1 /* 2 * Copyright (c) 2015, 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 * @bug 8080156 8060036 27 * @summary Test correctness of type propagation to CmpUNodes. 28 * 29 * @run main compiler.types.TestTypePropagationToCmpU 30 */ 31 32 package compiler.types; 33 34 public class TestTypePropagationToCmpU { 35 public static void main(String[] args) { 36 try { 37 // Trigger compilation 38 for (int i = 0; i < 100_000; ++i) { 39 test(); 40 } 41 } catch (NullPointerException e) { 42 // Test should never throw a NullPointerException 43 throw new RuntimeException("Test failed"); 44 } 45 } 46 47 static int global = 42; 48 49 public static void test() { 50 int a = Integer.MIN_VALUE; 51 int b = global; 52 char[] buf = { 0 }; 53 for (int i = 0; i <= b; ++i) { 54 a = i - b; 55 } 56 // C2 adds a range check and an uncommon trap here to ensure that the array index 57 // is in bounds. If type information is not propagated correctly to the corresponding 58 // CmpUNode, this trap may be always taken. Because C2 also removes the unnecessary 59 // allocation of 'buf', a NullPointerException is thrown in this case. 60 char c = buf[(a * 11) / 2 - a]; // a is 0 here if global >= 0 61 buf[0] = 0; 62 } 63 }