RFR: 8331168: Introduce PredicateEntryIterator to iterate through predicate entries

[Roland Westrelin]

On Fri, 14 Jun 2024 07:53:01 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> This is another small PR split off from the complete fix for Assertion Predicates.
> 
> Changes include:
> - Replace predicate matching/skipping code in `build_loop_late_post_work()` to use dedicated walker (i.e. new `PredicateEntryIterator` class) which uses predicate classes.
> - New predicate helper classes to improve readability.
> - Simple typos and code style updates.
> 
> Thanks,
> Christian

Looks good to me.

src/hotspot/share/opto/loopnode.cpp line 6385:

> 6383:     while (predicate_iterator.has_next()) {
> 6384:       Node* next_predicate_entry = predicate_iterator.next_entry();
> 6385:       if (is_dominator(next_predicate_entry, early) && next_predicate_entry != early) {

Maybe be want a `is_strict_dominator` method?

src/hotspot/share/opto/predicates.cpp line 35:

> 33: Node* AssertionPredicatesWithHalt::find_entry(Node* start_proj) {
> 34:   Node* entry = start_proj;
> 35:   while (AssertionPredicateWithHalt::is_predicate(entry)) {

Is it `AssertionPredicateWithHalt::is_predicate` instead of simply `is_predicate` on purpose?

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Marked as reviewed by roland (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/19716#pullrequestreview-2118584504
PR Review Comment: https://git.openjdk.org/jdk/pull/19716#discussion_r1639952727
PR Review Comment: https://git.openjdk.org/jdk/pull/19716#discussion_r1639949639