model : add LFM2-ColBert-350M (#18607)

* model : add LFM2-ColBert-350M

* llama_model_n_embd_out() - returns `hparams.n_embd_out` if set and fallbacks to `hparams.n_embd`
This commit is contained in:
Tarek Dakhran 2026-01-05 19:52:56 +01:00 committed by GitHub
parent df17a4c94f
commit 73d284a250
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GPG key ID: B5690EEEBB952194
16 changed files with 118 additions and 60 deletions

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@ -152,6 +152,7 @@ static const std::map<llm_kv, const char *> LLM_KV_NAMES = {
{ LLM_KV_VOCAB_SIZE, "%s.vocab_size" },
{ LLM_KV_CONTEXT_LENGTH, "%s.context_length" },
{ LLM_KV_EMBEDDING_LENGTH, "%s.embedding_length" },
{ LLM_KV_EMBEDDING_LENGTH_OUT, "%s.embedding_length_out" },
{ LLM_KV_FEATURES_LENGTH, "%s.features_length" },
{ LLM_KV_BLOCK_COUNT, "%s.block_count" },
{ LLM_KV_LEADING_DENSE_BLOCK_COUNT, "%s.leading_dense_block_count" },
@ -2075,6 +2076,7 @@ static std::set<llm_tensor> llm_get_tensor_names(llm_arch arch) {
LLM_TENSOR_TOKEN_EMBD,
LLM_TENSOR_OUTPUT_NORM_LFM2,
LLM_TENSOR_OUTPUT,
LLM_TENSOR_DENSE_2_OUT,
};
case LLM_ARCH_LFM2MOE:
return {

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@ -156,6 +156,7 @@ enum llm_kv {
LLM_KV_VOCAB_SIZE,
LLM_KV_CONTEXT_LENGTH,
LLM_KV_EMBEDDING_LENGTH,
LLM_KV_EMBEDDING_LENGTH_OUT,
LLM_KV_FEATURES_LENGTH,
LLM_KV_BLOCK_COUNT,
LLM_KV_LEADING_DENSE_BLOCK_COUNT,

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@ -758,7 +758,8 @@ float * llama_context::get_embeddings_ith(int32_t i) {
throw std::runtime_error(format("corrupt output buffer (j=%" PRId64 ", n_outputs=%d)", j, n_outputs));
}
return embd + j*model.hparams.n_embd;
const uint32_t n_embd_out = model.hparams.get_n_embd_out();
return embd + j*n_embd_out;
} catch (const std::exception & err) {
LLAMA_LOG_ERROR("%s: invalid embeddings id %d, reason: %s\n", __func__, i, err.what());
#ifndef NDEBUG
@ -1194,9 +1195,10 @@ int llama_context::encode(const llama_batch & batch_inp) {
{
// extract token embeddings
GGML_ASSERT(embd != nullptr);
const uint32_t n_embd_out = hparams.get_n_embd_out();
GGML_ASSERT(n_tokens*n_embd <= (int64_t) embd_size);
ggml_backend_tensor_get_async(backend_embd, t_embd, embd, 0, n_tokens*n_embd*sizeof(float));
GGML_ASSERT(n_tokens*n_embd_out <= (int64_t) embd_size);
ggml_backend_tensor_get_async(backend_embd, t_embd, embd, 0, n_tokens*n_embd_out*sizeof(float));
} break;
case LLAMA_POOLING_TYPE_MEAN:
case LLAMA_POOLING_TYPE_CLS:
@ -1600,12 +1602,13 @@ int llama_context::decode(const llama_batch & batch_inp) {
{
// extract token embeddings
GGML_ASSERT(embd != nullptr);
float * embd_out = embd + n_outputs_prev*n_embd;
const uint32_t n_embd_out = hparams.get_n_embd_out();
float * embd_out = embd + n_outputs_prev*n_embd_out;
if (n_outputs) {
GGML_ASSERT( n_outputs_prev + n_outputs <= n_outputs_all);
GGML_ASSERT((n_outputs_prev + n_outputs)*n_embd <= (int64_t) embd_size);
ggml_backend_tensor_get_async(backend_embd, t_embd, embd_out, 0, n_outputs*n_embd*sizeof(float));
GGML_ASSERT((n_outputs_prev + n_outputs)*n_embd_out <= (int64_t) embd_size);
ggml_backend_tensor_get_async(backend_embd, t_embd, embd_out, 0, n_outputs*n_embd_out*sizeof(float));
}
} break;
case LLAMA_POOLING_TYPE_MEAN:
@ -1730,9 +1733,9 @@ uint32_t llama_context::output_reserve(int32_t n_outputs, const llama_batch & ba
const int64_t n_outputs_max = std::max<int64_t>(n_outputs, n_seq_max());
const auto n_batch = cparams.n_batch;
const auto n_vocab = vocab.n_tokens();
const auto n_embd = hparams.n_embd;
const auto n_batch = cparams.n_batch;
const auto n_vocab = vocab.n_tokens();
const auto n_embd_out = hparams.get_n_embd_out();
bool has_logits = true;
bool has_embd = cparams.embeddings;
@ -1773,7 +1776,7 @@ uint32_t llama_context::output_reserve(int32_t n_outputs, const llama_batch & ba
// Allocate CPU logits buffer only if needed by sequences in this batch
logits_size = (has_logits && cpu_logits) ? n_vocab*n_outputs_max : 0;
embd_size = has_embd ? n_embd*n_outputs_max : 0;
embd_size = has_embd ? n_embd_out*n_outputs_max : 0;
// TODO: avoid this branching by working with the worst-case
if (!has_sampling) {

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@ -2071,14 +2071,18 @@ llm_graph_input_mem_hybrid * llm_graph_context::build_inp_mem_hybrid() const {
void llm_graph_context::build_dense_out(
ggml_tensor * dense_2,
ggml_tensor * dense_3) const {
if (!cparams.embeddings || dense_2 == nullptr || dense_3 == nullptr) {
if (!cparams.embeddings || !(dense_2 || dense_3)) {
return;
}
ggml_tensor * cur = res->t_embd_pooled != nullptr ? res->t_embd_pooled : res->t_embd;
GGML_ASSERT(cur != nullptr && "missing t_embd_pooled/t_embd");
cur = ggml_mul_mat(ctx0, dense_2, cur);
cur = ggml_mul_mat(ctx0, dense_3, cur);
if (dense_2) {
cur = ggml_mul_mat(ctx0, dense_2, cur);
}
if (dense_3) {
cur = ggml_mul_mat(ctx0, dense_3, cur);
}
cb(cur, "result_embd_pooled", -1);
res->t_embd_pooled = cur;
ggml_build_forward_expand(gf, cur);

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@ -72,6 +72,10 @@ uint32_t llama_hparams::n_embd_inp() const {
return n_embd_inp;
}
uint32_t llama_hparams::get_n_embd_out() const {
return n_embd_out > 0 ? n_embd_out : n_embd;
}
uint32_t llama_hparams::n_embd_k_gqa(uint32_t il) const {
const uint32_t n_head_kv = this->n_head_kv(il);

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@ -162,6 +162,9 @@ struct llama_hparams {
// for Classifiers
uint32_t n_cls_out = 1;
// output embedding dimension (0 = use n_embd)
uint32_t n_embd_out = 0;
// llama4 smallthinker
uint32_t n_moe_layer_step = 0;
uint32_t n_no_rope_layer_step = 4;
@ -234,6 +237,9 @@ struct llama_hparams {
// dimension of main + auxiliary input embeddings
uint32_t n_embd_inp() const;
// dimension of output embeddings
uint32_t get_n_embd_out() const;
// dimension of key embeddings across all k-v heads
uint32_t n_embd_k_gqa(uint32_t il = 0) const;

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@ -146,6 +146,9 @@ void llama_model_saver::add_kv_from_model() {
add_kv(LLM_KV_VOCAB_SIZE, vocab.n_tokens());
add_kv(LLM_KV_CONTEXT_LENGTH, hparams.n_ctx_train);
add_kv(LLM_KV_EMBEDDING_LENGTH, hparams.n_embd);
if (hparams.n_embd_out > 0) {
add_kv(LLM_KV_EMBEDDING_LENGTH_OUT, hparams.n_embd_out);
}
add_kv(LLM_KV_BLOCK_COUNT, hparams.n_layer);
add_kv(LLM_KV_LEADING_DENSE_BLOCK_COUNT, hparams.n_layer_dense_lead);
add_kv(LLM_KV_FEED_FORWARD_LENGTH, hparams.n_ff_arr, true);

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@ -507,6 +507,7 @@ void llama_model::load_hparams(llama_model_loader & ml) {
ml.get_key(LLM_KV_CONTEXT_LENGTH, hparams.n_ctx_train);
ml.get_key(LLM_KV_EMBEDDING_LENGTH, hparams.n_embd);
ml.get_key(LLM_KV_EMBEDDING_LENGTH_OUT, hparams.n_embd_out, false);
ml.get_key(LLM_KV_BLOCK_COUNT, hparams.n_layer);
ml.get_key(LLM_KV_EXPERT_COUNT, hparams.n_expert, false);
ml.get_key(LLM_KV_EXPERT_USED_COUNT, hparams.n_expert_used, false);
@ -6469,6 +6470,9 @@ bool llama_model::load_tensors(llama_model_loader & ml) {
layer.shortconv.out_proj = create_tensor(tn(LLM_TENSOR_SHORTCONV_OUTPROJ, "weight", i), {n_embd, n_embd}, 0);
}
}
// for LFM2-ColBert-350M
dense_2_out_layers = create_tensor(tn(LLM_TENSOR_DENSE_2_OUT, "weight"), {n_embd, hparams.get_n_embd_out()}, TENSOR_NOT_REQUIRED);
} break;
case LLM_ARCH_SMALLTHINKER:
{
@ -8003,6 +8007,10 @@ int32_t llama_model_n_embd_inp(const llama_model * model) {
return model->hparams.n_embd_inp();
}
int32_t llama_model_n_embd_out(const llama_model * model) {
return model->hparams.get_n_embd_out();
}
int32_t llama_model_n_layer(const llama_model * model) {
return model->hparams.n_layer;
}