viterbi_decoder_x86.h

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/*
 * Copyright (C) 2016 Bastian Bloessl <bloessl@ccs-labs.org>
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef INCLUDED_IEEE802_11_VITERBI_DECODER_X86_H
#define INCLUDED_IEEE802_11_VITERBI_DECODER_X86_H
 
#include "base.h"
#include <xmmintrin.h>
 
namespace gr {
namespace ieee802_11 {
 
/* This Viterbi decoder was taken from the gr-dvbt module of
 * GNU Radio. It is an SSE2 version of the Viterbi Decoder
 * created by Phil Karn. The SSE2 version was made by Bogdan
 * Diaconescu. For more info see: gr-dvbt/lib/d_viterbi.h
 */
class viterbi_decoder : public base
{
public:
    virtual uint8_t* decode(ofdm_param* ofdm, frame_param* frame, uint8_t* in);
 
private:
    union branchtab27 {
        unsigned char c[32];
        __m128i v[2];
    } d_branchtab27_sse2[2];
 
    alignas(16) __m128i d_metric0[4];
    alignas(16) __m128i d_metric1[4];
    alignas(16) __m128i d_path0[4];
    alignas(16) __m128i d_path1[4];
 
    virtual void reset();
 
    void viterbi_chunks_init_sse2();
    void viterbi_butterfly2_sse2(
        unsigned char* symbols, __m128i m0[], __m128i m1[], __m128i p0[], __m128i p1[]);
    unsigned char viterbi_get_output_sse2(__m128i* mm0,
                                          __m128i* pp0,
                                          int ntraceback,
                                          unsigned char* outbuf);
};
 
} // namespace ieee802_11
} // namespace gr
 
#endif /* INCLUDED_IEEE802_11_VITERBI_DECODER_X86_H */