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https://github.com/ggml-org/llama.cpp.git
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Add back top_k (#56)
* Add back top_k * Update utils.cpp * Update utils.h --------- Co-authored-by: Bill Hamilton <bill.hamilton@shopify.com> Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
This commit is contained in:
79
utils.cpp
79
utils.cpp
@@ -301,25 +301,8 @@ bool gpt_vocab_init(const std::string & fname, gpt_vocab & vocab) {
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return true;
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}
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gpt_vocab::id gpt_sample_top_k_top_p(
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const gpt_vocab & vocab,
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const float * logits,
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int top_k,
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double top_p,
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double temp,
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std::mt19937 & rng) {
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int n_logits = vocab.id_to_token.size();
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std::vector<std::pair<double, gpt_vocab::id>> logits_id;
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logits_id.reserve(n_logits);
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{
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const double scale = 1.0/temp;
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for (int i = 0; i < n_logits; ++i) {
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logits_id.push_back(std::make_pair(logits[i]*scale, i));
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}
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}
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void sample_top_k(std::vector<std::pair<double, gpt_vocab::id>> & logits_id, int top_k) {
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// find the top K tokens
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std::partial_sort(
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logits_id.begin(),
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@@ -329,63 +312,14 @@ gpt_vocab::id gpt_sample_top_k_top_p(
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});
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logits_id.resize(top_k);
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double maxl = -INFINITY;
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for (const auto & kv : logits_id) {
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maxl = std::max(maxl, kv.first);
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}
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// compute probs for the top K tokens
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std::vector<double> probs;
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probs.reserve(logits_id.size());
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double sum = 0.0;
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for (const auto & kv : logits_id) {
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double p = exp(kv.first - maxl);
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probs.push_back(p);
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sum += p;
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}
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// normalize the probs
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for (auto & p : probs) {
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p /= sum;
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}
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if (top_p < 1.0f) {
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double cumsum = 0.0f;
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for (int i = 0; i < top_k; i++) {
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cumsum += probs[i];
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if (cumsum >= top_p) {
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top_k = i + 1;
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probs.resize(top_k);
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logits_id.resize(top_k);
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break;
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}
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}
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cumsum = 1.0/cumsum;
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for (int i = 0; i < (int) probs.size(); i++) {
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probs[i] *= cumsum;
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}
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}
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//printf("\n");
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//for (int i = 0; i < (int) probs.size(); i++) {
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// printf("%d: '%s' %f\n", i, vocab.id_to_token.at(logits_id[i].second).c_str(), probs[i]);
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//}
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//exit(0);
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std::discrete_distribution<> dist(probs.begin(), probs.end());
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int idx = dist(rng);
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return logits_id[idx].second;
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}
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gpt_vocab::id llama_sample_top_p(
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gpt_vocab::id llama_sample_top_p_top_k(
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const gpt_vocab & vocab,
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const float * logits,
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std::vector<gpt_vocab::id> & last_n_tokens,
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double repeat_penalty,
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int top_k,
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double top_p,
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double temp,
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std::mt19937 & rng) {
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@@ -412,12 +346,7 @@ gpt_vocab::id llama_sample_top_p(
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}
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}
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std::sort(
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logits_id.begin(),
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logits_id.end(),
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[](const std::pair<double, gpt_vocab::id> & a, const std::pair<double, gpt_vocab::id> & b) {
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return a.first > b.first;
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});
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sample_top_k(logits_id, top_k);
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double maxl = -INFINITY;
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for (const auto & kv : logits_id) {
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