Re: [PATCH 1/4] core/conv: Add optimized Viterbi decoding

A beneficial change would be to modify the API to allow persistent decoder objects instead of performing an allocation and tear-down on every decoding call. From a performance standpoint, the current implementation is unnecessarily restricted by memory access and page faults for that reason.

Add a separate, faster convolution decoding implementation for rates up to N=4 and constraint lengths of K=5 and K=7, which covers the most GSM code uses. The decoding algorithm exploits the symmetric structure of the Viterbi add-compare-select (ACS) operation - commonly known as the ACS butterfly. This shift-register optimization can be found in the well-known text by Dave Forney. Forney, G.D., "The Viterbi Algorithm," Proc. of the IEEE, March 1973. Implementation is non-architecture specific and improves performance on x86 as well as ARM processors. Existing API is unchanged with optimized code being called internally for supported codes. Signed-off-by: Thomas Tsou &lt;tom(a)tsou.cc&gt; --- src/Makefile.am | 3 +- src/conv.c | 9 + src/viterbi.c | 603 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/viterbi_gen.c | 182 ++++++++++++++++ 4 files changed, 796 insertions(+), 1 deletion(-) create mode 100644 src/viterbi.c create mode 100644 src/viterbi_gen.c diff --git a/src/Makefile.am b/src/Makefile.am index e68c29a..262a4e6 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -13,7 +13,8 @@ libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c bits.c \ logging.c logging_syslog.c rate_ctr.c \ gsmtap_util.c crc16.c panic.c backtrace.c \ conv.c application.c rbtree.c strrb.c \ - loggingrb.c crc8gen.c crc16gen.c crc32gen.c crc64gen.c + loggingrb.c crc8gen.c crc16gen.c crc32gen.c crc64gen.c \ + viterbi.c viterbi_gen.c BUILT_SOURCES = crc8gen.c crc16gen.c crc32gen.c crc64gen.c diff --git a/src/conv.c b/src/conv.c index f13deef..79b3a7c 100644 --- a/src/conv.c +++ b/src/conv.c @@ -238,6 +238,11 @@ osmo_conv_encode(const struct osmo_conv_code *code, #define MAX_AE 0x00ffffff +/* Forward declaration for accerlated decoding with certain codes */ +int +osmo_conv_decode_acc(const struct osmo_conv_code *code, + const sbit_t *input, ubit_t *output); + void osmo_conv_decode_init(struct osmo_conv_decoder *decoder, const struct osmo_conv_code *code, int len, int start_state) @@ -606,6 +611,10 @@ osmo_conv_decode(const struct osmo_conv_code *code, struct osmo_conv_decoder decoder; int rv, l; + /* Use accelerated implementation for supported codes */ + if ((code->N <= 4) && ((code->K == 5) || (code->K == 7))) + return osmo_conv_decode_acc(code, input, output); + osmo_conv_decode_init(&decoder, code, 0, 0); if (code->term == CONV_TERM_TAIL_BITING) { diff --git a/src/viterbi.c b/src/viterbi.c new file mode 100644 index 0000000..db8d5c8 --- /dev/null +++ b/src/viterbi.c @@ -0,0 +1,603 @@ +/* + * Viterbi decoder + * Copyright (C) 2013, 2014 Thomas Tsou &lt;tom(a)tsou.cc&gt; + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "config.h" + +#include <stdlib.h> +#include <malloc.h> +#include <string.h> +#include <errno.h> +#include <osmocom/core/conv.h> + +/* Forward Metric Units */ +void gen_metrics_k5_n2(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +void gen_metrics_k5_n3(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +void gen_metrics_k5_n4(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +void gen_metrics_k7_n2(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +void gen_metrics_k7_n3(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +void gen_metrics_k7_n4(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm); +/* Trellis State + * state - Internal lshift register value + * prev - Register values of previous 0 and 1 states + */ +struct vstate { + unsigned state; + unsigned prev[2]; +}; + +/* Trellis Object + * num_states - Number of states in the trellis + * sums - Accumulated path metrics + * outputs - Trellis ouput values + * vals - Input value that led to each state + */ +struct vtrellis { + int num_states; + int16_t *sums; + int16_t *outputs; + uint8_t *vals; +}; + +/* Viterbi Decoder + * n - Code order + * k - Constraint length + * len - Horizontal length of trellis + * recursive - Set to '1' if the code is recursive + * intrvl - Normalization interval + * trellis - Trellis object + * punc - Puncturing sequence + * paths - Trellis paths + */ +struct vdecoder { + int n; + int k; + int len; + int recursive; + int intrvl; + struct vtrellis *trellis; + int *punc; + int16_t **paths; + + void (*metric_func)(const int8_t *, const int16_t *, + int16_t *, int16_t *, int); +}; + +/* Aligned Memory Allocator + * SSE requires 16-byte memory alignment. We store relevant trellis values + * (accumulated sums, outputs, and path decisions) as 16 bit signed integers + * so the allocated memory is casted as such. + */ +#define SSE_ALIGN 16 + +static int16_t *vdec_malloc(size_t n) +{ +#ifdef HAVE_SSE3 + return (int16_t *) memalign(SSE_ALIGN, sizeof(int16_t) * n); +#else + return (int16_t *) malloc(sizeof(int16_t) * n); +#endif +} + +/* Accessor calls */ +inline int conv_code_recursive(const struct osmo_conv_code *code) +{ + return code->next_term_output ? 1 : 0; +} + +/* Left shift and mask for finding the previous state */ +static unsigned vstate_lshift(unsigned reg, int k, int val) +{ + unsigned mask; + + if (k == 5) + mask = 0x0e; + else if (k == 7) + mask = 0x3e; + else + mask = 0; + + return ((reg << 1) & mask) | val; +} + +/* Bit endian manipulators */ +inline unsigned bitswap2(unsigned v) +{ + return ((v & 0x02) >> 1) | ((v & 0x01) << 1); +} + +inline unsigned bitswap3(unsigned v) +{ + return ((v & 0x04) >> 2) | ((v & 0x02) >> 0) | + ((v & 0x01) << 2); +} + +inline unsigned bitswap4(unsigned v) +{ + return ((v & 0x08) >> 3) | ((v & 0x04) >> 1) | + ((v & 0x02) << 1) | ((v & 0x01) << 3); +} + +inline unsigned bitswap5(unsigned v) +{ + return ((v & 0x10) >> 4) | ((v & 0x08) >> 2) | ((v & 0x04) >> 0) | + ((v & 0x02) << 2) | ((v & 0x01) << 4); +} + +inline unsigned bitswap6(unsigned v) +{ + return ((v & 0x20) >> 5) | ((v & 0x10) >> 3) | ((v & 0x08) >> 1) | + ((v & 0x04) << 1) | ((v & 0x02) << 3) | ((v & 0x01) << 5); +} + +static unsigned bitswap(unsigned v, unsigned n) +{ + switch (n) { + case 1: + return v; + case 2: + return bitswap2(v); + case 3: + return bitswap3(v); + case 4: + return bitswap4(v); + case 5: + return bitswap5(v); + case 6: + return bitswap6(v); + default: + break; + } + + return 0; +} + +/* Generate non-recursive state output from generator state table + * Note that the shift register moves right (i.e. the most recent bit is + * shifted into the register at k-1 bit of the register), which is typical + * textbook representation. The API transition table expects the most recent + * bit in the low order bit, or left shift. A bitswap operation is required + * to accommodate the difference. + */ +static unsigned gen_output(struct vstate *state, int val, + const struct osmo_conv_code *code) +{ + unsigned out, prev; + + prev = bitswap(state->prev[0], code->K - 1); + out = code->next_output[prev][val]; + out = bitswap(out, code->N); + + return out; +} + +#define BIT2NRZ(REG,N) (((REG >> N) & 0x01) * 2 - 1) * -1 + +/* Populate non-recursive trellis state + * For a given state defined by the k-1 length shift register, find the + * value of the input bit that drove the trellis to that state. Also + * generate the N outputs of the generator polynomial at that state. + */ +static int gen_state_info(uint8_t *val, unsigned reg, + int16_t *output, const struct osmo_conv_code *code) +{ + int i; + unsigned out; + struct vstate state; + + /* Previous '0' state */ + state.state = reg; + state.prev[0] = vstate_lshift(reg, code->K, 0); + state.prev[1] = vstate_lshift(reg, code->K, 1); + + *val = (reg >> (code->K - 2)) & 0x01; + + /* Transition output */ + out = gen_output(&state, *val, code); + + /* Unpack to NRZ */ + for (i = 0; i < code->N; i++) + output[i] = BIT2NRZ(out, i); + + return 0; +} + +/* Generate recursive state output from generator state table */ +static unsigned gen_recursive_output(struct vstate *state, + uint8_t *val, unsigned reg, + const struct osmo_conv_code *code, int pos) +{ + int val0, val1; + unsigned out, prev; + + /* Previous '0' state */ + prev = vstate_lshift(reg, code->K, 0); + prev = bitswap(prev, code->K - 1); + + /* Input value */ + val0 = (reg >> (code->K - 2)) & 0x01; + val1 = (code->next_term_output[prev] >> pos) & 0x01; + *val = val0 == val1 ? 0 : 1; + + /* Wrapper for osmocom state access */ + prev = bitswap(state->prev[0], code->K - 1); + + /* Compute the transition output */ + out = code->next_output[prev][*val]; + out = bitswap(out, code->N); + + return out; +} + +#define NUM_STATES(K) (K == 7 ? 64 : 16) + +/* Populate recursive trellis state + * The bit position of the systematic bit is not explicitly marked by the + * API, so it must be extracted from the generator table. Otherwise, + * populate the trellis similar to the non-recursive version. + * Non-systematic recursive codes are not supported. + */ +static int gen_recursive_state_info(uint8_t *val, + unsigned reg, + int16_t *output, + const struct osmo_conv_code *code) +{ + int i, j, pos = -1; + int ns = NUM_STATES(code->K); + unsigned out; + struct vstate state; + + /* Previous '0' and '1' states */ + state.state = reg; + state.prev[0] = vstate_lshift(reg, code->K, 0); + state.prev[1] = vstate_lshift(reg, code->K, 1); + + /* Find recursive bit location */ + for (i = 0; i < code->N; i++) { + for (j = 0; j < ns; j++) { + if ((code->next_output[j][0] >> i) & 0x01) + break; + } + if (j == ns) { + pos = i; + break; + } + } + + /* Non-systematic recursive code not supported */ + if (pos < 0) + return -EPROTO; + + /* Transition output */ + out = gen_recursive_output(&state, val, reg, code, pos); + + /* Unpack to NRZ */ + for (i = 0; i < code->N; i++) + output[i] = BIT2NRZ(out, i); + + return 0; +} + +/* Release the trellis */ +static void free_trellis(struct vtrellis *trellis) +{ + if (!trellis) + return; + + free(trellis->vals); + free(trellis->outputs); + free(trellis->sums); + free(trellis); +} + +/* Allocate and initialize the trellis object + * Initialization consists of generating the outputs and output value of a + * given state. Due to trellis symmetry and anti-symmetry, only one of the + * transition paths is utilized by the butterfly operation in the forward + * recursion, so only one set of N outputs is required per state variable. + */ +static struct vtrellis *generate_trellis(const struct osmo_conv_code *code) +{ + int i, rc = -1; + struct vtrellis *trellis; + int16_t *outputs; + + int ns = NUM_STATES(code->K); + int recursive = conv_code_recursive(code); + int olen = (code->N == 2) ? 2 : 4; + + trellis = (struct vtrellis *) calloc(1, sizeof(struct vtrellis)); + trellis->num_states = ns; + trellis->sums = vdec_malloc(ns); + trellis->outputs = vdec_malloc(ns * olen); + trellis->vals = (uint8_t *) malloc(ns * sizeof(uint8_t)); + + if (!trellis->sums || !trellis->outputs) + goto fail; + + /* Populate the trellis state objects */ + for (i = 0; i < ns; i++) { + outputs = &trellis->outputs[olen * i]; + + if (recursive) + rc = gen_recursive_state_info(&trellis->vals[i], + i, outputs, code); + else + rc = gen_state_info(&trellis->vals[i], + i, outputs, code); + } + + if (rc < 0) + goto fail; + + return trellis; +fail: + free_trellis(trellis); + return NULL; +} + +/* Reset decoder + * Set accumulated path metrics to zero. For termination other than + * tail-biting, initialize the zero state as the encoder starting state. + * Intialize with the maximum accumulated sum at length equal to the + * constraint length. + */ +static void reset_decoder(struct vdecoder *dec, int term) +{ + int ns = dec->trellis->num_states; + + memset(dec->trellis->sums, 0, sizeof(int16_t) * ns); + + if (term != CONV_TERM_TAIL_BITING) + dec->trellis->sums[0] = INT8_MAX * dec->n * dec->k; +} + +static void _traceback(struct vdecoder *dec, + unsigned state, uint8_t *out, int len) +{ + int i; + unsigned path; + + for (i = len - 1; i >= 0; i--) { + path = dec->paths[i][state] + 1; + out[i] = dec->trellis->vals[state]; + state = vstate_lshift(state, dec->k, path); + } +} + +static void _traceback_rec(struct vdecoder *dec, + unsigned state, uint8_t *out, int len) +{ + int i; + unsigned path; + + for (i = len - 1; i >= 0; i--) { + path = dec->paths[i][state] + 1; + out[i] = path ^ dec->trellis->vals[state]; + state = vstate_lshift(state, dec->k, path); + } +} + +/* Traceback and generate decoded output + * Find the largest accumulated path metric at the final state except for + * the zero terminated case, where we assume the final state is always zero. + */ +static int traceback(struct vdecoder *dec, uint8_t *out, int term, int len) +{ + int i, sum, max = -1; + unsigned path, state = 0; + + if (term != CONV_TERM_FLUSH) { + for (i = 0; i < dec->trellis->num_states; i++) { + sum = dec->trellis->sums[i]; + if (sum > max) { + max = sum; + state = i; + } + } + + if (max < 0) + return -EPROTO; + } + + for (i = dec->len - 1; i >= len; i--) { + path = dec->paths[i][state] + 1; + state = vstate_lshift(state, dec->k, path); + } + + if (dec->recursive) + _traceback_rec(dec, state, out, len); + else + _traceback(dec, state, out, len); + + return 0; +} + +/* Release decoder object */ +static void free_vdec(struct vdecoder *dec) +{ + if (!dec) + return; + + free(dec->paths[0]); + free(dec->paths); + free_trellis(dec->trellis); + free(dec); +} + +/* Allocate decoder object + * Subtract the constraint length K on the normalization interval to + * accommodate the initialization path metric at state zero. + */ +static struct vdecoder *alloc_vdec(const struct osmo_conv_code *code) +{ + int i, ns; + struct vdecoder *dec; + + ns = NUM_STATES(code->K); + + dec = (struct vdecoder *) calloc(1, sizeof(struct vdecoder)); + dec->n = code->N; + dec->k = code->K; + dec->recursive = conv_code_recursive(code); + dec->intrvl = INT16_MAX / (dec->n * INT8_MAX) - dec->k; + + if (dec->k == 5) { + switch (dec->n) { + case 2: + dec->metric_func = gen_metrics_k5_n2; + break; + case 3: + dec->metric_func = gen_metrics_k5_n3; + break; + case 4: + dec->metric_func = gen_metrics_k5_n4; + break; + default: + goto fail; + } + } else if (dec->k == 7) { + switch (dec->n) { + case 2: + dec->metric_func = gen_metrics_k7_n2; + break; + case 3: + dec->metric_func = gen_metrics_k7_n3; + break; + case 4: + dec->metric_func = gen_metrics_k7_n4; + break; + default: + goto fail; + } + } else { + goto fail; + } + + if (code->term == CONV_TERM_FLUSH) + dec->len = code->len + code->K - 1; + else + dec->len = code->len; + + dec->trellis = generate_trellis(code); + if (!dec->trellis) + goto fail; + + dec->paths = (int16_t **) malloc(sizeof(int16_t *) * dec->len); + dec->paths[0] = vdec_malloc(ns * dec->len); + for (i = 1; i < dec->len; i++) + dec->paths[i] = &dec->paths[0][i * ns]; + + return dec; +fail: + free_vdec(dec); + return NULL; +} + +/* Depuncture sequence with nagative value terminated puncturing matrix */ +static int depuncture(const int8_t *in, const int *punc, int8_t *out, int len) +{ + int i, n = 0, m = 0; + + for (i = 0; i < len; i++) { + if (i == punc[n]) { + out[i] = 0; + n++; + continue; + } + + out[i] = in[m++]; + } + + return 0; +} + +/* Forward trellis recursion + * Generate branch metrics and path metrics with a combined function. Only + * accumulated path metric sums and path selections are stored. Normalize on + * the interval specified by the decoder. + */ +static void _conv_decode(struct vdecoder *dec, const int8_t *seq, int _cnt) +{ + int i, len = dec->len; + struct vtrellis *trellis = dec->trellis; + + for (i = 0; i < len; i++) { + dec->metric_func(&seq[dec->n * i], + trellis->outputs, + trellis->sums, + dec->paths[i], + !(i % dec->intrvl)); + } +} + +/* Convolutional decode with a decoder object + * Initial puncturing run if necessary followed by the forward recursion. + * For tail-biting perform a second pass before running the backward + * traceback operation. + */ +static int conv_decode(struct vdecoder *dec, const int8_t *seq, + const int *punc, uint8_t *out, int len, int term) +{ + int cnt = 0; + int8_t depunc[dec->len * dec->n]; + + reset_decoder(dec, term); + + if (punc) { + depuncture(seq, punc, depunc, dec->len * dec->n); + seq = depunc; + } + + /* Propagate through the trellis with interval normalization */ + _conv_decode(dec, seq, cnt); + + if (term == CONV_TERM_TAIL_BITING) + _conv_decode(dec, seq, cnt); + + return traceback(dec, out, term, len); +} + +/* All-in-one viterbi decoding */ +int osmo_conv_decode_acc(const struct osmo_conv_code *code, + const sbit_t *input, ubit_t *output) +{ + int rc; + struct vdecoder *vdec; + + if ((code->N < 2) || (code->N > 4) || (code->len < 1) || + ((code->K != 5) && (code->K != 7))) + return -EINVAL; + + vdec = alloc_vdec(code); + if (!vdec) + return -EFAULT; + + rc = conv_decode(vdec, input, code->puncture, + output, code->len, code->term); + + free_vdec(vdec); + + return rc; +} diff --git a/src/viterbi_gen.c b/src/viterbi_gen.c new file mode 100644 index 0000000..894d5ae --- /dev/null +++ b/src/viterbi_gen.c @@ -0,0 +1,182 @@ +/* + * Viterbi decoder + * Copyright (C) 2013, 2014 Thomas Tsou &lt;tom(a)tsou.cc&gt; + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <stdint.h> +#include <string.h> + +/* Add-Compare-Select (ACS-Butterfly) + * Compute 4 accumulated path metrics and 4 path selections. Note that path + * selections are store as -1 and 0 rather than 0 and 1. This is to match + * the output format of the SSE packed compare instruction 'pmaxuw'. + */ +void acs_butterfly(int state, int num_states, + int16_t metric, int16_t *sum, + int16_t *new_sum, int16_t *path) +{ + int state0, state1; + int sum0, sum1, sum2, sum3; + + state0 = *(sum + (2 * state + 0)); + state1 = *(sum + (2 * state + 1)); + + sum0 = state0 + metric; + sum1 = state1 - metric; + sum2 = state0 - metric; + sum3 = state1 + metric; + + if (sum0 > sum1) { + *new_sum = sum0; + *path = -1; + } else { + *new_sum = sum1; + *path = 0; + } + + if (sum2 > sum3) { + *(new_sum + num_states / 2) = sum2; + *(path + num_states / 2) = -1; + } else { + *(new_sum + num_states / 2) = sum3; + *(path + num_states / 2) = 0; + } +} + +/* Branch metrics unit N=2 */ +void _gen_branch_metrics_n2(int num_states, const int8_t *seq, + const int16_t *out, int16_t *metrics) +{ + int i; + + for (i = 0; i < num_states / 2; i++) { + metrics[i] = seq[0] * out[2 * i + 0] + + seq[1] * out[2 * i + 1]; + } +} + +/* Branch metrics unit N=3 */ +void _gen_branch_metrics_n3(int num_states, const int8_t *seq, + const int16_t *out, int16_t *metrics) +{ + int i; + + for (i = 0; i < num_states / 2; i++) + metrics[i] = seq[0] * out[4 * i + 0] + + seq[1] * out[4 * i + 1] + + seq[2] * out[4 * i + 2]; +} + +/* Branch metrics unit N=4 */ +void _gen_branch_metrics_n4(int num_states, const int8_t *seq, + const int16_t *out, int16_t *metrics) +{ + int i; + + for (i = 0; i < num_states / 2; i++) + metrics[i] = seq[0] * out[4 * i + 0] + + seq[1] * out[4 * i + 1] + + seq[2] * out[4 * i + 2] + + seq[3] * out[4 * i + 3]; +} + +/* Path metric unit */ +void _gen_path_metrics(int num_states, int16_t *sums, + int16_t *metrics, int16_t *paths, int norm) +{ + int i; + int16_t min; + int16_t new_sums[num_states]; + + for (i = 0; i < num_states / 2; i++) { + acs_butterfly(i, num_states, metrics[i], + sums, &new_sums[i], &paths[i]); + } + + if (norm) { + min = new_sums[0]; + for (i = 1; i < num_states; i++) { + if (new_sums[i] < min) + min = new_sums[i]; + } + + for (i = 0; i < num_states; i++) + new_sums[i] -= min; + } + + memcpy(sums, new_sums, num_states * sizeof(int16_t)); +} + +/* 16-state branch-path metrics units (K=5) */ +void gen_metrics_k5_n2(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[8]; + + _gen_branch_metrics_n2(16, seq, out, metrics); + _gen_path_metrics(16, sums, metrics, paths, norm); +} + +void gen_metrics_k5_n3(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[8]; + + _gen_branch_metrics_n3(16, seq, out, metrics); + _gen_path_metrics(16, sums, metrics, paths, norm); + +} + +void gen_metrics_k5_n4(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[8]; + + _gen_branch_metrics_n4(16, seq, out, metrics); + _gen_path_metrics(16, sums, metrics, paths, norm); + +} + +/* 64-state branch-path metrics units (K=7) */ +void gen_metrics_k7_n2(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[32]; + + _gen_branch_metrics_n2(64, seq, out, metrics); + _gen_path_metrics(64, sums, metrics, paths, norm); + +} + +void gen_metrics_k7_n3(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[32]; + + _gen_branch_metrics_n3(64, seq, out, metrics); + _gen_path_metrics(64, sums, metrics, paths, norm); + +} + +void gen_metrics_k7_n4(const int8_t *seq, const int16_t *out, + int16_t *sums, int16_t *paths, int norm) +{ + int16_t metrics[32]; + + _gen_branch_metrics_n4(64, seq, out, metrics); + _gen_path_metrics(64, sums, metrics, paths, norm); +} -- 1.9.0