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/*
* 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 8283466
* @summary When skeleton predicates are not copied into peeled loop and initialized, this can happen:
* 1. The rangecheck from a load is hoisted outside of the counted loop.
* 2. The counted loop is peeled (we disable unswitching and unrolling with arguments)
* 3. The type inside the peeled loop may now be narrower.
* 4. The dataflow can die when a type becomes impossible.
* 5. The rangecheck is still before the peeling, and is not copied to the peeled loop. Hence
* we do not statically realize that the peeled loop can never be entered.
*
* @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+StressLCM -XX:+StressGCM -XX:+StressCCP -XX:+StressIGVN
* -Xcomp -XX:-TieredCompilation
* -XX:LoopMaxUnroll=0 -XX:LoopUnrollLimit=0 -XX:-LoopUnswitching
* -XX:CompileCommand=compileonly,compiler.loopopts.TestPeelingSkeletonPredicateInitialization::*
* compiler.loopopts.TestPeelingSkeletonPredicateInitialization
*/
package compiler.loopopts;
public class TestPeelingSkeletonPredicateInitialization {
int N = 400;
int array[] = new int[N];
int array2[] = new int[N];
void run(int X, int inv, boolean b) {
// have the arguments so the values are unknown to C2, cannot optimize things away
try {
// not sure why needed. maybe has sth to do with div_by_zero below?
int tmp = 1 / 0;
} catch (ArithmeticException e) {
}
for(int i = 2; i > X; i-=3) {
// potential div_by_zero: somehow the exit is not loop exit but rethrow
// also: i-1 only works in peeled iteration
// in peeled loop: ConvI2L dies because it knows dataflow is impossible
// If skeleton_predicate is missing for peeled loop, then controlflow does not die
array[i - 1] /= inv;
// loop invariant check that is not hoisted: this becomes reason for peeling
array[inv] += 1;
if (b) {
// seems to be required for the memory phi so that it can be mangled when data flow dies
array[inv] += 1;
array2[inv] += 1;
}
}
}
public static void main(String[] strArr) {
try {
TestPeelingSkeletonPredicateInitialization _instance = new TestPeelingSkeletonPredicateInitialization();
for (int i = 0; i < 10000; i++) {
_instance.run(100, 3, false);
}
} catch (Exception ex) {
}
}
}
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