/* -*- c++ -*- */

/*

 * Copyright 2007 Free Software Foundation, Inc.

 * 

 * This file is part of GNU Radio

 * 

 * GNU Radio is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3, or (at your option)

 * any later version.

 * 

 * GNU Radio is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with GNU Radio; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

#include <gri_glfsr.h>

#include <stdexcept>

static int s_polynomial_masks[] = {

  0x00000000,

  0x00000001,                        // x^1 + 1

  0x00000003,                   // x^2 + x^1 + 1

  0x00000005,                   // x^3 + x^1 + 1

  0x00000009,                        // x^4 + x^1 + 1

  0x00000012,                        // x^5 + x^2 + 1

  0x00000021,                        // x^6 + x^1 + 1

  0x00000041,                   // x^7 + x^1 + 1

  0x0000008E,                        // x^8 + x^4 + x^3 + x^2 + 1

  0x00000108,                        // x^9 + x^4 + 1

  0x00000204,                        // x^10 + x^4 + 1

  0x00000402,                        // x^11 + x^2 + 1

  0x00000829,                        // x^12 + x^6 + x^4 + x^1 + 1

  0x0000100D,                        // x^13 + x^4 + x^3 + x^1 + 1

  0x00002015,                        // x^14 + x^5 + x^3 + x^1 + 1

  0x00004001,                        // x^15 + x^1 + 1

  0x00008016,                        // x^16 + x^5 + x^3 + x^2 + 1

  0x00010004,                        // x^17 + x^3 + 1

  0x00020013,                        // x^18 + x^5 + x^2 + x^1 + 1

  0x00040013,                        // x^19 + x^5 + x^2 + x^1 + 1

  0x00080004,                        // x^20 + x^3 + 1

  0x00100002,                        // x^21 + x^2 + 1

  0x00200001,                        // x^22 + x^1 + 1

  0x00400010,                        // x^23 + x^5 + 1

  0x0080000D,                        // x^24 + x^4 + x^3 + x^1 + 1

  0x01000004,                        // x^25 + x^3 + 1

  0x02000023,                        // x^26 + x^6 + x^2 + x^1 + 1

  0x04000013,                        // x^27 + x^5 + x^2 + x^1 + 1

  0x08000004,                        // x^28 + x^3 + 1

  0x10000002,                        // x^29 + x^2 + 1

  0x20000029,                        // x^30 + x^4 + x^1 + 1

  0x40000004,                        // x^31 + x^3 + 1

  0x80000057                        // x^32 + x^7 + x^5 + x^3 + x^2 + x^1 + 1

};

int gri_glfsr::glfsr_mask(int degree)

{

  if (degree < 1 || degree > 32)

    throw std::runtime_error("gri_glfsr::glfsr_mask(): degree must be between 1 and 32 inclusive");

  return s_polynomial_masks[degree];

}