1#include "models.h"
  2
  3template <bool iswa>
  4llm_build_gemma3<iswa>::llm_build_gemma3(const llama_model & model, const llm_graph_params & params) : llm_graph_context(params) {
  5    const int64_t n_embd_head = hparams.n_embd_head_k;
  6
  7    ggml_tensor * cur;
  8    ggml_tensor * inpL;
  9
 10    inpL = build_inp_embd(model.tok_embd);
 11
 12    // important: do not normalize weights for raw embeddings input (i.e. encoded image emdeddings)
 13    inpL = ggml_scale(ctx0, inpL, ubatch.token ? sqrtf(n_embd) : 1.0f);
 14    cb(inpL, "inp_scaled", -1);
 15
 16    // inp_pos - contains the positions
 17    ggml_tensor * inp_pos = build_inp_pos();
 18
 19    // TODO: is causal == true correct? might need some changes
 20    using inp_attn_type = std::conditional_t<iswa, llm_graph_input_attn_kv_iswa, llm_graph_input_attn_kv>;
 21    inp_attn_type * inp_attn = nullptr;
 22
 23    if constexpr (iswa) {
 24        inp_attn = build_attn_inp_kv_iswa();
 25    } else {
 26        inp_attn = build_attn_inp_kv();
 27    }
 28
 29    ggml_tensor * inp_out_ids = build_inp_out_ids();
 30
 31    for (int il = 0; il < n_layer; ++il) {
 32        float freq_base_l  = 0.0f;
 33        float freq_scale_l = 0.0f;
 34
 35        if constexpr (iswa) {
 36            freq_base_l  = model.get_rope_freq_base (cparams, il);
 37            freq_scale_l = model.get_rope_freq_scale(cparams, il);
 38        } else {
 39            freq_base_l  = freq_base;
 40            freq_scale_l = freq_scale;
 41        }
 42
 43        // norm
 44        cur = build_norm(inpL, model.layers[il].attn_norm, NULL, LLM_NORM_RMS, il);
 45        cb(cur, "attn_norm", il);
 46
 47        // self-attention
 48        {
 49            // compute Q and K and RoPE them
 50            ggml_tensor * Qcur = build_lora_mm(model.layers[il].wq, cur);
 51            cb(Qcur, "Qcur", il);
 52
 53            ggml_tensor * Kcur = build_lora_mm(model.layers[il].wk, cur);
 54            cb(Kcur, "Kcur", il);
 55
 56            ggml_tensor * Vcur = build_lora_mm(model.layers[il].wv, cur);
 57            cb(Vcur, "Vcur", il);
 58
 59            Qcur = ggml_reshape_3d(ctx0, Qcur, n_embd_head, n_head,    n_tokens);
 60            Kcur = ggml_reshape_3d(ctx0, Kcur, n_embd_head, n_head_kv, n_tokens);
 61            Vcur = ggml_reshape_3d(ctx0, Vcur, n_embd_head, n_head_kv, n_tokens);
 62
 63            Qcur = build_norm(Qcur, model.layers[il].attn_q_norm, NULL, LLM_NORM_RMS, il);
 64            cb(Qcur, "Qcur_normed", il);
 65
 66            Qcur = ggml_rope_ext(
 67                    ctx0, Qcur, inp_pos, nullptr,
 68                    n_rot, rope_type, n_ctx_orig, freq_base_l, freq_scale_l,
 69                    ext_factor, attn_factor, beta_fast, beta_slow);
 70
 71            Kcur = build_norm(Kcur, model.layers[il].attn_k_norm, NULL, LLM_NORM_RMS, il);
 72            cb(Kcur, "Kcur_normed", il);
 73
 74            Kcur = ggml_rope_ext(
 75                    ctx0, Kcur, inp_pos, nullptr,
 76                    n_rot, rope_type, n_ctx_orig, freq_base_l, freq_scale_l,
 77                    ext_factor, attn_factor, beta_fast, beta_slow);
 78
 79            cb(Qcur, "Qcur", il);
 80            cb(Kcur, "Kcur", il);
 81            cb(Vcur, "Vcur", il);
 82
 83            // ref: https://github.com/google/gemma_pytorch/blob/014acb7ac4563a5f77c76d7ff98f31b568c16508/gemma/model.py#L315
 84            Qcur = ggml_scale(ctx0, Qcur, hparams.f_attention_scale);
 85
 86            cur = build_attn(inp_attn,
 87                    model.layers[il].wo, NULL,
 88                    Qcur, Kcur, Vcur, nullptr, nullptr, nullptr, 1.0f, il);
 89        }
 90        if (il == n_layer - 1 && inp_out_ids) {
 91            cur  = ggml_get_rows(ctx0,  cur, inp_out_ids);
 92            inpL = ggml_get_rows(ctx0, inpL, inp_out_ids);
 93        }
 94        cur = build_norm(cur,
 95                model.layers[il].attn_post_norm, NULL,
 96                LLM_NORM_RMS, il);
 97        cb(cur, "attn_post_norm", il);
 98
 99        ggml_tensor * sa_out = ggml_add(ctx0, cur, inpL);
100        cb(sa_out, "sa_out", il);
101
102        cur = build_norm(sa_out,
103                model.layers[il].ffn_norm, NULL,
104                LLM_NORM_RMS, il);
105        cb(cur, "ffn_norm", il);
106
107        // feed-forward network
108        {
109            cur = build_ffn(cur,
110                    model.layers[il].ffn_up,   NULL, NULL,
111                    model.layers[il].ffn_gate, NULL, NULL,
112                    model.layers[il].ffn_down, NULL, NULL,
113                    NULL,
114                    LLM_FFN_GELU, LLM_FFN_PAR, il);
115            cb(cur, "ffn_out", il);
116        }
117        cur = build_norm(cur,
118                model.layers[il].ffn_post_norm, NULL,
119                LLM_NORM_RMS, -1);
120        cb(cur, "ffn_post_norm", il);
121
122        cur = ggml_add(ctx0, cur, sa_out);
123
124        cur = build_cvec(cur, il);
125        cb(cur, "l_out", il);
126
127        // input for next layer
128        inpL = cur;
129    }
130    cur = inpL;
131
132    cur = build_norm(cur,
133            model.output_norm, NULL,
134            LLM_NORM_RMS, -1);
135
136    cb(cur, "result_norm", -1);
137    res->t_embd = cur;
138
139    // lm_head
140    cur = build_lora_mm(model.output, cur);
141
142    if (hparams.f_final_logit_softcapping) {
143        cur = ggml_scale(ctx0, cur, 1.0f / hparams.f_final_logit_softcapping);
144        cur = ggml_tanh(ctx0, cur);
145        cur = ggml_scale(ctx0, cur, hparams.f_final_logit_softcapping);
146    }
147
148    cb(cur, "result_output", -1);
149    res->t_logits = cur;
150
151    ggml_build_forward_expand(gf, cur);
152}
153
154template struct llm_build_gemma3<false>;
155template struct llm_build_gemma3<true>;