/* * Copyright (c) 2021, 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 8258272 * @summary Test that LoadVectorMaskedNodes works when the source array is known to only contain zeros * * @run main/othervm -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,*::testArrayCopy* * compiler.arraycopy.TestArrayCopyMaskedWithZeroSrc */ package compiler.arraycopy; import java.util.*; public class TestArrayCopyMaskedWithZeroSrc { public static void main(String[] args) { TestArrayCopyMaskedWithZeroSrc t = new TestArrayCopyMaskedWithZeroSrc(); t.test(); } void test() { for (int i = 0; i < 20000; i++) { testArrayCopy1(3); } } // src is allocated locally - it is known it only contains zeros. // The copy of will exapnd into LoadVectorMasked on AVX512 machines // LoadNode::value will try to replace the load from src with a zero constant. byte [] testArrayCopy1(int partial_len) { byte [] src = new byte[5]; byte [] dest = Arrays.copyOf(src, partial_len); return dest; } }