1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.rng.core.source64; 19 20 /** 21 * A fast all-purpose generator. 22 * 23 * <p>This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 512 bits 24 * and the period is 2<sup>512</sup>-1. Speed is expected to be slower than 25 * {@link XoShiRo256StarStar}.</p> 26 * 27 * @see <a href="http://xoshiro.di.unimi.it/xoshiro512starstar.c">Original source code</a> 28 * @see <a href="http://xoshiro.di.unimi.it/">xorshiro / xoroshiro generators</a> 29 * @since 1.3 30 */ 31 public class XoShiRo512StarStar extends AbstractXoShiRo512 { 32 /** 33 * Creates a new instance. 34 * 35 * @param seed Initial seed. 36 * If the length is larger than 8, only the first 8 elements will 37 * be used; if smaller, the remaining elements will be automatically 38 * set. A seed containing all zeros will create a non-functional generator. 39 */ 40 public XoShiRo512StarStar(long[] seed) { 41 super(seed); 42 } 43 44 /** 45 * Creates a new instance using an 8 element seed. 46 * A seed containing all zeros will create a non-functional generator. 47 * 48 * @param seed0 Initial seed element 0. 49 * @param seed1 Initial seed element 1. 50 * @param seed2 Initial seed element 2. 51 * @param seed3 Initial seed element 3. 52 * @param seed4 Initial seed element 4. 53 * @param seed5 Initial seed element 5. 54 * @param seed6 Initial seed element 6. 55 * @param seed7 Initial seed element 7. 56 */ 57 public XoShiRo512StarStar(long seed0, long seed1, long seed2, long seed3, 58 long seed4, long seed5, long seed6, long seed7) { 59 super(seed0, seed1, seed2, seed3, seed4, seed5, seed6, seed7); 60 } 61 62 /** 63 * Creates a copy instance. 64 * 65 * @param source Source to copy. 66 */ 67 protected XoShiRo512StarStar(XoShiRo512StarStar source) { 68 super(source); 69 } 70 71 /** {@inheritDoc} */ 72 @Override 73 protected long nextOutput() { 74 return Long.rotateLeft(state1 * 5, 7) * 9; 75 } 76 77 /** {@inheritDoc} */ 78 @Override 79 protected XoShiRo512StarStar copy() { 80 // This exists to ensure the jump function performed in the super class returns 81 // the correct class type. It should not be public. 82 return new XoShiRo512StarStar(this); 83 } 84 }