001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.rng.core.source64; 019 020/** 021 * A fast all-purpose generator. 022 * 023 * <p>This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 512 bits 024 * and the period is 2<sup>512</sup>-1. Speed is expected to be slower than 025 * {@link XoShiRo256StarStar}.</p> 026 * 027 * @see <a href="http://xoshiro.di.unimi.it/xoshiro512plusplus.c">Original source code</a> 028 * @see <a href="http://xoshiro.di.unimi.it/">xorshiro / xoroshiro generators</a> 029 * @since 1.3 030 */ 031public class XoShiRo512PlusPlus extends AbstractXoShiRo512 { 032 /** 033 * Creates a new instance. 034 * 035 * @param seed Initial seed. 036 * If the length is larger than 8, only the first 8 elements will 037 * be used; if smaller, the remaining elements will be automatically 038 * set. A seed containing all zeros will create a non-functional generator. 039 */ 040 public XoShiRo512PlusPlus(long[] seed) { 041 super(seed); 042 } 043 044 /** 045 * Creates a new instance using an 8 element seed. 046 * A seed containing all zeros will create a non-functional generator. 047 * 048 * @param seed0 Initial seed element 0. 049 * @param seed1 Initial seed element 1. 050 * @param seed2 Initial seed element 2. 051 * @param seed3 Initial seed element 3. 052 * @param seed4 Initial seed element 4. 053 * @param seed5 Initial seed element 5. 054 * @param seed6 Initial seed element 6. 055 * @param seed7 Initial seed element 7. 056 */ 057 public XoShiRo512PlusPlus(long seed0, long seed1, long seed2, long seed3, 058 long seed4, long seed5, long seed6, long seed7) { 059 super(seed0, seed1, seed2, seed3, seed4, seed5, seed6, seed7); 060 } 061 062 /** 063 * Creates a copy instance. 064 * 065 * @param source Source to copy. 066 */ 067 protected XoShiRo512PlusPlus(XoShiRo512PlusPlus source) { 068 super(source); 069 } 070 071 /** {@inheritDoc} */ 072 @Override 073 protected long nextOutput() { 074 return Long.rotateLeft(state0 + state2, 17) + state2; 075 } 076 077 /** {@inheritDoc} */ 078 @Override 079 protected XoShiRo512PlusPlus copy() { 080 // This exists to ensure the jump function performed in the super class returns 081 // the correct class type. It should not be public. 082 return new XoShiRo512PlusPlus(this); 083 } 084}