vbatts/llama.cpp
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perplexity: add top-token probability

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This commit is contained in:
Iwan Kawrakow 2024-01-22 17:11:57 +02:00
parent 6f9939d119
commit 8128fa0bd3
1 changed files with 20 additions and 4 deletions
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24
examples/perplexity/perplexity.cpp
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@ -222,13 +222,18 @@ struct kl_divergence_result {
double sum_kld2 = 0;
double sum_nll_diff = 0;
double sum_nll_diff2 = 0;
size_t n_same_top = 0;
size_t count = 0;
};
static void log_softmax(int n_vocab, const float * logits, const uint16_t * base_log_prob, int tok, kl_divergence_result & kld) {
float max_logit = logits[0];
int imax = 0;
for (int i = 1; i < n_vocab; ++i) {
max_logit = std::max(max_logit, logits[i]);
if (logits[i] > max_logit) {
max_logit = logits[i];
imax = i;
}
}
double sum_exp = 0.0;
for (int i = 0; i < n_vocab; ++i) {
@ -247,8 +252,14 @@ static void log_softmax(int n_vocab, const float * logits, const uint16_t * base
kld.sum_nll_diff2 += nll*nll;
max_logit += log_sum_exp;
double sum = 0;
int imax_base = -1;
float p_log_base_max = 0;
for (int i = 0; i < n_vocab; ++i) {
const float p_log_base = scale*base_log_prob[i] + min_log_prob;
if (i == 0 || p_log_base > p_log_base_max) {
p_log_base_max = p_log_base;
imax_base = i;
}
if (p_log_base > -16.f) {
const float p_base = expf(p_log_base);
sum += p_base * (p_log_base - logits[i] + max_logit);
@ -257,6 +268,7 @@ static void log_softmax(int n_vocab, const float * logits, const uint16_t * base
kld.sum_kld += sum;
kld.sum_kld2 += sum*sum;
++kld.count;
if (imax == imax_base) ++kld.n_same_top;
}
static void process_logits(int n_vocab, const float * logits, const int * tokens, int n_token,
@ -276,6 +288,7 @@ static void process_logits(int n_vocab, const float * logits, const int * tokens
kld.sum_kld2 += local_kld.sum_kld2;
kld.sum_nll_diff += local_kld.sum_nll_diff;
kld.sum_nll_diff2 += local_kld.sum_nll_diff2;
kld.n_same_top += local_kld.n_same_top;
kld.count += local_kld.count;
break;
}
@ -1705,7 +1718,7 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
}
fprintf(stderr, "%.2f minutes\n", total_seconds / 60.0);
printf("\nchunk PPL ln(PPL(Q)/PPL(base)) KL-Divergence\n");
printf("\nchunk PPL ln(PPL(Q)/PPL(base)) KL-Divergence Same top\n");
}
const int first = n_ctx/2;
@ -1716,9 +1729,12 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
auto ppl = mean_and_uncertainty(kld.sum_nll, kld.sum_nll2, kld.count);
auto log_ppl_ratio = mean_and_uncertainty(kld.sum_nll_diff, kld.sum_nll_diff2, kld.count);
auto kl_div = mean_and_uncertainty(kld.sum_kld, kld.sum_kld2, kld.count);
auto p_top = 1.*kld.n_same_top/kld.count;
auto d_p_top = sqrt(p_top*(1 - p_top)/(kld.count - 1));
printf("%4d %10.4lf %10.5lf ± %10.5f %10.5f ± %10.5lf\n", i+1, exp(ppl.first),
log_ppl_ratio.first, log_ppl_ratio.second, kl_div.first, kl_div.second);
printf("%4d %10.4lf %10.5lf ± %10.5f %10.5f ± %10.5lf %.5f ± %.5f\n", i+1, exp(ppl.first),
log_ppl_ratio.first, log_ppl_ratio.second, kl_div.first, kl_div.second,
p_top, d_p_top);
fflush(stdout);