llama.cpp/examples/perplexity/perplexity.cpp
Iwan Kawrakow ccc78a200e hellaswag: speed up even more by parallelizing log-prob evaluation
For Mistral-7B and fp16, time on my system goes down from 536 seconds
to 423 seconds for the full evaluation dataset (10042 tasks).
2024-01-18 18:25:29 +02:00

1072 lines
40 KiB
C++

#include "common.h"
#include "llama.h"
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <sstream>
#include <thread>
#include <mutex>
#include <atomic>
#include <vector>
#include <array>
#include <fstream>
#include <sstream>
#if defined(_MSC_VER)
#pragma warning(disable: 4244 4267) // possible loss of data
#endif
struct results_perplexity {
std::vector<llama_token> tokens;
double ppl_value;
std::vector<float> logits;
std::vector<float> probs;
};
struct results_log_softmax {
double log_softmax;
float logit;
float prob;
};
static void write_logfile(
const llama_context * ctx, const gpt_params & params, const llama_model * model,
const struct results_perplexity & results
) {
if (params.logdir.empty()) {
return;
}
if (params.hellaswag) {
fprintf(stderr, "%s: warning: logging results is not implemented for HellaSwag. No files will be written.\n", __func__);
return;
}
const std::string timestamp = get_sortable_timestamp();
const bool success = create_directory_with_parents(params.logdir);
if (!success) {
fprintf(stderr, "%s: warning: failed to create logdir %s, cannot write logfile\n",
__func__, params.logdir.c_str());
return;
}
const std::string logfile_path = params.logdir + timestamp + ".yml";
FILE * logfile = fopen(logfile_path.c_str(), "w");
if (logfile == NULL) {
fprintf(stderr, "%s: failed to open logfile %s\n", __func__, logfile_path.c_str());
return;
}
fprintf(logfile, "binary: main\n");
char model_desc[128];
llama_model_desc(model, model_desc, sizeof(model_desc));
dump_non_result_info_yaml(logfile, params, ctx, timestamp, results.tokens, model_desc);
fprintf(logfile, "\n");
fprintf(logfile, "######################\n");
fprintf(logfile, "# Perplexity Results #\n");
fprintf(logfile, "######################\n");
fprintf(logfile, "\n");
dump_vector_float_yaml(logfile, "logits", results.logits);
fprintf(logfile, "ppl_value: %f\n", results.ppl_value);
dump_vector_float_yaml(logfile, "probs", results.probs);
llama_dump_timing_info_yaml(logfile, ctx);
fclose(logfile);
}
static 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
const float logit = logits[i] - max_logit;
const float exp_logit = expf(logit);
sum_exp += exp_logit;
probs[i] = exp_logit;
}
for (size_t i = 0; i < probs.size(); i++) {
probs[i] /= sum_exp;
}
return probs;
}
static results_log_softmax log_softmax(int n_vocab, const float * logits, int tok) {
float max_logit = logits[0];
for (int i = 1; i < n_vocab; ++i) {
max_logit = std::max(max_logit, logits[i]);
}
double sum_exp = 0.0;
for (int i = 0; i < n_vocab; ++i) {
sum_exp += expf(logits[i] - max_logit);
}
return {logits[tok] - max_logit - log(sum_exp), logits[tok], expf(logits[tok] - max_logit) / (float) sum_exp};
}
static void process_logits(
int n_vocab, const float * logits, const int * tokens, int n_token, std::vector<std::thread> & workers,
double & nll, double & nll2, float * logit_history, float * prob_history
) {
std::mutex mutex;
int counter = 0;
auto compute = [&mutex, &counter, &nll, &nll2, logit_history, prob_history, n_vocab, logits, tokens, n_token] () {
double local_nll = 0;
double local_nll2 = 0;
while (true) {
std::unique_lock<std::mutex> lock(mutex);
int i = counter++;
if (i >= n_token) {
nll += local_nll; nll2 += local_nll2;
break;
}
lock.unlock();
const results_log_softmax results = log_softmax(n_vocab, logits + i*n_vocab, tokens[i+1]);
const double v = -results.log_softmax;
local_nll += v;
local_nll2 += v*v;
logit_history[i] = results.logit;
prob_history[i] = results.prob;
}
};
for (auto & w : workers) {
w = std::thread(compute);
}
compute();
for (auto & w : workers) {
w.join();
}
}
static results_perplexity perplexity_v2(llama_context * ctx, const gpt_params & params) {
// Download: https://s3.amazonaws.com/research.metamind.io/wikitext/wikitext-2-raw-v1.zip?ref=salesforce-research
// Run `./perplexity -m models/7B/ggml-model-q4_0.bin -f wiki.test.raw`
// Output: `perplexity: 13.5106 [114/114]`
// BOS tokens will be added for each chunk before eval
const bool add_bos = llama_should_add_bos_token(llama_get_model(ctx));
fprintf(stderr, "%s: tokenizing the input ..\n", __func__);
std::vector<llama_token> tokens = ::llama_tokenize(ctx, params.prompt, add_bos);
const int n_ctx = llama_n_ctx(ctx);
if (int(tokens.size()) < 2*n_ctx) {
fprintf(stderr, "%s: you need at least %d tokens to evaluate perplexity with a context of %d\n",__func__,2*n_ctx,
n_ctx);
fprintf(stderr, "%s: the data file you provided tokenizes to only %zu tokens\n",__func__,tokens.size());
return {std::move(tokens), 0., {}, {}};
}
std::vector<float> logit_history;
std::vector<float> prob_history;
logit_history.resize(tokens.size());
prob_history.resize(tokens.size());
if (params.ppl_stride <= 0) {
fprintf(stderr, "%s: stride is %d but must be greater than zero!\n",__func__,params.ppl_stride);
return {tokens, -1, logit_history, prob_history};
}
const int calc_chunk = n_ctx;
fprintf(stderr, "%s: have %zu tokens. Calculation chunk = %d\n", __func__, tokens.size(), calc_chunk);
if (int(tokens.size()) <= calc_chunk) {
fprintf(stderr, "%s: there are only %zu tokens, this is not enough for a context size of %d and stride %d\n",__func__,
tokens.size(), n_ctx, params.ppl_stride);
return {tokens, -1, logit_history, prob_history};
}
const int n_chunk_max = (tokens.size() - calc_chunk + params.ppl_stride - 1) / params.ppl_stride;
const int n_chunk = params.n_chunks < 0 ? n_chunk_max : std::min(params.n_chunks, n_chunk_max);
const int n_vocab = llama_n_vocab(llama_get_model(ctx));
const int n_batch = params.n_batch;
int count = 0;
double nll = 0.0;
fprintf(stderr, "%s: calculating perplexity over %d chunks, batch_size=%d\n", __func__, n_chunk, n_batch);
for (int i = 0; i < n_chunk; ++i) {
const int start = i * params.ppl_stride;
const int end = start + calc_chunk;
const int num_batches = (calc_chunk + n_batch - 1) / n_batch;
//fprintf(stderr, "%s: evaluating %d...%d using %d batches\n", __func__, start, end, num_batches);
std::vector<float> logits;
const auto t_start = std::chrono::high_resolution_clock::now();
// clear the KV cache
llama_kv_cache_clear(ctx);
for (int j = 0; j < num_batches; ++j) {
const int batch_start = start + j * n_batch;
const int batch_size = std::min(end - batch_start, n_batch);
//fprintf(stderr, " Batch %d: starts at %d, size is %d, n_past is %d\n",j,batch_start,batch_size,j * n_batch);
if (llama_decode(ctx, llama_batch_get_one(tokens.data() + batch_start, batch_size, j * n_batch, 0))) {
//fprintf(stderr, "%s : failed to eval\n", __func__);
return {tokens, -1, logit_history, prob_history};
}
// save original token and restore it after eval
const auto token_org = tokens[batch_start];
// add BOS token for the first batch of each chunk
if (add_bos && j == 0) {
tokens[batch_start] = llama_token_bos(llama_get_model(ctx));
}
const auto batch_logits = llama_get_logits(ctx);
logits.insert(logits.end(), batch_logits, batch_logits + batch_size * n_vocab);
if (j == 0) {
tokens[batch_start] = token_org;
}
}
const auto t_end = std::chrono::high_resolution_clock::now();
if (i == 0) {
const float t_total = std::chrono::duration<float>(t_end - t_start).count();
fprintf(stderr, "%s: %.2f seconds per pass - ETA ", __func__, t_total);
int total_seconds = (int)(t_total * n_chunk);
if (total_seconds >= 60*60) {
fprintf(stderr, "%d hours ", total_seconds / (60*60));
total_seconds = total_seconds % (60*60);
}
fprintf(stderr, "%.2f minutes\n", total_seconds / 60.0);
}
//fprintf(stderr, "%s: using tokens %d...%d\n",__func__,params.n_ctx - params.ppl_stride + start, params.n_ctx + start);
for (int j = n_ctx - params.ppl_stride - 1; j < n_ctx - 1; ++j) {
// Calculate probability of next token, given the previous ones.
const std::vector<float> tok_logits(
logits.begin() + (j + 0) * n_vocab,
logits.begin() + (j + 1) * n_vocab);
const float prob = softmax(tok_logits)[tokens[start + j + 1]];
logit_history[start + j + 1] = tok_logits[tokens[start + j + 1]];
prob_history[start + j + 1] = prob;
nll += -std::log(prob);
++count;
}
// perplexity is e^(average negative log-likelihood)
if (params.ppl_output_type == 0) {
printf("[%d]%.4lf,", i + 1, std::exp(nll / count));
} else {
printf("%8d %.4lf\n", i*params.ppl_stride, std::exp(nll / count));
}
fflush(stdout);
}
printf("\n");
return {tokens, std::exp(nll / count), logit_history, prob_history};
}
static results_perplexity perplexity(llama_context * ctx, const gpt_params & params) {
if (params.ppl_stride > 0) {
return perplexity_v2(ctx, params);
}
// Download: https://s3.amazonaws.com/research.metamind.io/wikitext/wikitext-2-raw-v1.zip?ref=salesforce-research
// Run `./perplexity -m models/7B/ggml-model-q4_0.bin -f wiki.test.raw`
// Output: `perplexity: 13.5106 [114/114]`
// BOS tokens will be added for each chunk before eval
const bool add_bos = llama_should_add_bos_token(llama_get_model(ctx));
const int n_ctx = llama_n_ctx(ctx);
auto tim1 = std::chrono::high_resolution_clock::now();
fprintf(stderr, "%s: tokenizing the input ..\n", __func__);
std::vector<llama_token> tokens = ::llama_tokenize(ctx, params.prompt, add_bos);
auto tim2 = std::chrono::high_resolution_clock::now();
fprintf(stderr, "%s: tokenization took %g ms\n",__func__,1e-3*std::chrono::duration_cast<std::chrono::microseconds>(tim2-tim1).count());
if (int(tokens.size()) < 2*n_ctx) {
fprintf(stderr, "%s: you need at least %d tokens to evaluate perplexity with a context of %d\n",__func__,2*n_ctx,
n_ctx);
fprintf(stderr, "%s: the data file you provided tokenizes to only %zu tokens\n",__func__,tokens.size());
return {std::move(tokens), 0., {}, {}};
}
std::vector<float> logit_history;
logit_history.resize(tokens.size());
std::vector<float> prob_history;
prob_history.resize(tokens.size());
const int n_chunk_max = tokens.size() / n_ctx;
const int n_chunk = params.n_chunks < 0 ? n_chunk_max : std::min(params.n_chunks, n_chunk_max);
const int n_vocab = llama_n_vocab(llama_get_model(ctx));
const int n_batch = params.n_batch;
int count = 0;
double nll = 0.0;
double nll2 = 0.0;
fprintf(stderr, "%s: calculating perplexity over %d chunks, batch_size=%d\n", __func__, n_chunk, n_batch);
std::vector<std::thread> workers(std::thread::hardware_concurrency() - 1);
for (int i = 0; i < n_chunk; ++i) {
const int start = i * n_ctx;
const int end = start + n_ctx;
const int num_batches = (n_ctx + n_batch - 1) / n_batch;
std::vector<float> logits;
const auto t_start = std::chrono::high_resolution_clock::now();
// clear the KV cache
llama_kv_cache_clear(ctx);
for (int j = 0; j < num_batches; ++j) {
const int batch_start = start + j * n_batch;
const int batch_size = std::min(end - batch_start, n_batch);
// save original token and restore it after eval
const auto token_org = tokens[batch_start];
// add BOS token for the first batch of each chunk
if (add_bos && j == 0) {
tokens[batch_start] = llama_token_bos(llama_get_model(ctx));
}
if (llama_decode(ctx, llama_batch_get_one(tokens.data() + batch_start, batch_size, j * n_batch, 0))) {
fprintf(stderr, "%s : failed to eval\n", __func__);
return {tokens, -1, logit_history, prob_history};
}
// restore the original token in case it was set to BOS
tokens[batch_start] = token_org;
const auto * batch_logits = llama_get_logits(ctx);
logits.insert(logits.end(), batch_logits, batch_logits + batch_size * n_vocab);
}
const auto t_end = std::chrono::high_resolution_clock::now();
if (i == 0) {
const float t_total = std::chrono::duration<float>(t_end - t_start).count();
fprintf(stderr, "%s: %.2f seconds per pass - ETA ", __func__, t_total);
int total_seconds = (int)(t_total * n_chunk);
if (total_seconds >= 60*60) {
fprintf(stderr, "%d hours ", total_seconds / (60*60));
total_seconds = total_seconds % (60*60);
}
fprintf(stderr, "%.2f minutes\n", total_seconds / 60.0);
}
// We get the logits for all the tokens in the context window (params.n_ctx)
// from llama_eval above. Now, based on https://huggingface.co/docs/transformers/perplexity,
// calculate the perplexity over the last half of the window (so the model always has
// some context to predict the token).
//
// We rely on the fact that attention in the forward pass only looks at previous
// tokens here, so the logits returned for each token are an accurate representation
// of what the model would have predicted at that point.
//
// Example, we have a context window of 512, we will compute perplexity for each of the
// last 256 tokens. Then, we split the input up into context window size chunks to
// process the entire prompt.
const int first = n_ctx/2;
process_logits(n_vocab, logits.data() + first*n_vocab, tokens.data() + start + first, n_ctx - 1 - first,
workers, nll, nll2, logit_history.data() + start + first, prob_history.data() + start + first);
count += n_ctx - first - 1;
// perplexity is e^(average negative log-likelihood)
if (params.ppl_output_type == 0) {
printf("[%d]%.4lf,", i + 1, std::exp(nll / count));
} else {
double av = nll/count;
double av2 = nll2/count - av*av;
if (av2 > 0) av2 = sqrt(av2/(count-1));
printf("%8d %.4lf %4lf %4lf\n", i*n_ctx, std::exp(nll / count), av, av2);
}
fflush(stdout);
}
printf("\n");
nll2 /= count;
nll /= count;
const double ppl = exp(nll);
nll2 -= nll * nll;
if (nll2 > 0) {
nll2 = sqrt(nll2/(count-1));
printf("Final estimate: PPL = %.4lf +/- %.5lf\n", ppl, nll2*ppl);
} else {
printf("Unexpected negative standard deviation of log(prob)\n");
}
return {tokens, ppl, logit_history, prob_history};
}
static std::vector<float> evaluate_tokens(llama_context * ctx, std::vector<int> & tokens,
int n_past, int n_batch, int n_vocab) {
std::vector<float> result;
result.reserve(tokens.size() * n_vocab);
size_t n_chunk = (tokens.size() + n_batch - 1)/n_batch;
for (size_t i_chunk = 0; i_chunk < n_chunk; ++i_chunk) {
size_t n_tokens = tokens.size() - i_chunk * n_batch;
n_tokens = std::min(n_tokens, size_t(n_batch));
llama_kv_cache_seq_rm(ctx, 0, n_past, -1);
if (llama_decode(ctx, llama_batch_get_one(tokens.data() + i_chunk * n_batch, n_tokens, n_past, 0))) {
fprintf(stderr, "%s : failed to eval\n", __func__);
return {};
}
const auto logits = llama_get_logits(ctx);
result.insert(result.end(), logits, logits + n_tokens * n_vocab);
n_past += n_tokens;
}
return result;
}
static void hellaswag_compute_logprobs(const float * batch_logits, int n_vocab, std::vector<std::thread>& workers,
const std::vector<std::pair<size_t, llama_token>>& eval_pairs, std::vector<float>& eval_results) {
constexpr int k_token_chunk = 4;
if (eval_results.size() != eval_pairs.size()) {
eval_results.resize(eval_pairs.size());
}
if (eval_pairs.empty()) return;
size_t max_threads = std::min((eval_pairs.size() + k_token_chunk - 1)/k_token_chunk, workers.size());
std::atomic<int> counter(0);
auto compute = [&counter, &eval_pairs, &eval_results, batch_logits, n_vocab] () {
float local_logprobs[k_token_chunk];
while (true) {
size_t first = counter.fetch_add(k_token_chunk, std::memory_order_relaxed);
if (first >= eval_results.size()) break;
size_t last = std::min(first + k_token_chunk, eval_results.size());
for (size_t i = first; i < last; ++i) {
auto logits = batch_logits + eval_pairs[i].first * n_vocab;
float max_logit = logits[0];
for (int j = 1; j < n_vocab; ++j) {
max_logit = std::max(max_logit, logits[j]);
}
float sum_p = 0.f;
for (int j = 0; j < n_vocab; ++j) {
sum_p += expf(logits[j] - max_logit);
}
local_logprobs[i - first] = logits[eval_pairs[i].second] - max_logit - std::log(sum_p);
}
std::memcpy(eval_results.data() + first, local_logprobs, (last - first)*sizeof(float));
}
};
for (size_t it = 0; it < max_threads; ++it) {
workers[it] = std::thread(compute);
}
for (size_t it = 0; it < max_threads; ++it) {
workers[it].join();
}
}
static void hellaswag_score(llama_context * ctx, const gpt_params & params) {
// Calculates hellaswag score (acc_norm) from prompt
//
// Data extracted from the HellaSwag validation dataset (MIT license) https://github.com/rowanz/hellaswag/blob/master/data/hellaswag_val.jsonl
// All used data fields are preprocessed as in https://github.com/EleutherAI/lm-evaluation-harness/blob/df3da98c5405deafd519c2ddca52bb7c3fe36bef/lm_eval/tasks/hellaswag.py#L62-L68
//
// All 10042 tasks should be extracted to keep the results standardized like other implementations.
//
// Datafile layout:
// ['??'] denotes json fields
// 6 lines per task:
// ['activity_label'] + ": " +['ctx'] - The first part of the query, the context
// ['label'] - The index the best common sense ending aka gold ending
// ['endings'][0] - Endings added to the first part of the query
// ['endings'][1]
// ['endings'][2]
// ['endings'][3]
std::vector<std::string> prompt_lines;
std::istringstream strstream(params.prompt);
std::string line;
while (std::getline(strstream,line,'\n')) {
prompt_lines.push_back(line);
}
if (prompt_lines.size() % 6 != 0) {
fprintf(stderr, "%s : number of lines in prompt not a multiple of 6.\n", __func__);
return;
}
size_t hs_task_count = prompt_lines.size()/6;
fprintf(stderr, "%s : loaded %zu tasks from prompt.\n", __func__, hs_task_count);
const bool is_spm = llama_vocab_type(llama_get_model(ctx)) == LLAMA_VOCAB_TYPE_SPM;
fprintf(stderr, "================================= is_spm = %d\n", is_spm);
// This is needed as usual for LLaMA models
const bool add_bos = llama_should_add_bos_token(llama_get_model(ctx));
// Number of tasks to use when computing the score
if (params.hellaswag_tasks < hs_task_count) {
hs_task_count = params.hellaswag_tasks;
}
// The tasks should be randomized so the score stabilizes quickly.
bool randomize_tasks = true;
// The random seed should not impact the final result if the computation is done over enough tasks, so kept hardcoded for now
std::mt19937 rng(1);
// Dataholder for hellaswag tasks
struct hs_data_t {
std::string context;
size_t gold_ending_idx;
std::string ending[4];
size_t ending_logprob_count[4];
double ending_logprob[4];
size_t i_batch; // starting index in the llama_batch
size_t common_prefix; // max number of initial tokens that are the same in all sentences
size_t required_tokens; // needed number of tokens to evaluate all 4 endings
std::vector<llama_token> seq_tokens[4];
};
fprintf(stderr, "%s : selecting %zu %s tasks.\n", __func__, hs_task_count, (randomize_tasks?"randomized":"the first") );
// Select and read data from prompt lines
std::vector<hs_data_t> hs_data(hs_task_count);
for (size_t i = 0; i < hs_task_count; i++) {
size_t idx = i;
auto & hs_cur = hs_data[i];
// Select a random example of those left in the prompt
if (randomize_tasks) {
std::uniform_int_distribution<size_t> dist(0, prompt_lines.size()/6-1 ) ;
idx = dist(rng);
}
hs_cur.context = prompt_lines[idx*6];
hs_cur.gold_ending_idx = std::stoi( prompt_lines[idx*6+1] );
for (size_t j = 0; j < 4; j++) {
hs_cur.ending[j] = prompt_lines[idx*6+2+j];
hs_cur.seq_tokens[j] = ::llama_tokenize(ctx, hs_cur.context + " " + hs_cur.ending[j], add_bos);
}
// determine the common prefix of the endings
hs_cur.common_prefix = 0;
hs_cur.required_tokens = 0;
for (size_t k = 0; k < hs_cur.seq_tokens[0].size(); k++) {
if (hs_cur.seq_tokens[0][k] != hs_cur.seq_tokens[1][k] ||
hs_cur.seq_tokens[0][k] != hs_cur.seq_tokens[2][k] ||
hs_cur.seq_tokens[0][k] != hs_cur.seq_tokens[3][k]) {
break;
}
hs_cur.common_prefix++;
}
hs_cur.required_tokens = hs_cur.common_prefix +
hs_cur.seq_tokens[0].size() - hs_cur.common_prefix +
hs_cur.seq_tokens[1].size() - hs_cur.common_prefix +
hs_cur.seq_tokens[2].size() - hs_cur.common_prefix +
hs_cur.seq_tokens[3].size() - hs_cur.common_prefix;
//GGML_ASSERT(hs_cur.common_prefix >= ::llama_tokenize(ctx, hs_cur.context, add_bos).size());
// Delete the selected random example from the prompt
if (randomize_tasks) {
prompt_lines.erase( std::next(prompt_lines.begin(),idx*6) , std::next(prompt_lines.begin(),idx*6+6) );
}
}
fprintf(stderr, "%s : calculating hellaswag score over selected tasks.\n", __func__);
printf("\ntask\tacc_norm\n");
double acc = 0.0f;
const int n_vocab = llama_n_vocab(llama_get_model(ctx));
const int n_ctx = llama_n_ctx(ctx);
const int n_batch = params.n_batch;
const int max_tasks_per_batch = params.n_parallel;
const int max_seq = 4*max_tasks_per_batch;
llama_batch batch = llama_batch_init(n_ctx, 0, max_seq);
std::vector<float> tok_logits(n_vocab);
std::vector<float> batch_logits(n_ctx*n_vocab);
std::vector<std::pair<size_t, llama_token>> eval_pairs;
std::vector<float> eval_results;
std::vector<std::thread> workers(std::thread::hardware_concurrency());
auto decode_helper = [&](llama_context * ctx, llama_batch & batch, int32_t n_batch) {
for (int32_t i = 0; i < (int32_t) batch.n_tokens; i += n_batch) {
const int32_t n_tokens = std::min(n_batch, (int32_t) (batch.n_tokens - i));
llama_batch batch_view = {
n_tokens,
batch.token + i,
nullptr,
batch.pos + i,
batch.n_seq_id + i,
batch.seq_id + i,
batch.logits + i,
0, 0, 0, // unused
};
const int ret = llama_decode(ctx, batch_view);
if (ret != 0) {
LOG_TEE("failed to decode the batch, n_batch = %d, ret = %d\n", n_batch, ret);
return false;
}
memcpy(batch_logits.data() + i*n_vocab, llama_get_logits(ctx), n_tokens*n_vocab*sizeof(float));
}
return true;
};
for (size_t i0 = 0; i0 < hs_task_count; i0++) {
int n_cur = 0;
size_t i1 = i0;
size_t i_batch = 0; // this tells us where in `llama_batch` we are currently
llama_batch_clear(batch);
// batch as much tasks as possible into the available context
// each task has 4 unique seuqnce ids - one for each ending
// the common prefix is shared among the 4 sequences to save tokens
// we extract logits only from the last common token and from all ending tokens of each sequence
while (n_cur + (int) hs_data[i1].required_tokens <= n_ctx) {
auto & hs_cur = hs_data[i1];
const int s0 = 4*(i1 - i0);
if (s0 + 4 > max_seq) {
break;
}
for (size_t i = 0; i < hs_cur.common_prefix; ++i) {
llama_batch_add(batch, hs_cur.seq_tokens[0][i], i, { s0 + 0, s0 + 1, s0 + 2, s0 + 3}, false);
}
batch.logits[batch.n_tokens - 1] = true; // we need logits for the last token of the common prefix
for (int s = 0; s < 4; ++s) {
for (size_t i = hs_cur.common_prefix; i < hs_cur.seq_tokens[s].size(); ++i) {
llama_batch_add(batch, hs_cur.seq_tokens[s][i], i, { s0 + s }, true);
}
}
hs_cur.i_batch = i_batch;
i_batch += hs_cur.required_tokens;
n_cur += hs_data[i1].required_tokens;
if (++i1 == hs_task_count) {
break;
}
}
if (i0 == i1) {
fprintf(stderr, "%s : task %zu does not fit in the context window\n", __func__, i0);
return;
}
llama_kv_cache_clear(ctx);
// decode all tasks [i0, i1)
if (!decode_helper(ctx, batch, n_batch)) {
fprintf(stderr, "%s: llama_decode() failed\n", __func__);
return;
}
// Compute log-probs in parallel
// First we collect all tasks
eval_pairs.clear();
for (size_t i = i0; i < i1; ++i) {
auto & hs_cur = hs_data[i];
size_t li = hs_cur.common_prefix;
for (int s = 0; s < 4; ++s) {
for (size_t j = hs_cur.common_prefix; j < hs_cur.seq_tokens[s].size() - 1; j++) {
eval_pairs.push_back(std::make_pair(hs_cur.i_batch + li++, hs_cur.seq_tokens[s][j + 1]));
}
++li;
}
}
// Then we do the actual calculation
hellaswag_compute_logprobs(batch_logits.data(), n_vocab, workers, eval_pairs, eval_results);
size_t ir = 0;
// compute the logprobs for each ending of the decoded tasks
for (size_t i = i0; i < i1; ++i) {
auto & hs_cur = hs_data[i];
std::memcpy(tok_logits.data(), batch_logits.data() + n_vocab*(hs_cur.i_batch + hs_cur.common_prefix - 1), n_vocab*sizeof(float));
const auto first_probs = softmax(tok_logits);
for (int s = 0; s < 4; ++s) {
hs_cur.ending_logprob_count[s] = 1;
hs_cur.ending_logprob[s] = std::log(first_probs[hs_cur.seq_tokens[s][hs_cur.common_prefix]]);
for (size_t j = hs_cur.common_prefix; j < hs_cur.seq_tokens[s].size() - 1; j++) {
hs_cur.ending_logprob[s] += eval_results[ir++];
hs_cur.ending_logprob_count[s]++;
}
hs_cur.ending_logprob[s] /= hs_cur.ending_logprob_count[s];
}
// Find the ending with maximum logprob
size_t ending_logprob_max_idx = 0;
double ending_logprob_max_val = hs_cur.ending_logprob[0];
for (size_t s = 1; s < 4; s++) {
if (hs_cur.ending_logprob[s] > ending_logprob_max_val) {
ending_logprob_max_idx = s;
ending_logprob_max_val = hs_cur.ending_logprob[s];
}
}
//printf("max logprob ending idx %lu, gold ending idx %lu\n", ending_logprob_max_idx, hs_cur.gold_ending_idx);
// If the gold ending got the maximum logprobe add one accuracy point
if (ending_logprob_max_idx == hs_cur.gold_ending_idx) {
acc += 1.0;
}
// Print the accumulated accuracy mean x 100
printf("%zu\t%.8lf\n", i + 1, acc/double(i + 1)*100.0);
fflush(stdout);
}
i0 = i1 - 1;
}
llama_batch_free(batch);
printf("\n");
}
struct winogrande_entry {
std::string first;
std::string second;
std::array<std::string, 2> choices;
int answer;
};
static std::vector<winogrande_entry> load_winogrande_from_csv(const std::string& prompt) {
std::vector<winogrande_entry> result;
std::istringstream in(prompt);
std::string line;
std::array<int, 4> comma_pos;
while (true) {
std::getline(in, line);
if (in.fail() || in.eof()) break;
int ipos = 0;
bool quote_open = false;
for (int i = 0; i < int(line.size()); ++i) {
if (!quote_open) {
if (line[i] == ',') {
comma_pos[ipos++] = i;
if (ipos == 4) break;
}
else if (line[i] == '"') {
quote_open = true;
}
}
else {
if (line[i] == '"') {
quote_open = false;
}
}
}
if (ipos != 4) {
printf("%s: failed to find comma separators in <%s>\n", __func__, line.c_str());
continue;
}
auto sentence = line[comma_pos[0]+1] == '"' ? line.substr(comma_pos[0]+2, comma_pos[1] - comma_pos[0] - 3)
: line.substr(comma_pos[0]+1, comma_pos[1] - comma_pos[0] - 1);
auto choice1 = line.substr(comma_pos[1]+1, comma_pos[2] - comma_pos[1] - 1);
auto choice2 = line.substr(comma_pos[2]+1, comma_pos[3] - comma_pos[2] - 1);
auto answer = line.substr(comma_pos[3]+1, line.size() - comma_pos[3] - 1);
auto index = line.substr(0, comma_pos[0]);
int where = 0;
for ( ; where < int(sentence.size()); ++where) {
if (sentence[where] == '_') break;
}
if (where == int(sentence.size())) {
printf("%s: no _ in <%s>\n", __func__, sentence.c_str());
continue;
}
std::istringstream stream(answer.c_str());
int i_answer; stream >> i_answer;
if (stream.fail() || i_answer < 1 || i_answer > 2) {
printf("%s: failed to parse answer <%s>\n", __func__, answer.c_str());
continue;
}
result.emplace_back();
auto& wg = result.back();
wg.first = sentence.substr(0, where);
wg.second = sentence.substr(where + 1, sentence.size() - where - 1);
wg.choices[0] = std::move(choice1);
wg.choices[1] = std::move(choice2);
wg.answer = i_answer;
}
return result;
}
/*
* Evaluates the Winogrande score.
* Uses a CSV containing task index, dentence, choice 1, choice 2, answer (1 or 2)
* You can get one such dataset from e.g. https://huggingface.co/datasets/ikawrakow/winogrande-eval-for-llama.cpp
* As an example, the 1st row in the above dataset is
*
* 0,Sarah was a much better surgeon than Maria so _ always got the easier cases.,Sarah,Maria,2
*
*/
static void winogrande_score(llama_context * ctx, const gpt_params & params) {
constexpr int k_min_trailing_ctx = 3;
auto data = load_winogrande_from_csv(params.prompt);
if (data.empty()) {
fprintf(stderr, "%s: no tasks\n", __func__);
return;
}
fprintf(stderr, "%s : loaded %zu tasks from prompt.\n", __func__, data.size());
if (params.winogrande_tasks > 0 && params.winogrande_tasks < data.size()) {
fprintf(stderr, "%s : selecting %zu random tasks\n", __func__, params.winogrande_tasks);
std::mt19937 rng(1);
std::vector<int> aux(data.size());
for (int i = 0; i < int(data.size()); ++i) {
aux[i] = i;
}
float scale = 1/(1.f + (float)rng.max());
std::vector<winogrande_entry> selected;
selected.reserve(params.winogrande_tasks);
for (int i = 0; i < int(params.winogrande_tasks); ++i) {
int j = int(scale*rng()*aux.size());
selected[i] = std::move(data[aux[j]]);
aux[j] = aux.back();
aux.pop_back();
}
data = std::move(selected);
}
// This is needed as usual for LLaMA models
const bool add_bos = llama_should_add_bos_token(llama_get_model(ctx));
fprintf(stderr, "%s : calculating winogrande score over selected tasks.\n", __func__);
const int n_vocab = llama_n_vocab(llama_get_model(ctx));
const int n_ctx = llama_n_ctx(ctx);
std::vector<float> tok_logits(n_vocab);
int n_correct = 0;
int n_done = 0;
for (size_t task_idx = 0; task_idx < data.size(); task_idx++) {
const auto& task = data[task_idx];
auto base_context = ::llama_tokenize(ctx, task.first, add_bos);
auto base_ctx_1st = ::llama_tokenize(ctx, task.first + task.choices[0], add_bos);
auto base_ctx_2nd = ::llama_tokenize(ctx, task.first + task.choices[1], add_bos);
auto sentence_1st = task.first + task.choices[0] + task.second;
auto sentence_2nd = task.first + task.choices[1] + task.second;
auto query_1st = ::llama_tokenize(ctx, sentence_1st, add_bos);
auto query_2nd = ::llama_tokenize(ctx, sentence_2nd, add_bos);
if (query_1st.size() > (size_t)n_ctx || query_2nd.size() > (size_t)n_ctx) {
fprintf(stderr, "%s : number of tokens in queries %zu, %zu > n_ctxl\n", __func__, query_1st.size(), query_2nd.size());
return;
}
auto query_1st_size = query_1st.size();
auto query_2nd_size = query_2nd.size();
// Speedup small evaluations by evaluating atleast 32 tokens
// For Winogrande this seems to slow it down rather than speed it up.
//if (query_1st.size() < 32) query_1st.resize(32);
//if (query_2nd.size() < 32) query_2nd.resize(32);
llama_kv_cache_clear(ctx);
auto logits_1st = evaluate_tokens(ctx, query_1st, 0, params.n_batch, n_vocab);
llama_kv_cache_clear(ctx);
auto logits_2nd = evaluate_tokens(ctx, query_2nd, 0, params.n_batch, n_vocab);
if (logits_1st.empty() || logits_2nd.empty()) {
fprintf(stderr, "%s : failed to eval\n", __func__);
return;
}
bool skip_choice = query_1st_size - base_ctx_1st.size() > k_min_trailing_ctx &&
query_2nd_size - base_ctx_2nd.size() > k_min_trailing_ctx;
float score_1st = 0;
bool is_nan_1st = false;
const auto& base_1 = skip_choice ? base_ctx_1st : base_context;
const int last_1st = query_1st_size - base_1.size() > 1 ? 1 : 0;
for (size_t j = base_1.size()-1; j < query_1st_size-1-last_1st; ++j) {
std::memcpy(tok_logits.data(), logits_1st.data() + j*n_vocab, n_vocab*sizeof(float));
const float prob = softmax(tok_logits)[query_1st[j+1]];
if (std::isnan(prob) || !prob) {
fprintf(stderr, "%s: %g probability for token %zu when evaluating <%s>. Base context has %zu tokens\n", __func__,
prob, j, sentence_1st.c_str(), base_context.size());
is_nan_1st = true;
break;
}
score_1st += std::log(prob);
}
score_1st /= (query_1st_size - base_1.size() - last_1st);
float score_2nd = 0;
bool is_nan_2nd = false;
const auto& base_2 = skip_choice ? base_ctx_2nd : base_context;
const int last_2nd = query_2nd_size - base_2.size() > 1 ? 1 : 0;
for (size_t j = base_2.size()-1; j < query_2nd_size-1-last_2nd; ++j) {
std::memcpy(tok_logits.data(), logits_2nd.data() + j*n_vocab, n_vocab*sizeof(float));
const float prob = softmax(tok_logits)[query_2nd[j+1]];
if (std::isnan(prob) || !prob) {
fprintf(stderr, "%s: %g probability for token %zu when evaluating <%s>. Base context has %zu tokens\n", __func__,
prob, j, sentence_2nd.c_str(), base_context.size());
is_nan_2nd = true;
break;
}
score_2nd += std::log(prob);
}
score_2nd /= (query_2nd_size - base_2.size() - last_2nd);
if (is_nan_1st || is_nan_2nd) {
continue;
}
if (std::isnan(score_1st) || std::isnan(score_2nd)) {
printf("================== NaN score %g, %g) for:\n", score_1st, score_2nd);
printf("Q1: <%s> - %zu tokens\n", sentence_1st.c_str(), query_1st_size);
printf("Q2: <%s> - %zu tokens\n", sentence_2nd.c_str(), query_2nd_size);
printf("B : <%s> - %zu tokens\n", task.first.c_str(), base_context.size());
printf("base_1 has %zu tokens, base_2 has %zu tokens, skip_choice = %d\n", base_1.size(), base_2.size(), skip_choice);
continue;
}
int result = score_1st > score_2nd ? 1 : 2;
if (result == task.answer) {
++n_correct;
}
++n_done;
// Print the accumulated accuracy mean x 100
printf("%zu\t%.4lf\t%10.6f %10.6f %d %d\n",task_idx+1, 100.0 * n_correct/n_done,score_1st,score_2nd,result,task.answer);
fflush(stdout);
}
printf("\n");
if (n_done < 100) return;
const float p = 1.f*n_correct/n_done;
const float sigma = 100.f*sqrt(p*(1-p)/(n_done-1));
printf("Final Winogrande score(%d tasks): %.4lf +/- %.4lf\n", n_done, 100*p, sigma);
}
int main(int argc, char ** argv) {
gpt_params params;
params.n_batch = 512;
if (!gpt_params_parse(argc, argv, params)) {
return 1;
}
params.logits_all = true;
params.n_batch = std::min(params.n_batch, params.n_ctx);
if (params.ppl_stride > 0) {
fprintf(stderr, "Will perform strided perplexity calculation -> adjusting context size from %d to %d\n",
params.n_ctx, params.n_ctx + params.ppl_stride/2);
params.n_ctx += params.ppl_stride/2;
}
print_build_info();
if (params.seed == LLAMA_DEFAULT_SEED) {
params.seed = time(NULL);
}
fprintf(stderr, "%s: seed = %u\n", __func__, params.seed);
std::mt19937 rng(params.seed);
if (params.random_prompt) {
params.prompt = gpt_random_prompt(rng);
}
llama_backend_init(params.numa);
llama_model * model;
llama_context * ctx;
// load the model and apply lora adapter, if any
std::tie(model, ctx) = llama_init_from_gpt_params(params);
if (model == NULL) {
fprintf(stderr, "%s: error: unable to load model\n", __func__);
return 1;
}
const int n_ctx_train = llama_n_ctx_train(model);
if (params.n_ctx > n_ctx_train) {
fprintf(stderr, "%s: warning: model was trained on only %d context tokens (%d specified)\n",
__func__, n_ctx_train, params.n_ctx);
}
// print system information
{
fprintf(stderr, "\n");
fprintf(stderr, "%s\n", get_system_info(params).c_str());
}
struct results_perplexity results;
if (params.hellaswag) {
hellaswag_score(ctx, params);
} else if (params.winogrande) {
winogrande_score(ctx, params);
} else {
results = perplexity(ctx, params);
}
llama_print_timings(ctx);
write_logfile(ctx, params, model, results);
llama_free(ctx);
llama_free_model(model);
llama_backend_free();
return 0;
}