1 /* 2 * Copyright (c) 2017, 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 import jdk.incubator.vector.IntVector; 25 import jdk.incubator.vector.VectorMask; 26 import jdk.incubator.vector.VectorShape; 27 import jdk.incubator.vector.VectorSpecies; 28 import jdk.incubator.vector.Vector; 29 30 import java.util.stream.IntStream; 31 32 /** 33 * @test 34 * @modules jdk.incubator.vector 35 */ 36 37 public class VectorRuns { 38 39 public static void main(String[] args) { 40 41 for (int i = 1; i < 1024; i++) { 42 int[] a = IntStream.range(0, 1024).toArray(); 43 a[i] = -1; 44 countRunAscending(a); 45 46 assertEquals(countRunAscending(a), i); 47 assertEquals(countRunAscendingVector(a), i); 48 } 49 } 50 51 static void assertEquals(Object a, Object b) { 52 if (!a.equals(b)) throw new AssertionError(a + " " + b); 53 } 54 55 // Count run of a[0] > a[1] > a[2] > ... 56 static int countRunAscending(int[] a) { 57 int r = 1; 58 if (r >= a.length) 59 return a.length; 60 61 while (r < a.length && a[r - 1] <= a[r]) { 62 r++; 63 } 64 return r; 65 } 66 67 68 static int countRunAscendingVector(int[] a) { 69 VectorSpecies<Integer> species = IntVector.SPECIES_256; 70 71 int r = 1; 72 if (r >= a.length) 73 return a.length; 74 75 int length = a.length & (species.length() - 1); 76 if (length == a.length) length -= species.length(); 77 while (r < length) { 78 IntVector vl = IntVector.fromArray(species, a, r - 1); 79 IntVector vr = IntVector.fromArray(species, a, r); 80 VectorMask<Integer> m = vl.greaterThan(vr); 81 if (m.anyTrue()) 82 return r + Long.numberOfTrailingZeros(m.toLong()); 83 r += species.length(); 84 } 85 86 while (r < a.length && a[r - 1] <= a[r]) { 87 r++; 88 } 89 return r; 90 } 91 }