1 /* 2 * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test 26 * @key stress randomness 27 * @bug 8333889 28 * @summary Test that speculative array access checks do not cause a load to be wrongly hoisted before its range check. 29 * @run main/othervm -XX:CompileCommand=dontinline,*::* -XX:CompileCommand=compileonly,*TestSpeculateArrayAccess::test 30 * -Xbatch -XX:+UnlockDiagnosticVMOptions -XX:+StressGCM -XX:StressSeed=1202682944 31 * compiler.valhalla.inlinetypes.TestSpeculateArrayAccess 32 * @run main/othervm -XX:CompileCommand=dontinline,*::* -XX:CompileCommand=compileonly,*TestSpeculateArrayAccess::test 33 * -Xbatch -XX:+UnlockDiagnosticVMOptions -XX:+StressGCM 34 * compiler.valhalla.inlinetypes.TestSpeculateArrayAccess 35 */ 36 37 package compiler.valhalla.inlinetypes; 38 39 public class TestSpeculateArrayAccess { 40 static Object[] oArr = new Object[100]; 41 static int iFld = 100; 42 43 public static void main(String[] args) { 44 for (int i = 0; i < 100; i++) { 45 oArr[i] = new Object(); 46 } 47 iFld = 1; 48 for (int i = 0; i < 1000; i++) { 49 test(); 50 } 51 iFld = -1; 52 53 try { 54 test(); 55 } catch (ArrayIndexOutOfBoundsException e) { 56 // Expected. 57 } 58 } 59 60 static void test() { 61 Object[] oA = oArr; // Load here to avoid G1 barriers being expanded inside loop which prevents Loop Predication. 62 for (float i = 0; i < 100; i++) { 63 // RangeCheck -> If-Speculative-Array-Type -> CastII 64 // 65 // At Loop Predication: 66 // - RangeCheck not hoisted because loop dependent 67 // - If-Speculative-Array-Type hoisted and CastII and LoadN ends up before loop 68 // 69 // Running with -XX:+StressGCM: We could execute the LoadN before entering the loop. 70 // This crashes when iFld = -1 because we then access an out-of-bounds element. 71 Object o = oA[(int)i*iFld]; 72 o.toString(); // Use the object with its speculated type. 73 } 74 } 75 } 76