1 /* 2 * Copyright (c) 2016, 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 8160425 27 * @summary Test vectorization with a signalling NaN. 28 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-OptimizeFill TestNaNVector 29 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-OptimizeFill -XX:MaxVectorSize=4 TestNaNVector 30 */ 31 public class TestNaNVector { 32 private char[] array; 33 private static final int LEN = 1024; 34 35 public static void main(String args[]) { 36 TestNaNVector test = new TestNaNVector(); 37 // Check double precision NaN 38 for (int i = 0; i < 10_000; ++i) { 39 test.vectorizeNaNDP(); 40 } 41 System.out.println("Checking double precision Nan"); 42 test.checkResult(0xfff7); 43 44 // Check single precision NaN 45 for (int i = 0; i < 10_000; ++i) { 46 test.vectorizeNaNSP(); 47 } 48 System.out.println("Checking single precision Nan"); 49 test.checkResult(0xff80); 50 } 51 52 public TestNaNVector() { 53 array = new char[LEN]; 54 } 55 56 public void vectorizeNaNDP() { 57 // This loop will be vectorized and the array store will be replaced by 58 // a 64-bit vector store to four subsequent array elements. The vector 59 // should look like this '0xfff7fff7fff7fff7' and is read from the constant 60 // table. However, in floating point arithmetic this is a signalling NaN 61 // which may be converted to a quiet NaN when processed by the x87 FPU. 62 // If the signalling bit is set, the vector ends up in the constant table 63 // as '0xfffffff7fff7fff7' which leads to an incorrect result. 64 for (int i = 0; i < LEN; ++i) { 65 array[i] = 0xfff7; 66 } 67 } 68 69 public void vectorizeNaNSP() { 70 // Same as above but with single precision 71 for (int i = 0; i < LEN; ++i) { 72 array[i] = 0xff80; 73 } 74 } 75 76 public void checkResult(int expected) { 77 for (int i = 0; i < LEN; ++i) { 78 if (array[i] != expected) { 79 throw new RuntimeException("Invalid result: array[" + i + "] = " + (int)array[i] + " != " + expected); 80 } 81 } 82 } 83 } 84