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.ByteVector; 25 import jdk.incubator.vector.Vector; 26 import jdk.incubator.vector.Vector.Species; 27 28 public class VectorArrays { 29 static boolean equals(byte[] a, byte[] b) { 30 if (a == b) 31 return true; 32 if (a == null || b == null) 33 return false; 34 35 int length = a.length; 36 if (b.length != length) 37 return false; 38 39 return mismatch(a, b) < 0; 40 } 41 42 static int compare(byte[] a, byte[] b) { 43 if (a == b) 44 return 0; 45 if (a == null || b == null) 46 return a == null ? -1 : 1; 47 48 int i = mismatch(a, b); 49 if (i >= 0) { 50 return Byte.compare(a[i], b[i]); 51 } 52 53 return a.length - b.length; 54 55 } 56 57 static int mismatch(byte[] a, byte[] b) { 58 Species<Byte> species = ByteVector.SPECIES_256; 59 return mismatch(a, b, species); 60 } 61 62 static int mismatch(byte[] a, byte[] b, Species<Byte> species) { 63 int length = Math.min(a.length, b.length); 64 if (a == b) 65 return -1; 66 67 int i = 0; 68 // @@@ Method on species to truncate the length? 69 for (; i < (length & ~(species.length() - 1)); i += species.length()) { 70 Vector<Byte> va = ByteVector.fromArray(species, a, i); 71 Vector<Byte> vb = ByteVector.fromArray(species, b, i); 72 Vector.Mask<Byte> m = va.notEqual(vb); 73 // @@@ count number of leading zeros with explicit method 74 if (m.anyTrue()) { 75 break; // mismatch found 76 } 77 } 78 79 // @@@ Can use a shape of half the bit size 80 // or a mask 81 for (; i < length; i++) { 82 if (a[i] != b[i]) 83 return i; 84 } 85 86 return (a.length != b.length) ? length : -1; 87 } 88 }