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Delaying the softmax() to avoid the pow()

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Now at 5x real-time, with all the low-hanging fruit done.
This commit is contained in:
Jean-Marc Valin 2018-11-29 20:09:36 -05:00
parent faf3fe3d24
commit d7f0abcd19
1 changed files with 19 additions and 0 deletions
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19
dnn/nnet.c
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@ -39,6 +39,8 @@
#include "nnet.h"
#include "nnet_data.h"
#define SOFTMAX_HACK
#ifdef __AVX2__
#include <immintrin.h>
static __m256 exp8_approx(__m256 X)
@ -340,6 +342,10 @@ void compute_activation(float *output, float *input, int N, int activation)
for (i=0;i<N;i++)
output[i] = relu(input[i]);
} else if (activation == ACTIVATION_SOFTMAX) {
#ifdef SOFTMAX_HACK
for (i=0;i<N;i++)
output[i] = input[i];
#else
float sum = 0;
softmax(output, input, N);
for (i=0;i<N;i++) {
@ -348,6 +354,7 @@ void compute_activation(float *output, float *input, int N, int activation)
sum = 1.f/(sum+1e-30);
for (i=0;i<N;i++)
output[i] = sum*output[i];
#endif
} else {
celt_assert(activation == ACTIVATION_LINEAR);
for (i=0;i<N;i++)
@ -619,12 +626,24 @@ int sample_from_pdf(const float *pdf, int N, float exp_boost, float pdf_floor)
float tmp[DUAL_FC_OUT_SIZE];
celt_assert(N <= DUAL_FC_OUT_SIZE);
sum = 0;
#ifdef SOFTMAX_HACK
for (i=0;i<N;i++)
{
tmp[i] = pdf[i] * (1.f+exp_boost);
}
softmax(tmp, tmp, N);
for (i=0;i<N;i++)
{
sum += tmp[i];
}
#else
/* Decrease the temperature of the sampling. */
for (i=0;i<N;i++)
{
tmp[i] = pow(pdf[i], 1.f+exp_boost);
sum += tmp[i];
}
#endif
norm = 1.f/sum;
/* Convert tmp to a CDF while subtracting the floor */
tmp[0] = MAX16(0, norm*tmp[0] - pdf_floor);