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/*
* Copyright (c) 2023, 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 8317121
* @summary Test masked vectors and unsafe access to memory modified by arraycopy
* @requires vm.compiler2.enabled
* @modules java.base/jdk.internal.misc
* @library /test/lib /
* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -Xbatch -XX:CompileCommand=quiet -XX:CompileCommand=compileonly,TestMaskedVectors::test* -XX:+StressLCM -XX:+StressGCM -XX:StressSeed=2210259638 TestMaskedVectors
* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -Xbatch -XX:CompileCommand=quiet -XX:CompileCommand=compileonly,TestMaskedVectors::test* -XX:+StressLCM -XX:+StressGCM TestMaskedVectors
*/
import java.lang.reflect.*;
import java.util.*;
import jdk.internal.misc.Unsafe;
public class TestMaskedVectors {
private static Unsafe UNSAFE = Unsafe.getUnsafe();
private static final long BASE_OFFSET = UNSAFE.arrayBaseOffset(byte[].class);
static void testLoadVectorMasked(byte[] src, byte[] dst, int len) {
byte[] tmp = new byte[64];
// (3) The LoadVectorMasked is found to be dependent on below arraycopy and
// therefore scheduled just below it. As a result, the LoadVectorMasked misses the
// updated elements at index 16..48 and dst will contain incorrect values.
System.arraycopy(src, 0, tmp, 0, 16);
// (2) The LoadVectorMasked is incorrectly found to be independent of this arraycopy
// because the LoadVectorMasked has offset 0 whereas the arraycopy writes offset >= 16.
// The problem is that MemNode::find_previous_store() -> LoadNode::find_previous_arraycopy()
// -> ArrayCopyNode::modifies does not account for the size of the load.
System.arraycopy(src, 0, tmp, 16, 48);
// (1) The following arraycopy is expanded into a LoadVectorMasked and a
// StoreVectorMasked in PhaseMacroExpand::generate_partial_inlining_block().
System.arraycopy(tmp, 0, dst, 0, len);
}
static long testUnsafeGetLong(byte[] src) {
byte[] tmp = new byte[16];
// (3) The unsafe load is found to be dependent on below arraycopy and
// therefore scheduled just below it. As a result, the unsafe load misses the
// updated elements at index 1..16 and therefore returns an incorrect result.
System.arraycopy(src, 0, tmp, 0, 16);
// (2) The unsafe load is incorrectly found to be independent of this arraycopy
// because the load has offset 0 in 'tmp' whereas the arraycopy writes offsets >= 1.
// The problem is that MemNode::find_previous_store() -> LoadNode::find_previous_arraycopy()
// -> ArrayCopyNode::modifies does not account for the size of the load.
System.arraycopy(src, 0, tmp, 1, 15);
// (1) Below unsafe load reads the first 8 (byte) array elements.
return UNSAFE.getLong(tmp, BASE_OFFSET);
}
public static void main(String[] args) {
// Initialize src array with increasing byte values
byte[] src = new byte[64];
for (byte i = 0; i < src.length; ++i) {
src[i] = (byte)i;
}
// Compute expected outputs once
byte[] golden1 = new byte[64];
testLoadVectorMasked(src, golden1, 64);
long golden2 = testUnsafeGetLong(src);
// Trigger compilation of test methods and verify the results
for (int i = 0; i < 50_000; ++i) {
int len = i % 32;
byte[] dst = new byte[len];
testLoadVectorMasked(src, dst, len);
boolean error = false;
for (int j = 0; j < dst.length; ++j) {
if (dst[j] != golden1[j]) {
System.out.println("Incorrect value of element " + j + ": Expected " + golden1[j] + " but got " + dst[j]);
error = true;
}
}
if (error) {
throw new RuntimeException("Test LoadVectorMasked failed");
}
long res = testUnsafeGetLong(src);
if (res != golden2) {
throw new RuntimeException("Incorrect result in test UnsafeGetLong: Expected " + golden2 + " but got " + res);
}
}
}
}
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