Robert Stupp created CASSANDRA-12343:
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Summary: Make 'static final boolean' easier to optimize for Hotspot
Key: CASSANDRA-12343
URL: https://issues.apache.org/jira/browse/CASSANDRA-12343
Project: Cassandra
Issue Type: Improvement
Reporter: Robert Stupp
Assignee: Robert Stupp
Priority: Trivial
Fix For: 3.x
Hotspot is able to optimize condition checks on `static final` fields. But the
compiler can only optimize if the referenced "constant" is the first condition
to check. (If I understood the optimization in Hotspot correctly.)
I.e. the first {{if}} block can be "eliminated" whereas the second cannot:
{code}
class Foo {
static final boolean CONST = /* some fragment evaluating to false */;
public void doSomeStuff(boolean param) {
if (!CONST) {
// this code block can be eliminated
}
if (!CONST && param) {
// this code block can be eliminated
}
if (param && !CONST) {
// this code block cannot be eliminated due to some compiler logic
}
}
}
{code}
Linked patch changes the order in some {{if}} statements and migrates a few
methods to static final fields.
||trunk|[branch|https://github.com/apache/cassandra/compare/trunk...snazy:boolean-hotspot]|[testall|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-boolean-hotspot-testall/lastSuccessfulBuild/]|[dtest|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-boolean-hotspot-dtest/lastSuccessfulBuild/]
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