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 large-state all-purpose 64-bit generator. 022 * 023 * <p>This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 1024 bits 024 * and the period is 2<sup>1024</sup>-1.</p> 025 * 026 * <p>Note: This can be used as a replacement for {@link XorShift1024Star}.</p> 027 * 028 * @see <a href="http://xorshift.di.unimi.it/xoroshiro1024plusplus.c">Original source code</a> 029 * @see <a href="http://xoshiro.di.unimi.it/">xorshiro / xoroshiro generators</a> 030 * @since 1.3 031 */ 032public class XoRoShiRo1024PlusPlus extends AbstractXoRoShiRo1024 { 033 /** 034 * Creates a new instance. 035 * 036 * @param seed Initial seed. 037 * If the length is larger than 16, only the first 16 elements will 038 * be used; if smaller, the remaining elements will be automatically 039 * set. A seed containing all zeros will create a non-functional generator. 040 */ 041 public XoRoShiRo1024PlusPlus(long[] seed) { 042 super(seed); 043 } 044 045 /** 046 * Creates a copy instance. 047 * 048 * @param source Source to copy. 049 */ 050 protected XoRoShiRo1024PlusPlus(XoRoShiRo1024PlusPlus source) { 051 super(source); 052 } 053 054 /** {@inheritDoc} */ 055 @Override 056 protected long transform(long s0, long s15) { 057 return Long.rotateLeft(s0 + s15, 23) + s15; 058 } 059 060 /** {@inheritDoc} */ 061 @Override 062 protected XoRoShiRo1024PlusPlus copy() { 063 // This exists to ensure the jump function returns 064 // the correct class type. It should not be public. 065 return new XoRoShiRo1024PlusPlus(this); 066 } 067}