[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_metal.m

```c
0,
                                          head_dim,
                                          pool_row_stride) ||
        !ds4_gpu_encode_concat_f32_dim1(cb,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score),
                                          4,
                                          state_row_stride,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score) + curr_offset,
                                          4,
                                          state_row_stride,
                                          g_compressor_pool_score_buffer,
                                          0,
                                          head_dim,
                                          pool_row_stride)) {
        return 0;
    }

    return ds4_gpu_encode_dsv4_softmax_pool(cb,
                                              out,
                                              g_compressor_pool_kv_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              g_compressor_pool_score_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              8,
                                              head_dim,
                                              1);
}

static int ds4_gpu_encode_compressor_shift_ratio4(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *state_kv,
        ds4_gpu_tensor    *state_score,
        uint32_t             width) {
    id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
    id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
    if (!cb || !statekvbuf || !statescbuf || !g_dsv4_ratio4_shift_pipeline || width == 0) return 0;

    ds4_gpu_dsv4_ratio4_shift_args args = { .width = width };
    const uint32_t n = 4u * width;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
```

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

File: ds4_metal.m

```c
0,
                                          head_dim,
                                          pool_row_stride) ||
        !ds4_gpu_encode_concat_f32_dim1(cb,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score),
                                          4,
                                          state_row_stride,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score) + curr_offset,
                                          4,
                                          state_row_stride,
                                          g_compressor_pool_score_buffer,
                                          0,
                                          head_dim,
                                          pool_row_stride)) {
        return 0;
    }

    return ds4_gpu_encode_dsv4_softmax_pool(cb,
                                              out,
                                              g_compressor_pool_kv_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              g_compressor_pool_score_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              8,
                                              head_dim,
                                              1);
}

static int ds4_gpu_encode_compressor_shift_ratio4(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *state_kv,
        ds4_gpu_tensor    *state_score,
        uint32_t             width) {
    id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
    id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
    if (!cb || !statekvbuf || !statescbuf || !g_dsv4_ratio4_shift_pipeline || width == 0) return 0;

    ds4_gpu_dsv4_ratio4_shift_args args = { .width = width };
    const uint32_t n = 4u * width;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
0,
                                          head_dim,
                                          pool_row_stride) ||
        !ds4_gpu_encode_concat_f32_dim1(cb,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score),
                                          4,
                                          state_row_stride,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score) + curr_offset,
                                          4,
                                          state_row_stride,
                                          g_compressor_pool_score_buffer,
                                          0,
                                          head_dim,
                                          pool_row_stride)) {
        return 0;
    }

    return ds4_gpu_encode_dsv4_softmax_pool(cb,
                                              out,
                                              g_compressor_pool_kv_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              g_compressor_pool_score_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              8,
                                              head_dim,
                                              1);
}

static int ds4_gpu_encode_compressor_shift_ratio4(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *state_kv,
        ds4_gpu_tensor    *state_score,
        uint32_t             width) {
    id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
    id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
    if (!cb || !statekvbuf || !statescbuf || !g_dsv4_ratio4_shift_pipeline || width == 0) return 0;

    ds4_gpu_dsv4_ratio4_shift_args args = { .width = width };
    const uint32_t n = 4u * width;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
```

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

File: ds4_metal.m

```c
0,
                                          head_dim,
                                          pool_row_stride) ||
        !ds4_gpu_encode_concat_f32_dim1(cb,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score),
                                          4,
                                          state_row_stride,
                                          statescbuf,
                                          ds4_gpu_tensor_offset(state_score) + curr_offset,
                                          4,
                                          state_row_stride,
                                          g_compressor_pool_score_buffer,
                                          0,
                                          head_dim,
                                          pool_row_stride)) {
        return 0;
    }

    return ds4_gpu_encode_dsv4_softmax_pool(cb,
                                              out,
                                              g_compressor_pool_kv_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              g_compressor_pool_score_buffer,
                                              0,
                                              pool_row_stride,
                                              sizeof(float),
                                              packed_bytes,
                                              8,
                                              head_dim,
                                              1);
}

static int ds4_gpu_encode_compressor_shift_ratio4(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *state_kv,
        ds4_gpu_tensor    *state_score,
        uint32_t             width) {
    id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
    id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
    if (!cb || !statekvbuf || !statescbuf || !g_dsv4_ratio4_shift_pipeline || width == 0) return 0;

    ds4_gpu_dsv4_ratio4_shift_args args = { .width = width };
    const uint32_t n = 4u * width;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:statekvbuf offset:ds4_gpu_tensor_offset(state_kv) atIndex:1];
    [enc setBuffer:statescbuf offset:ds4_gpu_tensor_offset(state_score) atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n + 255u) / 256u, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);
    return 1;
}

int ds4_gpu_compressor_prefill_tensor(
        ds4_gpu_tensor       *comp_cache,
        ds4_gpu_tensor       *state_kv,
        ds4_gpu_tensor       *state_score,
        const ds4_gpu_tensor *kv,
        const ds4_gpu_tensor *sc,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                ape_offset,
        uint32_t                ape_type,
        uint64_t                norm_offset,
        uint32_t                norm_type,
        uint32_t                head_dim,
        uint32_t                ratio,
        uint32_t                pos0,
        uint32_t                n_tokens,
        uint32_t                n_rot,
        uint32_t                n_ctx_orig,
        bool                    quantize_fp8,
        float                   freq_base,
        float                   freq_scale,
        float                   ext_factor,
        float                   attn_factor,
        float                   beta_fast,
        float                   beta_slow,
        float                   rms_eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!comp_cache || !state_kv || !state_score || !kv || !sc || !model_map ||
        head_dim == 0 || ratio == 0 || n_tokens == 0 ||
        n_rot > head_dim || (n_rot & 1u) != 0 ||
        (ape_type != 0u && ape_type != 1u) ||
        norm_type != 0u) {
        return 0;
    }

    @autoreleasepool {
        const uint32_t coff = ratio == 4u ? 2u : 1u;
        const uint32_t width = coff * head_dim;
        const uint32_t state_rows = coff * ratio;
        const uint32_t n_comp = n_tokens / ratio;
        const uint32_t cutoff = n_comp * ratio;
        const uint32_t rem = n_tokens - cutoff;
        const uint64_t elem_ape = ape_type == 1u ? 2u : 4u;
        const uint64_t kv_bytes = (uint64_t)n_tokens * width * sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
```

<｜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_metal.m

```c
MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:statekvbuf offset:ds4_gpu_tensor_offset(state_kv) atIndex:1];
    [enc setBuffer:statescbuf offset:ds4_gpu_tensor_offset(state_score) atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n + 255u) / 256u, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);
    return 1;
}

int ds4_gpu_compressor_prefill_tensor(
        ds4_gpu_tensor       *comp_cache,
        ds4_gpu_tensor       *state_kv,
        ds4_gpu_tensor       *state_score,
        const ds4_gpu_tensor *kv,
        const ds4_gpu_tensor *sc,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                ape_offset,
        uint32_t                ape_type,
        uint64_t                norm_offset,
        uint32_t                norm_type,
        uint32_t                head_dim,
        uint32_t                ratio,
        uint32_t                pos0,
        uint32_t                n_tokens,
        uint32_t                n_rot,
        uint32_t                n_ctx_orig,
        bool                    quantize_fp8,
        float                   freq_base,
        float                   freq_scale,
        float                   ext_factor,
        float                   attn_factor,
        float                   beta_fast,
        float                   beta_slow,
        float                   rms_eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!comp_cache || !state_kv || !state_score || !kv || !sc || !model_map ||
        head_dim == 0 || ratio == 0 || n_tokens == 0 ||
        n_rot > head_dim || (n_rot & 1u) != 0 ||
        (ape_type != 0u && ape_type != 1u) ||
        norm_type != 0u) {
        return 0;
    }

    @autoreleasepool {
        const uint32_t coff = ratio == 4u ? 2u : 1u;
        const uint32_t width = coff * head_dim;
        const uint32_t state_rows = coff * ratio;
        const uint32_t n_comp = n_tokens / ratio;
        const uint32_t cutoff = n_comp * ratio;
        const uint32_t rem = n_tokens - cutoff;
        const uint64_t elem_ape = ape_type == 1u ? 2u : 4u;
        const uint64_t kv_bytes = (uint64_t)n_tokens * width * sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
```<｜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_metal.m

```c
MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:statekvbuf offset:ds4_gpu_tensor_offset(state_kv) atIndex:1];
    [enc setBuffer:statescbuf offset:ds4_gpu_tensor_offset(state_score) atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n + 255u) / 256u, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);
    return 1;
}

int ds4_gpu_compressor_prefill_tensor(
        ds4_gpu_tensor       *comp_cache,
        ds4_gpu_tensor       *state_kv,
        ds4_gpu_tensor       *state_score,
        const ds4_gpu_tensor *kv,
        const ds4_gpu_tensor *sc,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                ape_offset,
        uint32_t                ape_type,
        uint64_t                norm_offset,
        uint32_t                norm_type,
        uint32_t                head_dim,
        uint32_t                ratio,
        uint32_t                pos0,
        uint32_t                n_tokens,
        uint32_t                n_rot,
        uint32_t                n_ctx_orig,
        bool                    quantize_fp8,
        float                   freq_base,
        float                   freq_scale,
        float                   ext_factor,
        float                   attn_factor,
        float                   beta_fast,
        float                   beta_slow,
        float                   rms_eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!comp_cache || !state_kv || !state_score || !kv || !sc || !model_map ||
        head_dim == 0 || ratio == 0 || n_tokens == 0 ||
        n_rot > head_dim || (n_rot & 1u) != 0 ||
        (ape_type != 0u && ape_type != 1u) ||
        norm_type != 0u) {
        return 0;
    }

    @autoreleasepool {
        const uint32_t coff = ratio == 4u ? 2u : 1u;
        const uint32_t width = coff * head_dim;
        const uint32_t state_rows = coff * ratio;
        const uint32_t n_comp = n_tokens / ratio;
        const uint32_t cutoff = n_comp * ratio;
        const uint32_t rem = n_tokens - cutoff;
        const uint64_t elem_ape = ape_type == 1u ? 2u : 4u;
        const uint64_t kv_bytes = (uint64_t)n_tokens * width * sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
```

<｜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_metal.m

```c
MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_dsv4_ratio4_shift_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:statekvbuf offset:ds4_gpu_tensor_offset(state_kv) atIndex:1];
    [enc setBuffer:statescbuf offset:ds4_gpu_tensor_offset(state_score) atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n + 255u) / 256u, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);
    return 1;
}

int ds4_gpu_compressor_prefill_tensor(
        ds4_gpu_tensor       *comp_cache,
        ds4_gpu_tensor       *state_kv,
        ds4_gpu_tensor       *state_score,
        const ds4_gpu_tensor *kv,
        const ds4_gpu_tensor *sc,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                ape_offset,
        uint32_t                ape_type,
        uint64_t                norm_offset,
        uint32_t                norm_type,
        uint32_t                head_dim,
        uint32_t                ratio,
        uint32_t                pos0,
        uint32_t                n_tokens,
        uint32_t                n_rot,
        uint32_t                n_ctx_orig,
        bool                    quantize_fp8,
        float                   freq_base,
        float                   freq_scale,
        float                   ext_factor,
        float                   attn_factor,
        float                   beta_fast,
        float                   beta_slow,
        float                   rms_eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!comp_cache || !state_kv || !state_score || !kv || !sc || !model_map ||
        head_dim == 0 || ratio == 0 || n_tokens == 0 ||
        n_rot > head_dim || (n_rot & 1u) != 0 ||
        (ape_type != 0u && ape_type != 1u) ||
        norm_type != 0u) {
        return 0;
    }

    @autoreleasepool {
        const uint32_t coff = ratio == 4u ? 2u : 1u;
        const uint32_t width = coff * head_dim;
        const uint32_t state_rows = coff * ratio;
        const uint32_t n_comp = n_tokens / ratio;
        const uint32_t cutoff = n_comp * ratio;
        const uint32_t rem = n_tokens - cutoff;
        const uint64_t elem_ape = ape_type == 1u ? 2u : 4u;
        const uint64_t kv_bytes = (uint64_t)n_tokens * width * sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
```<｜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_metal.m

```c
* sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
        const uint64_t ape_bytes = (uint64_t)width * ratio * elem_ape;
        const uint64_t norm_bytes = (uint64_t)head_dim * sizeof(float);

        if (ape_offset > model_size || ape_bytes > model_size - ape_offset ||
            norm_offset > model_size || norm_bytes > model_size - norm_offset) {
            fprintf(stderr, "ds4: Metal compressor prefill tensor range is outside the mapped model\n");
            return 0;
        }

        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> scbuf = ds4_gpu_tensor_buffer(sc);
        id<MTLBuffer> compbuf = ds4_gpu_tensor_buffer(comp_cache);
        id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
        id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
        if (!kvbuf || !scbuf || !compbuf || !statekvbuf || !statescbuf ||
            ds4_gpu_tensor_bytes(kv) < kv_bytes ||
            ds4_gpu_tensor_bytes(sc) < kv_bytes ||
            ds4_gpu_tensor_bytes(state_kv) < state_bytes ||
            ds4_gpu_tensor_bytes(state_score) < state_bytes ||
            (n_comp && ds4_gpu_tensor_bytes(comp_cache) < comp_bytes)) {
            fprintf(stderr, "ds4: Metal compressor prefill received undersized buffers\n");
            return 0;
        }

        uint64_t ape_inner = 0;
        id<MTLBuffer> apebuf = ds4_gpu_wrap_model_range(model_map, model_size, ape_offset, ape_bytes, &ape_inner);
        if (!apebuf) return 0;

        const bool had_batch = g_batch_cb != nil;
        if (!had_batch && ds4_gpu_begin_commands() == 0) return 0;

        int ok = 1;
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb || owned) ok = 0;

        if (ok) {
            ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                statekvbuf,
                                                ds4_gpu_tensor_offset(state_kv),
                                                width,
                                                state_rows,
                                                0.0f) &&
                 ds4_gpu_encode_fill_f32_rows(cb,
                                                statescbuf,
                                                ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
```

<｜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_metal.m

```c
* sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
        const uint64_t ape_bytes = (uint64_t)width * ratio * elem_ape;
        const uint64_t norm_bytes = (uint64_t)head_dim * sizeof(float);

        if (ape_offset > model_size || ape_bytes > model_size - ape_offset ||
            norm_offset > model_size || norm_bytes > model_size - norm_offset) {
            fprintf(stderr, "ds4: Metal compressor prefill tensor range is outside the mapped model\n");
            return 0;
        }

        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> scbuf = ds4_gpu_tensor_buffer(sc);
        id<MTLBuffer> compbuf = ds4_gpu_tensor_buffer(comp_cache);
        id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
        id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
        if (!kvbuf || !scbuf || !compbuf || !statekvbuf || !statescbuf ||
            ds4_gpu_tensor_bytes(kv) < kv_bytes ||
            ds4_gpu_tensor_bytes(sc) < kv_bytes ||
            ds4_gpu_tensor_bytes(state_kv) < state_bytes ||
            ds4_gpu_tensor_bytes(state_score) < state_bytes ||
            (n_comp && ds4_gpu_tensor_bytes(comp_cache) < comp_bytes)) {
            fprintf(stderr, "ds4: Metal compressor prefill received undersized buffers\n");
            return 0;
        }

        uint64_t ape_inner = 0;
        id<MTLBuffer> apebuf = ds4_gpu_wrap_model_range(model_map, model_size, ape_offset, ape_bytes, &ape_inner);
        if (!apebuf) return 0;

        const bool had_batch = g_batch_cb != nil;
        if (!had_batch && ds4_gpu_begin_commands() == 0) return 0;

        int ok = 1;
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb || owned) ok = 0;

        if (ok) {
            ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                statekvbuf,
                                                ds4_gpu_tensor_offset(state_kv),
                                                width,
                                                state_rows,
                                                0.0f) &&
                 ds4_gpu_encode_fill_f32_rows(cb,
                                                statescbuf,
                                                ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
```<｜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_metal.m

```c
* sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
        const uint64_t ape_bytes = (uint64_t)width * ratio * elem_ape;
        const uint64_t norm_bytes = (uint64_t)head_dim * sizeof(float);

        if (ape_offset > model_size || ape_bytes > model_size - ape_offset ||
            norm_offset > model_size || norm_bytes > model_size - norm_offset) {
            fprintf(stderr, "ds4: Metal compressor prefill tensor range is outside the mapped model\n");
            return 0;
        }

        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> scbuf = ds4_gpu_tensor_buffer(sc);
        id<MTLBuffer> compbuf = ds4_gpu_tensor_buffer(comp_cache);
        id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
        id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
        if (!kvbuf || !scbuf || !compbuf || !statekvbuf || !statescbuf ||
            ds4_gpu_tensor_bytes(kv) < kv_bytes ||
            ds4_gpu_tensor_bytes(sc) < kv_bytes ||
            ds4_gpu_tensor_bytes(state_kv) < state_bytes ||
            ds4_gpu_tensor_bytes(state_score) < state_bytes ||
            (n_comp && ds4_gpu_tensor_bytes(comp_cache) < comp_bytes)) {
            fprintf(stderr, "ds4: Metal compressor prefill received undersized buffers\n");
            return 0;
        }

        uint64_t ape_inner = 0;
        id<MTLBuffer> apebuf = ds4_gpu_wrap_model_range(model_map, model_size, ape_offset, ape_bytes, &ape_inner);
        if (!apebuf) return 0;

        const bool had_batch = g_batch_cb != nil;
        if (!had_batch && ds4_gpu_begin_commands() == 0) return 0;

        int ok = 1;
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb || owned) ok = 0;

        if (ok) {
            ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                statekvbuf,
                                                ds4_gpu_tensor_offset(state_kv),
                                                width,
                                                state_rows,
                                                0.0f) &&
                 ds4_gpu_encode_fill_f32_rows(cb,
                                                statescbuf,
                                                ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
```

<｜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_metal.m

```c
* sizeof(float);
        const uint64_t state_bytes = (uint64_t)state_rows * width * sizeof(float);
        const uint64_t comp_bytes = (uint64_t)n_comp * head_dim * sizeof(float);
        const uint64_t ape_bytes = (uint64_t)width * ratio * elem_ape;
        const uint64_t norm_bytes = (uint64_t)head_dim * sizeof(float);

        if (ape_offset > model_size || ape_bytes > model_size - ape_offset ||
            norm_offset > model_size || norm_bytes > model_size - norm_offset) {
            fprintf(stderr, "ds4: Metal compressor prefill tensor range is outside the mapped model\n");
            return 0;
        }

        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> scbuf = ds4_gpu_tensor_buffer(sc);
        id<MTLBuffer> compbuf = ds4_gpu_tensor_buffer(comp_cache);
        id<MTLBuffer> statekvbuf = ds4_gpu_tensor_buffer(state_kv);
        id<MTLBuffer> statescbuf = ds4_gpu_tensor_buffer(state_score);
        if (!kvbuf || !scbuf || !compbuf || !statekvbuf || !statescbuf ||
            ds4_gpu_tensor_bytes(kv) < kv_bytes ||
            ds4_gpu_tensor_bytes(sc) < kv_bytes ||
            ds4_gpu_tensor_bytes(state_kv) < state_bytes ||
            ds4_gpu_tensor_bytes(state_score) < state_bytes ||
            (n_comp && ds4_gpu_tensor_bytes(comp_cache) < comp_bytes)) {
            fprintf(stderr, "ds4: Metal compressor prefill received undersized buffers\n");
            return 0;
        }

        uint64_t ape_inner = 0;
        id<MTLBuffer> apebuf = ds4_gpu_wrap_model_range(model_map, model_size, ape_offset, ape_bytes, &ape_inner);
        if (!apebuf) return 0;

        const bool had_batch = g_batch_cb != nil;
        if (!had_batch && ds4_gpu_begin_commands() == 0) return 0;

        int ok = 1;
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb || owned) ok = 0;

        if (ok) {
            ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                statekvbuf,
                                                ds4_gpu_tensor_offset(state_kv),
                                                width,
                                                state_rows,
                                                0.0f) &&
                 ds4_gpu_encode_fill_f32_rows(cb,
                                                statescbuf,
                                                ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
```<｜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_metal.m

```c
ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
                                                ds4_gpu_negative_infinity());
        }

        if (ok && ratio == 4u) {
            int32_t rows_prev[4] = { 0, 1, 2, 3 };
            const int have_prev = cutoff >= ratio ? 1 : 0;
            const uint32_t prev_start = rem == 0 ? cutoff - ratio : cutoff - ratio;
            if (have_prev) {
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + prev_start,
                                                                     rows_prev,
                                                                     4,
                                                                     state_rows);
            }
            if (ok && rem != 0) {
                int32_t rows_cur[4];
                for (uint32_t i = 0; i < rem; i++) rows_cur[i] = (int32_t)(ratio + i);
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
```

<｜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_metal.m

```c
ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
                                                ds4_gpu_negative_infinity());
        }

        if (ok && ratio == 4u) {
            int32_t rows_prev[4] = { 0, 1, 2, 3 };
            const int have_prev = cutoff >= ratio ? 1 : 0;
            const uint32_t prev_start = rem == 0 ? cutoff - ratio : cutoff - ratio;
            if (have_prev) {
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + prev_start,
                                                                     rows_prev,
                                                                     4,
                                                                     state_rows);
            }
            if (ok && rem != 0) {
                int32_t rows_cur[4];
                for (uint32_t i = 0; i < rem; i++) rows_cur[i] = (int32_t)(ratio + i);
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
```<｜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_metal.m

```c
ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
                                                ds4_gpu_negative_infinity());
        }

        if (ok && ratio == 4u) {
            int32_t rows_prev[4] = { 0, 1, 2, 3 };
            const int have_prev = cutoff >= ratio ? 1 : 0;
            const uint32_t prev_start = rem == 0 ? cutoff - ratio : cutoff - ratio;
            if (have_prev) {
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + prev_start,
                                                                     rows_prev,
                                                                     4,
                                                                     state_rows);
            }
            if (ok && rem != 0) {
                int32_t rows_cur[4];
                for (uint32_t i = 0; i < rem; i++) rows_cur[i] = (int32_t)(ratio + i);
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
```

<｜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_metal.m

```c
ds4_gpu_tensor_offset(state_score),
                                                width,
                                                state_rows,
                                                ds4_gpu_negative_infinity());
        }

        if (ok && ratio == 4u) {
            int32_t rows_prev[4] = { 0, 1, 2, 3 };
            const int have_prev = cutoff >= ratio ? 1 : 0;
            const uint32_t prev_start = rem == 0 ? cutoff - ratio : cutoff - ratio;
            if (have_prev) {
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)prev_start * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + prev_start,
                                                                     rows_prev,
                                                                     4,
                                                                     state_rows);
            }
            if (ok && rem != 0) {
                int32_t rows_cur[4];
                for (uint32_t i = 0; i < rem; i++) rows_cur[i] = (int32_t)(ratio + i);
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
```<｜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_metal.m

```c
state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows_cur,
                                                                     rem,
                                                                     state_rows);
            }
        } else if (ok && rem != 0) {
            int32_t rows[128];
            if (rem > (uint32_t)(sizeof(rows) / sizeof(rows[0]))) {
                fprintf(stderr, "ds4: Metal compressor prefill remainder exceeds local row list\n");
                ok = 0;
            } else {
                for (uint32_t i = 0; i < rem; i++) rows[i] = (int32_t)i;
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
```

<｜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_metal.m

```c
state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows_cur,
                                                                     rem,
                                                                     state_rows);
            }
        } else if (ok && rem != 0) {
            int32_t rows[128];
            if (rem > (uint32_t)(sizeof(rows) / sizeof(rows[0]))) {
                fprintf(stderr, "ds4: Metal compressor prefill remainder exceeds local row list\n");
                ok = 0;
            } else {
                for (uint32_t i = 0; i < rem; i++) rows[i] = (int32_t)i;
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
```<｜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_metal.m

```c
state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows_cur,
                                                                     rem,
                                                                     state_rows);
            }
        } else if (ok && rem != 0) {
            int32_t rows[128];
            if (rem > (uint32_t)(sizeof(rows) / sizeof(rows[0]))) {
                fprintf(stderr, "ds4: Metal compressor prefill remainder exceeds local row list\n");
                ok = 0;
            } else {
                for (uint32_t i = 0; i < rem; i++) rows[i] = (int32_t)i;
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
```

<｜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_metal.m

```c
state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows_cur,
                                                                     rem,
                                                                     state_rows);
            }
        } else if (ok && rem != 0) {
            int32_t rows[128];
            if (rem > (uint32_t)(sizeof(rows) / sizeof(rows[0]))) {
                fprintf(stderr, "ds4: Metal compressor prefill remainder exceeds local row list\n");
                ok = 0;
            } else {
                for (uint32_t i = 0; i < rem; i++) rows[i] = (int32_t)i;
                ok = ds4_gpu_encode_compressor_set_rows_projected(cb,
                                                                     state_kv,
                                                                     state_score,
                                                                     kvbuf,
                                                                     ds4_gpu_tensor_offset(kv) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     scbuf,
                                                                     ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
```<｜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_metal.m

```c
ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows,
                                                                     rem,
                                                                     state_rows);
            }
        }

        if (ok && n_comp != 0) {
            const NSUInteger score_bytes = (NSUInteger)cutoff * width * sizeof(float);
            if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_store_score_buffer,
                                                 &g_compressor_store_score_bytes,
                                                 score_bytes,
                                                 "ds4_compressor_store_score")) {
                ok = 0;
            }
            if (ok) {
                ok = ds4_gpu_encode_compressor_score_with_ape(cb,
                                                                 scbuf,
                                                                 ds4_gpu_tensor_offset(sc),
                                                                 g_compressor_store_score_buffer,
                                                                 0,
                                                                 apebuf,
                                                                 (NSUInteger)ape_inner,
                                                                 ape_type,
                                                                 width,
                                                                 ratio,
                                                                 pos0,
                                                                 cutoff);
            }

            if (ok && ratio == 4u) {
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
```

<｜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_metal.m

```c
ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows,
                                                                     rem,
                                                                     state_rows);
            }
        }

        if (ok && n_comp != 0) {
            const NSUInteger score_bytes = (NSUInteger)cutoff * width * sizeof(float);
            if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_store_score_buffer,
                                                 &g_compressor_store_score_bytes,
                                                 score_bytes,
                                                 "ds4_compressor_store_score")) {
                ok = 0;
            }
            if (ok) {
                ok = ds4_gpu_encode_compressor_score_with_ape(cb,
                                                                 scbuf,
                                                                 ds4_gpu_tensor_offset(sc),
                                                                 g_compressor_store_score_buffer,
                                                                 0,
                                                                 apebuf,
                                                                 (NSUInteger)ape_inner,
                                                                 ape_type,
                                                                 width,
                                                                 ratio,
                                                                 pos0,
                                                                 cutoff);
            }

            if (ok && ratio == 4u) {
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
```<｜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_metal.m

```c
ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows,
                                                                     rem,
                                                                     state_rows);
            }
        }

        if (ok && n_comp != 0) {
            const NSUInteger score_bytes = (NSUInteger)cutoff * width * sizeof(float);
            if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_store_score_buffer,
                                                 &g_compressor_store_score_bytes,
                                                 score_bytes,
                                                 "ds4_compressor_store_score")) {
                ok = 0;
            }
            if (ok) {
                ok = ds4_gpu_encode_compressor_score_with_ape(cb,
                                                                 scbuf,
                                                                 ds4_gpu_tensor_offset(sc),
                                                                 g_compressor_store_score_buffer,
                                                                 0,
                                                                 apebuf,
                                                                 (NSUInteger)ape_inner,
                                                                 ape_type,
                                                                 width,
                                                                 ratio,
                                                                 pos0,
                                                                 cutoff);
            }

            if (ok && ratio == 4u) {
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
```

<｜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_metal.m

```c
ds4_gpu_tensor_offset(sc) +
                                                                             (NSUInteger)cutoff * width * sizeof(float),
                                                                     apebuf,
                                                                     (NSUInteger)ape_inner,
                                                                     ape_type,
                                                                     width,
                                                                     ratio,
                                                                     pos0 + cutoff,
                                                                     rows,
                                                                     rem,
                                                                     state_rows);
            }
        }

        if (ok && n_comp != 0) {
            const NSUInteger score_bytes = (NSUInteger)cutoff * width * sizeof(float);
            if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_store_score_buffer,
                                                 &g_compressor_store_score_bytes,
                                                 score_bytes,
                                                 "ds4_compressor_store_score")) {
                ok = 0;
            }
            if (ok) {
                ok = ds4_gpu_encode_compressor_score_with_ape(cb,
                                                                 scbuf,
                                                                 ds4_gpu_tensor_offset(sc),
                                                                 g_compressor_store_score_buffer,
                                                                 0,
                                                                 apebuf,
                                                                 (NSUInteger)ape_inner,
                                                                 ape_type,
                                                                 width,
                                                                 ratio,
                                                                 pos0,
                                                                 cutoff);
            }

            if (ok && ratio == 4u) {
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
```<｜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_metal.m

```c
const uint64_t bytes = g_model_views[i].bytes;
        const uint64_t n = (bytes + stride - 1) / stride;
        [enc setBuffer:g_model_views[i].buffer offset:0 atIndex:0];
        [enc setBuffer:out offset:0 atIndex:1];
        [enc setBytes:&stride length:sizeof(stride) atIndex:2];
        [enc setBytes:&bytes length:sizeof(bytes) atIndex:3];
        [enc setBytes:&dst_offset length:sizeof(dst_offset) atIndex:4];
        [enc dispatchThreadgroups:MTLSizeMake((NSUInteger)((n + 255) / 256), 1, 1)
             threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
        dst_offset += n;
    }
    ds4_gpu_end_compute_encoder(cb, enc);

    [cb commit];
    [cb waitUntilCompleted];

    if (cb.status == MTLCommandBufferStatusError) {
        fprintf(stderr, "ds4: Metal model warmup failed: %s\n",
                [[cb.error localizedDescription] UTF8String]);
        return 0;
    }

    return 1;
}

static const char *ds4_gpu_mul_mm_id_map0_name(uint32_t ne20) {
    switch (ne20) {
        case 1:  return "kernel_mul_mm_id_map0_ne20_1";
        case 2:  return "kernel_mul_mm_id_map0_ne20_2";
        case 4:  return "kernel_mul_mm_id_map0_ne20_4";
        case 5:  return "kernel_mul_mm_id_map0_ne20_5";
        case 6:  return "kernel_mul_mm_id_map0_ne20_6";
        case 8:  return "kernel_mul_mm_id_map0_ne20_8";
        case 10: return "kernel_mul_mm_id_map0_ne20_10";
        case 16: return "kernel_mul_mm_id_map0_ne20_16";
        case 22: return "kernel_mul_mm_id_map0_ne20_22";
        default: return NULL;
    }
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mv_pipeline(
        const char *function_name,
        int16_t     nsg) {
    NSString *key = [NSString stringWithFormat:@"%s_nsg=%d", function_name, (int)nsg];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&nsg type:MTLDataTypeShort atIndex:600];

    NSError *error = nil;
    NSString *name = [NSString stringWithUTF8String:function_name];
    id<MTLFunction> fn = [g_library newFunctionWithName:name
                                         constantValues:constants
                                                  error:&error];
    if (!fn) {
        fprintf(stderr, "ds4: Metal %s function not found: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    error = nil;
```

<｜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_metal.m

```c
const uint64_t bytes = g_model_views[i].bytes;
        const uint64_t n = (bytes + stride - 1) / stride;
        [enc setBuffer:g_model_views[i].buffer offset:0 atIndex:0];
        [enc setBuffer:out offset:0 atIndex:1];
        [enc setBytes:&stride length:sizeof(stride) atIndex:2];
        [enc setBytes:&bytes length:sizeof(bytes) atIndex:3];
        [enc setBytes:&dst_offset length:sizeof(dst_offset) atIndex:4];
        [enc dispatchThreadgroups:MTLSizeMake((NSUInteger)((n + 255) / 256), 1, 1)
             threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
        dst_offset += n;
    }
    ds4_gpu_end_compute_encoder(cb, enc);

    [cb commit];
    [cb waitUntilCompleted];

    if (cb.status == MTLCommandBufferStatusError) {
        fprintf(stderr, "ds4: Metal model warmup failed: %s\n",
                [[cb.error localizedDescription] UTF8String]);
        return 0;
    }

    return 1;
}

static const char *ds4_gpu_mul_mm_id_map0_name(uint32_t ne20) {
    switch (ne20) {
        case 1:  return "kernel_mul_mm_id_map0_ne20_1";
        case 2:  return "kernel_mul_mm_id_map0_ne20_2";
        case 4:  return "kernel_mul_mm_id_map0_ne20_4";
        case 5:  return "kernel_mul_mm_id_map0_ne20_5";
        case 6:  return "kernel_mul_mm_id_map0_ne20_6";
        case 8:  return "kernel_mul_mm_id_map0_ne20_8";
        case 10: return "kernel_mul_mm_id_map0_ne20_10";
        case 16: return "kernel_mul_mm_id_map0_ne20_16";
        case 22: return "kernel_mul_mm_id_map0_ne20_22";
        default: return NULL;
    }
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mv_pipeline(
        const char *function_name,
        int16_t     nsg) {
    NSString *key = [NSString stringWithFormat:@"%s_nsg=%d", function_name, (int)nsg];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&nsg type:MTLDataTypeShort atIndex:600];

    NSError *error = nil;
    NSString *name = [NSString stringWithUTF8String:function_name];
    id<MTLFunction> fn = [g_library newFunctionWithName:name
                                         constantValues:constants
                                                  error:&error];
    if (!fn) {
        fprintf(stderr, "ds4: Metal %s function not found: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    error = nil;
```<｜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_metal.m

```c
const uint64_t bytes = g_model_views[i].bytes;
        const uint64_t n = (bytes + stride - 1) / stride;
        [enc setBuffer:g_model_views[i].buffer offset:0 atIndex:0];
        [enc setBuffer:out offset:0 atIndex:1];
        [enc setBytes:&stride length:sizeof(stride) atIndex:2];
        [enc setBytes:&bytes length:sizeof(bytes) atIndex:3];
        [enc setBytes:&dst_offset length:sizeof(dst_offset) atIndex:4];
        [enc dispatchThreadgroups:MTLSizeMake((NSUInteger)((n + 255) / 256), 1, 1)
             threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
        dst_offset += n;
    }
    ds4_gpu_end_compute_encoder(cb, enc);

    [cb commit];
    [cb waitUntilCompleted];

    if (cb.status == MTLCommandBufferStatusError) {
        fprintf(stderr, "ds4: Metal model warmup failed: %s\n",
                [[cb.error localizedDescription] UTF8String]);
        return 0;
    }

    return 1;
}

static const char *ds4_gpu_mul_mm_id_map0_name(uint32_t ne20) {
    switch (ne20) {
        case 1:  return "kernel_mul_mm_id_map0_ne20_1";
        case 2:  return "kernel_mul_mm_id_map0_ne20_2";
        case 4:  return "kernel_mul_mm_id_map0_ne20_4";
        case 5:  return "kernel_mul_mm_id_map0_ne20_5";
        case 6:  return "kernel_mul_mm_id_map0_ne20_6";
        case 8:  return "kernel_mul_mm_id_map0_ne20_8";
        case 10: return "kernel_mul_mm_id_map0_ne20_10";
        case 16: return "kernel_mul_mm_id_map0_ne20_16";
        case 22: return "kernel_mul_mm_id_map0_ne20_22";
        default: return NULL;
    }
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mv_pipeline(
        const char *function_name,
        int16_t     nsg) {
    NSString *key = [NSString stringWithFormat:@"%s_nsg=%d", function_name, (int)nsg];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&nsg type:MTLDataTypeShort atIndex:600];

    NSError *error = nil;
    NSString *name = [NSString stringWithUTF8String:function_name];
    id<MTLFunction> fn = [g_library newFunctionWithName:name
                                         constantValues:constants
                                                  error:&error];
    if (!fn) {
        fprintf(stderr, "ds4: Metal %s function not found: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    error = nil;
```

<｜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_metal.m

```c
const uint64_t bytes = g_model_views[i].bytes;
        const uint64_t n = (bytes + stride - 1) / stride;
        [enc setBuffer:g_model_views[i].buffer offset:0 atIndex:0];
        [enc setBuffer:out offset:0 atIndex:1];
        [enc setBytes:&stride length:sizeof(stride) atIndex:2];
        [enc setBytes:&bytes length:sizeof(bytes) atIndex:3];
        [enc setBytes:&dst_offset length:sizeof(dst_offset) atIndex:4];
        [enc dispatchThreadgroups:MTLSizeMake((NSUInteger)((n + 255) / 256), 1, 1)
             threadsPerThreadgroup:MTLSizeMake(256, 1, 1)];
        dst_offset += n;
    }
    ds4_gpu_end_compute_encoder(cb, enc);

    [cb commit];
    [cb waitUntilCompleted];

    if (cb.status == MTLCommandBufferStatusError) {
        fprintf(stderr, "ds4: Metal model warmup failed: %s\n",
                [[cb.error localizedDescription] UTF8String]);
        return 0;
    }

    return 1;
}

static const char *ds4_gpu_mul_mm_id_map0_name(uint32_t ne20) {
    switch (ne20) {
        case 1:  return "kernel_mul_mm_id_map0_ne20_1";
        case 2:  return "kernel_mul_mm_id_map0_ne20_2";
        case 4:  return "kernel_mul_mm_id_map0_ne20_4";
        case 5:  return "kernel_mul_mm_id_map0_ne20_5";
        case 6:  return "kernel_mul_mm_id_map0_ne20_6";
        case 8:  return "kernel_mul_mm_id_map0_ne20_8";
        case 10: return "kernel_mul_mm_id_map0_ne20_10";
        case 16: return "kernel_mul_mm_id_map0_ne20_16";
        case 22: return "kernel_mul_mm_id_map0_ne20_22";
        default: return NULL;
    }
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mv_pipeline(
        const char *function_name,
        int16_t     nsg) {
    NSString *key = [NSString stringWithFormat:@"%s_nsg=%d", function_name, (int)nsg];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&nsg type:MTLDataTypeShort atIndex:600];

    NSError *error = nil;
    NSString *name = [NSString stringWithUTF8String:function_name];
    id<MTLFunction> fn = [g_library newFunctionWithName:name
                                         constantValues:constants
                                                  error:&error];
    if (!fn) {
        fprintf(stderr, "ds4: Metal %s function not found: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    error = nil;
```<｜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_metal.m

```c
{
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
                                                     &g_compressor_pool_kv_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_kv") ||
                    !ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_score_buffer,
                                                     &g_compressor_pool_score_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_score")) {
                    ok = 0;
                }
                if (ok) {
                    ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_kv_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        0.0f) &&
                         ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_score_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        ds4_gpu_negative_infinity());
                }
                if (ok) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv) +
                                                                 (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
```

<｜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_metal.m

```c
{
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
                                                     &g_compressor_pool_kv_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_kv") ||
                    !ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_score_buffer,
                                                     &g_compressor_pool_score_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_score")) {
                    ok = 0;
                }
                if (ok) {
                    ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_kv_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        0.0f) &&
                         ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_score_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        ds4_gpu_negative_infinity());
                }
                if (ok) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv) +
                                                                 (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
```<｜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_metal.m

```c
{
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
                                                     &g_compressor_pool_kv_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_kv") ||
                    !ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_score_buffer,
                                                     &g_compressor_pool_score_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_score")) {
                    ok = 0;
                }
                if (ok) {
                    ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_kv_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        0.0f) &&
                         ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_score_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        ds4_gpu_negative_infinity());
                }
                if (ok) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv) +
                                                                 (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
```

<｜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_metal.m

```c
{
                const NSUInteger pack_bytes = (NSUInteger)n_comp * 8u * head_dim * sizeof(float);
                if (!ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_kv_buffer,
                                                     &g_compressor_pool_kv_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_kv") ||
                    !ds4_gpu_ensure_scratch_buffer(&g_compressor_pool_score_buffer,
                                                     &g_compressor_pool_score_bytes,
                                                     pack_bytes,
                                                     "ds4_compressor_pool_score")) {
                    ok = 0;
                }
                if (ok) {
                    ok = ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_kv_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        0.0f) &&
                         ds4_gpu_encode_fill_f32_rows(cb,
                                                        g_compressor_pool_score_buffer,
                                                        0,
                                                        head_dim,
                                                        8u * n_comp,
                                                        ds4_gpu_negative_infinity());
                }
                if (ok) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv) +
                                                                 (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
```<｜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_metal.m

```c
ol_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
                                                         ratio,
                                                         n_comp,
                                                         src_row_stride,
                                                         src_plane_stride,
                                                         dst_row_stride,
                                                         dst_plane_stride) &&
                         ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         g_compressor_store_score_buffer,
                                                         (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_score_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
                                                         ratio,
                                                         n_comp,
                                                         src_row_stride,
                                                         src_plane_stride,
                                                         dst_row_stride,
                                                         dst_plane_stride);
                }
                if (ok && n_comp > 1u) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv),
                                                         g_compressor_pool_kv_buffer,
                                                         dst_plane_stride,
                                                         head_dim,
                                                         ratio,
                                                         n_comp - 1u,
                                                         src_row_stride,
```

<｜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_metal.m

```c
ol_kv_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
                                                         ratio,
                                                         n_comp,
                                                         src_row_stride,
                                                         src_plane_stride,
                                                         dst_row_stride,
                                                         dst_plane_stride) &&
                         ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         g_compressor_store_score_buffer,
                                                         (NSUInteger)head_dim * sizeof(float),
                                                         g_compressor_pool_score_buffer,
                                                         (NSUInteger)4u * head_dim * sizeof(float),
                                                         head_dim,
                                                         ratio,
                                                         n_comp,
                                                         src_row_stride,
                                                         src_plane_stride,
                                                         dst_row_stride,
                                                         dst_plane_stride);
                }
                if (ok && n_comp > 1u) {
                    const uint64_t src_row_stride = (uint64_t)width * sizeof(float);
                    const uint64_t src_plane_stride = (uint64_t)ratio * src_row_stride;
                    const uint64_t dst_row_stride = (uint64_t)head_dim * sizeof(float);
                    const uint64_t dst_plane_stride = 8ull * dst_row_stride;
                    ok = ds4_gpu_encode_cpy_f32_f32_3d(cb,
                                                         kvbuf,
                                                         ds4_gpu_tensor_offset(kv),
                                                         g_compressor_pool_kv_buffer,
                                                         dst_plane_stride,
                                                         head_dim,
                                                         ratio,
                                                         n_comp - 1u,
                                                         src_row_stride,
```<｜Assistant｜></think>