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Diffstat (limited to 'llama.cpp/common/speculative.cpp')
| -rw-r--r-- | llama.cpp/common/speculative.cpp | 1074 |
1 files changed, 1074 insertions, 0 deletions
diff --git a/llama.cpp/common/speculative.cpp b/llama.cpp/common/speculative.cpp new file mode 100644 index 0000000..3e68c38 --- /dev/null +++ b/llama.cpp/common/speculative.cpp @@ -0,0 +1,1074 @@ +#include "speculative.h" + +#include "common.h" +#include "ggml.h" +#include "llama.h" +#include "log.h" +#include "ngram-cache.h" +#include "ngram-map.h" +#include "ngram-mod.h" +#include "sampling.h" + +#include <algorithm> +#include <cstring> +#include <iomanip> +#include <map> + +#define SPEC_VOCAB_MAX_SIZE_DIFFERENCE 128 +#define SPEC_VOCAB_CHECK_START_TOKEN_ID 5 + +const std::vector<enum common_speculative_type> common_speculative_types = { + COMMON_SPECULATIVE_TYPE_NONE, + COMMON_SPECULATIVE_TYPE_DRAFT, + COMMON_SPECULATIVE_TYPE_EAGLE3, + COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE, + COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K, + COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V, + COMMON_SPECULATIVE_TYPE_NGRAM_MOD, + COMMON_SPECULATIVE_TYPE_NGRAM_CACHE +}; + +const std::map<std::string, enum common_speculative_type> common_speculative_type_from_name_map = { + {"none", COMMON_SPECULATIVE_TYPE_NONE}, + {"draft", COMMON_SPECULATIVE_TYPE_DRAFT}, + {"eagle3", COMMON_SPECULATIVE_TYPE_EAGLE3}, + {"ngram_simple", COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE}, + {"ngram_map_k", COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K}, + {"ngram_map_k4v", COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V}, + {"ngram_mod", COMMON_SPECULATIVE_TYPE_NGRAM_MOD}, + {"ngram_cache", COMMON_SPECULATIVE_TYPE_NGRAM_CACHE} +}; + +struct common_speculative_config { + common_speculative_type type; + common_params_speculative params; + + common_speculative_config(common_speculative_type t, + const common_params_speculative & p = common_params_speculative{}) : type(t), params(p) {} +}; + +static bool common_speculative_are_compatible( + const llama_model * model_tgt, + const llama_model * model_dft) { + const llama_vocab * vocab_tgt = llama_model_get_vocab(model_tgt); + const llama_vocab * vocab_dft = llama_model_get_vocab(model_dft); + + const bool vocab_type_tgt = llama_vocab_type(vocab_tgt); + LOG_DBG("%s: vocab_type tgt: %d\n", __func__, vocab_type_tgt); + + const bool vocab_type_dft = llama_vocab_type(vocab_dft); + LOG_DBG("%s: vocab_type dft: %d\n", __func__, vocab_type_dft); + + if (vocab_type_tgt != vocab_type_dft) { + LOG_DBG("%s: draft model vocab type must match target model to use speculation but ", __func__); + LOG_DBG("vocab_type_dft = %d while vocab_type_tgt = %d\n", vocab_type_dft, vocab_type_tgt); + return false; + } + + if ( + llama_vocab_get_add_bos(vocab_tgt) != llama_vocab_get_add_bos(vocab_dft) || + llama_vocab_get_add_eos(vocab_tgt) != llama_vocab_get_add_eos(vocab_dft) || + llama_vocab_bos(vocab_tgt) != llama_vocab_bos(vocab_dft) || + llama_vocab_eos(vocab_tgt) != llama_vocab_eos(vocab_dft) + ) { + LOG_DBG("%s: draft model special tokens must match target model to use speculation\n", __func__); + return false; + } + + { + const int n_vocab_tgt = llama_vocab_n_tokens(vocab_tgt); + const int n_vocab_dft = llama_vocab_n_tokens(vocab_dft); + const int vocab_diff = n_vocab_tgt > n_vocab_dft + ? n_vocab_tgt - n_vocab_dft + : n_vocab_dft - n_vocab_tgt; + + if (vocab_diff > SPEC_VOCAB_MAX_SIZE_DIFFERENCE) { + LOG_DBG("%s: draft model vocab must closely match target model to use speculation but ", __func__); + LOG_DBG("target vocab size %d does not match draft vocab size %d - difference %d, max allowed %d\n", + n_vocab_tgt, llama_vocab_n_tokens(vocab_dft), vocab_diff, SPEC_VOCAB_MAX_SIZE_DIFFERENCE); + return false; + } + + for (int i = SPEC_VOCAB_CHECK_START_TOKEN_ID; i < std::min(n_vocab_tgt, n_vocab_dft); ++i) { + const char * token_text_tgt = llama_vocab_get_text(vocab_tgt, i); + const char * token_text_dft = llama_vocab_get_text(vocab_dft, i); + + if (std::strcmp(token_text_tgt, token_text_dft) != 0) { + LOG_DBG("%s: draft model vocab must match target model to use speculation but ", __func__); + LOG_DBG("token %d content differs - target '%s', draft '%s'\n", i, + common_token_to_piece(vocab_tgt, i).c_str(), + common_token_to_piece(vocab_dft, i).c_str()); + return false; + } + } + } + + return true; +} + +// state of an implementation of speculative decoding +// +// each implementation has a unique type and a state that is implementation-specific +// in a subclass of common_speculative_state +struct common_speculative_state { + const enum common_speculative_type type; + + size_t n_call_begin = 0; // number of times this implementation was called for refresh. + size_t n_call_draft = 0; // number of times this implementation was called for generation. + size_t n_call_accept = 0; // number of times this implementation was called for accumulation. + + size_t n_gen_drafts = 0; // number of times a draft or part was generated by this implementation. + size_t n_acc_drafts = 0; // number of times a draft or part was accepted by the target model. + size_t n_gen_tokens = 0; // number of tokens generated by this implementation. + size_t n_acc_tokens = 0; // number of tokens accepted by the target model. + + // TODO: track performance of most recent calls + const bool gen_perf = true; // whether to generate performance stats. + + int64_t t_begin_us = 0; // total time spent in refresh of this implementation in microseconds. + int64_t t_draft_us = 0; // total time spent in generating drafts in this implementation in microseconds. + int64_t t_accept_us = 0; // total time spent in accumulation of this implementation in microseconds. + + common_speculative_state(enum common_speculative_type type) : type(type) {} + + virtual ~common_speculative_state() = default; + + virtual void begin(const llama_tokens & prompt) = 0; + + virtual void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) = 0; + + virtual void accept(uint16_t n_accepted) = 0; +}; + +struct common_speculative_state_draft : public common_speculative_state { + llama_context * ctx_tgt; // only used for retokenizing from ctx_dft + llama_context * ctx_dft; + + common_sampler * smpl; + + llama_batch batch; + llama_tokens prompt_dft; + + bool vocab_cmpt = true; // whether retokenization is needed + std::unordered_map<std::string, std::string> vocab_map; + + common_speculative_state_draft( + enum common_speculative_type type, + llama_context * ctx_tgt, + llama_context * ctx_dft, + const std::vector<std::pair<std::string, std::string>> & replacements) + : common_speculative_state(type) + , ctx_tgt(ctx_tgt) + , ctx_dft(ctx_dft) + { + batch = llama_batch_init(llama_n_batch(ctx_dft), 0, 1); + smpl = nullptr; + + // TODO: optimize or pass from outside? + // { + // common_params_sampling params; + // params.no_perf = false; + // + // params.top_k = 40; + // params.top_p = 0.9; + // + // params.samplers = { + // COMMON_SAMPLER_TYPE_TOP_K, + // COMMON_SAMPLER_TYPE_TOP_P, + // COMMON_SAMPLER_TYPE_INFILL, + // }; + // + // result->smpl = common_sampler_init(llama_get_model(ctx_dft), params); + // } + { + common_params_sampling params; + params.no_perf = false; + params.top_k = 10; + params.samplers = { + COMMON_SAMPLER_TYPE_TOP_K, + }; + + smpl = common_sampler_init(llama_get_model(ctx_dft), params); + } + + vocab_cmpt = common_speculative_are_compatible(llama_get_model(ctx_tgt), llama_get_model(ctx_dft)); + LOG_DBG("vocab_cmpt = %d\n", vocab_cmpt); + + if (!vocab_cmpt) { + LOG_WRN("the target and draft vocabs are not compatible - tokens will be translated between the two\n"); + + for (const auto & pair : replacements) { + vocab_map[pair.first] = pair.second; + } + } + } + + ~common_speculative_state_draft() override { + llama_perf_context_print(ctx_dft); + + llama_free(ctx_dft); + + common_sampler_free(smpl); + + llama_batch_free(batch); + } + + void begin(const llama_tokens & prompt) override { + GGML_UNUSED(prompt); + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) override { + auto * spec = this; + + auto & batch = spec->batch; + auto & ctx_tgt = spec->ctx_tgt; + auto & ctx_dft = spec->ctx_dft; + auto & smpl = spec->smpl; + auto & prompt_dft = spec->prompt_dft; + + auto * mem_dft = llama_get_memory(ctx_dft); + + int reuse_i = 0; + int reuse_n = 0; + + const int n_ctx = llama_n_ctx(ctx_dft) - params.n_max; + + llama_tokens prompt_cnv; + if (!spec->vocab_cmpt) { + std::string text; + + text = common_detokenize(ctx_tgt, prompt_tgt, true); + text = replace_to_dft(text); + + LOG_DBG("%s: main->draft detokenized string: '%s'\n", __func__, text.c_str()); + + prompt_cnv = common_tokenize(ctx_dft, text, false, true); + + // convert id_last to draft vocab. llama_detokenize is called directly to avoid an allocation + const auto * model_tgt = llama_get_model(ctx_tgt); + const auto * vocab_tgt = llama_model_get_vocab(model_tgt); + + int32_t n_chars = llama_detokenize(vocab_tgt, &id_last, 1, nullptr, 0, false, false); + GGML_ASSERT(n_chars < 0 && "failed to detokenize id_last"); + + text.resize(-n_chars); + llama_detokenize(vocab_tgt, &id_last, 1, text.data(), text.size(), false, false); + text = replace_to_dft(text); + + LOG_DBG("main->draft detokenized id_last(%d): '%s'\n", id_last, text.c_str()); + id_last = common_tokenize(ctx_dft, text, false, true)[0]; + } + + const llama_tokens & prompt_cur = spec->vocab_cmpt ? prompt_tgt : prompt_cnv; + + const int i_start = std::max<int>(0, (int) prompt_cur.size() - n_ctx); + + // reuse as much as possible from the old draft context + // ideally, the draft context should be as big as the target context and we will always reuse the entire prompt + for (int i = 0; i < (int) prompt_dft.size(); ++i) { + int cur = 0; + while (i_start + cur < (int) prompt_cur.size() && + i + cur < (int) prompt_dft.size() && + prompt_cur[i_start + cur] == prompt_dft[i + cur]) { + cur++; + } + + if ((cur >= 256 || n_ctx >= (int) prompt_cur.size()) && cur > reuse_n) { + reuse_i = i; + reuse_n = cur; + } + } + + LOG_DBG("%s: reuse_i = %d, reuse_n = %d, prompt = %d\n", __func__, reuse_i, reuse_n, (int) prompt_dft.size()); + + result.clear(); + result.reserve(params.n_max); + + if (reuse_n == 0) { + llama_memory_clear(mem_dft, false); + prompt_dft.clear(); + } else { + // this happens when a previous draft has been discarded (for example, due to being too small), but the + // target model agreed with it. in this case, we simply pass back the previous results to save compute + if (reuse_i + reuse_n < (int) prompt_dft.size() && prompt_dft[reuse_i + reuse_n] == id_last) { + for (int i = reuse_i + reuse_n + 1; i < (int) prompt_dft.size(); ++i) { + result.push_back(prompt_dft[i]); + + if (params.n_max <= (int) result.size()) { + break; + } + } + + return; + } + + if (reuse_i > 0) { + llama_memory_seq_rm (mem_dft, 0, 0, reuse_i); + llama_memory_seq_add(mem_dft, 0, reuse_i, -1, -reuse_i); + + prompt_dft.erase(prompt_dft.begin(), prompt_dft.begin() + reuse_i); + } + + if (reuse_n < (int) prompt_dft.size()) { + llama_memory_seq_rm (mem_dft, 0, reuse_n, -1); + prompt_dft.erase(prompt_dft.begin() + reuse_n, prompt_dft.end()); + } + } + + // prepare a batch to evaluate any new tokens in the prompt + common_batch_clear(batch); + + for (size_t i = i_start + reuse_n; i < prompt_cur.size(); ++i) { + //LOG_DBG("i = %d, i_start = %d, reuse_n = %d, i - i_start = %d, id = %6d\n", i, i_start, reuse_n, i - i_start, prompt_cur[i]); + common_batch_add(batch, prompt_cur[i], i - i_start, { 0 }, false); + + prompt_dft.push_back(prompt_cur[i]); + } + + // we should rarely end-up here during normal decoding + if (batch.n_tokens > 0) { + //LOG_DBG("%s: draft prompt batch: %s\n", __func__, string_from(ctx, batch).c_str()); + + llama_decode(ctx_dft, batch); + } + + const llama_pos n_past = prompt_dft.size(); + + LOG_DBG("%s: n_past = %d\n", __func__, n_past); + + common_batch_clear(batch); + common_batch_add (batch, id_last, n_past, { 0 }, true); + + prompt_dft.push_back(id_last); + + LOG_DBG("%s: draft prompt: %s\n", __func__, string_from(ctx_dft, prompt_dft).c_str()); + + llama_decode(ctx_dft, batch); + + common_sampler_reset(smpl); + + // sample n_draft tokens from the draft model + for (int i = 0; i < params.n_max; ++i) { + common_batch_clear(batch); + + common_sampler_sample(smpl, ctx_dft, 0, true); + + const auto * cur_p = common_sampler_get_candidates(smpl, true); + + for (int k = 0; k < std::min(3, (int) cur_p->size); ++k) { + LOG_DBG(" - draft candidate %3d, pos %3d: %6d (%8.3f) '%s'\n", + k, i, cur_p->data[k].id, cur_p->data[k].p, common_token_to_piece(ctx_dft, cur_p->data[k].id).c_str()); + } + + // add drafted token for each sequence + const llama_token id = cur_p->data[0].id; + + common_sampler_accept(smpl, id, true); + + result.push_back(id); + + if (params.n_max <= (int) result.size()) { + break; + } + + // only collect very high-confidence draft tokens + if (cur_p->data[0].p < params.p_min) { + break; + } + + common_batch_add(batch, id, n_past + i + 1, { 0 }, true); + + // evaluate the drafted tokens on the draft model + llama_decode(ctx_dft, batch); + + prompt_dft.push_back(id); + } + + if (!spec->vocab_cmpt) { + std::string detokenized = common_detokenize(ctx_dft, result, true); + detokenized = replace_to_tgt(detokenized); + LOG_DBG("draft->main detokenized string: '%s'\n", detokenized.c_str()); + result = common_tokenize(ctx_tgt, detokenized, false, true); + if (result.size() > (size_t)params.n_max) { + result.resize(params.n_max); + } + } + } + + void accept(uint16_t n_accepted) override { + // noop + GGML_UNUSED(n_accepted); + } + + std::string replace_to_dft(const std::string & input) const { + std::string result = input; + + for (const auto & pair : this->vocab_map) { + size_t pos = result.find(pair.first); + while (pos != std::string::npos) { + result.replace(pos, pair.first.length(), pair.second); + pos = result.find(pair.first, pos + pair.second.length()); + } + } + + return result; + } + + std::string replace_to_tgt(const std::string & input) const { + std::string result = input; + + for (const auto & pair : this->vocab_map) { + size_t pos = result.find(pair.second); + while (pos != std::string::npos) { + result.replace(pos, pair.second.length(), pair.first); + pos = result.find(pair.second, pos + pair.first.length()); + } + } + + return result; + } +}; + +struct common_speculative_state_eagle3 : public common_speculative_state { + common_speculative_state_eagle3(enum common_speculative_type type) : common_speculative_state(type) {} + + void begin(const llama_tokens & prompt) override { + GGML_UNUSED(prompt); + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & draft_tokens) override { + // TODO: implement + GGML_UNUSED(params); + GGML_UNUSED(prompt_tgt); + GGML_UNUSED(id_last); + GGML_UNUSED(draft_tokens); + } + + void accept(uint16_t n_accepted) override { + // noop + GGML_UNUSED(n_accepted); + } +}; + +// state of self-speculation (simple implementation, not ngram-map) +struct common_speculative_state_ngram_simple : public common_speculative_state { + common_ngram_simple_config config; + + common_speculative_state_ngram_simple( + enum common_speculative_type type, + common_ngram_simple_config config) + : common_speculative_state(type), config(config) {} + + void begin(const llama_tokens & prompt) override { + GGML_UNUSED(prompt); + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) override { + + result = common_ngram_simple_draft(config, prompt_tgt, id_last); + GGML_UNUSED(params); + } + + void accept(uint16_t n_accepted) override { + // noop + GGML_UNUSED(n_accepted); + } +}; + +struct common_speculative_state_ngram_map_k : public common_speculative_state { + // draft ngram map for speculative decoding without draft model + common_ngram_map map; + + common_speculative_state_ngram_map_k( + enum common_speculative_type type, + common_ngram_map map) + : common_speculative_state(type), map(std::move(map)) {} + + void begin(const llama_tokens & prompt) override { + common_ngram_map_begin(map, prompt); + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) override { + common_ngram_map_draft(map, prompt_tgt, id_last, result); + GGML_UNUSED(params); + } + + void accept(uint16_t n_accepted) override { + common_ngram_map_accept(map, n_accepted); + } +}; + +struct common_speculative_state_ngram_mod : public common_speculative_state { + common_ngram_mod & mod; + + // the last position in the prompt that was added to the ngram container + size_t i_last = 0; + + // length of the last drafted n‑gram (number of tokens returned by draft) + size_t n_draft_last = 0; + + // consecutive accept rounds with low acceptance fraction (< 0.5) + int n_low = 0; + + // enable trace logging if LLAMA_TRACE is set + const bool verbose; + + common_speculative_state_ngram_mod(enum common_speculative_type type, common_ngram_mod & mod) + : common_speculative_state(type), mod(mod), verbose(std::getenv("LLAMA_TRACE") != nullptr) { + static_assert(sizeof(llama_token) == sizeof(common_ngram_mod::entry_t)); + } + + void begin(const llama_tokens & prompt) override { + i_last = 0; + + n_draft_last = 0; + + const size_t n = mod.get_n(); + + if (prompt.size() < n) { + return; + } + + for (size_t i = 0; i < prompt.size() - n; ++i) { + mod.add(prompt.data() + i); + } + + i_last = prompt.size() - n; + + const double f = (double)mod.get_used() / (double)mod.size(); + LOG_INF("%s: ngram_mod occupancy = %zu/%zu (%.2f)\n", __func__, mod.get_used(), mod.size(), f); + + constexpr double f_thold = 0.25; + if (f > f_thold) { + LOG_WRN("%s: ngram_mod occupancy %.2f exceeds threshold (%.2f) - resetting\n", __func__, f, f_thold); + + mod.reset(); + } + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) override { + GGML_UNUSED(params); + + n_draft_last = 0; + + const size_t cur_len = prompt_tgt.size(); + if (cur_len < mod.get_n()) { + return; + } + + const size_t n = mod.get_n(); + + // add new ngrams in chunks + if (i_last + 32 < cur_len) { + for (size_t i = i_last; i < cur_len - n; ++i) { + mod.add(prompt_tgt.data() + i); + } + + i_last = cur_len - n; + } + + result.resize(n + params.n_max); + for (size_t i = 0; i < n - 1; ++i) { + result[i] = prompt_tgt[cur_len - n + 1 + i]; + } + result[n - 1] = id_last; + + for (int i = 0; i < params.n_max; ++i) { + const llama_token token = mod.get(result.data() + i); + if (token == common_ngram_mod::EMPTY) { + if (i < params.n_min) { + result.clear(); + return; + } + + result.resize(n + i); + break; + } + result[n + i] = token; + } + + // only return the m tokens that were drafted + for (size_t i = 0; n + i < result.size(); ++i) { + result[i] = result[n + i]; + } + result.resize(result.size() - n); + + // store length of drafted n‑gram for later acceptance analysis + n_draft_last = result.size(); + } + + void accept(uint16_t n_accepted) override { + if (verbose) { + LOG_INF("%s: accepted %d tokens from %zu drafted tokens\n", __func__, n_accepted, n_draft_last); + } + + // compute acceptance fraction if we have a recorded draft length + if (n_draft_last > 0) { + const double f_acc = (double)n_accepted / (double)n_draft_last; + if (f_acc < 0.5) { + n_low++; + if (n_low >= 3) { + LOG_WRN("%s: low acceptance streak (%d) – resetting ngram_mod\n", __func__, n_low); + + mod.reset(); + n_low = 0; + } + } else { + n_low = 0; + } + } + } +}; + +struct common_speculative_state_ngram_cache : public common_speculative_state { + uint16_t n_draft; + bool save_dynamic; + bool save_static; + + common_ngram_cache ngram_cache_context; + common_ngram_cache ngram_cache_dynamic; + common_ngram_cache ngram_cache_static; + + size_t cache_size = 0; // number of tokens in n-gram cache + + common_speculative_state_ngram_cache( + const enum common_speculative_type type, + const std::string & path_static, + const std::string & path_dynamic, + uint16_t n_draft, + bool save_dynamic, + bool save_static) + : common_speculative_state(type) + , n_draft(n_draft) + , save_dynamic(save_dynamic) + , save_static(save_static) + { + if (!path_static.empty()) { + try { + ngram_cache_static = common_ngram_cache_load(path_static); + } catch (...) { + LOG_ERR("failed to open static lookup cache: %s", path_static.c_str()); + GGML_ABORT("Couldn't read static lookup cache"); + } + } + + if (!path_dynamic.empty()) { + try { + ngram_cache_dynamic = common_ngram_cache_load(path_dynamic); + } catch (...) { + LOG_ERR("failed to open dynamic lookup cache: %s", path_dynamic.c_str()); + GGML_ABORT("Couldn't read dynamic lookup cache"); + } + } + } + + void begin(const llama_tokens & prompt) override { + GGML_UNUSED(prompt); + } + + void draft( + const common_params_speculative & params, + const llama_tokens & prompt_tgt, + llama_token id_last, + llama_tokens & result) override { + GGML_UNUSED(params); + + if (cache_size < prompt_tgt.size() + 1) { + llama_tokens tokens_new; + tokens_new.reserve(prompt_tgt.size() + 1 - cache_size); + for (size_t j = cache_size; j < prompt_tgt.size(); ++j) { + tokens_new.push_back(prompt_tgt[j]); + } + tokens_new.push_back(id_last); // add the last token + + // Update context ngram cache with new prompt_tgt: + common_ngram_cache_update(ngram_cache_context, LLAMA_NGRAM_MIN, LLAMA_NGRAM_MAX, + tokens_new, tokens_new.size(), false); + cache_size = prompt_tgt.size() + 1; + } + + llama_tokens inp; + inp.reserve(prompt_tgt.size() + 1); + for (size_t j = 0; j < prompt_tgt.size(); ++j) { + inp.push_back(prompt_tgt[j]); + } + inp.push_back(id_last); + + result.push_back(id_last); + + common_ngram_cache_draft(inp, result, n_draft, LLAMA_NGRAM_MIN, LLAMA_NGRAM_MAX, + ngram_cache_context, + ngram_cache_dynamic, + ngram_cache_static); + + if (result.size() > 0) { + // delete first token in result (which is the id_last token) + result.erase(result.begin()); + } + } + + void accept(uint16_t n_accepted) override { + // TODO: noop + GGML_UNUSED(n_accepted); + } +}; + +struct common_speculative { + std::vector<std::unique_ptr<common_speculative_state>> impls; // list of implementations to use and their states + common_speculative_state * curr_impl = nullptr; // current implementation in use (for stats) +}; + +static common_ngram_map get_common_ngram_map(const common_speculative_config & config) { + uint16_t size_key = config.params.ngram_size_n; + uint16_t size_value = config.params.ngram_size_m; + bool key_only = (config.type == COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K); + uint16_t min_hits = config.params.ngram_min_hits; + + return common_ngram_map(size_key, size_value, key_only, min_hits); +} + +static common_speculative_state_ngram_cache create_state_ngram_cache( + const std::string & path_static, const std::string & path_dynamic, + const common_speculative_config & config) { + uint16_t n_draft = 8; // TODO get from config? + + // TODO bool param in common/common.h to set save_static/save_dynamic? + bool save_static = false; + bool save_dynamic = false; + + common_speculative_state_ngram_cache state(config.type, path_static, path_dynamic, n_draft, save_static, save_dynamic); + + return state; +} + +std::string common_speculative_type_name_str() { + std::string result; + for (size_t i = 0; i < common_speculative_types.size(); i++) { + if (i > 0) { + result += ", "; + } + result += common_speculative_type_to_str(common_speculative_types[i]); + } + return result; +} + +std::string common_speculative_type_to_str(enum common_speculative_type type) { + switch (type) { + case COMMON_SPECULATIVE_TYPE_NONE: return "none"; + case COMMON_SPECULATIVE_TYPE_DRAFT: return "draft"; + case COMMON_SPECULATIVE_TYPE_EAGLE3: return "eagle3"; + case COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE: return "ngram_simple"; + case COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K: return "ngram_map_k"; + case COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V: return "ngram_map_k4v"; + case COMMON_SPECULATIVE_TYPE_NGRAM_MOD: return "ngram_mod"; + case COMMON_SPECULATIVE_TYPE_NGRAM_CACHE: return "ngram_cache"; + default: return "unknown"; + } +} + +enum common_speculative_type common_speculative_type_from_name(const std::string & name) { + const auto it = common_speculative_type_from_name_map.find(name); + if (it == common_speculative_type_from_name_map.end()) { + return COMMON_SPECULATIVE_TYPE_COUNT; + } + return it->second; +} + +bool common_speculative_is_compat(llama_context * ctx_tgt) { + auto * mem = llama_get_memory(ctx_tgt); + if (mem == nullptr) { + return false; + } + + bool res = true; + + llama_memory_clear(mem, true); + + // eval 2 tokens to check if the context is compatible + std::vector<llama_token> tmp; + tmp.push_back(0); + tmp.push_back(0); + + int ret = llama_decode(ctx_tgt, llama_batch_get_one(tmp.data(), tmp.size())); + if (ret != 0) { + LOG_ERR("%s: llama_decode() failed: %d\n", __func__, ret); + res = false; + goto done; + } + + // try to remove the last tokens + if (!llama_memory_seq_rm(mem, 0, 1, -1)) { + LOG_WRN("%s: the target context does not support partial sequence removal\n", __func__); + res = false; + goto done; + } + +done: + llama_memory_clear(mem, true); + llama_synchronize(ctx_tgt); + + return res; +} + +// initialization of the speculative decoding system +// +common_speculative * common_speculative_init( + common_params_speculative & params, + llama_context * ctx_tgt) { + llama_context * ctx_dft = nullptr; + if (params.model_dft) { + ctx_dft = llama_init_from_model(params.model_dft, params.cparams_dft); + if (ctx_dft == nullptr) { + LOG_ERR("%s", "failed to create draft context\n"); + return nullptr; + } + } + + // Compute the implementations to use based on the config and their order of preference + std::vector<common_speculative_config> configs = {}; // list of speculative configs to try + { + bool has_draft = !params.mparams_dft.path.empty(); + bool has_draft_eagle3 = false; // TODO PR-18039: if params.speculative.eagle3 + + bool has_ngram_cache = (params.type == COMMON_SPECULATIVE_TYPE_NGRAM_CACHE); + bool has_ngram_simple = (params.type == COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE); + bool has_ngram_map_k = (params.type == COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K); + bool has_ngram_map_k4v = (params.type == COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V); + bool has_ngram_mod = (params.type == COMMON_SPECULATIVE_TYPE_NGRAM_MOD); + + // In a more complex implementation we could use the same implementation but with different parameters. + // This was initially used in PR-18471 but removed to simplify the code. + if (has_ngram_simple) { + // This implementation can guess a lot of tokens without any draft model. + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE, params)); + } + if (has_ngram_map_k) { + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K, params)); + } + if (has_ngram_map_k4v) { + // This implementation can guess tokens with high acceptance rate but is more expensive. + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V, params)); + } + if (has_ngram_mod) { + // shared instance for all speculative decoding contexts + if (!params.ngram_mod) { + params.ngram_mod = std::make_shared<common_ngram_mod>(params.ngram_size_n, 4*1024*1024); + + LOG_INF("%s: initialized ngram_mod with n=%d, size=%zu (%.3f MB)\n", __func__, + params.ngram_size_n, params.ngram_mod->size(), + (float)(params.ngram_mod->size_bytes())/1024/1024); + + if (params.ngram_size_n < 16) { + LOG_WRN("%s: ngram_mod n=%d is too small - poor quality is possible, see: https://github.com/ggml-org/llama.cpp/pull/19164\n", __func__, params.ngram_size_n); + } + } + + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_NGRAM_MOD, params)); + } + if (has_ngram_cache) { + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_NGRAM_CACHE, params)); + } + if (has_draft) { + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_DRAFT, params)); + } + if (has_draft_eagle3) { + configs.push_back(common_speculative_config(COMMON_SPECULATIVE_TYPE_EAGLE3, params)); + } + } + + std::vector<std::unique_ptr<common_speculative_state>> impls = {}; + + for (const common_speculative_config & config : configs) { + LOG_DBG("%s: adding implementation %s\n", __func__, common_speculative_type_to_str(config.type).c_str()); + switch (config.type) { + case COMMON_SPECULATIVE_TYPE_NONE: + break; + case COMMON_SPECULATIVE_TYPE_DRAFT: { + impls.push_back(std::make_unique<common_speculative_state_draft>(config.type, + /* .ctx_tgt = */ ctx_tgt, + /* .ctx_dft = */ ctx_dft, + /* .replacements = */ params.replacements + )); + break; + } + case COMMON_SPECULATIVE_TYPE_EAGLE3: { + impls.push_back(std::make_unique<common_speculative_state_eagle3>(config.type)); + break; + } + case COMMON_SPECULATIVE_TYPE_NGRAM_SIMPLE: { + common_ngram_map ngram_map = get_common_ngram_map(config); + + uint16_t ngram_size_key = ngram_map.size_key; + uint16_t mgram_size_value = ngram_map.size_value; + + auto config_simple = common_ngram_simple_config { + /* .size_ngram = */ ngram_size_key, + /* .size_mgram = */ mgram_size_value + }; + auto state = std::make_unique<common_speculative_state_ngram_simple>( + /* .type = */ config.type, + /* .state = */ config_simple + ); + impls.push_back(std::move(state)); + break; + } + case COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K: + case COMMON_SPECULATIVE_TYPE_NGRAM_MAP_K4V: { + impls.push_back(std::make_unique<common_speculative_state_ngram_map_k>( + (config.type), + get_common_ngram_map(config) + )); + break; + } + case COMMON_SPECULATIVE_TYPE_NGRAM_MOD: { + GGML_ASSERT(config.params.ngram_mod); + impls.push_back(std::make_unique<common_speculative_state_ngram_mod>(config.type, *config.params.ngram_mod)); + break; + } + case COMMON_SPECULATIVE_TYPE_NGRAM_CACHE: { + auto state = create_state_ngram_cache( + params.lookup_cache_static, params.lookup_cache_dynamic, config); + impls.push_back(std::make_unique<common_speculative_state_ngram_cache>(state)); + break; + } + default: + break; + } + } + + if (impls.empty()) { + LOG_WRN("%s", "no implementations specified for speculative decoding\n"); + return nullptr; + } + + auto * result = new common_speculative { + /* .impls = */ std::move(impls) + }; + + return result; +} + +void common_speculative_free(common_speculative * spec) { + if (spec == nullptr) { + return; + } + + delete spec; +} + +void common_speculative_begin(common_speculative * spec, const llama_tokens & prompt) { + if (spec == nullptr) { + return; + } + + for (auto & impl : spec->impls) { + common_time_meas tm(impl->t_begin_us, !impl->gen_perf); + impl->begin(prompt); + impl->n_call_begin++; + } +} + +llama_tokens common_speculative_draft( + common_speculative * spec, + const common_params_speculative & params, + const llama_tokens & prompt_tgt, // specified in target model vocab + llama_token id_last) { + llama_tokens result; + + spec->curr_impl = nullptr; // reset current implementation + + for (auto & impl : spec->impls) { + { + common_time_meas tm(impl->t_draft_us, !impl->gen_perf); + impl->draft(params, prompt_tgt, id_last, result); + impl->n_call_draft++; + } + + if (!result.empty()) { + LOG_DBG("%s: called impl %s, hist size = %zu, call_count = %zu, gen = %zu\n", __func__, + common_speculative_type_to_str(impl.get()->type).c_str(), prompt_tgt.size(), + impl.get()->n_call_draft, result.size()); + + spec->curr_impl = impl.get(); // set current implementation for stats + impl->n_gen_drafts++; + impl->n_gen_tokens += result.size(); + + break; // We have a draft, so break out of the loop and return it. + } + } + + return result; +} + +void common_speculative_accept(common_speculative * spec, uint16_t n_accepted) { + if (n_accepted == 0) { + return; + } + + common_speculative_state * impl = spec->curr_impl; + + GGML_ASSERT(impl); + + { + common_time_meas tm(impl->t_accept_us, !impl->gen_perf); + if (n_accepted > 0) { + impl->n_acc_drafts++; + impl->n_acc_tokens += n_accepted; + } + + impl->accept(n_accepted); + impl->n_call_accept++; + } +} + +void common_speculative_print_stats(const common_speculative * spec) { + if (spec == nullptr) { + return; + } + + for (const auto & impl : spec->impls) { + std::string str_perf; + if (impl->gen_perf) { + std::ostringstream oss; + oss << std::fixed << std::setprecision(3) << impl->t_begin_us / 1000.0 << ", "; + oss << std::fixed << std::setprecision(3) << impl->t_draft_us / 1000.0 << ", "; + oss << std::fixed << std::setprecision(3) << impl->t_accept_us / 1000.0; + str_perf = ", dur(b,g,a) = " + oss.str() + " ms"; + } else { + str_perf = ""; + } + + LOG_INF("statistics %s: #calls(b,g,a) = %zu %zu %zu, #gen drafts = %zu, #acc drafts = %zu, #gen tokens = %zu, #acc tokens = %zu%s\n", + common_speculative_type_to_str(impl->type).c_str(), + impl->n_call_begin, impl->n_call_draft, impl->n_call_accept, + impl->n_gen_drafts, + impl->n_acc_drafts, + impl->n_gen_tokens, + impl->n_acc_tokens, + str_perf.c_str()); + } +} |