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/*
* Copyright (c) 2024, 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 8325746
* @summary Test Loop Unswitching with BaseCountedLoopEnd nodes as unswitch candidate.
* @requires vm.compiler2.enabled
* @run main/othervm -XX:CompileCommand=compileonly,compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate::test*
* -Xcomp -XX:LoopMaxUnroll=0 -XX:-UseLoopPredicate -XX:-RangeCheckElimination
* compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate
* @run main compiler.loopopts.TestBaseCountedEndLoopUnswitchCandidate
*/
package compiler.loopopts;
public class TestBaseCountedEndLoopUnswitchCandidate {
static int iFld;
static long lFld;
static A a = new A();
static boolean flag;
public static void main(String[] k) {
for (int i = 0; i < 10000; i++) {
testLongCountedLoopEnd();
testCountedLoopEnd();
}
}
public static void testLongCountedLoopEnd() {
long limit = lFld;
for (int i = 0; i < 100; i++) {
// After peeling & IGNV:
// LongCountedEndLoop
// / \
// True False
// / \ /
// Store Region
//
// LongCountedEndLoop has both paths inside loop and is therefore selected as unswitch candidate If in
// Loop Unswitching.
// Use stride > Integer.MAX_VALUE such that LongCountedLoopNode is not split further into loop nests.
for (long j = 0; j < limit; j+=2147483648L) {
a.i += 34; // NullCheck with trap on false path -> reason to peel
if (j > 0) { // After peeling: j > 0 always true -> loop folded away
break;
}
}
}
}
public static void testCountedLoopEnd() {
int limit = iFld;
for (int i = 0; i < 100; i++) {
// After peeling & IGNV:
// CountedLoopEnd
// / \
// True False
// / \ /
// Store Region
//
// CountedEndLoop has both paths inside loop and is therefore selected as unswitch candidate If in
// Loop Unswitching.
for (int j = 0; j < limit; j++) {
a.i += 34; // NullCheck with trap on false path -> reason to peel
if (j > 0) { // After peeling: j > 0 always true -> loop folded away
break;
}
}
}
}
}
class A {
int i;
}
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