[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
] && scores[c] > best_score) {
                best = c;
                best_score = scores[c];
            }
        }
        allowed[best] = true;
    }

    return allowed;
}

/* Single-token attention sublayer with raw SWA cache and DS4 compression. */
static void layer_attention_raw_swa_one(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  il,
        uint32_t                  pos,
        const float             * steering_dirs,
        float                     steering_scale) {
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_hc * DS4_N_EMBD * sizeof(attn_residual[0]));
    float *q = xmalloc((size_t)q_dim * sizeof(q[0]));
    float *qr_norm = xmalloc(1024 * sizeof(qr_norm[0]));
    float *kv = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = xmalloc((size_t)q_dim * sizeof(heads[0]));
    float *attn_out = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_out[0]));
    bool *comp_allowed = NULL;
    float post[4];
    float comb[16];

    memcpy(attn_residual, inp_hc, (size_t)n_hc * DS4_N_EMBD * sizeof(inp_hc[0]));
    hc_pre_from_state_one(model,
                          layer->hc_attn_fn,
                          layer->hc_attn_scale,
                          layer->hc_attn_base,
                          attn_residual, attn_cur, post, comb);

    layer_attn_norm_one(attn_norm, model, layer, attn_cur);
    layer_q_projection_with_lora_one(model, layer, attn_norm, q, qr_norm);
    layer_kv_projection_normed_one(model, layer, attn_norm, kv);

    rope_tail_layer_inplace(q, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
    rope_tail_layer_inplace(kv, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
    dsv4_fp8_kv_quantize_row_inplace_cpu(kv, DS4_N_HEAD_DIM, DS4_N_ROT);

    kv_cache_push_raw(cache, kv);

    const uint32_t ratio = cache->compress_ratio;
    if (ratio != 0) {
        float *comp = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
] && scores[c] > best_score) {
                best = c;
                best_score = scores[c];
            }
        }
        allowed[best] = true;
    }

    return allowed;
}

/* Single-token attention sublayer with raw SWA cache and DS4 compression. */
static void layer_attention_raw_swa_one(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  il,
        uint32_t                  pos,
        const float             * steering_dirs,
        float                     steering_scale) {
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_hc * DS4_N_EMBD * sizeof(attn_residual[0]));
    float *q = xmalloc((size_t)q_dim * sizeof(q[0]));
    float *qr_norm = xmalloc(1024 * sizeof(qr_norm[0]));
    float *kv = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = xmalloc((size_t)q_dim * sizeof(heads[0]));
    float *attn_out = xmalloc((size_t)DS4_N_EMBD * sizeof(attn_out[0]));
    bool *comp_allowed = NULL;
    float post[4];
    float comb[16];

    memcpy(attn_residual, inp_hc, (size_t)n_hc * DS4_N_EMBD * sizeof(inp_hc[0]));
    hc_pre_from_state_one(model,
                          layer->hc_attn_fn,
                          layer->hc_attn_scale,
                          layer->hc_attn_base,
                          attn_residual, attn_cur, post, comb);

    layer_attn_norm_one(attn_norm, model, layer, attn_cur);
    layer_q_projection_with_lora_one(model, layer, attn_norm, q, qr_norm);
    layer_kv_projection_normed_one(model, layer, attn_norm, kv);

    rope_tail_layer_inplace(q, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
    rope_tail_layer_inplace(kv, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
    dsv4_fp8_kv_quantize_row_inplace_cpu(kv, DS4_N_HEAD_DIM, DS4_N_ROT);

    kv_cache_push_raw(cache, kv);

    const uint32_t ratio = cache->compress_ratio;
    if (ratio != 0) {
        float *comp = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
omp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
                                  layer->attn_compressor_ape,
                                  layer->attn_compressor_norm,
                                  attn_norm,
                                  cache->attn_state_kv,
                                  cache->attn_state_score,
                                  DS4_N_HEAD_DIM,
                                  ratio,
                                  il,
                                  pos)) {
            kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
        }
        free(comp);

        if (ratio == 4) {
            float *index_comp = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp[0]));
            if (compressor_decode_one(index_comp, model,
                                      layer->indexer_compressor_kv,
                                      layer->indexer_compressor_gate,
                                      layer->indexer_compressor_ape,
                                      layer->indexer_compressor_norm,
                                      attn_norm,
                                      cache->index_state_kv,
                                      cache->index_state_score,
                                      DS4_N_INDEXER_HEAD_DIM,
                                      ratio,
                                      il,
                                      pos)) {
                kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
            }
            free(index_comp);

            comp_allowed = indexer_allowed_decode_one(model, layer,
                                                      attn_norm, qr_norm,
                                                      cache->index_comp_kv,
                                                      cache->n_index_comp,
                                                      il, pos);
        }

        layer_attention_mixed_one(heads, model, layer, q,
                                  cache->raw_kv, cache->n_raw,
                                  cache->attn_comp_kv, cache->n_comp,
                                  comp_allowed);
    } else {
        layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
omp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
                                  layer->attn_compressor_ape,
                                  layer->attn_compressor_norm,
                                  attn_norm,
                                  cache->attn_state_kv,
                                  cache->attn_state_score,
                                  DS4_N_HEAD_DIM,
                                  ratio,
                                  il,
                                  pos)) {
            kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
        }
        free(comp);

        if (ratio == 4) {
            float *index_comp = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp[0]));
            if (compressor_decode_one(index_comp, model,
                                      layer->indexer_compressor_kv,
                                      layer->indexer_compressor_gate,
                                      layer->indexer_compressor_ape,
                                      layer->indexer_compressor_norm,
                                      attn_norm,
                                      cache->index_state_kv,
                                      cache->index_state_score,
                                      DS4_N_INDEXER_HEAD_DIM,
                                      ratio,
                                      il,
                                      pos)) {
                kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
            }
            free(index_comp);

            comp_allowed = indexer_allowed_decode_one(model, layer,
                                                      attn_norm, qr_norm,
                                                      cache->index_comp_kv,
                                                      cache->n_index_comp,
                                                      il, pos);
        }

        layer_attention_mixed_one(heads, model, layer, q,
                                  cache->raw_kv, cache->n_raw,
                                  cache->attn_comp_kv, cache->n_comp,
                                  comp_allowed);
    } else {
        layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
omp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
                                  layer->attn_compressor_ape,
                                  layer->attn_compressor_norm,
                                  attn_norm,
                                  cache->attn_state_kv,
                                  cache->attn_state_score,
                                  DS4_N_HEAD_DIM,
                                  ratio,
                                  il,
                                  pos)) {
            kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
        }
        free(comp);

        if (ratio == 4) {
            float *index_comp = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp[0]));
            if (compressor_decode_one(index_comp, model,
                                      layer->indexer_compressor_kv,
                                      layer->indexer_compressor_gate,
                                      layer->indexer_compressor_ape,
                                      layer->indexer_compressor_norm,
                                      attn_norm,
                                      cache->index_state_kv,
                                      cache->index_state_score,
                                      DS4_N_INDEXER_HEAD_DIM,
                                      ratio,
                                      il,
                                      pos)) {
                kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
            }
            free(index_comp);

            comp_allowed = indexer_allowed_decode_one(model, layer,
                                                      attn_norm, qr_norm,
                                                      cache->index_comp_kv,
                                                      cache->n_index_comp,
                                                      il, pos);
        }

        layer_attention_mixed_one(heads, model, layer, q,
                                  cache->raw_kv, cache->n_raw,
                                  cache->attn_comp_kv, cache->n_comp,
                                  comp_allowed);
    } else {
        layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
omp[0]));
        if (compressor_decode_one(comp, model,
                                  layer->attn_compressor_kv,
                                  layer->attn_compressor_gate,
                                  layer->attn_compressor_ape,
                                  layer->attn_compressor_norm,
                                  attn_norm,
                                  cache->attn_state_kv,
                                  cache->attn_state_score,
                                  DS4_N_HEAD_DIM,
                                  ratio,
                                  il,
                                  pos)) {
            kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
        }
        free(comp);

        if (ratio == 4) {
            float *index_comp = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp[0]));
            if (compressor_decode_one(index_comp, model,
                                      layer->indexer_compressor_kv,
                                      layer->indexer_compressor_gate,
                                      layer->indexer_compressor_ape,
                                      layer->indexer_compressor_norm,
                                      attn_norm,
                                      cache->index_state_kv,
                                      cache->index_state_score,
                                      DS4_N_INDEXER_HEAD_DIM,
                                      ratio,
                                      il,
                                      pos)) {
                kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
            }
            free(index_comp);

            comp_allowed = indexer_allowed_decode_one(model, layer,
                                                      attn_norm, qr_norm,
                                                      cache->index_comp_kv,
                                                      cache->n_index_comp,
                                                      il, pos);
        }

        layer_attention_mixed_one(heads, model, layer, q,
                                  cache->raw_kv, cache->n_raw,
                                  cache->attn_comp_kv, cache->n_comp,
                                  comp_allowed);
    } else {
        layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
    layer_grouped_out_one(attn_out, model, layer, heads);
    cpu_directional_steering_project_rows(attn_out, steering_dirs, il, 1, steering_scale);
    hc_post_one(after_attn_hc, attn_out, attn_residual, post, comb, DS4_N_EMBD, n_hc);

    free(comp_allowed);
    free(attn_out);
    free(heads);
    free(kv);
    free(qr_norm);
    free(q);
    free(attn_residual);
    free(attn_norm);
    free(attn_cur);
}

/* Batched prefill attention.  It projects Q/KV for all tokens, streams them
 * through the same raw/compressed cache updates, then runs prefix attention. */
static void layer_attention_raw_swa_batch(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  n_tok,
        uint32_t                  il,
        uint32_t                  pos0,
        const float             * steering_dirs,
        float                     steering_scale) {
    const bool profile = getenv("DS4_PREFILL_PROFILE_DETAIL") != NULL;
    const double t_start = profile ? now_sec() : 0.0;
    double t_hc_norm = 0.0;
    double t_q = 0.0;
    double t_kv = 0.0;
    double t_token_loop = 0.0;
    double t_tl_rope_cache = 0.0;
    double t_tl_compress = 0.0;
    double t_tl_indexer = 0.0;
    double t_tl_attn_rows = 0.0;
    double t_tl_inv_rope = 0.0;
    double t_out = 0.0;
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t hc_dim = (uint64_t)n_hc * DS4_N_EMBD;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_tok * hc_dim * sizeof(attn_residual[0]));
    float *qr = xmalloc((size_t)n_tok * 1024 * sizeof(qr[0]));
    float *qr_norm = xmalloc((size_t)n_tok * 1024 * sizeof(qr_norm[0]));
    float *q = xmalloc((size_t)n_tok * q_dim * sizeof(q[0]));
    float *kv_raw = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv_raw[0]));
    float *kv = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
    layer_grouped_out_one(attn_out, model, layer, heads);
    cpu_directional_steering_project_rows(attn_out, steering_dirs, il, 1, steering_scale);
    hc_post_one(after_attn_hc, attn_out, attn_residual, post, comb, DS4_N_EMBD, n_hc);

    free(comp_allowed);
    free(attn_out);
    free(heads);
    free(kv);
    free(qr_norm);
    free(q);
    free(attn_residual);
    free(attn_norm);
    free(attn_cur);
}

/* Batched prefill attention.  It projects Q/KV for all tokens, streams them
 * through the same raw/compressed cache updates, then runs prefix attention. */
static void layer_attention_raw_swa_batch(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  n_tok,
        uint32_t                  il,
        uint32_t                  pos0,
        const float             * steering_dirs,
        float                     steering_scale) {
    const bool profile = getenv("DS4_PREFILL_PROFILE_DETAIL") != NULL;
    const double t_start = profile ? now_sec() : 0.0;
    double t_hc_norm = 0.0;
    double t_q = 0.0;
    double t_kv = 0.0;
    double t_token_loop = 0.0;
    double t_tl_rope_cache = 0.0;
    double t_tl_compress = 0.0;
    double t_tl_indexer = 0.0;
    double t_tl_attn_rows = 0.0;
    double t_tl_inv_rope = 0.0;
    double t_out = 0.0;
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t hc_dim = (uint64_t)n_hc * DS4_N_EMBD;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_tok * hc_dim * sizeof(attn_residual[0]));
    float *qr = xmalloc((size_t)n_tok * 1024 * sizeof(qr[0]));
    float *qr_norm = xmalloc((size_t)n_tok * 1024 * sizeof(qr_norm[0]));
    float *q = xmalloc((size_t)n_tok * q_dim * sizeof(q[0]));
    float *kv_raw = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv_raw[0]));
    float *kv = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
    layer_grouped_out_one(attn_out, model, layer, heads);
    cpu_directional_steering_project_rows(attn_out, steering_dirs, il, 1, steering_scale);
    hc_post_one(after_attn_hc, attn_out, attn_residual, post, comb, DS4_N_EMBD, n_hc);

    free(comp_allowed);
    free(attn_out);
    free(heads);
    free(kv);
    free(qr_norm);
    free(q);
    free(attn_residual);
    free(attn_norm);
    free(attn_cur);
}

/* Batched prefill attention.  It projects Q/KV for all tokens, streams them
 * through the same raw/compressed cache updates, then runs prefix attention. */
static void layer_attention_raw_swa_batch(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  n_tok,
        uint32_t                  il,
        uint32_t                  pos0,
        const float             * steering_dirs,
        float                     steering_scale) {
    const bool profile = getenv("DS4_PREFILL_PROFILE_DETAIL") != NULL;
    const double t_start = profile ? now_sec() : 0.0;
    double t_hc_norm = 0.0;
    double t_q = 0.0;
    double t_kv = 0.0;
    double t_token_loop = 0.0;
    double t_tl_rope_cache = 0.0;
    double t_tl_compress = 0.0;
    double t_tl_indexer = 0.0;
    double t_tl_attn_rows = 0.0;
    double t_tl_inv_rope = 0.0;
    double t_out = 0.0;
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t hc_dim = (uint64_t)n_hc * DS4_N_EMBD;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_tok * hc_dim * sizeof(attn_residual[0]));
    float *qr = xmalloc((size_t)n_tok * 1024 * sizeof(qr[0]));
    float *qr_norm = xmalloc((size_t)n_tok * 1024 * sizeof(qr_norm[0]));
    float *q = xmalloc((size_t)n_tok * q_dim * sizeof(q[0]));
    float *kv_raw = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv_raw[0]));
    float *kv = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
layer_attention_rows_one(heads, model, layer, q, cache->raw_kv, cache->n_raw);
    }

    rope_tail_layer_inplace(heads, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, true);
    layer_grouped_out_one(attn_out, model, layer, heads);
    cpu_directional_steering_project_rows(attn_out, steering_dirs, il, 1, steering_scale);
    hc_post_one(after_attn_hc, attn_out, attn_residual, post, comb, DS4_N_EMBD, n_hc);

    free(comp_allowed);
    free(attn_out);
    free(heads);
    free(kv);
    free(qr_norm);
    free(q);
    free(attn_residual);
    free(attn_norm);
    free(attn_cur);
}

/* Batched prefill attention.  It projects Q/KV for all tokens, streams them
 * through the same raw/compressed cache updates, then runs prefix attention. */
static void layer_attention_raw_swa_batch(
        float                   * after_attn_hc,
        const ds4_model         * model,
        const ds4_layer_weights * layer,
        ds4_layer_cache         * cache,
        const float             * inp_hc,
        uint32_t                  n_tok,
        uint32_t                  il,
        uint32_t                  pos0,
        const float             * steering_dirs,
        float                     steering_scale) {
    const bool profile = getenv("DS4_PREFILL_PROFILE_DETAIL") != NULL;
    const double t_start = profile ? now_sec() : 0.0;
    double t_hc_norm = 0.0;
    double t_q = 0.0;
    double t_kv = 0.0;
    double t_token_loop = 0.0;
    double t_tl_rope_cache = 0.0;
    double t_tl_compress = 0.0;
    double t_tl_indexer = 0.0;
    double t_tl_attn_rows = 0.0;
    double t_tl_inv_rope = 0.0;
    double t_out = 0.0;
    const uint32_t n_hc = DS4_N_HC;
    const uint64_t hc_dim = (uint64_t)n_hc * DS4_N_EMBD;
    const uint64_t q_dim = (uint64_t)DS4_N_HEAD * DS4_N_HEAD_DIM;

    float *attn_cur = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_cur[0]));
    float *attn_norm = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_norm[0]));
    float *attn_residual = xmalloc((size_t)n_tok * hc_dim * sizeof(attn_residual[0]));
    float *qr = xmalloc((size_t)n_tok * 1024 * sizeof(qr[0]));
    float *qr_norm = xmalloc((size_t)n_tok * 1024 * sizeof(qr_norm[0]));
    float *q = xmalloc((size_t)n_tok * q_dim * sizeof(q[0]));
    float *kv_raw = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv_raw[0]));
    float *kv = xmalloc((size_t)n_tok * DS4_N_HEAD_DIM * sizeof(kv[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
v[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
    float *comb = xmalloc((size_t)n_tok * n_hc * n_hc * sizeof(comb[0]));

    const float *q_a_norm = tensor_data(model, layer->attn_q_a_norm);
    const float *kv_norm = tensor_data(model, layer->attn_kv_a_norm);

    double t0 = profile ? now_sec() : 0.0;
    hc_pre_norm_batch(model,
                      layer->hc_attn_fn,
                      layer->hc_attn_scale,
                      layer->hc_attn_base,
                      layer->attn_norm,
                      inp_hc,
                      attn_residual,
                      attn_cur,
                      attn_norm,
                      post,
                      comb,
                      n_tok);
    if (profile) t_hc_norm = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(qr, model, layer->attn_q_a, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(qr_norm + (uint64_t)t * 1024,
                        qr + (uint64_t)t * 1024,
                        q_a_norm,
                        1024,
                        DS4_RMS_EPS);
    }
    matmul_q8_0_batch(q, model, layer->attn_q_b, qr_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        head_rms_norm_inplace(q + (uint64_t)t * q_dim,
                              DS4_N_HEAD,
                              DS4_N_HEAD_DIM,
                              DS4_RMS_EPS);
    }
    if (profile) t_q = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(kv_raw, model, layer->attn_kv, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(kv + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_raw + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_norm,
                        DS4_N_HEAD_DIM,
                        DS4_RMS_EPS);
    }
    if (profile) t_kv = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    const uint32_t ratio = cache->compress_ratio;
    const bool prefer_parallel_attn = getenv("DS4_PARALLEL_ATTN_ROWS") != NULL;
    const bool prefix_batch_attn =
        prefer_parallel_attn &&
        getenv("DS4_NO_PARALLEL_ATTN_ROWS") == NULL &&
        cache->n_raw == 0 &&
        pos0 == 0;
    if (!prefix_batch_attn) {
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
v[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
    float *comb = xmalloc((size_t)n_tok * n_hc * n_hc * sizeof(comb[0]));

    const float *q_a_norm = tensor_data(model, layer->attn_q_a_norm);
    const float *kv_norm = tensor_data(model, layer->attn_kv_a_norm);

    double t0 = profile ? now_sec() : 0.0;
    hc_pre_norm_batch(model,
                      layer->hc_attn_fn,
                      layer->hc_attn_scale,
                      layer->hc_attn_base,
                      layer->attn_norm,
                      inp_hc,
                      attn_residual,
                      attn_cur,
                      attn_norm,
                      post,
                      comb,
                      n_tok);
    if (profile) t_hc_norm = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(qr, model, layer->attn_q_a, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(qr_norm + (uint64_t)t * 1024,
                        qr + (uint64_t)t * 1024,
                        q_a_norm,
                        1024,
                        DS4_RMS_EPS);
    }
    matmul_q8_0_batch(q, model, layer->attn_q_b, qr_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        head_rms_norm_inplace(q + (uint64_t)t * q_dim,
                              DS4_N_HEAD,
                              DS4_N_HEAD_DIM,
                              DS4_RMS_EPS);
    }
    if (profile) t_q = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(kv_raw, model, layer->attn_kv, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(kv + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_raw + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_norm,
                        DS4_N_HEAD_DIM,
                        DS4_RMS_EPS);
    }
    if (profile) t_kv = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    const uint32_t ratio = cache->compress_ratio;
    const bool prefer_parallel_attn = getenv("DS4_PARALLEL_ATTN_ROWS") != NULL;
    const bool prefix_batch_attn =
        prefer_parallel_attn &&
        getenv("DS4_NO_PARALLEL_ATTN_ROWS") == NULL &&
        cache->n_raw == 0 &&
        pos0 == 0;
    if (!prefix_batch_attn) {
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
v[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
    float *comb = xmalloc((size_t)n_tok * n_hc * n_hc * sizeof(comb[0]));

    const float *q_a_norm = tensor_data(model, layer->attn_q_a_norm);
    const float *kv_norm = tensor_data(model, layer->attn_kv_a_norm);

    double t0 = profile ? now_sec() : 0.0;
    hc_pre_norm_batch(model,
                      layer->hc_attn_fn,
                      layer->hc_attn_scale,
                      layer->hc_attn_base,
                      layer->attn_norm,
                      inp_hc,
                      attn_residual,
                      attn_cur,
                      attn_norm,
                      post,
                      comb,
                      n_tok);
    if (profile) t_hc_norm = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(qr, model, layer->attn_q_a, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(qr_norm + (uint64_t)t * 1024,
                        qr + (uint64_t)t * 1024,
                        q_a_norm,
                        1024,
                        DS4_RMS_EPS);
    }
    matmul_q8_0_batch(q, model, layer->attn_q_b, qr_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        head_rms_norm_inplace(q + (uint64_t)t * q_dim,
                              DS4_N_HEAD,
                              DS4_N_HEAD_DIM,
                              DS4_RMS_EPS);
    }
    if (profile) t_q = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(kv_raw, model, layer->attn_kv, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(kv + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_raw + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_norm,
                        DS4_N_HEAD_DIM,
                        DS4_RMS_EPS);
    }
    if (profile) t_kv = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    const uint32_t ratio = cache->compress_ratio;
    const bool prefer_parallel_attn = getenv("DS4_PARALLEL_ATTN_ROWS") != NULL;
    const bool prefix_batch_attn =
        prefer_parallel_attn &&
        getenv("DS4_NO_PARALLEL_ATTN_ROWS") == NULL &&
        cache->n_raw == 0 &&
        pos0 == 0;
    if (!prefix_batch_attn) {
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
v[0]));
    float *heads = NULL;
    float *attn_out = xmalloc((size_t)n_tok * DS4_N_EMBD * sizeof(attn_out[0]));
    float *post = xmalloc((size_t)n_tok * n_hc * sizeof(post[0]));
    float *comb = xmalloc((size_t)n_tok * n_hc * n_hc * sizeof(comb[0]));

    const float *q_a_norm = tensor_data(model, layer->attn_q_a_norm);
    const float *kv_norm = tensor_data(model, layer->attn_kv_a_norm);

    double t0 = profile ? now_sec() : 0.0;
    hc_pre_norm_batch(model,
                      layer->hc_attn_fn,
                      layer->hc_attn_scale,
                      layer->hc_attn_base,
                      layer->attn_norm,
                      inp_hc,
                      attn_residual,
                      attn_cur,
                      attn_norm,
                      post,
                      comb,
                      n_tok);
    if (profile) t_hc_norm = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(qr, model, layer->attn_q_a, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(qr_norm + (uint64_t)t * 1024,
                        qr + (uint64_t)t * 1024,
                        q_a_norm,
                        1024,
                        DS4_RMS_EPS);
    }
    matmul_q8_0_batch(q, model, layer->attn_q_b, qr_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        head_rms_norm_inplace(q + (uint64_t)t * q_dim,
                              DS4_N_HEAD,
                              DS4_N_HEAD_DIM,
                              DS4_RMS_EPS);
    }
    if (profile) t_q = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    matmul_q8_0_batch(kv_raw, model, layer->attn_kv, attn_norm, n_tok);
    for (uint32_t t = 0; t < n_tok; t++) {
        rms_norm_weight(kv + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_raw + (uint64_t)t * DS4_N_HEAD_DIM,
                        kv_norm,
                        DS4_N_HEAD_DIM,
                        DS4_RMS_EPS);
    }
    if (profile) t_kv = now_sec() - t0;

    t0 = profile ? now_sec() : 0.0;
    const uint32_t ratio = cache->compress_ratio;
    const bool prefer_parallel_attn = getenv("DS4_PARALLEL_ATTN_ROWS") != NULL;
    const bool prefix_batch_attn =
        prefer_parallel_attn &&
        getenv("DS4_NO_PARALLEL_ATTN_ROWS") == NULL &&
        cache->n_raw == 0 &&
        pos0 == 0;
    if (!prefix_batch_attn) {
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
{
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
    if (batch_rope_max_env && batch_rope_max_env[0]) {
        long v = strtol(batch_rope_max_env, NULL, 10);
        if (v >= 0 && v <= 65536) batch_rope_max = (uint32_t)v;
    }
    const bool batch_prefix_rope =
        prefix_batch_attn &&
        getenv("DS4_NO_BATCHED_ROPE") == NULL &&
        n_tok <= batch_rope_max;
    uint32_t *comp_counts = prefix_batch_attn ?
        xcalloc((size_t)n_tok, sizeof(comp_counts[0])) : NULL;
    uint8_t *allowed_mask = prefix_batch_attn && ratio == 4 ?
        xcalloc((size_t)n_tok, sizeof(allowed_mask[0])) : NULL;
    uint8_t *allowed_bits = NULL;
    const uint64_t allowed_stride = ratio == 4 ? ((uint64_t)cache->comp_cap + 7u) / 8u : 0;
    float *comp_scratch = NULL;
    float *index_comp_scratch = NULL;

    if (ratio != 0) {
        comp_scratch = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp_scratch[0]));

        if (ratio == 4) {
            index_comp_scratch = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp_scratch[0]));
        }
    }

    if (batch_prefix_rope) {
        double tx = profile ? now_sec() : 0.0;
        rope_tail_layer_batch_inplace(q,
                                      q_dim,
                                      DS4_N_HEAD,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        rope_tail_layer_batch_inplace(kv,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_HEAD_KV,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        if (profile) t_tl_rope_cache += now_sec() - tx;
    }

    for (uint32_t t = 0; t < n_tok; t++) {
        const uint32_t pos = pos0 + t;
        float *q_t = q + (uint64_t)t * q_dim;
        float *kv_t = kv + (uint64_t)t * DS4_N_HEAD_DIM;
        bool *comp_allowed = NULL;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
{
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
    if (batch_rope_max_env && batch_rope_max_env[0]) {
        long v = strtol(batch_rope_max_env, NULL, 10);
        if (v >= 0 && v <= 65536) batch_rope_max = (uint32_t)v;
    }
    const bool batch_prefix_rope =
        prefix_batch_attn &&
        getenv("DS4_NO_BATCHED_ROPE") == NULL &&
        n_tok <= batch_rope_max;
    uint32_t *comp_counts = prefix_batch_attn ?
        xcalloc((size_t)n_tok, sizeof(comp_counts[0])) : NULL;
    uint8_t *allowed_mask = prefix_batch_attn && ratio == 4 ?
        xcalloc((size_t)n_tok, sizeof(allowed_mask[0])) : NULL;
    uint8_t *allowed_bits = NULL;
    const uint64_t allowed_stride = ratio == 4 ? ((uint64_t)cache->comp_cap + 7u) / 8u : 0;
    float *comp_scratch = NULL;
    float *index_comp_scratch = NULL;

    if (ratio != 0) {
        comp_scratch = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp_scratch[0]));

        if (ratio == 4) {
            index_comp_scratch = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp_scratch[0]));
        }
    }

    if (batch_prefix_rope) {
        double tx = profile ? now_sec() : 0.0;
        rope_tail_layer_batch_inplace(q,
                                      q_dim,
                                      DS4_N_HEAD,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        rope_tail_layer_batch_inplace(kv,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_HEAD_KV,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        if (profile) t_tl_rope_cache += now_sec() - tx;
    }

    for (uint32_t t = 0; t < n_tok; t++) {
        const uint32_t pos = pos0 + t;
        float *q_t = q + (uint64_t)t * q_dim;
        float *kv_t = kv + (uint64_t)t * DS4_N_HEAD_DIM;
        bool *comp_allowed = NULL;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
{
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
    if (batch_rope_max_env && batch_rope_max_env[0]) {
        long v = strtol(batch_rope_max_env, NULL, 10);
        if (v >= 0 && v <= 65536) batch_rope_max = (uint32_t)v;
    }
    const bool batch_prefix_rope =
        prefix_batch_attn &&
        getenv("DS4_NO_BATCHED_ROPE") == NULL &&
        n_tok <= batch_rope_max;
    uint32_t *comp_counts = prefix_batch_attn ?
        xcalloc((size_t)n_tok, sizeof(comp_counts[0])) : NULL;
    uint8_t *allowed_mask = prefix_batch_attn && ratio == 4 ?
        xcalloc((size_t)n_tok, sizeof(allowed_mask[0])) : NULL;
    uint8_t *allowed_bits = NULL;
    const uint64_t allowed_stride = ratio == 4 ? ((uint64_t)cache->comp_cap + 7u) / 8u : 0;
    float *comp_scratch = NULL;
    float *index_comp_scratch = NULL;

    if (ratio != 0) {
        comp_scratch = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp_scratch[0]));

        if (ratio == 4) {
            index_comp_scratch = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp_scratch[0]));
        }
    }

    if (batch_prefix_rope) {
        double tx = profile ? now_sec() : 0.0;
        rope_tail_layer_batch_inplace(q,
                                      q_dim,
                                      DS4_N_HEAD,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        rope_tail_layer_batch_inplace(kv,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_HEAD_KV,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        if (profile) t_tl_rope_cache += now_sec() - tx;
    }

    for (uint32_t t = 0; t < n_tok; t++) {
        const uint32_t pos = pos0 + t;
        float *q_t = q + (uint64_t)t * q_dim;
        float *kv_t = kv + (uint64_t)t * DS4_N_HEAD_DIM;
        bool *comp_allowed = NULL;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
{
        heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
    }
    uint32_t batch_rope_max = 4096;
    const char *batch_rope_max_env = getenv("DS4_BATCHED_ROPE_MAX");
    if (batch_rope_max_env && batch_rope_max_env[0]) {
        long v = strtol(batch_rope_max_env, NULL, 10);
        if (v >= 0 && v <= 65536) batch_rope_max = (uint32_t)v;
    }
    const bool batch_prefix_rope =
        prefix_batch_attn &&
        getenv("DS4_NO_BATCHED_ROPE") == NULL &&
        n_tok <= batch_rope_max;
    uint32_t *comp_counts = prefix_batch_attn ?
        xcalloc((size_t)n_tok, sizeof(comp_counts[0])) : NULL;
    uint8_t *allowed_mask = prefix_batch_attn && ratio == 4 ?
        xcalloc((size_t)n_tok, sizeof(allowed_mask[0])) : NULL;
    uint8_t *allowed_bits = NULL;
    const uint64_t allowed_stride = ratio == 4 ? ((uint64_t)cache->comp_cap + 7u) / 8u : 0;
    float *comp_scratch = NULL;
    float *index_comp_scratch = NULL;

    if (ratio != 0) {
        comp_scratch = xmalloc((size_t)DS4_N_HEAD_DIM * sizeof(comp_scratch[0]));

        if (ratio == 4) {
            index_comp_scratch = xmalloc((size_t)DS4_N_INDEXER_HEAD_DIM * sizeof(index_comp_scratch[0]));
        }
    }

    if (batch_prefix_rope) {
        double tx = profile ? now_sec() : 0.0;
        rope_tail_layer_batch_inplace(q,
                                      q_dim,
                                      DS4_N_HEAD,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        rope_tail_layer_batch_inplace(kv,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_HEAD_KV,
                                      DS4_N_HEAD_DIM,
                                      DS4_N_ROT,
                                      pos0,
                                      il,
                                      false,
                                      n_tok);
        if (profile) t_tl_rope_cache += now_sec() - tx;
    }

    for (uint32_t t = 0; t < n_tok; t++) {
        const uint32_t pos = pos0 + t;
        float *q_t = q + (uint64_t)t * q_dim;
        float *kv_t = kv + (uint64_t)t * DS4_N_HEAD_DIM;
        bool *comp_allowed = NULL;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
            rope_tail_layer_inplace(kv_t, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
        }
        dsv4_fp8_kv_quantize_row_inplace_cpu(kv_t, DS4_N_HEAD_DIM, DS4_N_ROT);

        kv_cache_push_raw(cache, kv_t);
        if (profile) t_tl_rope_cache += now_sec() - tx;

        if (ratio != 0) {
            tx = profile ? now_sec() : 0.0;
            float *comp = comp_scratch;
            const bool have_comp = compressor_decode_one(comp, model,
                                                         layer->attn_compressor_kv,
                                                         layer->attn_compressor_gate,
                                                         layer->attn_compressor_ape,
                                                         layer->attn_compressor_norm,
                                                         attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                         cache->attn_state_kv,
                                                         cache->attn_state_score,
                                                         DS4_N_HEAD_DIM,
                                                         ratio,
                                                         il,
                                                         pos);
            if (have_comp) {
                kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
            }

            if (ratio == 4) {
                float *index_comp = index_comp_scratch;
                const bool have_index_comp = compressor_decode_one(index_comp, model,
                                                                   layer->indexer_compressor_kv,
                                                                   layer->indexer_compressor_gate,
                                                                   layer->indexer_compressor_ape,
                                                                   layer->indexer_compressor_norm,
                                                                   attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                                   cache->index_state_kv,
                                                                   cache->index_state_score,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
            rope_tail_layer_inplace(kv_t, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
        }
        dsv4_fp8_kv_quantize_row_inplace_cpu(kv_t, DS4_N_HEAD_DIM, DS4_N_ROT);

        kv_cache_push_raw(cache, kv_t);
        if (profile) t_tl_rope_cache += now_sec() - tx;

        if (ratio != 0) {
            tx = profile ? now_sec() : 0.0;
            float *comp = comp_scratch;
            const bool have_comp = compressor_decode_one(comp, model,
                                                         layer->attn_compressor_kv,
                                                         layer->attn_compressor_gate,
                                                         layer->attn_compressor_ape,
                                                         layer->attn_compressor_norm,
                                                         attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                         cache->attn_state_kv,
                                                         cache->attn_state_score,
                                                         DS4_N_HEAD_DIM,
                                                         ratio,
                                                         il,
                                                         pos);
            if (have_comp) {
                kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
            }

            if (ratio == 4) {
                float *index_comp = index_comp_scratch;
                const bool have_index_comp = compressor_decode_one(index_comp, model,
                                                                   layer->indexer_compressor_kv,
                                                                   layer->indexer_compressor_gate,
                                                                   layer->indexer_compressor_ape,
                                                                   layer->indexer_compressor_norm,
                                                                   attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                                   cache->index_state_kv,
                                                                   cache->index_state_score,
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
            rope_tail_layer_inplace(kv_t, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
        }
        dsv4_fp8_kv_quantize_row_inplace_cpu(kv_t, DS4_N_HEAD_DIM, DS4_N_ROT);

        kv_cache_push_raw(cache, kv_t);
        if (profile) t_tl_rope_cache += now_sec() - tx;

        if (ratio != 0) {
            tx = profile ? now_sec() : 0.0;
            float *comp = comp_scratch;
            const bool have_comp = compressor_decode_one(comp, model,
                                                         layer->attn_compressor_kv,
                                                         layer->attn_compressor_gate,
                                                         layer->attn_compressor_ape,
                                                         layer->attn_compressor_norm,
                                                         attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                         cache->attn_state_kv,
                                                         cache->attn_state_score,
                                                         DS4_N_HEAD_DIM,
                                                         ratio,
                                                         il,
                                                         pos);
            if (have_comp) {
                kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
            }

            if (ratio == 4) {
                float *index_comp = index_comp_scratch;
                const bool have_index_comp = compressor_decode_one(index_comp, model,
                                                                   layer->indexer_compressor_kv,
                                                                   layer->indexer_compressor_gate,
                                                                   layer->indexer_compressor_ape,
                                                                   layer->indexer_compressor_norm,
                                                                   attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                                   cache->index_state_kv,
                                                                   cache->index_state_score,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4.c

```c
;

        double tx = profile ? now_sec() : 0.0;
        if (!batch_prefix_rope) {
            rope_tail_layer_inplace(q_t, DS4_N_HEAD, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
            rope_tail_layer_inplace(kv_t, DS4_N_HEAD_KV, DS4_N_HEAD_DIM, DS4_N_ROT, pos, il, false);
        }
        dsv4_fp8_kv_quantize_row_inplace_cpu(kv_t, DS4_N_HEAD_DIM, DS4_N_ROT);

        kv_cache_push_raw(cache, kv_t);
        if (profile) t_tl_rope_cache += now_sec() - tx;

        if (ratio != 0) {
            tx = profile ? now_sec() : 0.0;
            float *comp = comp_scratch;
            const bool have_comp = compressor_decode_one(comp, model,
                                                         layer->attn_compressor_kv,
                                                         layer->attn_compressor_gate,
                                                         layer->attn_compressor_ape,
                                                         layer->attn_compressor_norm,
                                                         attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                         cache->attn_state_kv,
                                                         cache->attn_state_score,
                                                         DS4_N_HEAD_DIM,
                                                         ratio,
                                                         il,
                                                         pos);
            if (have_comp) {
                kv_cache_push_comp(cache->attn_comp_kv, &cache->n_comp, cache->comp_cap, DS4_N_HEAD_DIM, comp);
            }

            if (ratio == 4) {
                float *index_comp = index_comp_scratch;
                const bool have_index_comp = compressor_decode_one(index_comp, model,
                                                                   layer->indexer_compressor_kv,
                                                                   layer->indexer_compressor_gate,
                                                                   layer->indexer_compressor_ape,
                                                                   layer->indexer_compressor_norm,
                                                                   attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                                   cache->index_state_kv,
                                                                   cache->index_state_score,
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
cache->index_state_kv,
                                                                   cache->index_state_score,
                                                                   DS4_N_INDEXER_HEAD_DIM,
                                                                   ratio,
                                                                   il,
                                                                   pos);
                if (have_index_comp) {
                    kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
                }
                if (profile) t_tl_compress += now_sec() - tx;

                tx = profile ? now_sec() : 0.0;
                comp_allowed = indexer_allowed_decode_one(model, layer,
                                                          attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                          qr_norm + (uint64_t)t * 1024,
                                                          cache->index_comp_kv,
                                                          cache->n_index_comp,
                                                          il, pos);
                if (profile) t_tl_indexer += now_sec() - tx;
            } else {
                if (profile) t_tl_compress += now_sec() - tx;
            }

            if (comp_counts) comp_counts[t] = cache->n_comp;
            if (prefix_batch_attn && comp_allowed) {
                if (!allowed_bits) {
                    allowed_bits = xcalloc((size_t)n_tok * allowed_stride, sizeof(allowed_bits[0]));
                }
                allowed_mask[t] = 1;
                uint8_t *bits = allowed_bits + (uint64_t)t * allowed_stride;
                for (uint32_t c = 0; c < cache->n_comp; c++) {
                    if (comp_allowed[c]) bits[c >> 3] |= (uint8_t)(1u << (c & 7u));
                }
            }

            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_mixed_one(heads + (uint64_t)t * q_dim, model, layer, q_t,
                                          cache->raw_kv, cache->n_raw,
                                          cache->attn_comp_kv, cache->n_comp,
                                          comp_allowed);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
cache->index_state_kv,
                                                                   cache->index_state_score,
                                                                   DS4_N_INDEXER_HEAD_DIM,
                                                                   ratio,
                                                                   il,
                                                                   pos);
                if (have_index_comp) {
                    kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
                }
                if (profile) t_tl_compress += now_sec() - tx;

                tx = profile ? now_sec() : 0.0;
                comp_allowed = indexer_allowed_decode_one(model, layer,
                                                          attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                          qr_norm + (uint64_t)t * 1024,
                                                          cache->index_comp_kv,
                                                          cache->n_index_comp,
                                                          il, pos);
                if (profile) t_tl_indexer += now_sec() - tx;
            } else {
                if (profile) t_tl_compress += now_sec() - tx;
            }

            if (comp_counts) comp_counts[t] = cache->n_comp;
            if (prefix_batch_attn && comp_allowed) {
                if (!allowed_bits) {
                    allowed_bits = xcalloc((size_t)n_tok * allowed_stride, sizeof(allowed_bits[0]));
                }
                allowed_mask[t] = 1;
                uint8_t *bits = allowed_bits + (uint64_t)t * allowed_stride;
                for (uint32_t c = 0; c < cache->n_comp; c++) {
                    if (comp_allowed[c]) bits[c >> 3] |= (uint8_t)(1u << (c & 7u));
                }
            }

            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_mixed_one(heads + (uint64_t)t * q_dim, model, layer, q_t,
                                          cache->raw_kv, cache->n_raw,
                                          cache->attn_comp_kv, cache->n_comp,
                                          comp_allowed);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
cache->index_state_kv,
                                                                   cache->index_state_score,
                                                                   DS4_N_INDEXER_HEAD_DIM,
                                                                   ratio,
                                                                   il,
                                                                   pos);
                if (have_index_comp) {
                    kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
                }
                if (profile) t_tl_compress += now_sec() - tx;

                tx = profile ? now_sec() : 0.0;
                comp_allowed = indexer_allowed_decode_one(model, layer,
                                                          attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                          qr_norm + (uint64_t)t * 1024,
                                                          cache->index_comp_kv,
                                                          cache->n_index_comp,
                                                          il, pos);
                if (profile) t_tl_indexer += now_sec() - tx;
            } else {
                if (profile) t_tl_compress += now_sec() - tx;
            }

            if (comp_counts) comp_counts[t] = cache->n_comp;
            if (prefix_batch_attn && comp_allowed) {
                if (!allowed_bits) {
                    allowed_bits = xcalloc((size_t)n_tok * allowed_stride, sizeof(allowed_bits[0]));
                }
                allowed_mask[t] = 1;
                uint8_t *bits = allowed_bits + (uint64_t)t * allowed_stride;
                for (uint32_t c = 0; c < cache->n_comp; c++) {
                    if (comp_allowed[c]) bits[c >> 3] |= (uint8_t)(1u << (c & 7u));
                }
            }

            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_mixed_one(heads + (uint64_t)t * q_dim, model, layer, q_t,
                                          cache->raw_kv, cache->n_raw,
                                          cache->attn_comp_kv, cache->n_comp,
                                          comp_allowed);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4.c

```c
cache->index_state_kv,
                                                                   cache->index_state_score,
                                                                   DS4_N_INDEXER_HEAD_DIM,
                                                                   ratio,
                                                                   il,
                                                                   pos);
                if (have_index_comp) {
                    kv_cache_push_comp(cache->index_comp_kv, &cache->n_index_comp, cache->comp_cap, DS4_N_INDEXER_HEAD_DIM, index_comp);
                }
                if (profile) t_tl_compress += now_sec() - tx;

                tx = profile ? now_sec() : 0.0;
                comp_allowed = indexer_allowed_decode_one(model, layer,
                                                          attn_norm + (uint64_t)t * DS4_N_EMBD,
                                                          qr_norm + (uint64_t)t * 1024,
                                                          cache->index_comp_kv,
                                                          cache->n_index_comp,
                                                          il, pos);
                if (profile) t_tl_indexer += now_sec() - tx;
            } else {
                if (profile) t_tl_compress += now_sec() - tx;
            }

            if (comp_counts) comp_counts[t] = cache->n_comp;
            if (prefix_batch_attn && comp_allowed) {
                if (!allowed_bits) {
                    allowed_bits = xcalloc((size_t)n_tok * allowed_stride, sizeof(allowed_bits[0]));
                }
                allowed_mask[t] = 1;
                uint8_t *bits = allowed_bits + (uint64_t)t * allowed_stride;
                for (uint32_t c = 0; c < cache->n_comp; c++) {
                    if (comp_allowed[c]) bits[c >> 3] |= (uint8_t)(1u << (c & 7u));
                }
            }

            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_mixed_one(heads + (uint64_t)t * q_dim, model, layer, q_t,
                                          cache->raw_kv, cache->n_raw,
                                          cache->attn_comp_kv, cache->n_comp,
                                          comp_allowed);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_rows_one(heads + (uint64_t)t * q_dim, model, layer, q_t, cache->raw_kv, cache->n_raw);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        }

        if (!prefix_batch_attn) {
            tx = profile ? now_sec() : 0.0;
            rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                    DS4_N_HEAD,
                                    DS4_N_HEAD_DIM,
                                    DS4_N_ROT,
                                    pos,
                                    il,
                                    true);
            if (profile) t_tl_inv_rope += now_sec() - tx;
        }

        free(comp_allowed);
    }

    if (prefix_batch_attn) {
        double tx = profile ? now_sec() : 0.0;
        const float *comp_kv_for_prefix = cache->attn_comp_kv ? cache->attn_comp_kv : kv;
        if (!heads) {
            heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
        }
        layer_attention_prefix_batch(heads, model, layer,
                                     q,
                                     kv,
                                     comp_kv_for_prefix,
                                     comp_counts,
                                     allowed_mask,
                                     allowed_bits,
                                     allowed_stride,
                                     n_tok,
                                     cache->cap_raw);
        if (profile) t_tl_attn_rows += now_sec() - tx;
        tx = profile ? now_sec() : 0.0;
        if (batch_prefix_rope) {
            rope_tail_layer_batch_inplace(heads,
                                          q_dim,
                                          DS4_N_HEAD,
                                          DS4_N_HEAD_DIM,
                                          DS4_N_ROT,
                                          pos0,
                                          il,
                                          true,
                                          n_tok);
        } else {
            for (uint32_t t = 0; t < n_tok; t++) {
                rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                        DS4_N_HEAD,
                                        DS4_N_HEAD_DIM,
                                        DS4_N_ROT,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_rows_one(heads + (uint64_t)t * q_dim, model, layer, q_t, cache->raw_kv, cache->n_raw);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        }

        if (!prefix_batch_attn) {
            tx = profile ? now_sec() : 0.0;
            rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                    DS4_N_HEAD,
                                    DS4_N_HEAD_DIM,
                                    DS4_N_ROT,
                                    pos,
                                    il,
                                    true);
            if (profile) t_tl_inv_rope += now_sec() - tx;
        }

        free(comp_allowed);
    }

    if (prefix_batch_attn) {
        double tx = profile ? now_sec() : 0.0;
        const float *comp_kv_for_prefix = cache->attn_comp_kv ? cache->attn_comp_kv : kv;
        if (!heads) {
            heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
        }
        layer_attention_prefix_batch(heads, model, layer,
                                     q,
                                     kv,
                                     comp_kv_for_prefix,
                                     comp_counts,
                                     allowed_mask,
                                     allowed_bits,
                                     allowed_stride,
                                     n_tok,
                                     cache->cap_raw);
        if (profile) t_tl_attn_rows += now_sec() - tx;
        tx = profile ? now_sec() : 0.0;
        if (batch_prefix_rope) {
            rope_tail_layer_batch_inplace(heads,
                                          q_dim,
                                          DS4_N_HEAD,
                                          DS4_N_HEAD_DIM,
                                          DS4_N_ROT,
                                          pos0,
                                          il,
                                          true,
                                          n_tok);
        } else {
            for (uint32_t t = 0; t < n_tok; t++) {
                rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                        DS4_N_HEAD,
                                        DS4_N_HEAD_DIM,
                                        DS4_N_ROT,
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_rows_one(heads + (uint64_t)t * q_dim, model, layer, q_t, cache->raw_kv, cache->n_raw);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        }

        if (!prefix_batch_attn) {
            tx = profile ? now_sec() : 0.0;
            rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                    DS4_N_HEAD,
                                    DS4_N_HEAD_DIM,
                                    DS4_N_ROT,
                                    pos,
                                    il,
                                    true);
            if (profile) t_tl_inv_rope += now_sec() - tx;
        }

        free(comp_allowed);
    }

    if (prefix_batch_attn) {
        double tx = profile ? now_sec() : 0.0;
        const float *comp_kv_for_prefix = cache->attn_comp_kv ? cache->attn_comp_kv : kv;
        if (!heads) {
            heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
        }
        layer_attention_prefix_batch(heads, model, layer,
                                     q,
                                     kv,
                                     comp_kv_for_prefix,
                                     comp_counts,
                                     allowed_mask,
                                     allowed_bits,
                                     allowed_stride,
                                     n_tok,
                                     cache->cap_raw);
        if (profile) t_tl_attn_rows += now_sec() - tx;
        tx = profile ? now_sec() : 0.0;
        if (batch_prefix_rope) {
            rope_tail_layer_batch_inplace(heads,
                                          q_dim,
                                          DS4_N_HEAD,
                                          DS4_N_HEAD_DIM,
                                          DS4_N_ROT,
                                          pos0,
                                          il,
                                          true,
                                          n_tok);
        } else {
            for (uint32_t t = 0; t < n_tok; t++) {
                rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                        DS4_N_HEAD,
                                        DS4_N_HEAD_DIM,
                                        DS4_N_ROT,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4.c

```c
if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        } else {
            if (!prefix_batch_attn) {
                tx = profile ? now_sec() : 0.0;
                layer_attention_rows_one(heads + (uint64_t)t * q_dim, model, layer, q_t, cache->raw_kv, cache->n_raw);
                if (profile) t_tl_attn_rows += now_sec() - tx;
            }
        }

        if (!prefix_batch_attn) {
            tx = profile ? now_sec() : 0.0;
            rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                    DS4_N_HEAD,
                                    DS4_N_HEAD_DIM,
                                    DS4_N_ROT,
                                    pos,
                                    il,
                                    true);
            if (profile) t_tl_inv_rope += now_sec() - tx;
        }

        free(comp_allowed);
    }

    if (prefix_batch_attn) {
        double tx = profile ? now_sec() : 0.0;
        const float *comp_kv_for_prefix = cache->attn_comp_kv ? cache->attn_comp_kv : kv;
        if (!heads) {
            heads = xmalloc((size_t)n_tok * q_dim * sizeof(heads[0]));
        }
        layer_attention_prefix_batch(heads, model, layer,
                                     q,
                                     kv,
                                     comp_kv_for_prefix,
                                     comp_counts,
                                     allowed_mask,
                                     allowed_bits,
                                     allowed_stride,
                                     n_tok,
                                     cache->cap_raw);
        if (profile) t_tl_attn_rows += now_sec() - tx;
        tx = profile ? now_sec() : 0.0;
        if (batch_prefix_rope) {
            rope_tail_layer_batch_inplace(heads,
                                          q_dim,
                                          DS4_N_HEAD,
                                          DS4_N_HEAD_DIM,
                                          DS4_N_ROT,
                                          pos0,
                                          il,
                                          true,
                                          n_tok);
        } else {
            for (uint32_t t = 0; t < n_tok; t++) {
                rope_tail_layer_inplace(heads + (uint64_t)t * q_dim,
                                        DS4_N_HEAD,
                                        DS4_N_HEAD_DIM,
                                        DS4_N_ROT,
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
(*v));
}

static bool cursor_u64(ds4_cursor *c, uint64_t *v) {
    return cursor_read(c, v, sizeof(*v));
}

static bool cursor_string(ds4_cursor *c, ds4_str *s) {
    uint64_t len;
    if (!cursor_u64(c, &len)) return false;
    if (!cursor_has(c, len)) return false;
    s->ptr = (const char *)(c->base + c->pos);
    s->len = len;
    c->pos += len;
    return true;
}

static uint64_t align_up(uint64_t value, uint64_t alignment) {
    uint64_t rem = value % alignment;
    return rem == 0 ? value : value + alignment - rem;
}

/* =========================================================================
 * GGUF Parsing and Model Mapping.
 * =========================================================================
 *
 * The loader maps the model once, records metadata/tensor descriptors, and
 * leaves tensor bytes in place.  Inference code accesses weights by adding
 * tensor offsets to the mapping instead of copying the GGUF into private
 * structures.
 */

enum {
    GGUF_VALUE_UINT8   = 0,
    GGUF_VALUE_INT8    = 1,
    GGUF_VALUE_UINT16  = 2,
    GGUF_VALUE_INT16   = 3,
    GGUF_VALUE_UINT32  = 4,
    GGUF_VALUE_INT32   = 5,
    GGUF_VALUE_FLOAT32 = 6,
    GGUF_VALUE_BOOL    = 7,
    GGUF_VALUE_STRING  = 8,
    GGUF_VALUE_ARRAY   = 9,
    GGUF_VALUE_UINT64  = 10,
    GGUF_VALUE_INT64   = 11,
    GGUF_VALUE_FLOAT64 = 12,
};

typedef struct {
    const char *name;
    uint32_t block_elems;
    uint32_t block_bytes;
} gguf_type_info;

static const gguf_type_info gguf_types[] = {
    [0]  = {"f32",      1,   4},
    [1]  = {"f16",      1,   2},
    [2]  = {"q4_0",    32,  18},
    [3]  = {"q4_1",    32,  20},
    [6]  = {"q5_0",    32,  22},
    [7]  = {"q5_1",    32,  24},
    [8]  = {"q8_0",    32,  34},
    [9]  = {"q8_1",    32,  40},
    [10] = {"q2_k",   256,  84},
    [11] = {"q3_k",   256, 110},
    [12] = {"q4_k",   256, 144},
    [13] = {"q5_k",   256, 176},
    [14] = {"q6_k",   256, 210},
    [15] = {"q8_k",   256, 292},
    [16] = {"iq2_xxs",256,  66},
    [17] = {"iq2_xs", 256,  74},
    [18] = {"iq3_xxs",256,  98},
    [19] = {"iq1_s",  256, 110},
    [20] = {"iq4_nl", 256,  50},
    [21] = {"iq3_s",  256, 110},
    [22] = {"iq2_s",  256,  82},
    [23] = {"iq4_xs", 256, 136},
    [24] = {"i8",       1,   1},
    [25] = {"i16",      1,   2},
    [26] = {"i32",      1,   4},
    [27] = {"i64",      1,   8},
    [28] = {"f64",      1,   8},
    [29] = {"iq1_m",  256,  56},
    [30] = {"bf16",     1,   2},
};

enum {
    DS4_TENSOR_F32      = 0,
    DS4_TENSOR_F16      = 1,
    DS4_TENSOR_Q8_0     = 8,
    DS4_TENSOR_Q2_K     = 10,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
(*v));
}

static bool cursor_u64(ds4_cursor *c, uint64_t *v) {
    return cursor_read(c, v, sizeof(*v));
}

static bool cursor_string(ds4_cursor *c, ds4_str *s) {
    uint64_t len;
    if (!cursor_u64(c, &len)) return false;
    if (!cursor_has(c, len)) return false;
    s->ptr = (const char *)(c->base + c->pos);
    s->len = len;
    c->pos += len;
    return true;
}

static uint64_t align_up(uint64_t value, uint64_t alignment) {
    uint64_t rem = value % alignment;
    return rem == 0 ? value : value + alignment - rem;
}

/* =========================================================================
 * GGUF Parsing and Model Mapping.
 * =========================================================================
 *
 * The loader maps the model once, records metadata/tensor descriptors, and
 * leaves tensor bytes in place.  Inference code accesses weights by adding
 * tensor offsets to the mapping instead of copying the GGUF into private
 * structures.
 */

enum {
    GGUF_VALUE_UINT8   = 0,
    GGUF_VALUE_INT8    = 1,
    GGUF_VALUE_UINT16  = 2,
    GGUF_VALUE_INT16   = 3,
    GGUF_VALUE_UINT32  = 4,
    GGUF_VALUE_INT32   = 5,
    GGUF_VALUE_FLOAT32 = 6,
    GGUF_VALUE_BOOL    = 7,
    GGUF_VALUE_STRING  = 8,
    GGUF_VALUE_ARRAY   = 9,
    GGUF_VALUE_UINT64  = 10,
    GGUF_VALUE_INT64   = 11,
    GGUF_VALUE_FLOAT64 = 12,
};

typedef struct {
    const char *name;
    uint32_t block_elems;
    uint32_t block_bytes;
} gguf_type_info;

static const gguf_type_info gguf_types[] = {
    [0]  = {"f32",      1,   4},
    [1]  = {"f16",      1,   2},
    [2]  = {"q4_0",    32,  18},
    [3]  = {"q4_1",    32,  20},
    [6]  = {"q5_0",    32,  22},
    [7]  = {"q5_1",    32,  24},
    [8]  = {"q8_0",    32,  34},
    [9]  = {"q8_1",    32,  40},
    [10] = {"q2_k",   256,  84},
    [11] = {"q3_k",   256, 110},
    [12] = {"q4_k",   256, 144},
    [13] = {"q5_k",   256, 176},
    [14] = {"q6_k",   256, 210},
    [15] = {"q8_k",   256, 292},
    [16] = {"iq2_xxs",256,  66},
    [17] = {"iq2_xs", 256,  74},
    [18] = {"iq3_xxs",256,  98},
    [19] = {"iq1_s",  256, 110},
    [20] = {"iq4_nl", 256,  50},
    [21] = {"iq3_s",  256, 110},
    [22] = {"iq2_s",  256,  82},
    [23] = {"iq4_xs", 256, 136},
    [24] = {"i8",       1,   1},
    [25] = {"i16",      1,   2},
    [26] = {"i32",      1,   4},
    [27] = {"i64",      1,   8},
    [28] = {"f64",      1,   8},
    [29] = {"iq1_m",  256,  56},
    [30] = {"bf16",     1,   2},
};

enum {
    DS4_TENSOR_F32      = 0,
    DS4_TENSOR_F16      = 1,
    DS4_TENSOR_Q8_0     = 8,
    DS4_TENSOR_Q2_K     = 10,
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
(*v));
}

static bool cursor_u64(ds4_cursor *c, uint64_t *v) {
    return cursor_read(c, v, sizeof(*v));
}

static bool cursor_string(ds4_cursor *c, ds4_str *s) {
    uint64_t len;
    if (!cursor_u64(c, &len)) return false;
    if (!cursor_has(c, len)) return false;
    s->ptr = (const char *)(c->base + c->pos);
    s->len = len;
    c->pos += len;
    return true;
}

static uint64_t align_up(uint64_t value, uint64_t alignment) {
    uint64_t rem = value % alignment;
    return rem == 0 ? value : value + alignment - rem;
}

/* =========================================================================
 * GGUF Parsing and Model Mapping.
 * =========================================================================
 *
 * The loader maps the model once, records metadata/tensor descriptors, and
 * leaves tensor bytes in place.  Inference code accesses weights by adding
 * tensor offsets to the mapping instead of copying the GGUF into private
 * structures.
 */

enum {
    GGUF_VALUE_UINT8   = 0,
    GGUF_VALUE_INT8    = 1,
    GGUF_VALUE_UINT16  = 2,
    GGUF_VALUE_INT16   = 3,
    GGUF_VALUE_UINT32  = 4,
    GGUF_VALUE_INT32   = 5,
    GGUF_VALUE_FLOAT32 = 6,
    GGUF_VALUE_BOOL    = 7,
    GGUF_VALUE_STRING  = 8,
    GGUF_VALUE_ARRAY   = 9,
    GGUF_VALUE_UINT64  = 10,
    GGUF_VALUE_INT64   = 11,
    GGUF_VALUE_FLOAT64 = 12,
};

typedef struct {
    const char *name;
    uint32_t block_elems;
    uint32_t block_bytes;
} gguf_type_info;

static const gguf_type_info gguf_types[] = {
    [0]  = {"f32",      1,   4},
    [1]  = {"f16",      1,   2},
    [2]  = {"q4_0",    32,  18},
    [3]  = {"q4_1",    32,  20},
    [6]  = {"q5_0",    32,  22},
    [7]  = {"q5_1",    32,  24},
    [8]  = {"q8_0",    32,  34},
    [9]  = {"q8_1",    32,  40},
    [10] = {"q2_k",   256,  84},
    [11] = {"q3_k",   256, 110},
    [12] = {"q4_k",   256, 144},
    [13] = {"q5_k",   256, 176},
    [14] = {"q6_k",   256, 210},
    [15] = {"q8_k",   256, 292},
    [16] = {"iq2_xxs",256,  66},
    [17] = {"iq2_xs", 256,  74},
    [18] = {"iq3_xxs",256,  98},
    [19] = {"iq1_s",  256, 110},
    [20] = {"iq4_nl", 256,  50},
    [21] = {"iq3_s",  256, 110},
    [22] = {"iq2_s",  256,  82},
    [23] = {"iq4_xs", 256, 136},
    [24] = {"i8",       1,   1},
    [25] = {"i16",      1,   2},
    [26] = {"i32",      1,   4},
    [27] = {"i64",      1,   8},
    [28] = {"f64",      1,   8},
    [29] = {"iq1_m",  256,  56},
    [30] = {"bf16",     1,   2},
};

enum {
    DS4_TENSOR_F32      = 0,
    DS4_TENSOR_F16      = 1,
    DS4_TENSOR_Q8_0     = 8,
    DS4_TENSOR_Q2_K     = 10,
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4.c

```c
(*v));
}

static bool cursor_u64(ds4_cursor *c, uint64_t *v) {
    return cursor_read(c, v, sizeof(*v));
}

static bool cursor_string(ds4_cursor *c, ds4_str *s) {
    uint64_t len;
    if (!cursor_u64(c, &len)) return false;
    if (!cursor_has(c, len)) return false;
    s->ptr = (const char *)(c->base + c->pos);
    s->len = len;
    c->pos += len;
    return true;
}

static uint64_t align_up(uint64_t value, uint64_t alignment) {
    uint64_t rem = value % alignment;
    return rem == 0 ? value : value + alignment - rem;
}

/* =========================================================================
 * GGUF Parsing and Model Mapping.
 * =========================================================================
 *
 * The loader maps the model once, records metadata/tensor descriptors, and
 * leaves tensor bytes in place.  Inference code accesses weights by adding
 * tensor offsets to the mapping instead of copying the GGUF into private
 * structures.
 */

enum {
    GGUF_VALUE_UINT8   = 0,
    GGUF_VALUE_INT8    = 1,
    GGUF_VALUE_UINT16  = 2,
    GGUF_VALUE_INT16   = 3,
    GGUF_VALUE_UINT32  = 4,
    GGUF_VALUE_INT32   = 5,
    GGUF_VALUE_FLOAT32 = 6,
    GGUF_VALUE_BOOL    = 7,
    GGUF_VALUE_STRING  = 8,
    GGUF_VALUE_ARRAY   = 9,
    GGUF_VALUE_UINT64  = 10,
    GGUF_VALUE_INT64   = 11,
    GGUF_VALUE_FLOAT64 = 12,
};

typedef struct {
    const char *name;
    uint32_t block_elems;
    uint32_t block_bytes;
} gguf_type_info;

static const gguf_type_info gguf_types[] = {
    [0]  = {"f32",      1,   4},
    [1]  = {"f16",      1,   2},
    [2]  = {"q4_0",    32,  18},
    [3]  = {"q4_1",    32,  20},
    [6]  = {"q5_0",    32,  22},
    [7]  = {"q5_1",    32,  24},
    [8]  = {"q8_0",    32,  34},
    [9]  = {"q8_1",    32,  40},
    [10] = {"q2_k",   256,  84},
    [11] = {"q3_k",   256, 110},
    [12] = {"q4_k",   256, 144},
    [13] = {"q5_k",   256, 176},
    [14] = {"q6_k",   256, 210},
    [15] = {"q8_k",   256, 292},
    [16] = {"iq2_xxs",256,  66},
    [17] = {"iq2_xs", 256,  74},
    [18] = {"iq3_xxs",256,  98},
    [19] = {"iq1_s",  256, 110},
    [20] = {"iq4_nl", 256,  50},
    [21] = {"iq3_s",  256, 110},
    [22] = {"iq2_s",  256,  82},
    [23] = {"iq4_xs", 256, 136},
    [24] = {"i8",       1,   1},
    [25] = {"i16",      1,   2},
    [26] = {"i32",      1,   4},
    [27] = {"i64",      1,   8},
    [28] = {"f64",      1,   8},
    [29] = {"iq1_m",  256,  56},
    [30] = {"bf16",     1,   2},
};

enum {
    DS4_TENSOR_F32      = 0,
    DS4_TENSOR_F16      = 1,
    DS4_TENSOR_Q8_0     = 8,
    DS4_TENSOR_Q2_K     = 10,
```<｜Assistant｜><think>