diff options
Diffstat (limited to 'examples/perplexity')
-rw-r--r-- | examples/perplexity/perplexity.cpp | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/examples/perplexity/perplexity.cpp b/examples/perplexity/perplexity.cpp index 75d526d..07ed0a8 100644 --- a/examples/perplexity/perplexity.cpp +++ b/examples/perplexity/perplexity.cpp @@ -1,15 +1,17 @@ #include "common.h" #include "llama.h" -std::vector<double> softmax(const std::vector<float>& logits) { - std::vector<double> probs(logits.size()); +#include <cmath> + +std::vector<float> softmax(const std::vector<float>& logits) { + std::vector<float> probs(logits.size()); float max_logit = logits[0]; for (float v : logits) max_logit = std::max(max_logit, v); double sum_exp = 0.0; for (size_t i = 0; i < logits.size(); i++) { // Subtract the maximum logit value from the current logit value for numerical stability - float logit = logits[i] - max_logit; - double exp_logit = std::exp(logit); + const float logit = logits[i] - max_logit; + const float exp_logit = expf(logit); sum_exp += exp_logit; probs[i] = exp_logit; } @@ -24,14 +26,16 @@ void perplexity(llama_context * ctx, const gpt_params & params) { auto tokens = ::llama_tokenize(ctx, params.prompt, true); int count = 0; - double nll = 0.0; int seq_count = tokens.size() / params.n_ctx; + double nll = 0.0; + fprintf(stderr, "%s : calculating perplexity over %d chunks\n", __func__, seq_count); for (int i = 0; i < seq_count; ++i) { int start = i * params.n_ctx; - int end = start + params.n_ctx - 1; + int end = start + params.n_ctx - 1; // TODO: this is not optimal, e.g. it makes the batch 511 instead of 512 + // it is better to always be power of 2 for better performance std::vector<llama_token> embd(tokens.begin() + start, tokens.begin() + end); auto start_t = std::chrono::high_resolution_clock::now(); if (llama_eval(ctx, embd.data(), embd.size(), 0, params.n_threads)) { @@ -40,7 +44,7 @@ void perplexity(llama_context * ctx, const gpt_params & params) { } auto end_t = std::chrono::high_resolution_clock::now(); if (i == 0) { - double seconds = std::chrono::duration<double>(end_t - start_t).count(); + const float seconds = std::chrono::duration<float>(end_t - start_t).count(); printf("%.2f seconds per pass - ETA %.2f hours\n", seconds, (seconds * seq_count) / (60.0*60.0)); } // We get the logits for all the tokens in the context window (params.n_ctx) @@ -63,7 +67,7 @@ void perplexity(llama_context * ctx, const gpt_params & params) { std::vector<float> tok_logits( logits + j * n_vocab, logits + (j + 1) * n_vocab); - double prob = softmax(tok_logits)[tokens[start + j + 1]]; + const float prob = softmax(tok_logits)[tokens[start + j + 1]]; nll += -std::log(prob); ++count; } |