llama : minor sampling refactor (2) (#9386)

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slaren 2024-09-09 17:10:46 +02:00 committed by GitHub
parent 38ca6f644b
commit 5fb5e24811
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12 changed files with 115 additions and 113 deletions

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@ -8,49 +8,44 @@
#include <cstring>
#include <ctime>
#include <cfloat>
#include <cmath>
#include <numeric>
#include <random>
#include <unordered_map>
static int llama_sample_dist(llama_token_data_array * cur_p, std::mt19937 & rng, std::vector<float> & probs) {
#if 1
probs.resize(cur_p->size);
for (size_t i = 0; i < cur_p->size; ++i) {
probs[i] = cur_p->data[i].p;
}
std::discrete_distribution<size_t> dist(probs.begin(), probs.end());
#else
// avoid the copy with a custom iterator
static int llama_sample_dist(llama_token_data_array * cur_p, std::mt19937 & rng) {
// iterator for the probabilities
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#endif
struct probs_iterator {
typedef std::input_iterator_tag iterator_category;
typedef float value_type;
typedef float * pointer;
typedef float & reference;
typedef size_t difference_type;
typedef ptrdiff_t difference_type;
const llama_token_data_array * data;
size_t i;
const llama_token_data * data;
bool operator==(const probs_iterator & other) const { return data + i == other.data + other.i; }
bool operator!=(const probs_iterator & other) const { return data + i != other.data + other.i; }
float operator*() const { return data->data[i].p; }
probs_iterator & operator++() { ++i; return *this; }
probs_iterator operator++(int) { probs_iterator tmp = *this; ++i; return tmp; }
bool operator==(const probs_iterator & other) const { return data == other.data; }
bool operator!=(const probs_iterator & other) const { return data != other.data; }
const float & operator*() const { return data->p; }
probs_iterator & operator++() { ++data; return *this; }
probs_iterator operator++(int) { probs_iterator tmp = *this; ++data; return tmp; }
};
#ifdef __GNUC__
#pragma GCC diagnostic pop
std::discrete_distribution<size_t> dist(probs_iterator{cur_p, 0}, probs_iterator{cur_p, cur_p->size});
GGML_UNUSED(probs);
#endif
std::discrete_distribution<int> dist(probs_iterator{cur_p->data}, probs_iterator{cur_p->data + cur_p->size});
return dist(rng);
}
/*
static void llama_log_softmax(float * array, size_t size) {
float max_l = *std::max_element(array, array + size);
float sum = 0.f;
@ -64,6 +59,7 @@ static void llama_log_softmax(float * array, size_t size) {
array[i] = logf(array[i] / sum);
}
}
*/
static void llama_sampler_softmax_impl(llama_token_data_array * cur_p) {
GGML_ASSERT(cur_p->size > 0);
@ -231,67 +227,92 @@ llama_token llama_sampler_sample(struct llama_sampler * smpl, struct llama_conte
cur[token_id] = llama_token_data{token_id, logits[token_id], 0.0f};
}
llama_token_data_array cur_p = { cur.data(), cur.size(), -1, false };
llama_token_data_array cur_p = {
/* .data = */ cur.data(),
/* .size = */ cur.size(),
/* .selected = */ -1,
/* .sorted = */ false,
};
llama_sampler_apply(smpl, &cur_p);
return cur_p.data[cur_p.selected].id;
GGML_ASSERT(cur_p.selected >= 0 && cur_p.selected < (int32_t) cur_p.size);
auto token = cur_p.data[cur_p.selected].id;
llama_sampler_accept(smpl, token);
return token;
}
// sampler chain
static const char * llama_sampler_chain_name(const struct llama_sampler * /*smpl*/) {
return "chain";
}
static void llama_sampler_chain_accept(struct llama_sampler * smpl, llama_token token) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
time_meas tm(chain->t_sample_us, chain->params.no_perf);
for (auto * smpl : chain->samplers) {
llama_sampler_accept(smpl, token);
}
chain->n_sample++;
}
static void llama_sampler_chain_apply(struct llama_sampler * smpl, llama_token_data_array * cur_p) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
time_meas tm(chain->t_sample_us, chain->params.no_perf);
for (auto * smpl : chain->samplers) {
llama_sampler_apply(smpl, cur_p);
}
}
static void llama_sampler_chain_reset(struct llama_sampler * smpl) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
for (auto * smpl : chain->samplers) {
llama_sampler_reset(smpl);
}
chain->t_sample_us = 0;
chain->n_sample = 0;
}
static struct llama_sampler * llama_sampler_chain_clone(const struct llama_sampler * smpl) {
const auto * chain_src = (const llama_sampler_chain *) smpl->ctx;
auto * result = llama_sampler_chain_init(chain_src->params);
for (auto * smpl : chain_src->samplers) {
llama_sampler_chain_add(result, llama_sampler_clone(smpl));
}
return result;
}
static void llama_sampler_chain_free(struct llama_sampler * smpl) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
for (auto * smpl : chain->samplers) {
llama_sampler_free(smpl);
}
delete chain;
}
static struct llama_sampler_i llama_sampler_chain_i = {
/* .name = */ [](const struct llama_sampler * /*smpl*/) { return "chain"; },
/* .accept = */ [](struct llama_sampler * smpl, llama_token token) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
time_meas tm(chain->t_sample_us, chain->params.no_perf);
for (auto * smpl : chain->samplers) {
llama_sampler_accept(smpl, token);
}
chain->n_sample++;
},
/* .apply = */ [](struct llama_sampler * smpl, llama_token_data_array * cur_p) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
time_meas tm(chain->t_sample_us, chain->params.no_perf);
for (auto * smpl : chain->samplers) {
llama_sampler_apply(smpl, cur_p);
}
},
/* .reset = */ [](struct llama_sampler * smpl) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
for (auto * smpl : chain->samplers) {
llama_sampler_reset(smpl);
}
chain->t_sample_us = 0;
chain->n_sample = 0;
},
/* .clone = */ [](const struct llama_sampler * smpl) {
const auto * chain_src = (const llama_sampler_chain *) smpl->ctx;
auto * result = llama_sampler_chain_init(chain_src->params);
for (auto * smpl : chain_src->samplers) {
llama_sampler_chain_add(result, llama_sampler_clone(smpl));
}
return result;
},
/* .free = */ [](struct llama_sampler * smpl) {
auto * chain = (llama_sampler_chain *) smpl->ctx;
for (auto * smpl : chain->samplers) {
llama_sampler_free(smpl);
}
delete chain;
},
/* .name = */ llama_sampler_chain_name,
/* .accept = */ llama_sampler_chain_accept,
/* .apply = */ llama_sampler_chain_apply,
/* .reset = */ llama_sampler_chain_reset,
/* .clone = */ llama_sampler_chain_clone,
/* .free = */ llama_sampler_chain_free,
};
struct llama_sampler * llama_sampler_chain_init(struct llama_sampler_chain_params params) {
@ -368,8 +389,6 @@ struct llama_sampler_dist {
const uint32_t seed;
std::mt19937 rng;
std::vector<float> probs; // work array
};
static const char * llama_sampler_dist_name(const struct llama_sampler * /*smpl*/) {
@ -378,7 +397,7 @@ static const char * llama_sampler_dist_name(const struct llama_sampler * /*smpl*
static void llama_sampler_dist_apply(struct llama_sampler * smpl, llama_token_data_array * cur_p) {
auto * ctx = (llama_sampler_dist *) smpl->ctx;
cur_p->selected = llama_sample_dist(cur_p, ctx->rng, ctx->probs);
cur_p->selected = llama_sample_dist(cur_p, ctx->rng);
}
static struct llama_sampler * llama_sampler_dist_clone(const struct llama_sampler * smpl) {
@ -419,7 +438,6 @@ struct llama_sampler * llama_sampler_init_dist(uint32_t seed) {
/* .ctx = */ new llama_sampler_dist {
/* .seed = */ seed,
/* .rng = */ std::mt19937(seed),
/* .probs = */ {},
},
};
}
@ -1023,8 +1041,6 @@ struct llama_sampler_mirostat {
float mu;
std::mt19937 rng;
std::vector<float> probs;
};
static const char * llama_sampler_mirostat_name(const struct llama_sampler * /*smpl*/) {
@ -1055,7 +1071,7 @@ static void llama_sampler_mirostat_apply(struct llama_sampler * smpl, llama_toke
llama_sampler_top_k_impl(cur_p, std::max(int(k), 1));
llama_sampler_softmax_impl(cur_p);
const int idx = llama_sample_dist(cur_p, ctx->rng, ctx->probs);
const int idx = llama_sample_dist(cur_p, ctx->rng);
cur_p->selected = idx;
@ -1111,7 +1127,6 @@ struct llama_sampler * llama_sampler_init_mirostat(int32_t n_vocab, uint32_t see
/* .m = */ m,
/* .mu = */ 2.0f*tau,
/* .rng = */ std::mt19937(seed),
/* .probs = */ {},
},
};
}
@ -1127,8 +1142,6 @@ struct llama_sampler_mirostat_v2 {
float mu;
std::mt19937 rng;
std::vector<float> probs;
};
static const char * llama_sampler_mirostat_v2_name(const struct llama_sampler * /*smpl*/) {
@ -1152,7 +1165,7 @@ static void llama_sampler_mirostat_v2_apply(struct llama_sampler * smpl, llama_t
// Normalize the probabilities of the remaining words
llama_sampler_softmax_impl(cur_p);
const int idx = llama_sample_dist(cur_p, ctx->rng, ctx->probs);
const int idx = llama_sample_dist(cur_p, ctx->rng);
cur_p->selected = idx;
@ -1207,7 +1220,6 @@ struct llama_sampler * llama_sampler_init_mirostat_v2(uint32_t seed, float tau,
/* .eta = */ eta,
/* .mu = */ 2.0f*tau,
/* .rng = */ std::mt19937(seed),
/* .probs = */ {},
},
};
}
@ -1527,6 +1539,10 @@ static const char * llama_sampler_logit_bias_name(const struct llama_sampler * /
static void llama_sampler_logit_bias_apply(struct llama_sampler * smpl, llama_token_data_array * cur_p) {
auto * ctx = (llama_sampler_logit_bias *) smpl->ctx;
if (ctx->logit_bias.empty()) {
return;
}
ctx->to_search.clear();
// update the candidates that have not been shuffled in the vocabulary (i.e. idx == id)
@ -1538,6 +1554,10 @@ static void llama_sampler_logit_bias_apply(struct llama_sampler * smpl, llama_to
}
}
if (ctx->to_search.empty()) {
return;
}
// search for the remaining candidates that were not found in the previous step
for (size_t i = 0; i < cur_p->size; ++i) {
for (const auto & lb : ctx->to_search) {