Gabriele Cosmo
49 lines
2.0 KiB
C++
49 lines
2.0 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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//
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#ifndef G4QUICKRAND_HH
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#define G4QUICKRAND_HH
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#include "G4Types.hh"
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#include <cstdint>
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inline G4double G4QuickRand()
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{
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static const G4double f = 1. / 4294967296.; // 2^-32
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// Algorithm "xor" from p.4 of G.Marsaglia, "Xorshift RNGs"
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static G4ThreadLocal uint32_t y = 2463534242;
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uint32_t x = y;
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x ^= x << 13;
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x ^= x >> 17;
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x ^= x << 5;
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y = x;
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return x * f;
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}
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#endif // G4QUICKRAND_HH
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