RFR: 8223051: support loops with long (64b) trip counts

[Tobias Hartmann]

On Wed, 23 Sep 2020 09:08:59 GMT, Roland Westrelin <roland at openjdk.org> wrote:

> Last webrev was:
> 
> https://cr.openjdk.java.net/~roland/8223051/webrev.03/
> 
> This PR includes a few minor changes:
> 
> - The change in callnode.cpp that Vladimir requested in:
>   https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-August/039551.html
> 
> - Extra comments that John requested in:
>   https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-August/039621.html
> 
> - A couple extra counters to collect more detailed statistics
> 
> 8252696 (Loop unswitching may cause out of bound array load to be
> executed) was the only bug that was uncovered by extended testing and
> it's fixed now.
> 
> This was previously reviewed by Tobias, Vladimir and John. Given the
> last changes were either requested by reviewers or a straighforward
> improvement to statistics, and unless someone objects, I intend to
> push this in the next few days with the reviewer list I just
> mentioned.

Looks good to me.

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Marked as reviewed by thartmann (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/318