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/* -*- c++ -*- */
/*
* Copyright 2006,2012 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "util.h"
namespace gr {
namespace pager {
unsigned char
reverse_bits8(unsigned char val)
{
// This method was attributed to Rich Schroeppel in the Programming
// Hacks section of Beeler, M., Gosper, R. W., and Schroeppel, R.
// HAKMEM. MIT AI Memo 239, Feb. 29, 1972.
//
// Reverses 8 bits in 5 machine operations with 64 bit arch
return (val * 0x0202020202ULL & 0x010884422010ULL) % 1023;
}
int32_t
reverse_bits32(int32_t val)
{
int32_t out = 0x00000000;
out |= (reverse_bits8((val >> 24) & 0x000000FF) );
out |= (reverse_bits8((val >> 16) & 0x000000FF) << 8);
out |= (reverse_bits8((val >> 8) & 0x000000FF) << 16);
out |= (reverse_bits8((val ) & 0x000000FF) << 24);
return out;
}
} /* namespace pager */
} /* namespace gr */
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