ref: 1f891e3616b4e8b17276830930c296c9f88332e3
dir: /src/mlp.c/
/* Copyright (c) 2008-2011 Octasic Inc.
2012-2017 Jean-Marc Valin */
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include "opus_types.h"
#include "opus_defines.h"
#include "arch.h"
#include "tansig_table.h"
#include "mlp.h"
static OPUS_INLINE float tansig_approx(float x)
{
int i;
float y, dy;
float sign=1;
/* Tests are reversed to catch NaNs */
if (!(x<8))
return 1;
if (!(x>-8))
return -1;
#ifndef FIXED_POINT
/* Another check in case of -ffast-math */
if (celt_isnan(x))
return 0;
#endif
if (x<0)
{
x=-x;
sign=-1;
}
i = (int)floor(.5f+25*x);
x -= .04f*i;
y = tansig_table[i];
dy = 1-y*y;
y = y + x*dy*(1 - y*x);
return sign*y;
}
static OPUS_INLINE float sigmoid_approx(float x)
{
return .5f + .5f*tansig_approx(.5f*x);
}
static void gemm_accum(float *out, const opus_int8 *weights, int rows, int cols, int col_stride, const float *x)
{
int i, j;
for (i=0;i<rows;i++)
{
for (j=0;j<cols;j++)
out[i] += weights[j*col_stride + i]*x[j];
}
}
void compute_dense(const DenseLayer *layer, float *output, const float *input)
{
int i;
int N, M;
int stride;
M = layer->nb_inputs;
N = layer->nb_neurons;
stride = N;
for (i=0;i<N;i++)
output[i] = layer->bias[i];
gemm_accum(output, layer->input_weights, N, M, stride, input);
for (i=0;i<N;i++)
output[i] *= WEIGHTS_SCALE;
if (layer->sigmoid) {
for (i=0;i<N;i++)
output[i] = sigmoid_approx(output[i]);
} else {
for (i=0;i<N;i++)
output[i] = tansig_approx(output[i]);
}
}
void compute_gru(const GRULayer *gru, float *state, const float *input)
{
int i;
int N, M;
int stride;
float tmp[MAX_NEURONS];
float z[MAX_NEURONS];
float r[MAX_NEURONS];
float h[MAX_NEURONS];
M = gru->nb_inputs;
N = gru->nb_neurons;
stride = 3*N;
/* Compute update gate. */
for (i=0;i<N;i++)
z[i] = gru->bias[i];
gemm_accum(z, gru->input_weights, N, M, stride, input);
gemm_accum(z, gru->recurrent_weights, N, N, stride, state);
for (i=0;i<N;i++)
z[i] = sigmoid_approx(WEIGHTS_SCALE*z[i]);
/* Compute reset gate. */
for (i=0;i<N;i++)
r[i] = gru->bias[N + i];
gemm_accum(r, &gru->input_weights[N], N, M, stride, input);
gemm_accum(r, &gru->recurrent_weights[N], N, N, stride, state);
for (i=0;i<N;i++)
r[i] = sigmoid_approx(WEIGHTS_SCALE*r[i]);
/* Compute output. */
for (i=0;i<N;i++)
h[i] = gru->bias[2*N + i];
for (i=0;i<N;i++)
tmp[i] = state[i] * r[i];
gemm_accum(h, &gru->input_weights[2*N], N, M, stride, input);
gemm_accum(h, &gru->recurrent_weights[2*N], N, N, stride, tmp);
for (i=0;i<N;i++)
h[i] = z[i]*state[i] + (1-z[i])*tansig_approx(WEIGHTS_SCALE*h[i]);
for (i=0;i<N;i++)
state[i] = h[i];
}