/ tests / test-sampling.cpp
test-sampling.cpp
  1  #include "ggml.h"
  2  #include "llama.h"
  3  
  4  #ifdef NDEBUG
  5  #undef NDEBUG
  6  #endif
  7  
  8  #include <algorithm>
  9  #include <cmath>
 10  #include <string>
 11  #include <vector>
 12  
 13  static void dump(const llama_token_data_array * candidates) {
 14      for (size_t i = 0; i < candidates->size; i++) {
 15          printf("%d: %f (%f)\n", candidates->data[i].id, candidates->data[i].p, candidates->data[i].logit);
 16      }
 17  }
 18  
 19  #define DUMP(__candidates) do { printf("%s:%d (%s)\n", __FILE__, __LINE__, __func__); dump((__candidates)); printf("-\n"); } while(0)
 20  
 21  static void test_top_k(const std::vector<float> & probs, const std::vector<float> & expected_probs, int k) {
 22      const size_t n_vocab = probs.size();
 23      std::vector<llama_token_data> candidates;
 24      candidates.reserve(n_vocab);
 25      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
 26          const float logit = logf(probs[token_id]);
 27          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
 28      }
 29  
 30      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
 31      llama_sample_softmax(nullptr, &candidates_p);
 32      DUMP(&candidates_p);
 33      llama_sample_top_k(nullptr, &candidates_p, k, 1);
 34      DUMP(&candidates_p);
 35  
 36      GGML_ASSERT(candidates_p.size == expected_probs.size());
 37      for (size_t i = 0; i < candidates_p.size; i++) {
 38          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-5);
 39      }
 40  }
 41  
 42  static void test_top_p(const std::vector<float> & probs, const std::vector<float> & expected_probs, float p) {
 43      const size_t n_vocab = probs.size();
 44      std::vector<llama_token_data> candidates;
 45      candidates.reserve(n_vocab);
 46      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
 47          const float logit = logf(probs[token_id]);
 48          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
 49      }
 50  
 51      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
 52      llama_sample_softmax(nullptr, &candidates_p);
 53      DUMP(&candidates_p);
 54      llama_sample_top_p(nullptr, &candidates_p, p, 1);
 55      DUMP(&candidates_p);
 56  
 57      GGML_ASSERT(candidates_p.size == expected_probs.size());
 58      for (size_t i = 0; i < candidates_p.size; i++) {
 59          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-3);
 60      }
 61  }
 62  
 63  static void test_tfs(const std::vector<float> & probs, const std::vector<float> & expected_probs, float z) {
 64      const size_t n_vocab = probs.size();
 65      std::vector<llama_token_data> candidates;
 66      candidates.reserve(n_vocab);
 67      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
 68          const float logit = logf(probs[token_id]);
 69          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
 70      }
 71  
 72      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
 73      DUMP(&candidates_p);
 74      llama_sample_tail_free(nullptr, &candidates_p, z, 1);
 75      DUMP(&candidates_p);
 76  
 77      GGML_ASSERT(candidates_p.size == expected_probs.size());
 78      for (size_t i = 0; i < candidates_p.size; i++) {
 79          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-3);
 80      }
 81  }
 82  
 83  static void test_min_p(const std::vector<float> & probs, const std::vector<float> & expected_probs, float p) {
 84      const size_t n_vocab = probs.size();
 85      std::vector<llama_token_data> candidates;
 86      candidates.reserve(n_vocab);
 87      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
 88          const float logit = logf(probs[token_id]);
 89          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
 90      }
 91  
 92      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
 93      DUMP(&candidates_p);
 94      llama_sample_min_p(nullptr, &candidates_p, p, 1);
 95      DUMP(&candidates_p);
 96      llama_sample_softmax(nullptr, &candidates_p);
 97  
 98      GGML_ASSERT(candidates_p.size == expected_probs.size());
 99      for (size_t i = 0; i < candidates_p.size; i++) {
100          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-3);
101      }
102  }
103  
104  static void test_typical(const std::vector<float> & probs, const std::vector<float> & expected_probs, float p) {
105      const size_t n_vocab = probs.size();
106      std::vector<llama_token_data> candidates;
107      candidates.reserve(n_vocab);
108      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
109          const float logit = logf(probs[token_id]);
110          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
111      }
112  
113      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
114      DUMP(&candidates_p);
115      llama_sample_typical(nullptr, &candidates_p, p, 1);
116      DUMP(&candidates_p);
117  
118      GGML_ASSERT(candidates_p.size == expected_probs.size());
119      for (size_t i = 0; i < candidates_p.size; i++) {
120          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-3);
121      }
122  }
123  
124  static void test_repetition_penalties(
125      const std::vector<float> & probs, const std::vector<llama_token> & last_tokens,
126      const std::vector<float> & expected_probs, float repeat_penalty, float alpha_frequency, float alpha_presence
127  ) {
128      GGML_ASSERT(probs.size() == expected_probs.size());
129  
130      const size_t n_vocab = probs.size();
131      std::vector<llama_token_data> candidates;
132      candidates.reserve(n_vocab);
133      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
134          const float logit = logf(probs[token_id]);
135          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
136      }
137  
138      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
139      llama_sample_softmax(nullptr, &candidates_p);
140      DUMP(&candidates_p);
141      llama_sample_repetition_penalties(nullptr, &candidates_p, (const llama_token *) last_tokens.data(), last_tokens.size(), repeat_penalty, alpha_frequency, alpha_presence);
142      llama_sample_softmax(nullptr, &candidates_p);
143      DUMP(&candidates_p);
144  
145      GGML_ASSERT(candidates_p.size == expected_probs.size());
146      for (size_t i = 0; i < candidates_p.size; i++) {
147          GGML_ASSERT(fabs(candidates_p.data[i].p - expected_probs[i]) < 1e-3);
148      }
149  }
150  
151  static void test_sampler_queue(
152      const size_t n_vocab, const std::string samplers_sequence, const int top_k, const float top_p, const float min_p
153  ) {
154      std::vector<llama_token_data> candidates;
155      candidates.reserve(n_vocab);
156      for (llama_token token_id = 0; token_id < (llama_token)n_vocab; token_id++) {
157          const float logit = logf(token_id);
158          candidates.emplace_back(llama_token_data{token_id, logit, 0.0f});
159      }
160  
161      llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
162  
163            llama_token min_token_id = 0;
164      const llama_token max_token_id = n_vocab-1;
165  
166      for (auto s : samplers_sequence) {
167          switch (s){
168              case 'k': llama_sample_top_k    (nullptr, &candidates_p, top_k, 1); break;
169              case 'f': GGML_ASSERT(false && "tail_free test not implemented");   break;
170              case 'y': GGML_ASSERT(false && "typical test not implemented");     break;
171              case 'p': llama_sample_top_p    (nullptr, &candidates_p, top_p, 1); break;
172              case 'm': llama_sample_min_p    (nullptr, &candidates_p, min_p, 1); break;
173              case 't': GGML_ASSERT(false && "temperature test not implemented"); break;
174              default : GGML_ASSERT(false && "Unknown sampler");                  break;
175          }
176  
177          llama_sample_softmax(nullptr, &candidates_p); // make sure tokens are sorted for tests
178  
179          const int size = candidates_p.size;
180  
181          if (s == 'k') {
182              const int expected_size = std::min(size, top_k);
183              min_token_id = std::max(min_token_id, (llama_token)(n_vocab - top_k));
184  
185              GGML_ASSERT(size == expected_size);
186              GGML_ASSERT(candidates_p.data[0].id == max_token_id);
187              GGML_ASSERT(candidates_p.data[expected_size-1].id == min_token_id);
188          } else if (s == 'p') {
189              const int softmax_divisor = n_vocab * (n_vocab-1) / 2 - min_token_id * (min_token_id-1) / 2;
190              const int softmax_numerator_target = ceilf(top_p * softmax_divisor);
191  
192                  min_token_id  = n_vocab;
193              int expected_size = 0;
194              int cumsum        = 0;
195              do { // do-while because always at least one token is sampled
196                  min_token_id--;
197                  expected_size++;
198  
199                  cumsum += min_token_id;
200              } while (cumsum < softmax_numerator_target);
201  
202              // token 0 has p == 0, need special consideration for cumsum because top_p immediately returns
203              if (min_token_id == 1) {
204                  min_token_id--;
205                  expected_size += 1;
206              }
207  
208              GGML_ASSERT(size == expected_size);
209              GGML_ASSERT(candidates_p.data[0].id == max_token_id);
210              GGML_ASSERT(candidates_p.data[expected_size-1].id == min_token_id);
211          } else if (s == 'm') {
212              int expected_size = ceilf((1.0f-min_p) * n_vocab);
213              expected_size = std::max(expected_size, 1);
214              expected_size = std::min(expected_size, size);
215  
216              min_token_id = floorf(min_p * n_vocab);
217              min_token_id = std::max(min_token_id, 1);
218              min_token_id = std::max(min_token_id, (llama_token)(n_vocab - size));
219              min_token_id = std::min(min_token_id, (llama_token)(n_vocab - 1));
220  
221              GGML_ASSERT(size == expected_size);
222              GGML_ASSERT(candidates_p.data[0].id == max_token_id);
223              GGML_ASSERT(candidates_p.data[expected_size-1].id == min_token_id);
224          } else {
225              GGML_ASSERT(false);
226          }
227      }
228  
229      printf("Sampler queue %3s OK with n_vocab=%05ld top_k=%05d top_p=%f min_p=%f\n",
230             samplers_sequence.c_str(), n_vocab, top_k, top_p, min_p);
231  }
232  
233  int main(void) {
234      ggml_time_init();
235  
236      test_top_k({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f}, 1);
237      test_top_k({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f, 0.2f}, 3);
238      test_top_k({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f, 0.2f, 0.1f}, 4);
239      test_top_k({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f, 0.2f, 0.1f}, 0);
240  
241      test_top_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f}, 0);
242      test_top_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f}, 0.7f);
243      test_top_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f, 0.2f}, 0.8f);
244      test_top_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f, 0.3f, 0.2f, 0.1f}, 1);
245  
246      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/1.0f, 0.3f/1.0f, 0.2f/1.0f, 0.1f/1.0f}, 0.00f);
247      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/1.0f, 0.3f/1.0f, 0.2f/1.0f, 0.1f/1.0f}, 0.24f);
248      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.9f, 0.3f/0.9f, 0.2f/0.9f},            0.26f);
249      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.9f, 0.3f/0.9f, 0.2f/0.9f},            0.49f);
250      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.7f, 0.3f/0.7f},                       0.51f);
251      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.7f, 0.3f/0.7f},                       0.74f);
252      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.4f},                                  0.76f);
253      test_min_p({0.1f, 0.2f, 0.3f, 0.4f}, {0.4f/0.4f},                                  1.00f);
254  
255      test_tfs({0.1f, 0.15f, 0.2f, 0.25f, 0.3f}, {0.3f}, 0.25f);
256      test_tfs({0.1f, 0.15f, 0.2f, 0.25f, 0.3f}, {0.3f, 0.25f}, 0.75f);
257      test_tfs({0.1f, 0.15f, 0.2f, 0.25f, 0.3f}, {0.3f, 0.25f}, 0.99f);
258  
259      test_typical({0.97f, 0.01f, 0.01f, 0.01f}, {0.97f}, 0.5f);
260      test_typical({0.4f, 0.2f, 0.2f, 0.2f}, {0.2f, 0.2f, 0.2f}, 0.5f);
261  
262      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0}, {0.25f, 0.25f, 0.25f, 0.25f, 0},   50.0f, 0.0f, 0.0f);
263      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0, 1, 2}, {0.5f, 0.5f, 0, 0, 0},       50.0f, 0.0f, 0.0f);
264      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0, 1, 2, 0, 0}, {0.5f, 0.5f, 0, 0, 0}, 50.0f, 0.0f, 0.0f);
265  
266      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0},             {0.249997f, 0.249997f, 0.249997f, 0.249997f, 0.000011f}, 1.0f, 5.0f, 5.0f);
267      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0, 1, 2},       {0.499966f, 0.499966f, 0.000023f, 0.000023f, 0.000023f}, 1.0f, 5.0f, 5.0f);
268      test_repetition_penalties({0.2f, 0.2f, 0.2f, 0.2f, 0.2f}, {0, 1, 2, 0, 0}, {0.499977f, 0.499977f, 0.000023f, 0.000023f, 0.000000f}, 1.0f, 5.0f, 5.0f);
269  
270      test_sampler_queue(10000, "k", 10000, 1.0f, 1.0f);
271      test_sampler_queue(10000, "k",     1, 1.0f, 1.0f);
272      test_sampler_queue(10000, "p", 10000, 1.0f, 1.0f);
273      test_sampler_queue(10000, "p", 10000, 0.0f, 1.0f);
274      test_sampler_queue(10000, "m", 10000, 1.0f, 1.0f);
275      test_sampler_queue(10000, "m", 10000, 1.0f, 1e-12);
276  
277      test_sampler_queue(10000, "k",   100, 1.0000f, 1.0f);
278      test_sampler_queue(10000, "p", 10000, 0.0002f, 1.0f);
279      test_sampler_queue(10000, "p", 10000, 0.8000f, 1.0f);
280      test_sampler_queue(10000, "m", 10000, 1.0000f, 9997.9f/9999.0f);
281      test_sampler_queue(10000, "m", 10000, 1.0000f, 0.1f);
282  
283      test_sampler_queue(10000, "kp", 100, 0.8f, 0.1f);
284      test_sampler_queue(10000, "km", 100, 0.8f, 0.1f);
285      test_sampler_queue(10000, "pk", 100, 0.8f, 0.1f);
286      test_sampler_queue(10000, "pm", 100, 0.8f, 0.1f);
287      test_sampler_queue(10000, "mk", 100, 0.8f, 0.1f);
288      test_sampler_queue(10000, "mp", 100, 0.8f, 9997.9f/9999.0f);
289      test_sampler_queue(10000, "mp", 100, 0.8f, 0.1f);
290  
291      test_sampler_queue(10000, "kpm", 100, 0.8f, 0.1f);
292      test_sampler_queue(10000, "kmp", 100, 0.8f, 0.1f);
293      test_sampler_queue(10000, "pkm", 100, 0.8f, 0.1f);
294      test_sampler_queue(10000, "pmk", 100, 0.8f, 0.1f);
295      test_sampler_queue(10000, "mkp", 100, 0.8f, 0.1f);
296      test_sampler_queue(10000, "mpk", 100, 0.8f, 0.1f);
297  
298      printf("OK\n");
299  
300      return 0;
301  }