conv_acc.c File Reference

Accelerated Viterbi decoder implementation. More...

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "config.h"
#include <osmocom/core/conv.h>

Data Structures
struct	vtrellis
struct	vdecoder

Macros
#define	BIT2NRZ(REG, N)
#define	NUM_STATES(K)
#define	INIT_POINTERS(simd)

Functions
	__attribute__ ((visibility("hidden")))
static int	conv_code_recursive (const struct osmo_conv_code *code)
static unsigned	vstate_lshift (unsigned reg, int k, int val)
static unsigned	bitswap2 (unsigned v)
static unsigned	bitswap3 (unsigned v)
static unsigned	bitswap4 (unsigned v)
static unsigned	bitswap5 (unsigned v)
static unsigned	bitswap6 (unsigned v)
static unsigned	bitswap (unsigned v, unsigned n)
static unsigned	gen_output (struct vstate *state, int val, const struct osmo_conv_code *code)
static int	gen_state_info (uint8_t *val, unsigned reg, int16_t *output, const struct osmo_conv_code *code)
static unsigned	gen_recursive_output (struct vstate *state, uint8_t *val, unsigned reg, const struct osmo_conv_code *code, int pos)
static int	gen_recursive_state_info (uint8_t *val, unsigned reg, int16_t *output, const struct osmo_conv_code *code)
static void	free_trellis (struct vtrellis *trellis)
static int	generate_trellis (struct vdecoder *dec, const struct osmo_conv_code *code)
static void	_traceback (struct vdecoder *dec, unsigned state, uint8_t *out, int len)
static void	_traceback_rec (struct vdecoder *dec, unsigned state, uint8_t *out, int len)
static int	traceback (struct vdecoder *dec, uint8_t *out, int term, int len)
static void	vdec_deinit (struct vdecoder *dec)
static int	vdec_init (struct vdecoder *dec, const struct osmo_conv_code *code)
static int	depuncture (const int8_t *in, const int *punc, int8_t *out, int len)
static void	forward_traverse (struct vdecoder *dec, const int8_t *seq)
static int	conv_decode (struct vdecoder *dec, const int8_t *seq, const int *punc, uint8_t *out, int len, int term)
static void	osmo_conv_init (void)
int	osmo_conv_decode_acc (const struct osmo_conv_code *code, const sbit_t *input, ubit_t *output)

Variables
static int	init_complete = 0

Detailed Description

Accelerated Viterbi decoder implementation.

Macro Definition Documentation

BIT2NRZ

#define BIT2NRZ	(		REG,
			N )

Value:

(((REG >> N) & 0x01) * 2 - 1) * -1

Referenced by gen_recursive_state_info(), and gen_state_info().

INIT_POINTERS

#define INIT_POINTERS

(

simd

)

Value:

{ \
        osmo_conv_metrics_k5_n2 = osmo_conv_##simd##_metrics_k5_n2; \
        osmo_conv_metrics_k5_n3 = osmo_conv_##simd##_metrics_k5_n3; \
        osmo_conv_metrics_k5_n4 = osmo_conv_##simd##_metrics_k5_n4; \
        osmo_conv_metrics_k7_n2 = osmo_conv_##simd##_metrics_k7_n2; \
        osmo_conv_metrics_k7_n3 = osmo_conv_##simd##_metrics_k7_n3; \
        osmo_conv_metrics_k7_n4 = osmo_conv_##simd##_metrics_k7_n4; \
        vdec_malloc = &osmo_conv_##simd##_vdec_malloc; \
        vdec_free = &osmo_conv_##simd##_vdec_free; \
}

Referenced by osmo_conv_init().

NUM_STATES

#define NUM_STATES

(

K

)

Value:

(K == 7 ? 64 : 16)

Referenced by gen_recursive_state_info(), generate_trellis(), and vdec_init().

Function Documentation

__attribute__()

__attribute__

(

(visibility("hidden"))

)

References __attribute__, and sse41_supported.

_traceback()

void _traceback ( struct vdecoder * dec, unsigned state, uint8_t * out, int len )

static

References _traceback(), vdecoder::k, vdecoder::paths, vdecoder::trellis, vtrellis::vals, and vstate_lshift().

Referenced by _traceback(), and traceback().

_traceback_rec()

void _traceback_rec ( struct vdecoder * dec, unsigned state, uint8_t * out, int len )

static

References _traceback_rec(), vdecoder::k, vdecoder::paths, vdecoder::trellis, vtrellis::vals, and vstate_lshift().

Referenced by _traceback_rec(), and traceback().

bitswap()

unsigned bitswap ( unsigned v, unsigned n )

static

References bitswap(), bitswap2(), bitswap3(), bitswap4(), bitswap5(), and bitswap6().

Referenced by bitswap(), gen_output(), and gen_recursive_output().

bitswap2()

unsigned bitswap2 ( unsigned v )

inlinestatic

References bitswap2().

Referenced by bitswap(), and bitswap2().

bitswap3()

unsigned bitswap3 ( unsigned v )

inlinestatic

References bitswap3().

Referenced by bitswap(), and bitswap3().

bitswap4()

unsigned bitswap4 ( unsigned v )

inlinestatic

References bitswap4().

Referenced by bitswap(), and bitswap4().

bitswap5()

unsigned bitswap5 ( unsigned v )

inlinestatic

References bitswap5().

Referenced by bitswap(), and bitswap5().

bitswap6()

unsigned bitswap6 ( unsigned v )

inlinestatic

References bitswap6().

Referenced by bitswap(), and bitswap6().

conv_code_recursive()

int conv_code_recursive ( const struct osmo_conv_code * code )

inlinestatic

References conv_code_recursive(), and osmo_conv_code::next_term_output.

Referenced by conv_code_recursive(), and vdec_init().

conv_decode()

int conv_decode ( struct vdecoder * dec, const int8_t * seq, const int * punc, uint8_t * out, int len, int term )

static

References conv_decode(), CONV_TERM_TAIL_BITING, depuncture(), forward_traverse(), vdecoder::len, vdecoder::n, and traceback().

Referenced by conv_decode(), and osmo_conv_decode_acc().

depuncture()

int depuncture ( const int8_t * in, const int * punc, int8_t * out, int len )

static

References depuncture().

Referenced by conv_decode(), and depuncture().

forward_traverse()

void forward_traverse ( struct vdecoder * dec, const int8_t * seq )

static

References forward_traverse(), vdecoder::intrvl, vdecoder::len, vdecoder::metric_func, vdecoder::n, vtrellis::outputs, vdecoder::paths, vtrellis::sums, and vdecoder::trellis.

Referenced by conv_decode(), and forward_traverse().

free_trellis()

void free_trellis ( struct vtrellis * trellis )

static

References free_trellis(), vtrellis::outputs, vtrellis::sums, and vtrellis::vals.

Referenced by free_trellis(), generate_trellis(), and vdec_deinit().

gen_output()

unsigned gen_output ( struct vstate * state, int val, const struct osmo_conv_code * code )

static

References bitswap(), gen_output(), osmo_conv_code::K, osmo_conv_code::N, and osmo_conv_code::next_output.

Referenced by gen_output(), and gen_state_info().

gen_recursive_output()

unsigned gen_recursive_output ( struct vstate * state, uint8_t * val, unsigned reg, const struct osmo_conv_code * code, int pos )

static

References bitswap(), gen_recursive_output(), osmo_conv_code::K, osmo_conv_code::N, osmo_conv_code::next_output, osmo_conv_code::next_term_output, and vstate_lshift().

Referenced by gen_recursive_output(), and gen_recursive_state_info().

gen_recursive_state_info()

int gen_recursive_state_info ( uint8_t * val, unsigned reg, int16_t * output, const struct osmo_conv_code * code )

static

References BIT2NRZ, gen_recursive_output(), gen_recursive_state_info(), osmo_conv_code::K, osmo_conv_code::N, osmo_conv_code::next_output, NUM_STATES, and vstate_lshift().

Referenced by gen_recursive_state_info(), and generate_trellis().

gen_state_info()

int gen_state_info ( uint8_t * val, unsigned reg, int16_t * output, const struct osmo_conv_code * code )

static

References BIT2NRZ, gen_output(), gen_state_info(), osmo_conv_code::K, osmo_conv_code::N, and vstate_lshift().

Referenced by gen_state_info(), and generate_trellis().

generate_trellis()

int generate_trellis ( struct vdecoder * dec, const struct osmo_conv_code * code )

static

For termination other than tail-biting, initialize the zero state as the encoder starting state. Initialize with the maximum accumulated sum at length equal to the constraint length.

References CONV_TERM_TAIL_BITING, free_trellis(), gen_recursive_state_info(), gen_state_info(), generate_trellis(), osmo_conv_code::K, osmo_conv_code::N, NUM_STATES, vtrellis::num_states, vtrellis::outputs, vdecoder::recursive, vtrellis::sums, osmo_conv_code::term, vdecoder::trellis, and vtrellis::vals.

Referenced by generate_trellis(), and vdec_init().

osmo_conv_init()

void osmo_conv_init ( void )

static

Usage of curly braces is mandatory, because we use multi-line define.

References init_complete, INIT_POINTERS, osmo_conv_init(), and sse41_supported.

Referenced by osmo_conv_decode_acc(), and osmo_conv_init().

traceback()

int traceback ( struct vdecoder * dec, uint8_t * out, int term, int len )

static

References _traceback(), _traceback_rec(), CONV_TERM_FLUSH, CONV_TERM_TAIL_BITING, vdecoder::k, vdecoder::len, vtrellis::num_states, vdecoder::paths, vdecoder::recursive, vtrellis::sums, traceback(), vdecoder::trellis, and vstate_lshift().

Referenced by conv_decode(), and traceback().

vdec_deinit()

void vdec_deinit ( struct vdecoder * dec )

static

References free_trellis(), vdecoder::paths, vdecoder::trellis, and vdec_deinit().

Referenced by osmo_conv_decode_acc(), vdec_deinit(), and vdec_init().

vdec_init()

int vdec_init ( struct vdecoder * dec, const struct osmo_conv_code * code )

static

References conv_code_recursive(), CONV_TERM_FLUSH, generate_trellis(), vdecoder::intrvl, osmo_conv_code::K, vdecoder::k, osmo_conv_code::len, vdecoder::len, vdecoder::metric_func, osmo_conv_code::N, vdecoder::n, NUM_STATES, vdecoder::paths, vdecoder::recursive, osmo_conv_code::term, vdec_deinit(), and vdec_init().

Referenced by osmo_conv_decode_acc(), and vdec_init().

vstate_lshift()

unsigned vstate_lshift ( unsigned reg, int k, int val )

static

References vstate_lshift().

Referenced by _traceback(), _traceback_rec(), gen_recursive_output(), gen_recursive_state_info(), gen_state_info(), traceback(), and vstate_lshift().

Variable Documentation

init_complete

int init_complete = 0

static

Referenced by osmo_conv_decode_acc(), and osmo_conv_init().