[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
inline float f16_to_f32(uint16_t h) {
#if defined(__ARM_NEON)
    const float16x4_t hv = vreinterpret_f16_u16(vdup_n_u16(h));
    return vgetq_lane_f32(vcvt_f32_f16(hv), 0);
#else
    uint32_t sign = (uint32_t)(h & 0x8000) << 16;
    uint32_t exp  = (h >> 10) & 0x1f;
    uint32_t mant = h & 0x03ff;
    uint32_t bits;

    if (exp == 0) {
        if (mant == 0) {
            bits = sign;
        } else {
            exp = 1;
            while ((mant & 0x0400) == 0) {
                mant <<= 1;
                exp--;
            }
            mant &= 0x03ff;
            bits = sign | ((exp + 127 - 15) << 23) | (mant << 13);
        }
    } else if (exp == 31) {
        bits = sign | 0x7f800000u | (mant << 13);
    } else {
        bits = sign | ((exp + 127 - 15) << 23) | (mant << 13);
    }

    float f;
    memcpy(&f, &bits, sizeof(f));
    return f;
#endif
}

static inline uint16_t f32_to_f16(float f) {
#if defined(__ARM_NEON)
    const float32x4_t fv = vdupq_n_f32(f);
    const float16x4_t hv = vcvt_f16_f32(fv);
    return vget_lane_u16(vreinterpret_u16_f16(hv), 0);
#else
    uint32_t bits;
    memcpy(&bits, &f, sizeof(bits));

    const uint32_t sign = (bits >> 16) & 0x8000u;
    int32_t exp = (int32_t)((bits >> 23) & 0xffu) - 127 + 15;
    uint32_t mant = bits & 0x7fffffu;

    if (exp <= 0) {
        if (exp < -10) return (uint16_t)sign;
        mant |= 0x800000u;
        const uint32_t shift = (uint32_t)(14 - exp);
        uint32_t half_mant = mant >> shift;
        const uint32_t round_bit = (mant >> (shift - 1)) & 1u;
        const uint32_t sticky = mant & ((1u << (shift - 1)) - 1u);
        if (round_bit && (sticky || (half_mant & 1u))) half_mant++;
        return (uint16_t)(sign | half_mant);
    }

    if (exp >= 31) {
        if (((bits >> 23) & 0xffu) == 0xffu && mant != 0) {
            return (uint16_t)(sign | 0x7e00u);
        }
        return (uint16_t)(sign | 0x7c00u);
    }

    uint32_t half = sign | ((uint32_t)exp << 10) | (mant >> 13);
    const uint32_t round = mant & 0x1fffu;
    if (round > 0x1000u || (round == 0x1000u && (half & 1u))) half++;
    return (uint16_t)half;
#endif
}

static void f16_round_inplace_cpu(float *x, uint32_t n) {
    for (uint32_t i = 0; i < n; i++) x[i] = f16_to_f32(f32_to_f16(x[i]));
}

static float dsv4_e4m3fn_value_cpu(int i) {
    static const float exp_scale[16] = {
        0.0f, 0.015625f, 0.03125f, 0.0625f,
        0.125f, 0.25f, 0.5f, 1.0f,
        2.0f, 4.0f, 8.0f, 16.0f,
        32.0f, 64.0f, 128.0f, 256.0f,
    };

    const int exp = (i >> 3) & 0x0f;
    const int mant = i & 0x07;
```

<｜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
inline float f16_to_f32(uint16_t h) {
#if defined(__ARM_NEON)
    const float16x4_t hv = vreinterpret_f16_u16(vdup_n_u16(h));
    return vgetq_lane_f32(vcvt_f32_f16(hv), 0);
#else
    uint32_t sign = (uint32_t)(h & 0x8000) << 16;
    uint32_t exp  = (h >> 10) & 0x1f;
    uint32_t mant = h & 0x03ff;
    uint32_t bits;

    if (exp == 0) {
        if (mant == 0) {
            bits = sign;
        } else {
            exp = 1;
            while ((mant & 0x0400) == 0) {
                mant <<= 1;
                exp--;
            }
            mant &= 0x03ff;
            bits = sign | ((exp + 127 - 15) << 23) | (mant << 13);
        }
    } else if (exp == 31) {
        bits = sign | 0x7f800000u | (mant << 13);
    } else {
        bits = sign | ((exp + 127 - 15) << 23) | (mant << 13);
    }

    float f;
    memcpy(&f, &bits, sizeof(f));
    return f;
#endif
}

static inline uint16_t f32_to_f16(float f) {
#if defined(__ARM_NEON)
    const float32x4_t fv = vdupq_n_f32(f);
    const float16x4_t hv = vcvt_f16_f32(fv);
    return vget_lane_u16(vreinterpret_u16_f16(hv), 0);
#else
    uint32_t bits;
    memcpy(&bits, &f, sizeof(bits));

    const uint32_t sign = (bits >> 16) & 0x8000u;
    int32_t exp = (int32_t)((bits >> 23) & 0xffu) - 127 + 15;
    uint32_t mant = bits & 0x7fffffu;

    if (exp <= 0) {
        if (exp < -10) return (uint16_t)sign;
        mant |= 0x800000u;
        const uint32_t shift = (uint32_t)(14 - exp);
        uint32_t half_mant = mant >> shift;
        const uint32_t round_bit = (mant >> (shift - 1)) & 1u;
        const uint32_t sticky = mant & ((1u << (shift - 1)) - 1u);
        if (round_bit && (sticky || (half_mant & 1u))) half_mant++;
        return (uint16_t)(sign | half_mant);
    }

    if (exp >= 31) {
        if (((bits >> 23) & 0xffu) == 0xffu && mant != 0) {
            return (uint16_t)(sign | 0x7e00u);
        }
        return (uint16_t)(sign | 0x7c00u);
    }

    uint32_t half = sign | ((uint32_t)exp << 10) | (mant >> 13);
    const uint32_t round = mant & 0x1fffu;
    if (round > 0x1000u || (round == 0x1000u && (half & 1u))) half++;
    return (uint16_t)half;
#endif
}

static void f16_round_inplace_cpu(float *x, uint32_t n) {
    for (uint32_t i = 0; i < n; i++) x[i] = f16_to_f32(f32_to_f16(x[i]));
}

static float dsv4_e4m3fn_value_cpu(int i) {
    static const float exp_scale[16] = {
        0.0f, 0.015625f, 0.03125f, 0.0625f,
        0.125f, 0.25f, 0.5f, 1.0f,
        2.0f, 4.0f, 8.0f, 16.0f,
        32.0f, 64.0f, 128.0f, 256.0f,
    };

    const int exp = (i >> 3) & 0x0f;
    const int mant = i & 0x07;
```<｜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
DS4_RMS_EPS) != 0;
                        if (ok && emit) g->layer_n_index_comp[il]++;
                        if (index_counts) index_counts[t] = g->layer_n_index_comp[il];
                        if (ok && t == 0) ok = metal_graph_capture_prefix1_index_state(g, il);
                        ds4_gpu_tensor_free(sc_view);
                        ds4_gpu_tensor_free(kv_view);
                    }
                }
            }
        }
        if (ratio == 4) DS4_METAL_PROFILE_ATTN_STAGE("indexer_setup");

        if (ok && !zero_prefix && n_tokens <= g->raw_cap) {
            const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos0, n_tokens);
            /* See the raw-only branch above: batched mixed attention also
             * consumes a logical raw window, linearized out of the ring. */
            const uint32_t raw_start = metal_graph_raw_start_for_span(g,
                                                                      pos0 + n_tokens - 1u,
                                                                      n_raw);
            uint32_t use_comp_mask = 0;
            bool use_indexed_comp = false;
            double index_stage_t0 = 0.0;

            ok = ds4_gpu_store_raw_kv_batch_tensor(g->layer_raw_cache[il],
                                                     g->batch_kv,
                                                     g->raw_cap,
                                                     pos0,
                                                     n_tokens,
                                                     DS4_N_HEAD_DIM) != 0;
            if (ok && ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K) {
                const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                if (index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                ok = ds4_gpu_indexer_scores_decode_batch_tensor(g->indexer_scores,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
```

<｜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
DS4_RMS_EPS) != 0;
                        if (ok && emit) g->layer_n_index_comp[il]++;
                        if (index_counts) index_counts[t] = g->layer_n_index_comp[il];
                        if (ok && t == 0) ok = metal_graph_capture_prefix1_index_state(g, il);
                        ds4_gpu_tensor_free(sc_view);
                        ds4_gpu_tensor_free(kv_view);
                    }
                }
            }
        }
        if (ratio == 4) DS4_METAL_PROFILE_ATTN_STAGE("indexer_setup");

        if (ok && !zero_prefix && n_tokens <= g->raw_cap) {
            const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos0, n_tokens);
            /* See the raw-only branch above: batched mixed attention also
             * consumes a logical raw window, linearized out of the ring. */
            const uint32_t raw_start = metal_graph_raw_start_for_span(g,
                                                                      pos0 + n_tokens - 1u,
                                                                      n_raw);
            uint32_t use_comp_mask = 0;
            bool use_indexed_comp = false;
            double index_stage_t0 = 0.0;

            ok = ds4_gpu_store_raw_kv_batch_tensor(g->layer_raw_cache[il],
                                                     g->batch_kv,
                                                     g->raw_cap,
                                                     pos0,
                                                     n_tokens,
                                                     DS4_N_HEAD_DIM) != 0;
            if (ok && ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K) {
                const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                if (index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                ok = ds4_gpu_indexer_scores_decode_batch_tensor(g->indexer_scores,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
```<｜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
DS4_RMS_EPS) != 0;
                        if (ok && emit) g->layer_n_index_comp[il]++;
                        if (index_counts) index_counts[t] = g->layer_n_index_comp[il];
                        if (ok && t == 0) ok = metal_graph_capture_prefix1_index_state(g, il);
                        ds4_gpu_tensor_free(sc_view);
                        ds4_gpu_tensor_free(kv_view);
                    }
                }
            }
        }
        if (ratio == 4) DS4_METAL_PROFILE_ATTN_STAGE("indexer_setup");

        if (ok && !zero_prefix && n_tokens <= g->raw_cap) {
            const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos0, n_tokens);
            /* See the raw-only branch above: batched mixed attention also
             * consumes a logical raw window, linearized out of the ring. */
            const uint32_t raw_start = metal_graph_raw_start_for_span(g,
                                                                      pos0 + n_tokens - 1u,
                                                                      n_raw);
            uint32_t use_comp_mask = 0;
            bool use_indexed_comp = false;
            double index_stage_t0 = 0.0;

            ok = ds4_gpu_store_raw_kv_batch_tensor(g->layer_raw_cache[il],
                                                     g->batch_kv,
                                                     g->raw_cap,
                                                     pos0,
                                                     n_tokens,
                                                     DS4_N_HEAD_DIM) != 0;
            if (ok && ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K) {
                const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                if (index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                ok = ds4_gpu_indexer_scores_decode_batch_tensor(g->indexer_scores,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
```

<｜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
DS4_RMS_EPS) != 0;
                        if (ok && emit) g->layer_n_index_comp[il]++;
                        if (index_counts) index_counts[t] = g->layer_n_index_comp[il];
                        if (ok && t == 0) ok = metal_graph_capture_prefix1_index_state(g, il);
                        ds4_gpu_tensor_free(sc_view);
                        ds4_gpu_tensor_free(kv_view);
                    }
                }
            }
        }
        if (ratio == 4) DS4_METAL_PROFILE_ATTN_STAGE("indexer_setup");

        if (ok && !zero_prefix && n_tokens <= g->raw_cap) {
            const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos0, n_tokens);
            /* See the raw-only branch above: batched mixed attention also
             * consumes a logical raw window, linearized out of the ring. */
            const uint32_t raw_start = metal_graph_raw_start_for_span(g,
                                                                      pos0 + n_tokens - 1u,
                                                                      n_raw);
            uint32_t use_comp_mask = 0;
            bool use_indexed_comp = false;
            double index_stage_t0 = 0.0;

            ok = ds4_gpu_store_raw_kv_batch_tensor(g->layer_raw_cache[il],
                                                     g->batch_kv,
                                                     g->raw_cap,
                                                     pos0,
                                                     n_tokens,
                                                     DS4_N_HEAD_DIM) != 0;
            if (ok && ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K) {
                const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                if (index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                ok = ds4_gpu_indexer_scores_decode_batch_tensor(g->indexer_scores,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
```<｜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
s,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
                                                                  g->layer_index_comp_cache[il],
                                                                  n_comp,
                                                                  n_tokens,
                                                                  pos0,
                                                                  DS4_N_INDEXER_HEAD,
                                                                  DS4_N_INDEXER_HEAD_DIM,
                                                                  ratio,
                                                                  index_scale) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_tensor("indexer_scores",
                                                  g->indexer_scores,
                                                  (uint64_t)n_comp * n_tokens,
                                                  il,
                                                  pos0);
                }
                if (ok) {
                    ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                       g->indexer_scores,
                                                       n_comp,
                                                       n_tokens,
                                                       DS4_N_INDEXER_TOP_K) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
```

<｜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
s,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
                                                                  g->layer_index_comp_cache[il],
                                                                  n_comp,
                                                                  n_tokens,
                                                                  pos0,
                                                                  DS4_N_INDEXER_HEAD,
                                                                  DS4_N_INDEXER_HEAD_DIM,
                                                                  ratio,
                                                                  index_scale) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_tensor("indexer_scores",
                                                  g->indexer_scores,
                                                  (uint64_t)n_comp * n_tokens,
                                                  il,
                                                  pos0);
                }
                if (ok) {
                    ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                       g->indexer_scores,
                                                       n_comp,
                                                       n_tokens,
                                                       DS4_N_INDEXER_TOP_K) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
```<｜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
s,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
                                                                  g->layer_index_comp_cache[il],
                                                                  n_comp,
                                                                  n_tokens,
                                                                  pos0,
                                                                  DS4_N_INDEXER_HEAD,
                                                                  DS4_N_INDEXER_HEAD_DIM,
                                                                  ratio,
                                                                  index_scale) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_tensor("indexer_scores",
                                                  g->indexer_scores,
                                                  (uint64_t)n_comp * n_tokens,
                                                  il,
                                                  pos0);
                }
                if (ok) {
                    ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                       g->indexer_scores,
                                                       n_comp,
                                                       n_tokens,
                                                       DS4_N_INDEXER_TOP_K) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
```

<｜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
s,
                                                                  g->batch_indexer_q,
                                                                  g->batch_indexer_weights,
                                                                  g->layer_index_comp_cache[il],
                                                                  n_comp,
                                                                  n_tokens,
                                                                  pos0,
                                                                  DS4_N_INDEXER_HEAD,
                                                                  DS4_N_INDEXER_HEAD_DIM,
                                                                  ratio,
                                                                  index_scale) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_tensor("indexer_scores",
                                                  g->indexer_scores,
                                                  (uint64_t)n_comp * n_tokens,
                                                  il,
                                                  pos0);
                }
                if (ok) {
                    ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                       g->indexer_scores,
                                                       n_comp,
                                                       n_tokens,
                                                       DS4_N_INDEXER_TOP_K) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
```<｜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
pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                    if (ok) {
                        metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                          g->comp_selected,
                                                          (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                          il,
                                                          pos0);
                    }
                }
                if (ok) {
                    use_indexed_comp = true;
                }
                use_comp_mask = 1;
            }
            if (ok) {
                if (use_indexed_comp) {
                    ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                              model->map,
                                                                              model->size,
                                                                              layer->attn_sinks->abs_offset,
                                                                              g->batch_q,
                                                                              g->layer_raw_cache[il],
                                                                              g->layer_attn_comp_cache[il],
                                                                              g->comp_selected,
                                                                              n_tokens,
                                                                              pos0,
                                                                              n_raw,
                                                                              g->raw_cap,
                                                                              raw_start,
                                                                              n_comp,
                                                                              DS4_N_INDEXER_TOP_K,
                                                                              g->raw_window,
                                                                              ratio,
```

<｜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
pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                    if (ok) {
                        metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                          g->comp_selected,
                                                          (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                          il,
                                                          pos0);
                    }
                }
                if (ok) {
                    use_indexed_comp = true;
                }
                use_comp_mask = 1;
            }
            if (ok) {
                if (use_indexed_comp) {
                    ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                              model->map,
                                                                              model->size,
                                                                              layer->attn_sinks->abs_offset,
                                                                              g->batch_q,
                                                                              g->layer_raw_cache[il],
                                                                              g->layer_attn_comp_cache[il],
                                                                              g->comp_selected,
                                                                              n_tokens,
                                                                              pos0,
                                                                              n_raw,
                                                                              g->raw_cap,
                                                                              raw_start,
                                                                              n_comp,
                                                                              DS4_N_INDEXER_TOP_K,
                                                                              g->raw_window,
                                                                              ratio,
```<｜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
pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                    if (ok) {
                        metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                          g->comp_selected,
                                                          (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                          il,
                                                          pos0);
                    }
                }
                if (ok) {
                    use_indexed_comp = true;
                }
                use_comp_mask = 1;
            }
            if (ok) {
                if (use_indexed_comp) {
                    ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                              model->map,
                                                                              model->size,
                                                                              layer->attn_sinks->abs_offset,
                                                                              g->batch_q,
                                                                              g->layer_raw_cache[il],
                                                                              g->layer_attn_comp_cache[il],
                                                                              g->comp_selected,
                                                                              n_tokens,
                                                                              pos0,
                                                                              n_raw,
                                                                              g->raw_cap,
                                                                              raw_start,
                                                                              n_comp,
                                                                              DS4_N_INDEXER_TOP_K,
                                                                              g->raw_window,
                                                                              ratio,
```

<｜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
pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                    if (ok) {
                        metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                          g->comp_selected,
                                                          (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                          il,
                                                          pos0);
                    }
                }
                if (ok) {
                    use_indexed_comp = true;
                }
                use_comp_mask = 1;
            }
            if (ok) {
                if (use_indexed_comp) {
                    ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                              model->map,
                                                                              model->size,
                                                                              layer->attn_sinks->abs_offset,
                                                                              g->batch_q,
                                                                              g->layer_raw_cache[il],
                                                                              g->layer_attn_comp_cache[il],
                                                                              g->comp_selected,
                                                                              n_tokens,
                                                                              pos0,
                                                                              n_raw,
                                                                              g->raw_cap,
                                                                              raw_start,
                                                                              n_comp,
                                                                              DS4_N_INDEXER_TOP_K,
                                                                              g->raw_window,
                                                                              ratio,
```<｜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
K,
                                                                              g->raw_window,
                                                                              ratio,
                                                                              DS4_N_HEAD,
                                                                              DS4_N_HEAD_DIM) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                } else {
                    ok = ds4_gpu_attention_decode_mixed_batch_heads_tensor(g->batch_heads,
                                                                             model->map,
                                                                             model->size,
                                                                             layer->attn_sinks->abs_offset,
                                                                             g->batch_q,
                                                                             g->layer_raw_cache[il],
                                                                             g->layer_attn_comp_cache[il],
                                                                             use_comp_mask ? g->comp_mask : NULL,
                                                                             use_comp_mask,
                                                                             n_tokens,
                                                                             pos0,
                                                                             n_raw,
                                                                             g->raw_cap,
                                                                             raw_start,
                                                                             n_comp,
                                                                             g->raw_window,
                                                                             ratio,
```

<｜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
K,
                                                                              g->raw_window,
                                                                              ratio,
                                                                              DS4_N_HEAD,
                                                                              DS4_N_HEAD_DIM) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                } else {
                    ok = ds4_gpu_attention_decode_mixed_batch_heads_tensor(g->batch_heads,
                                                                             model->map,
                                                                             model->size,
                                                                             layer->attn_sinks->abs_offset,
                                                                             g->batch_q,
                                                                             g->layer_raw_cache[il],
                                                                             g->layer_attn_comp_cache[il],
                                                                             use_comp_mask ? g->comp_mask : NULL,
                                                                             use_comp_mask,
                                                                             n_tokens,
                                                                             pos0,
                                                                             n_raw,
                                                                             g->raw_cap,
                                                                             raw_start,
                                                                             n_comp,
                                                                             g->raw_window,
                                                                             ratio,
```<｜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
K,
                                                                              g->raw_window,
                                                                              ratio,
                                                                              DS4_N_HEAD,
                                                                              DS4_N_HEAD_DIM) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                } else {
                    ok = ds4_gpu_attention_decode_mixed_batch_heads_tensor(g->batch_heads,
                                                                             model->map,
                                                                             model->size,
                                                                             layer->attn_sinks->abs_offset,
                                                                             g->batch_q,
                                                                             g->layer_raw_cache[il],
                                                                             g->layer_attn_comp_cache[il],
                                                                             use_comp_mask ? g->comp_mask : NULL,
                                                                             use_comp_mask,
                                                                             n_tokens,
                                                                             pos0,
                                                                             n_raw,
                                                                             g->raw_cap,
                                                                             raw_start,
                                                                             n_comp,
                                                                             g->raw_window,
                                                                             ratio,
```

<｜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
K,
                                                                              g->raw_window,
                                                                              ratio,
                                                                              DS4_N_HEAD,
                                                                              DS4_N_HEAD_DIM) != 0;
                    if (ok && index_stage_profile) {
                        ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                        il,
                                                                        pos0,
                                                                        n_tokens,
                                                                        n_comp,
                                                                        &index_stage_t0);
                    }
                } else {
                    ok = ds4_gpu_attention_decode_mixed_batch_heads_tensor(g->batch_heads,
                                                                             model->map,
                                                                             model->size,
                                                                             layer->attn_sinks->abs_offset,
                                                                             g->batch_q,
                                                                             g->layer_raw_cache[il],
                                                                             g->layer_attn_comp_cache[il],
                                                                             use_comp_mask ? g->comp_mask : NULL,
                                                                             use_comp_mask,
                                                                             n_tokens,
                                                                             pos0,
                                                                             n_raw,
                                                                             g->raw_cap,
                                                                             raw_start,
                                                                             n_comp,
                                                                             g->raw_window,
                                                                             ratio,
```<｜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
omp,
                                                                             g->raw_window,
                                                                             ratio,
                                                                             DS4_N_HEAD,
                                                                             DS4_N_HEAD_DIM) != 0;
                }
            }
            if (ok) batch_attention_done = true;
        }

        const bool topk_prefill_needed = ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K;
        if (ok && zero_prefix && topk_prefill_needed && n_comp != 0) {
            const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
            double index_stage_t0 = 0.0;
            if (index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            ok = ds4_gpu_indexer_scores_prefill_tensor(g->indexer_scores,
                                                         g->batch_indexer_q,
                                                         g->batch_indexer_weights,
                                                         g->layer_index_comp_cache[il],
                                                         n_comp,
                                                         n_tokens,
                                                         DS4_N_INDEXER_HEAD,
                                                         DS4_N_INDEXER_HEAD_DIM,
                                                         ratio,
                                                         index_scale) != 0;
            if (ok && index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
```

<｜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
omp,
                                                                             g->raw_window,
                                                                             ratio,
                                                                             DS4_N_HEAD,
                                                                             DS4_N_HEAD_DIM) != 0;
                }
            }
            if (ok) batch_attention_done = true;
        }

        const bool topk_prefill_needed = ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K;
        if (ok && zero_prefix && topk_prefill_needed && n_comp != 0) {
            const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
            double index_stage_t0 = 0.0;
            if (index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            ok = ds4_gpu_indexer_scores_prefill_tensor(g->indexer_scores,
                                                         g->batch_indexer_q,
                                                         g->batch_indexer_weights,
                                                         g->layer_index_comp_cache[il],
                                                         n_comp,
                                                         n_tokens,
                                                         DS4_N_INDEXER_HEAD,
                                                         DS4_N_INDEXER_HEAD_DIM,
                                                         ratio,
                                                         index_scale) != 0;
            if (ok && index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
```<｜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
omp,
                                                                             g->raw_window,
                                                                             ratio,
                                                                             DS4_N_HEAD,
                                                                             DS4_N_HEAD_DIM) != 0;
                }
            }
            if (ok) batch_attention_done = true;
        }

        const bool topk_prefill_needed = ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K;
        if (ok && zero_prefix && topk_prefill_needed && n_comp != 0) {
            const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
            double index_stage_t0 = 0.0;
            if (index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            ok = ds4_gpu_indexer_scores_prefill_tensor(g->indexer_scores,
                                                         g->batch_indexer_q,
                                                         g->batch_indexer_weights,
                                                         g->layer_index_comp_cache[il],
                                                         n_comp,
                                                         n_tokens,
                                                         DS4_N_INDEXER_HEAD,
                                                         DS4_N_INDEXER_HEAD_DIM,
                                                         ratio,
                                                         index_scale) != 0;
            if (ok && index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
```

<｜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
omp,
                                                                             g->raw_window,
                                                                             ratio,
                                                                             DS4_N_HEAD,
                                                                             DS4_N_HEAD_DIM) != 0;
                }
            }
            if (ok) batch_attention_done = true;
        }

        const bool topk_prefill_needed = ratio == 4 && n_comp > DS4_N_INDEXER_TOP_K;
        if (ok && zero_prefix && topk_prefill_needed && n_comp != 0) {
            const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
            double index_stage_t0 = 0.0;
            if (index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary(NULL,
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            ok = ds4_gpu_indexer_scores_prefill_tensor(g->indexer_scores,
                                                         g->batch_indexer_q,
                                                         g->batch_indexer_weights,
                                                         g->layer_index_comp_cache[il],
                                                         n_comp,
                                                         n_tokens,
                                                         DS4_N_INDEXER_HEAD,
                                                         DS4_N_INDEXER_HEAD_DIM,
                                                         ratio,
                                                         index_scale) != 0;
            if (ok && index_stage_profile) {
                ok = metal_graph_indexer_stage_profile_boundary("score",
                                                                il,
                                                                pos0,
                                                                n_tokens,
                                                                n_comp,
                                                                &index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
```<｜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
&index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
                                              g->indexer_scores,
                                              (uint64_t)n_comp * n_tokens,
                                              il,
                                              pos0);
            }
            if (ok) {
                ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                   g->indexer_scores,
                                                   n_comp,
                                                   n_tokens,
                                                   DS4_N_INDEXER_TOP_K) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                      g->comp_selected,
                                                      (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                      il,
                                                      pos0);
                }
            }
            if (ok) {
                ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                          model->map,
                                                                          model->size,
                                                                          layer->attn_sinks->abs_offset,
                                                                          g->batch_q,
                                                                          g->layer_raw_cache[il],
                                                                          g->layer_attn_comp_cache[il],
                                                                          g->comp_selected,
                                                                          n_tokens,
```

<｜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
&index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
                                              g->indexer_scores,
                                              (uint64_t)n_comp * n_tokens,
                                              il,
                                              pos0);
            }
            if (ok) {
                ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                   g->indexer_scores,
                                                   n_comp,
                                                   n_tokens,
                                                   DS4_N_INDEXER_TOP_K) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                      g->comp_selected,
                                                      (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                      il,
                                                      pos0);
                }
            }
            if (ok) {
                ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                          model->map,
                                                                          model->size,
                                                                          layer->attn_sinks->abs_offset,
                                                                          g->batch_q,
                                                                          g->layer_raw_cache[il],
                                                                          g->layer_attn_comp_cache[il],
                                                                          g->comp_selected,
                                                                          n_tokens,
```<｜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
&index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
                                              g->indexer_scores,
                                              (uint64_t)n_comp * n_tokens,
                                              il,
                                              pos0);
            }
            if (ok) {
                ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                   g->indexer_scores,
                                                   n_comp,
                                                   n_tokens,
                                                   DS4_N_INDEXER_TOP_K) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                      g->comp_selected,
                                                      (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                      il,
                                                      pos0);
                }
            }
            if (ok) {
                ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                          model->map,
                                                                          model->size,
                                                                          layer->attn_sinks->abs_offset,
                                                                          g->batch_q,
                                                                          g->layer_raw_cache[il],
                                                                          g->layer_attn_comp_cache[il],
                                                                          g->comp_selected,
                                                                          n_tokens,
```

<｜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
&index_stage_t0);
            }
            if (ok) {
                metal_graph_debug_dump_tensor("indexer_scores",
                                              g->indexer_scores,
                                              (uint64_t)n_comp * n_tokens,
                                              il,
                                              pos0);
            }
            if (ok) {
                ok = ds4_gpu_indexer_topk_tensor(g->comp_selected,
                                                   g->indexer_scores,
                                                   n_comp,
                                                   n_tokens,
                                                   DS4_N_INDEXER_TOP_K) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("topk",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
                if (ok) {
                    metal_graph_debug_dump_i32_tensor("indexer_topk",
                                                      g->comp_selected,
                                                      (uint64_t)n_tokens * DS4_N_INDEXER_TOP_K,
                                                      il,
                                                      pos0);
                }
            }
            if (ok) {
                ok = ds4_gpu_attention_indexed_mixed_batch_heads_tensor(g->batch_heads,
                                                                          model->map,
                                                                          model->size,
                                                                          layer->attn_sinks->abs_offset,
                                                                          g->batch_q,
                                                                          g->layer_raw_cache[il],
                                                                          g->layer_attn_comp_cache[il],
                                                                          g->comp_selected,
                                                                          n_tokens,
```<｜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
il],
                                                                          g->comp_selected,
                                                                          n_tokens,
                                                                          pos0,
                                                                          n_tokens,
                                                                          g->raw_cap,
                                                                          0,
                                                                          n_comp,
                                                                          DS4_N_INDEXER_TOP_K,
                                                                          g->raw_window,
                                                                          ratio,
                                                                          DS4_N_HEAD,
                                                                          DS4_N_HEAD_DIM) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
            }
            if (ok) batch_attention_done = true;
        }
        if (ok && zero_prefix && !topk_prefill_needed && n_comp != 0) {
            ok = ds4_gpu_attention_prefill_static_mixed_heads_tensor(g->batch_heads,
                                                                       model->map,
                                                                       model->size,
                                                                       layer->attn_sinks->abs_offset,
                                                                       g->batch_q,
                                                                       g->batch_kv,
                                                                       g->layer_attn_comp_cache[il],
                                                                       n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
```

<｜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
il],
                                                                          g->comp_selected,
                                                                          n_tokens,
                                                                          pos0,
                                                                          n_tokens,
                                                                          g->raw_cap,
                                                                          0,
                                                                          n_comp,
                                                                          DS4_N_INDEXER_TOP_K,
                                                                          g->raw_window,
                                                                          ratio,
                                                                          DS4_N_HEAD,
                                                                          DS4_N_HEAD_DIM) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
            }
            if (ok) batch_attention_done = true;
        }
        if (ok && zero_prefix && !topk_prefill_needed && n_comp != 0) {
            ok = ds4_gpu_attention_prefill_static_mixed_heads_tensor(g->batch_heads,
                                                                       model->map,
                                                                       model->size,
                                                                       layer->attn_sinks->abs_offset,
                                                                       g->batch_q,
                                                                       g->batch_kv,
                                                                       g->layer_attn_comp_cache[il],
                                                                       n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
```<｜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
il],
                                                                          g->comp_selected,
                                                                          n_tokens,
                                                                          pos0,
                                                                          n_tokens,
                                                                          g->raw_cap,
                                                                          0,
                                                                          n_comp,
                                                                          DS4_N_INDEXER_TOP_K,
                                                                          g->raw_window,
                                                                          ratio,
                                                                          DS4_N_HEAD,
                                                                          DS4_N_HEAD_DIM) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
            }
            if (ok) batch_attention_done = true;
        }
        if (ok && zero_prefix && !topk_prefill_needed && n_comp != 0) {
            ok = ds4_gpu_attention_prefill_static_mixed_heads_tensor(g->batch_heads,
                                                                       model->map,
                                                                       model->size,
                                                                       layer->attn_sinks->abs_offset,
                                                                       g->batch_q,
                                                                       g->batch_kv,
                                                                       g->layer_attn_comp_cache[il],
                                                                       n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
```

<｜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
il],
                                                                          g->comp_selected,
                                                                          n_tokens,
                                                                          pos0,
                                                                          n_tokens,
                                                                          g->raw_cap,
                                                                          0,
                                                                          n_comp,
                                                                          DS4_N_INDEXER_TOP_K,
                                                                          g->raw_window,
                                                                          ratio,
                                                                          DS4_N_HEAD,
                                                                          DS4_N_HEAD_DIM) != 0;
                if (ok && index_stage_profile) {
                    ok = metal_graph_indexer_stage_profile_boundary("attention",
                                                                    il,
                                                                    pos0,
                                                                    n_tokens,
                                                                    n_comp,
                                                                    &index_stage_t0);
                }
            }
            if (ok) batch_attention_done = true;
        }
        if (ok && zero_prefix && !topk_prefill_needed && n_comp != 0) {
            ok = ds4_gpu_attention_prefill_static_mixed_heads_tensor(g->batch_heads,
                                                                       model->map,
                                                                       model->size,
                                                                       layer->attn_sinks->abs_offset,
                                                                       g->batch_q,
                                                                       g->batch_kv,
                                                                       g->layer_attn_comp_cache[il],
                                                                       n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
```<｜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
n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
                                                                       ratio,
                                                                       DS4_N_HEAD,
                                                                       DS4_N_HEAD_DIM) != 0;
            if (ok) batch_attention_done = true;
        }
    }

    if (ok && !raw_batch_attention && !batch_attention_done) {
        uint32_t raw_prefix_tokens = 0;
        if (zero_prefix && ratio != 0 && n_tokens <= g->raw_cap && comp_counts != NULL) {
            while (raw_prefix_tokens < n_tokens && comp_counts[raw_prefix_tokens] == 0u) {
                raw_prefix_tokens++;
            }
        }

        if (raw_prefix_tokens != 0) {
            ok = ds4_gpu_attention_prefill_raw_heads_tensor(g->batch_heads,
                                                              model->map,
                                                              model->size,
                                                              layer->attn_sinks->abs_offset,
                                                              g->batch_q,
                                                              g->batch_kv,
                                                              raw_prefix_tokens,
                                                              g->raw_window,
                                                              DS4_N_HEAD,
                                                              DS4_N_HEAD_DIM) != 0;
        }
        if (raw_prefix_tokens < n_tokens) {
            for (uint32_t t = raw_prefix_tokens; ok && t < n_tokens; t++) {
                const uint32_t pos = pos0 + t;
                const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos, 1);
                const uint32_t raw_start = metal_graph_raw_start_for_span(g, pos, n_raw);
                const uint32_t cur_comp = comp_counts ? comp_counts[t] : 0u;
                const uint32_t cur_index = index_counts ? index_counts[t] : 0u;
                uint32_t n_selected = 0;
                ds4_gpu_tensor *comp_mask = NULL;

                if (ratio == 4 && cur_comp > DS4_N_INDEXER_TOP_K) {
                    const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                    ds4_gpu_tensor *indexer_q_view = metal_graph_tensor_row_view(
```

<｜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
n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
                                                                       ratio,
                                                                       DS4_N_HEAD,
                                                                       DS4_N_HEAD_DIM) != 0;
            if (ok) batch_attention_done = true;
        }
    }

    if (ok && !raw_batch_attention && !batch_attention_done) {
        uint32_t raw_prefix_tokens = 0;
        if (zero_prefix && ratio != 0 && n_tokens <= g->raw_cap && comp_counts != NULL) {
            while (raw_prefix_tokens < n_tokens && comp_counts[raw_prefix_tokens] == 0u) {
                raw_prefix_tokens++;
            }
        }

        if (raw_prefix_tokens != 0) {
            ok = ds4_gpu_attention_prefill_raw_heads_tensor(g->batch_heads,
                                                              model->map,
                                                              model->size,
                                                              layer->attn_sinks->abs_offset,
                                                              g->batch_q,
                                                              g->batch_kv,
                                                              raw_prefix_tokens,
                                                              g->raw_window,
                                                              DS4_N_HEAD,
                                                              DS4_N_HEAD_DIM) != 0;
        }
        if (raw_prefix_tokens < n_tokens) {
            for (uint32_t t = raw_prefix_tokens; ok && t < n_tokens; t++) {
                const uint32_t pos = pos0 + t;
                const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos, 1);
                const uint32_t raw_start = metal_graph_raw_start_for_span(g, pos, n_raw);
                const uint32_t cur_comp = comp_counts ? comp_counts[t] : 0u;
                const uint32_t cur_index = index_counts ? index_counts[t] : 0u;
                uint32_t n_selected = 0;
                ds4_gpu_tensor *comp_mask = NULL;

                if (ratio == 4 && cur_comp > DS4_N_INDEXER_TOP_K) {
                    const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                    ds4_gpu_tensor *indexer_q_view = metal_graph_tensor_row_view(
```<｜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
n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
                                                                       ratio,
                                                                       DS4_N_HEAD,
                                                                       DS4_N_HEAD_DIM) != 0;
            if (ok) batch_attention_done = true;
        }
    }

    if (ok && !raw_batch_attention && !batch_attention_done) {
        uint32_t raw_prefix_tokens = 0;
        if (zero_prefix && ratio != 0 && n_tokens <= g->raw_cap && comp_counts != NULL) {
            while (raw_prefix_tokens < n_tokens && comp_counts[raw_prefix_tokens] == 0u) {
                raw_prefix_tokens++;
            }
        }

        if (raw_prefix_tokens != 0) {
            ok = ds4_gpu_attention_prefill_raw_heads_tensor(g->batch_heads,
                                                              model->map,
                                                              model->size,
                                                              layer->attn_sinks->abs_offset,
                                                              g->batch_q,
                                                              g->batch_kv,
                                                              raw_prefix_tokens,
                                                              g->raw_window,
                                                              DS4_N_HEAD,
                                                              DS4_N_HEAD_DIM) != 0;
        }
        if (raw_prefix_tokens < n_tokens) {
            for (uint32_t t = raw_prefix_tokens; ok && t < n_tokens; t++) {
                const uint32_t pos = pos0 + t;
                const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos, 1);
                const uint32_t raw_start = metal_graph_raw_start_for_span(g, pos, n_raw);
                const uint32_t cur_comp = comp_counts ? comp_counts[t] : 0u;
                const uint32_t cur_index = index_counts ? index_counts[t] : 0u;
                uint32_t n_selected = 0;
                ds4_gpu_tensor *comp_mask = NULL;

                if (ratio == 4 && cur_comp > DS4_N_INDEXER_TOP_K) {
                    const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                    ds4_gpu_tensor *indexer_q_view = metal_graph_tensor_row_view(
```

<｜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
n_tokens,
                                                                       n_comp,
                                                                       g->raw_window,
                                                                       ratio,
                                                                       DS4_N_HEAD,
                                                                       DS4_N_HEAD_DIM) != 0;
            if (ok) batch_attention_done = true;
        }
    }

    if (ok && !raw_batch_attention && !batch_attention_done) {
        uint32_t raw_prefix_tokens = 0;
        if (zero_prefix && ratio != 0 && n_tokens <= g->raw_cap && comp_counts != NULL) {
            while (raw_prefix_tokens < n_tokens && comp_counts[raw_prefix_tokens] == 0u) {
                raw_prefix_tokens++;
            }
        }

        if (raw_prefix_tokens != 0) {
            ok = ds4_gpu_attention_prefill_raw_heads_tensor(g->batch_heads,
                                                              model->map,
                                                              model->size,
                                                              layer->attn_sinks->abs_offset,
                                                              g->batch_q,
                                                              g->batch_kv,
                                                              raw_prefix_tokens,
                                                              g->raw_window,
                                                              DS4_N_HEAD,
                                                              DS4_N_HEAD_DIM) != 0;
        }
        if (raw_prefix_tokens < n_tokens) {
            for (uint32_t t = raw_prefix_tokens; ok && t < n_tokens; t++) {
                const uint32_t pos = pos0 + t;
                const uint32_t n_raw = metal_graph_raw_span_for_batch(g, pos, 1);
                const uint32_t raw_start = metal_graph_raw_start_for_span(g, pos, n_raw);
                const uint32_t cur_comp = comp_counts ? comp_counts[t] : 0u;
                const uint32_t cur_index = index_counts ? index_counts[t] : 0u;
                uint32_t n_selected = 0;
                ds4_gpu_tensor *comp_mask = NULL;

                if (ratio == 4 && cur_comp > DS4_N_INDEXER_TOP_K) {
                    const float index_scale = 1.0f / sqrtf((float)(DS4_N_INDEXER_HEAD_DIM * DS4_N_INDEXER_HEAD));
                    ds4_gpu_tensor *indexer_q_view = metal_graph_tensor_row_view(
```<｜Assistant｜><think>