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/*
* Copyright (c) 2024 Alibaba Group Holding Limited. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package compiler.c2.irTests.scalarReplacement;
import compiler.lib.ir_framework.*;
/*
* @test
* @bug 8333334
* @summary Tests that dead barrier control flows do not affect the scalar replacement.
* @library /test/lib /
* @requires vm.compiler2.enabled
* @requires vm.gc.G1
* @run driver compiler.c2.irTests.scalarReplacement.ScalarReplacementWithGCBarrierTests
*/
public class ScalarReplacementWithGCBarrierTests {
static class List {
public Node head;
public void push(int value) {
Node n = new Node();
n.value = value;
n.next = head;
head = n;
}
@ForceInline
public Iter iter() {
Iter iter = new Iter();
iter.list = this;
iter.n = head;
iter.sum = 0;
return iter;
}
}
static class Node {
public int value;
public Node next;
}
static class Iter {
public List list;
public Node n;
public Integer sum;
@ForceInline
public boolean next() {
int lastSum = sum;
while (sum - lastSum < 1000) {
while (n != null && n.value < 30) n = n.next;
if (n == null) return false;
sum += n.value;
n = n.next;
}
return true;
}
}
private static final int SIZE = 1000;
public static void main(String[] args) {
// Must use G1 GC to ensure there is a pre-barrier
// before the first field write.
TestFramework.runWithFlags("-XX:+UseG1GC");
}
@Run(test = "testScalarReplacementWithGCBarrier")
private void runner() {
List list = new List();
for (int i = 0; i < SIZE; i++) {
list.push(i);
}
testScalarReplacementWithGCBarrier(list);
}
// Allocation of `Iter iter` should be eliminated by scalar replacement, and
// the allocation of `Integer sum` can not be eliminated, so there should be
// 1 allocation after allocations and locks elimination.
//
// Before the patch of JDK-8333334, both allocations of `Iter` and `Integer`
// could not be eliminated.
@Test
@IR(phase = { CompilePhase.AFTER_PARSING }, counts = { IRNode.ALLOC, "1" })
@IR(phase = { CompilePhase.INCREMENTAL_BOXING_INLINE }, counts = { IRNode.ALLOC, "2" })
@IR(phase = { CompilePhase.ITER_GVN_AFTER_ELIMINATION }, counts = { IRNode.ALLOC, "1" })
private int testScalarReplacementWithGCBarrier(List list) {
Iter iter = list.iter();
while (true) {
while (iter.next()) {}
if (list.head == null) break;
list.head = list.head.next;
iter.n = list.head;
}
return iter.sum;
}
}
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