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/*
* Copyright (c) 2019, Huawei Technologies Co. Ltd. All rights reserved.
* Copyright (c) 2022, Oracle and/or its affiliates. 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.
*/
/**
* @test
* @bug 8231988 8293996
* @summary Unexpected test result caused by C2 IdealLoopTree::do_remove_empty_loop
*
* @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation
* compiler.loopopts.TestRemoveEmptyLoop
*/
package compiler.loopopts;
public class TestRemoveEmptyLoop {
public void test_cmp_helper() {
int i = 34;
// The empty loop that collapses
for (; i > 0; i -= 11);
// If uses same Cmp node as the loop condition
if (i < 0) {
// do nothing
} else {
throw new RuntimeException("Test failed.");
}
}
public void test_cmp() {
// Loop is OSR compiled, and test_cmp_helper inlined
for (int i = 0; i < 50000; i++) {
test_cmp_helper();
}
}
void test_collapse_helper() {
int o = 11;
int e = 43542;
for (int i = 524; i < 19325; i += 1) {
// The empty loop that is supposed to collapse
for (int j = 0; j < 32767; j++) {
o++;
}
for (int k = 0; k < o; k++) {
e++;
}
}
}
public void test_collapse() {
// Loop is OSR compiled, and test_collapse_helper inlined
for (int i = 0; i < 50000; i++) {
test_collapse_helper();
}
}
public static void main(String[] args) {
TestRemoveEmptyLoop _instance = new TestRemoveEmptyLoop();
_instance.test_cmp();
_instance.test_collapse();
System.out.println("Test passed.");
}
}
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