.java.net/~roland/8203197/webrev.00-01/
>
> The new webrev doesn't include the MDO change anymore as it was pushed
> under a separate CR. I fixed the issues that Nils reported as well.
>
> Also, to properly leverage the MDO change, I realized that the previous
> patch was not sufficient: ideally we would want a profile_predicate trap
> to be recorded in the header of an existing profile data entry but there
> might not be one where the predicates are added (in the loop
> header). To work around that problem, the new patch tries to add the
> predicates at a if that dominates the loop header.
>
> Roland.