[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
!write_clamped_moe &&
            getenv("DS4_METAL_DISABLE_ROUTED_PAIR_SWIGLU_FUSION") == NULL &&
            pair_swiglu_pipeline != nil;
        if (fuse_pair_swiglu) {
            ds4_gpu_dsv4_moe_swiglu_weight_args act_args = {
                .width = expert_mid_dim,
                .rows = pair_rows,
                .gate_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .up_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .mid_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .weight_stride = sizeof(float),
                .write_clamped = 0,
                .clamp_value = clamp,
            };
            ok = ds4_gpu_encode_mul_mv_id_pair_swiglu(cb,
                                                        pair_swiglu_pipeline,
                                                        &gate_args,
                                                        &act_args,
                                                        gate_buf,
                                                        (NSUInteger)gate_inner,
                                                        up_buf,
                                                        (NSUInteger)up_inner,
                                                        xbuf,
                                                        ds4_gpu_tensor_offset(x),
                                                        gatebuf,
                                                        ds4_gpu_tensor_offset(gate),
                                                        upbuf,
                                                        ds4_gpu_tensor_offset(up),
                                                        midbuf,
                                                        ds4_gpu_tensor_offset(mid),
                                                        selectedbuf,
                                                        ds4_gpu_tensor_offset(selected),
                                                        weightsbuf,
                                                        ds4_gpu_tensor_offset(weights),
                                                        gate_smem,
                                                        2,
                                                        false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
```

<｜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
!write_clamped_moe &&
            getenv("DS4_METAL_DISABLE_ROUTED_PAIR_SWIGLU_FUSION") == NULL &&
            pair_swiglu_pipeline != nil;
        if (fuse_pair_swiglu) {
            ds4_gpu_dsv4_moe_swiglu_weight_args act_args = {
                .width = expert_mid_dim,
                .rows = pair_rows,
                .gate_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .up_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .mid_row_stride = (uint64_t)expert_mid_dim * sizeof(float),
                .weight_stride = sizeof(float),
                .write_clamped = 0,
                .clamp_value = clamp,
            };
            ok = ds4_gpu_encode_mul_mv_id_pair_swiglu(cb,
                                                        pair_swiglu_pipeline,
                                                        &gate_args,
                                                        &act_args,
                                                        gate_buf,
                                                        (NSUInteger)gate_inner,
                                                        up_buf,
                                                        (NSUInteger)up_inner,
                                                        xbuf,
                                                        ds4_gpu_tensor_offset(x),
                                                        gatebuf,
                                                        ds4_gpu_tensor_offset(gate),
                                                        upbuf,
                                                        ds4_gpu_tensor_offset(up),
                                                        midbuf,
                                                        ds4_gpu_tensor_offset(mid),
                                                        selectedbuf,
                                                        ds4_gpu_tensor_offset(selected),
                                                        weightsbuf,
                                                        ds4_gpu_tensor_offset(weights),
                                                        gate_smem,
                                                        2,
                                                        false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
```<｜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
b,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f32_3d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f32_3d_src_strided(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_col_stride,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f16_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f16_2d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint64_t             src_row_stride,
        uint64_t             dst_row_stride);

static int ds4_gpu_encode_cpy_f16_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_fill_f32_rows(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        buf,
        NSUInteger           offset,
        uint32_t             width,
        uint32_t             rows,
        float                value);

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
```

<｜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
b,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f32_3d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f32_3d_src_strided(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_col_stride,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f16_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f16_2d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint64_t             src_row_stride,
        uint64_t             dst_row_stride);

static int ds4_gpu_encode_cpy_f16_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_fill_f32_rows(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        buf,
        NSUInteger           offset,
        uint32_t             width,
        uint32_t             rows,
        float                value);

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
```<｜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
b,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f32_3d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f32_3d_src_strided(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_col_stride,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f16_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f16_2d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint64_t             src_row_stride,
        uint64_t             dst_row_stride);

static int ds4_gpu_encode_cpy_f16_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_fill_f32_rows(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        buf,
        NSUInteger           offset,
        uint32_t             width,
        uint32_t             rows,
        float                value);

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
```

<｜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
b,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f32_3d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f32_3d_src_strided(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint32_t             planes,
        uint64_t             src_col_stride,
        uint64_t             src_row_stride,
        uint64_t             src_plane_stride,
        uint64_t             dst_row_stride,
        uint64_t             dst_plane_stride);

static int ds4_gpu_encode_cpy_f32_f16_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_cpy_f32_f16_2d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             cols,
        uint32_t             rows,
        uint64_t             src_row_stride,
        uint64_t             dst_row_stride);

static int ds4_gpu_encode_cpy_f16_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        src,
        NSUInteger           src_off,
        id<MTLBuffer>        dst,
        NSUInteger           dst_off,
        uint32_t             n);

static int ds4_gpu_encode_fill_f32_rows(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        buf,
        NSUInteger           offset,
        uint32_t             width,
        uint32_t             rows,
        float                value);

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
```<｜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
y_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_iq2_xxs_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_Q4_K &&
                   g_moe_mul_mv_id_q4_k_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_q4_k_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
```

<｜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
y_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_iq2_xxs_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_Q4_K &&
                   g_moe_mul_mv_id_q4_k_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_q4_k_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
```<｜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
y_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_iq2_xxs_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_Q4_K &&
                   g_moe_mul_mv_id_q4_k_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_q4_k_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
```

<｜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
y_mode &&
                   gate_type == DS4_METAL_TENSOR_IQ2_XXS &&
                   g_moe_mul_mv_id_iq2_xxs_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_iq2_xxs_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else if (!g_quality_mode &&
                   gate_type == DS4_METAL_TENSOR_Q4_K &&
                   g_moe_mul_mv_id_q4_k_pair_pipeline) {
            ok = ds4_gpu_encode_mul_mv_id_pair(cb,
                                                 g_moe_mul_mv_id_q4_k_pair_pipeline,
                                                 &gate_args,
                                                 gate_buf,
                                                 (NSUInteger)gate_inner,
                                                 up_buf,
                                                 (NSUInteger)up_inner,
                                                 xbuf,
                                                 ds4_gpu_tensor_offset(x),
                                                 gatebuf,
                                                 ds4_gpu_tensor_offset(gate),
                                                 upbuf,
                                                 ds4_gpu_tensor_offset(up),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
```<｜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(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            gate_buf,
                                            (NSUInteger)gate_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            gatebuf,
                                            ds4_gpu_tensor_offset(gate),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false) &&
                 ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            up_buf,
                                            (NSUInteger)up_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            upbuf,
                                            ds4_gpu_tensor_offset(up),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false);
        }
        if (ok && !fuse_pair_swiglu) {
            ok = ds4_gpu_encode_moe_swiglu_weight(cb,
                                                    gatebuf,
                                                    ds4_gpu_tensor_offset(gate),
                                                    upbuf,
                                                    ds4_gpu_tensor_offset(up),
                                                    midbuf,
                                                    ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
```

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            gate_buf,
                                            (NSUInteger)gate_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            gatebuf,
                                            ds4_gpu_tensor_offset(gate),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false) &&
                 ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            up_buf,
                                            (NSUInteger)up_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            upbuf,
                                            ds4_gpu_tensor_offset(up),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false);
        }
        if (ok && !fuse_pair_swiglu) {
            ok = ds4_gpu_encode_moe_swiglu_weight(cb,
                                                    gatebuf,
                                                    ds4_gpu_tensor_offset(gate),
                                                    upbuf,
                                                    ds4_gpu_tensor_offset(up),
                                                    midbuf,
                                                    ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            gate_buf,
                                            (NSUInteger)gate_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            gatebuf,
                                            ds4_gpu_tensor_offset(gate),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false) &&
                 ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            up_buf,
                                            (NSUInteger)up_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            upbuf,
                                            ds4_gpu_tensor_offset(up),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false);
        }
        if (ok && !fuse_pair_swiglu) {
            ok = ds4_gpu_encode_moe_swiglu_weight(cb,
                                                    gatebuf,
                                                    ds4_gpu_tensor_offset(gate),
                                                    upbuf,
                                                    ds4_gpu_tensor_offset(up),
                                                    midbuf,
                                                    ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
```

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(selected),
                                                 gate_smem,
                                                 2,
                                                 false);
        } else {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            gate_buf,
                                            (NSUInteger)gate_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            gatebuf,
                                            ds4_gpu_tensor_offset(gate),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false) &&
                 ds4_gpu_encode_mul_mv_id(cb,
                                            gate_mv_pipeline,
                                            &gate_args,
                                            up_buf,
                                            (NSUInteger)up_inner,
                                            xbuf,
                                            ds4_gpu_tensor_offset(x),
                                            upbuf,
                                            ds4_gpu_tensor_offset(up),
                                            selectedbuf,
                                            ds4_gpu_tensor_offset(selected),
                                            gate_smem,
                                            2,
                                            false);
        }
        if (ok && !fuse_pair_swiglu) {
            ok = ds4_gpu_encode_moe_swiglu_weight(cb,
                                                    gatebuf,
                                                    ds4_gpu_tensor_offset(gate),
                                                    upbuf,
                                                    ds4_gpu_tensor_offset(up),
                                                    midbuf,
                                                    ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
                                                    expert_mid_dim,
                                                    pair_rows,
                                                    clamp,
                                                    false);
        }

        id<MTLBuffer> down_dst = n_expert == 1 ? outbuf : (expertsbuf ? expertsbuf : g_moe_down_scratch_buffer);
        NSUInteger down_dst_off = n_expert == 1 ? ds4_gpu_tensor_offset(out) :
            (expertsbuf ? ds4_gpu_tensor_offset(experts) : 0);
        id<MTLComputePipelineState> down_sum6_pipeline = nil;
        if (down_type == DS4_METAL_TENSOR_Q2_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q2_k_sum6_pipeline;
        } else if (down_type == DS4_METAL_TENSOR_Q4_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q4_k_sum6_pipeline;
        }
        const bool direct_down_sum =
            !g_quality_mode &&
            n_expert == 6 &&
            n_tokens == 1 &&
            down_sum6_pipeline != nil;
        if (ok && direct_down_sum) {
            ok = ds4_gpu_encode_mul_mv_id_sum6(cb,
                                                 down_sum6_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 outbuf,
                                                 ds4_gpu_tensor_offset(out),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2);
        } else if (ok) {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                                 down_mv_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
```

<｜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
ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
                                                    expert_mid_dim,
                                                    pair_rows,
                                                    clamp,
                                                    false);
        }

        id<MTLBuffer> down_dst = n_expert == 1 ? outbuf : (expertsbuf ? expertsbuf : g_moe_down_scratch_buffer);
        NSUInteger down_dst_off = n_expert == 1 ? ds4_gpu_tensor_offset(out) :
            (expertsbuf ? ds4_gpu_tensor_offset(experts) : 0);
        id<MTLComputePipelineState> down_sum6_pipeline = nil;
        if (down_type == DS4_METAL_TENSOR_Q2_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q2_k_sum6_pipeline;
        } else if (down_type == DS4_METAL_TENSOR_Q4_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q4_k_sum6_pipeline;
        }
        const bool direct_down_sum =
            !g_quality_mode &&
            n_expert == 6 &&
            n_tokens == 1 &&
            down_sum6_pipeline != nil;
        if (ok && direct_down_sum) {
            ok = ds4_gpu_encode_mul_mv_id_sum6(cb,
                                                 down_sum6_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 outbuf,
                                                 ds4_gpu_tensor_offset(out),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2);
        } else if (ok) {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                                 down_mv_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
```<｜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
ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
                                                    expert_mid_dim,
                                                    pair_rows,
                                                    clamp,
                                                    false);
        }

        id<MTLBuffer> down_dst = n_expert == 1 ? outbuf : (expertsbuf ? expertsbuf : g_moe_down_scratch_buffer);
        NSUInteger down_dst_off = n_expert == 1 ? ds4_gpu_tensor_offset(out) :
            (expertsbuf ? ds4_gpu_tensor_offset(experts) : 0);
        id<MTLComputePipelineState> down_sum6_pipeline = nil;
        if (down_type == DS4_METAL_TENSOR_Q2_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q2_k_sum6_pipeline;
        } else if (down_type == DS4_METAL_TENSOR_Q4_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q4_k_sum6_pipeline;
        }
        const bool direct_down_sum =
            !g_quality_mode &&
            n_expert == 6 &&
            n_tokens == 1 &&
            down_sum6_pipeline != nil;
        if (ok && direct_down_sum) {
            ok = ds4_gpu_encode_mul_mv_id_sum6(cb,
                                                 down_sum6_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 outbuf,
                                                 ds4_gpu_tensor_offset(out),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2);
        } else if (ok) {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                                 down_mv_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
```

<｜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
ds4_gpu_tensor_offset(mid),
                                                    weightsbuf,
                                                    ds4_gpu_tensor_offset(weights),
                                                    expert_mid_dim,
                                                    pair_rows,
                                                    clamp,
                                                    false);
        }

        id<MTLBuffer> down_dst = n_expert == 1 ? outbuf : (expertsbuf ? expertsbuf : g_moe_down_scratch_buffer);
        NSUInteger down_dst_off = n_expert == 1 ? ds4_gpu_tensor_offset(out) :
            (expertsbuf ? ds4_gpu_tensor_offset(experts) : 0);
        id<MTLComputePipelineState> down_sum6_pipeline = nil;
        if (down_type == DS4_METAL_TENSOR_Q2_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q2_k_sum6_pipeline;
        } else if (down_type == DS4_METAL_TENSOR_Q4_K) {
            down_sum6_pipeline = g_moe_mul_mv_id_q4_k_sum6_pipeline;
        }
        const bool direct_down_sum =
            !g_quality_mode &&
            n_expert == 6 &&
            n_tokens == 1 &&
            down_sum6_pipeline != nil;
        if (ok && direct_down_sum) {
            ok = ds4_gpu_encode_mul_mv_id_sum6(cb,
                                                 down_sum6_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 outbuf,
                                                 ds4_gpu_tensor_offset(out),
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2);
        } else if (ok) {
            ok = ds4_gpu_encode_mul_mv_id(cb,
                                                 down_mv_pipeline,
                                                 &down_args,
                                                 down_buf,
                                                 (NSUInteger)down_inner,
                                                 midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
```<｜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
midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
                                                 down_dst_off,
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2,
                                                 false);
        }
        if (ok && n_expert > 1 && !direct_down_sum) {
            ok = ds4_gpu_encode_moe_sum_experts(cb,
                                                       down_dst,
                                                       down_dst_off,
                                                       outbuf,
                                                       ds4_gpu_tensor_offset(out),
                                                       out_dim,
                                                       n_expert,
                                                       n_tokens);
        }
        if (!ok) return 0;

        if (!ds4_gpu_finish_command_buffer(cb, owned, "routed tensor MoE")) return 0;
    }

    return 1;
}

int ds4_gpu_routed_moe_batch_tensor(
        ds4_gpu_tensor       *out,
        ds4_gpu_tensor       *gate,
        ds4_gpu_tensor       *up,
        ds4_gpu_tensor       *mid,
        ds4_gpu_tensor       *experts,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                gate_offset,
        uint64_t                up_offset,
        uint64_t                down_offset,
        uint32_t                gate_type,
        uint32_t                down_type,
        uint64_t                gate_expert_bytes,
        uint64_t                gate_row_bytes,
        uint64_t                down_expert_bytes,
        uint64_t                down_row_bytes,
        uint32_t                expert_in_dim,
        uint32_t                expert_mid_dim,
        uint32_t                out_dim,
        const ds4_gpu_tensor *selected,
        const ds4_gpu_tensor *weights,
        uint32_t                n_expert,
        float                   clamp,
        const ds4_gpu_tensor *x,
        uint32_t                n_tokens,
        bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
```

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

File: ds4_metal.m

```c
midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
                                                 down_dst_off,
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2,
                                                 false);
        }
        if (ok && n_expert > 1 && !direct_down_sum) {
            ok = ds4_gpu_encode_moe_sum_experts(cb,
                                                       down_dst,
                                                       down_dst_off,
                                                       outbuf,
                                                       ds4_gpu_tensor_offset(out),
                                                       out_dim,
                                                       n_expert,
                                                       n_tokens);
        }
        if (!ok) return 0;

        if (!ds4_gpu_finish_command_buffer(cb, owned, "routed tensor MoE")) return 0;
    }

    return 1;
}

int ds4_gpu_routed_moe_batch_tensor(
        ds4_gpu_tensor       *out,
        ds4_gpu_tensor       *gate,
        ds4_gpu_tensor       *up,
        ds4_gpu_tensor       *mid,
        ds4_gpu_tensor       *experts,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                gate_offset,
        uint64_t                up_offset,
        uint64_t                down_offset,
        uint32_t                gate_type,
        uint32_t                down_type,
        uint64_t                gate_expert_bytes,
        uint64_t                gate_row_bytes,
        uint64_t                down_expert_bytes,
        uint64_t                down_row_bytes,
        uint32_t                expert_in_dim,
        uint32_t                expert_mid_dim,
        uint32_t                out_dim,
        const ds4_gpu_tensor *selected,
        const ds4_gpu_tensor *weights,
        uint32_t                n_expert,
        float                   clamp,
        const ds4_gpu_tensor *x,
        uint32_t                n_tokens,
        bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
                                                 down_dst_off,
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2,
                                                 false);
        }
        if (ok && n_expert > 1 && !direct_down_sum) {
            ok = ds4_gpu_encode_moe_sum_experts(cb,
                                                       down_dst,
                                                       down_dst_off,
                                                       outbuf,
                                                       ds4_gpu_tensor_offset(out),
                                                       out_dim,
                                                       n_expert,
                                                       n_tokens);
        }
        if (!ok) return 0;

        if (!ds4_gpu_finish_command_buffer(cb, owned, "routed tensor MoE")) return 0;
    }

    return 1;
}

int ds4_gpu_routed_moe_batch_tensor(
        ds4_gpu_tensor       *out,
        ds4_gpu_tensor       *gate,
        ds4_gpu_tensor       *up,
        ds4_gpu_tensor       *mid,
        ds4_gpu_tensor       *experts,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                gate_offset,
        uint64_t                up_offset,
        uint64_t                down_offset,
        uint32_t                gate_type,
        uint32_t                down_type,
        uint64_t                gate_expert_bytes,
        uint64_t                gate_row_bytes,
        uint64_t                down_expert_bytes,
        uint64_t                down_row_bytes,
        uint32_t                expert_in_dim,
        uint32_t                expert_mid_dim,
        uint32_t                out_dim,
        const ds4_gpu_tensor *selected,
        const ds4_gpu_tensor *weights,
        uint32_t                n_expert,
        float                   clamp,
        const ds4_gpu_tensor *x,
        uint32_t                n_tokens,
        bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
```

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

File: ds4_metal.m

```c
midbuf,
                                                 ds4_gpu_tensor_offset(mid),
                                                 down_dst,
                                                 down_dst_off,
                                                 selectedbuf,
                                                 ds4_gpu_tensor_offset(selected),
                                                 down_smem,
                                                 2,
                                                 false);
        }
        if (ok && n_expert > 1 && !direct_down_sum) {
            ok = ds4_gpu_encode_moe_sum_experts(cb,
                                                       down_dst,
                                                       down_dst_off,
                                                       outbuf,
                                                       ds4_gpu_tensor_offset(out),
                                                       out_dim,
                                                       n_expert,
                                                       n_tokens);
        }
        if (!ok) return 0;

        if (!ds4_gpu_finish_command_buffer(cb, owned, "routed tensor MoE")) return 0;
    }

    return 1;
}

int ds4_gpu_routed_moe_batch_tensor(
        ds4_gpu_tensor       *out,
        ds4_gpu_tensor       *gate,
        ds4_gpu_tensor       *up,
        ds4_gpu_tensor       *mid,
        ds4_gpu_tensor       *experts,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                gate_offset,
        uint64_t                up_offset,
        uint64_t                down_offset,
        uint32_t                gate_type,
        uint32_t                down_type,
        uint64_t                gate_expert_bytes,
        uint64_t                gate_row_bytes,
        uint64_t                down_expert_bytes,
        uint64_t                down_row_bytes,
        uint32_t                expert_in_dim,
        uint32_t                expert_mid_dim,
        uint32_t                out_dim,
        const ds4_gpu_tensor *selected,
        const ds4_gpu_tensor *weights,
        uint32_t                n_expert,
        float                   clamp,
        const ds4_gpu_tensor *x,
        uint32_t                n_tokens,
        bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
        n_tokens == 0 || n_expert == 0 || n_expert > 6) {
        return 0;
    }
    if ((expert_in_dim % 256u) != 0 || (expert_mid_dim % 256u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> gatebuf = ds4_gpu_tensor_buffer(gate);
        id<MTLBuffer> upbuf = ds4_gpu_tensor_buffer(up);
        id<MTLBuffer> midbuf = ds4_gpu_tensor_buffer(mid);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        id<MTLBuffer> expertsbuf = ds4_gpu_tensor_buffer(experts);
        id<MTLBuffer> selectedbuf = ds4_gpu_tensor_buffer(selected);
        id<MTLBuffer> weightsbuf = ds4_gpu_tensor_buffer(weights);
        const uint64_t x_bytes = (uint64_t)n_tokens * expert_in_dim * sizeof(float);
        const uint64_t mid_bytes = (uint64_t)n_tokens * n_expert * expert_mid_dim * sizeof(float);
        const uint64_t out_bytes = (uint64_t)n_tokens * out_dim * sizeof(float);
        const uint64_t selected_bytes = (uint64_t)n_tokens * n_expert * sizeof(int);
        const uint64_t weights_bytes = (uint64_t)n_tokens * n_expert * sizeof(float);
        if (!xbuf || !gatebuf || !upbuf || !midbuf || !outbuf || !selectedbuf || !weightsbuf ||
            ds4_gpu_tensor_bytes(x) < x_bytes ||
            ds4_gpu_tensor_bytes(gate) < mid_bytes ||
            ds4_gpu_tensor_bytes(up) < mid_bytes ||
            ds4_gpu_tensor_bytes(mid) < mid_bytes ||
            ds4_gpu_tensor_bytes(out) < out_bytes ||
            ds4_gpu_tensor_bytes(selected) < selected_bytes ||
            ds4_gpu_tensor_bytes(weights) < weights_bytes) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized activation buffers\n");
            return 0;
        }
        if (n_expert > 1 &&
            (!expertsbuf ||
             ds4_gpu_tensor_bytes(experts) < (uint64_t)n_tokens * n_expert * out_dim * sizeof(float))) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized expert output buffer\n");
            return 0;
        }

        const uint64_t gate_tensor_bytes = 256ull * gate_expert_bytes;
        const uint64_t down_tensor_bytes = 256ull * down_expert_bytes;
        uint64_t gate_inner = 0;
        uint64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
```

<｜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
bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
        n_tokens == 0 || n_expert == 0 || n_expert > 6) {
        return 0;
    }
    if ((expert_in_dim % 256u) != 0 || (expert_mid_dim % 256u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> gatebuf = ds4_gpu_tensor_buffer(gate);
        id<MTLBuffer> upbuf = ds4_gpu_tensor_buffer(up);
        id<MTLBuffer> midbuf = ds4_gpu_tensor_buffer(mid);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        id<MTLBuffer> expertsbuf = ds4_gpu_tensor_buffer(experts);
        id<MTLBuffer> selectedbuf = ds4_gpu_tensor_buffer(selected);
        id<MTLBuffer> weightsbuf = ds4_gpu_tensor_buffer(weights);
        const uint64_t x_bytes = (uint64_t)n_tokens * expert_in_dim * sizeof(float);
        const uint64_t mid_bytes = (uint64_t)n_tokens * n_expert * expert_mid_dim * sizeof(float);
        const uint64_t out_bytes = (uint64_t)n_tokens * out_dim * sizeof(float);
        const uint64_t selected_bytes = (uint64_t)n_tokens * n_expert * sizeof(int);
        const uint64_t weights_bytes = (uint64_t)n_tokens * n_expert * sizeof(float);
        if (!xbuf || !gatebuf || !upbuf || !midbuf || !outbuf || !selectedbuf || !weightsbuf ||
            ds4_gpu_tensor_bytes(x) < x_bytes ||
            ds4_gpu_tensor_bytes(gate) < mid_bytes ||
            ds4_gpu_tensor_bytes(up) < mid_bytes ||
            ds4_gpu_tensor_bytes(mid) < mid_bytes ||
            ds4_gpu_tensor_bytes(out) < out_bytes ||
            ds4_gpu_tensor_bytes(selected) < selected_bytes ||
            ds4_gpu_tensor_bytes(weights) < weights_bytes) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized activation buffers\n");
            return 0;
        }
        if (n_expert > 1 &&
            (!expertsbuf ||
             ds4_gpu_tensor_bytes(experts) < (uint64_t)n_tokens * n_expert * out_dim * sizeof(float))) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized expert output buffer\n");
            return 0;
        }

        const uint64_t gate_tensor_bytes = 256ull * gate_expert_bytes;
        const uint64_t down_tensor_bytes = 256ull * down_expert_bytes;
        uint64_t gate_inner = 0;
        uint64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
```<｜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
bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
        n_tokens == 0 || n_expert == 0 || n_expert > 6) {
        return 0;
    }
    if ((expert_in_dim % 256u) != 0 || (expert_mid_dim % 256u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> gatebuf = ds4_gpu_tensor_buffer(gate);
        id<MTLBuffer> upbuf = ds4_gpu_tensor_buffer(up);
        id<MTLBuffer> midbuf = ds4_gpu_tensor_buffer(mid);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        id<MTLBuffer> expertsbuf = ds4_gpu_tensor_buffer(experts);
        id<MTLBuffer> selectedbuf = ds4_gpu_tensor_buffer(selected);
        id<MTLBuffer> weightsbuf = ds4_gpu_tensor_buffer(weights);
        const uint64_t x_bytes = (uint64_t)n_tokens * expert_in_dim * sizeof(float);
        const uint64_t mid_bytes = (uint64_t)n_tokens * n_expert * expert_mid_dim * sizeof(float);
        const uint64_t out_bytes = (uint64_t)n_tokens * out_dim * sizeof(float);
        const uint64_t selected_bytes = (uint64_t)n_tokens * n_expert * sizeof(int);
        const uint64_t weights_bytes = (uint64_t)n_tokens * n_expert * sizeof(float);
        if (!xbuf || !gatebuf || !upbuf || !midbuf || !outbuf || !selectedbuf || !weightsbuf ||
            ds4_gpu_tensor_bytes(x) < x_bytes ||
            ds4_gpu_tensor_bytes(gate) < mid_bytes ||
            ds4_gpu_tensor_bytes(up) < mid_bytes ||
            ds4_gpu_tensor_bytes(mid) < mid_bytes ||
            ds4_gpu_tensor_bytes(out) < out_bytes ||
            ds4_gpu_tensor_bytes(selected) < selected_bytes ||
            ds4_gpu_tensor_bytes(weights) < weights_bytes) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized activation buffers\n");
            return 0;
        }
        if (n_expert > 1 &&
            (!expertsbuf ||
             ds4_gpu_tensor_bytes(experts) < (uint64_t)n_tokens * n_expert * out_dim * sizeof(float))) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized expert output buffer\n");
            return 0;
        }

        const uint64_t gate_tensor_bytes = 256ull * gate_expert_bytes;
        const uint64_t down_tensor_bytes = 256ull * down_expert_bytes;
        uint64_t gate_inner = 0;
        uint64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
```

<｜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
bool                   *mid_is_f16) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!out || !gate || !up || !mid || !x || !model_map || !selected || !weights ||
        n_tokens == 0 || n_expert == 0 || n_expert > 6) {
        return 0;
    }
    if ((expert_in_dim % 256u) != 0 || (expert_mid_dim % 256u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> gatebuf = ds4_gpu_tensor_buffer(gate);
        id<MTLBuffer> upbuf = ds4_gpu_tensor_buffer(up);
        id<MTLBuffer> midbuf = ds4_gpu_tensor_buffer(mid);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        id<MTLBuffer> expertsbuf = ds4_gpu_tensor_buffer(experts);
        id<MTLBuffer> selectedbuf = ds4_gpu_tensor_buffer(selected);
        id<MTLBuffer> weightsbuf = ds4_gpu_tensor_buffer(weights);
        const uint64_t x_bytes = (uint64_t)n_tokens * expert_in_dim * sizeof(float);
        const uint64_t mid_bytes = (uint64_t)n_tokens * n_expert * expert_mid_dim * sizeof(float);
        const uint64_t out_bytes = (uint64_t)n_tokens * out_dim * sizeof(float);
        const uint64_t selected_bytes = (uint64_t)n_tokens * n_expert * sizeof(int);
        const uint64_t weights_bytes = (uint64_t)n_tokens * n_expert * sizeof(float);
        if (!xbuf || !gatebuf || !upbuf || !midbuf || !outbuf || !selectedbuf || !weightsbuf ||
            ds4_gpu_tensor_bytes(x) < x_bytes ||
            ds4_gpu_tensor_bytes(gate) < mid_bytes ||
            ds4_gpu_tensor_bytes(up) < mid_bytes ||
            ds4_gpu_tensor_bytes(mid) < mid_bytes ||
            ds4_gpu_tensor_bytes(out) < out_bytes ||
            ds4_gpu_tensor_bytes(selected) < selected_bytes ||
            ds4_gpu_tensor_bytes(weights) < weights_bytes) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized activation buffers\n");
            return 0;
        }
        if (n_expert > 1 &&
            (!expertsbuf ||
             ds4_gpu_tensor_bytes(experts) < (uint64_t)n_tokens * n_expert * out_dim * sizeof(float))) {
            fprintf(stderr, "ds4: Metal routed batch MoE received undersized expert output buffer\n");
            return 0;
        }

        const uint64_t gate_tensor_bytes = 256ull * gate_expert_bytes;
        const uint64_t down_tensor_bytes = 256ull * down_expert_bytes;
        uint64_t gate_inner = 0;
        uint64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
```<｜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
nt64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
        id<MTLBuffer> up_buf = ds4_gpu_wrap_model_range(model_map, model_size, up_offset, gate_tensor_bytes, &up_inner);
        id<MTLBuffer> down_buf = ds4_gpu_wrap_model_range(model_map, model_size, down_offset, down_tensor_bytes, &down_inner);
        if (!gate_buf || !up_buf || !down_buf) return 0;

        const uint32_t pair_rows = n_tokens * n_expert;
        const uint64_t down_scratch_bytes = (uint64_t)pair_rows * out_dim * sizeof(float);
        if ((n_expert > 1 && !expertsbuf &&
             !ds4_gpu_ensure_scratch_buffer(&g_moe_down_scratch_buffer,
                                              &g_moe_down_scratch_bytes,
                                              (NSUInteger)down_scratch_bytes,
                                              "ds4_moe_down_scratch"))) {
            return 0;
        }

        const uint32_t gate_nr0 = ds4_gpu_routed_mv_nr0(gate_type);
        const uint32_t down_nr0 = ds4_gpu_routed_mv_nr0(down_type);
        id<MTLComputePipelineState> gate_mv_pipeline = ds4_gpu_routed_mv_pipeline(gate_type);
        id<MTLComputePipelineState> down_mv_pipeline = ds4_gpu_routed_mv_pipeline(down_type);
        id<MTLComputePipelineState> gate_mm_pipeline = nil;
        id<MTLComputePipelineState> down_mm_pipeline = nil;
        if (gate_nr0 == 0 || down_nr0 == 0 || !gate_mv_pipeline || !down_mv_pipeline) {
            fprintf(stderr, "ds4: unsupported Metal routed batch MoE quant types gate=%u down=%u\n",
                    gate_type, down_type);
            return 0;
        }

        ds4_gpu_mul_mv_id_args gate_args =
            ds4_gpu_make_mul_mv_id_args(expert_in_dim, expert_mid_dim, 256,
                                          gate_row_bytes, gate_expert_bytes,
                                          1, n_expert, n_tokens, gate_nr0);
        ds4_gpu_mul_mv_id_args down_args =
            ds4_gpu_make_mul_mv_id_args(expert_mid_dim, out_dim, 256,
                                          down_row_bytes, down_expert_bytes,
                                          n_expert, n_expert, n_tokens, down_nr0);
        const bool use_mm_id = n_tokens >= 32u && ds4_gpu_mul_mm_id_map0_name(n_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
```

<｜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
nt64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
        id<MTLBuffer> up_buf = ds4_gpu_wrap_model_range(model_map, model_size, up_offset, gate_tensor_bytes, &up_inner);
        id<MTLBuffer> down_buf = ds4_gpu_wrap_model_range(model_map, model_size, down_offset, down_tensor_bytes, &down_inner);
        if (!gate_buf || !up_buf || !down_buf) return 0;

        const uint32_t pair_rows = n_tokens * n_expert;
        const uint64_t down_scratch_bytes = (uint64_t)pair_rows * out_dim * sizeof(float);
        if ((n_expert > 1 && !expertsbuf &&
             !ds4_gpu_ensure_scratch_buffer(&g_moe_down_scratch_buffer,
                                              &g_moe_down_scratch_bytes,
                                              (NSUInteger)down_scratch_bytes,
                                              "ds4_moe_down_scratch"))) {
            return 0;
        }

        const uint32_t gate_nr0 = ds4_gpu_routed_mv_nr0(gate_type);
        const uint32_t down_nr0 = ds4_gpu_routed_mv_nr0(down_type);
        id<MTLComputePipelineState> gate_mv_pipeline = ds4_gpu_routed_mv_pipeline(gate_type);
        id<MTLComputePipelineState> down_mv_pipeline = ds4_gpu_routed_mv_pipeline(down_type);
        id<MTLComputePipelineState> gate_mm_pipeline = nil;
        id<MTLComputePipelineState> down_mm_pipeline = nil;
        if (gate_nr0 == 0 || down_nr0 == 0 || !gate_mv_pipeline || !down_mv_pipeline) {
            fprintf(stderr, "ds4: unsupported Metal routed batch MoE quant types gate=%u down=%u\n",
                    gate_type, down_type);
            return 0;
        }

        ds4_gpu_mul_mv_id_args gate_args =
            ds4_gpu_make_mul_mv_id_args(expert_in_dim, expert_mid_dim, 256,
                                          gate_row_bytes, gate_expert_bytes,
                                          1, n_expert, n_tokens, gate_nr0);
        ds4_gpu_mul_mv_id_args down_args =
            ds4_gpu_make_mul_mv_id_args(expert_mid_dim, out_dim, 256,
                                          down_row_bytes, down_expert_bytes,
                                          n_expert, n_expert, n_tokens, down_nr0);
        const bool use_mm_id = n_tokens >= 32u && ds4_gpu_mul_mm_id_map0_name(n_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
```<｜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
nt64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
        id<MTLBuffer> up_buf = ds4_gpu_wrap_model_range(model_map, model_size, up_offset, gate_tensor_bytes, &up_inner);
        id<MTLBuffer> down_buf = ds4_gpu_wrap_model_range(model_map, model_size, down_offset, down_tensor_bytes, &down_inner);
        if (!gate_buf || !up_buf || !down_buf) return 0;

        const uint32_t pair_rows = n_tokens * n_expert;
        const uint64_t down_scratch_bytes = (uint64_t)pair_rows * out_dim * sizeof(float);
        if ((n_expert > 1 && !expertsbuf &&
             !ds4_gpu_ensure_scratch_buffer(&g_moe_down_scratch_buffer,
                                              &g_moe_down_scratch_bytes,
                                              (NSUInteger)down_scratch_bytes,
                                              "ds4_moe_down_scratch"))) {
            return 0;
        }

        const uint32_t gate_nr0 = ds4_gpu_routed_mv_nr0(gate_type);
        const uint32_t down_nr0 = ds4_gpu_routed_mv_nr0(down_type);
        id<MTLComputePipelineState> gate_mv_pipeline = ds4_gpu_routed_mv_pipeline(gate_type);
        id<MTLComputePipelineState> down_mv_pipeline = ds4_gpu_routed_mv_pipeline(down_type);
        id<MTLComputePipelineState> gate_mm_pipeline = nil;
        id<MTLComputePipelineState> down_mm_pipeline = nil;
        if (gate_nr0 == 0 || down_nr0 == 0 || !gate_mv_pipeline || !down_mv_pipeline) {
            fprintf(stderr, "ds4: unsupported Metal routed batch MoE quant types gate=%u down=%u\n",
                    gate_type, down_type);
            return 0;
        }

        ds4_gpu_mul_mv_id_args gate_args =
            ds4_gpu_make_mul_mv_id_args(expert_in_dim, expert_mid_dim, 256,
                                          gate_row_bytes, gate_expert_bytes,
                                          1, n_expert, n_tokens, gate_nr0);
        ds4_gpu_mul_mv_id_args down_args =
            ds4_gpu_make_mul_mv_id_args(expert_mid_dim, out_dim, 256,
                                          down_row_bytes, down_expert_bytes,
                                          n_expert, n_expert, n_tokens, down_nr0);
        const bool use_mm_id = n_tokens >= 32u && ds4_gpu_mul_mm_id_map0_name(n_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
```

<｜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
nt64_t up_inner = 0;
        uint64_t down_inner = 0;
        id<MTLBuffer> gate_buf = ds4_gpu_wrap_model_range(model_map, model_size, gate_offset, gate_tensor_bytes, &gate_inner);
        id<MTLBuffer> up_buf = ds4_gpu_wrap_model_range(model_map, model_size, up_offset, gate_tensor_bytes, &up_inner);
        id<MTLBuffer> down_buf = ds4_gpu_wrap_model_range(model_map, model_size, down_offset, down_tensor_bytes, &down_inner);
        if (!gate_buf || !up_buf || !down_buf) return 0;

        const uint32_t pair_rows = n_tokens * n_expert;
        const uint64_t down_scratch_bytes = (uint64_t)pair_rows * out_dim * sizeof(float);
        if ((n_expert > 1 && !expertsbuf &&
             !ds4_gpu_ensure_scratch_buffer(&g_moe_down_scratch_buffer,
                                              &g_moe_down_scratch_bytes,
                                              (NSUInteger)down_scratch_bytes,
                                              "ds4_moe_down_scratch"))) {
            return 0;
        }

        const uint32_t gate_nr0 = ds4_gpu_routed_mv_nr0(gate_type);
        const uint32_t down_nr0 = ds4_gpu_routed_mv_nr0(down_type);
        id<MTLComputePipelineState> gate_mv_pipeline = ds4_gpu_routed_mv_pipeline(gate_type);
        id<MTLComputePipelineState> down_mv_pipeline = ds4_gpu_routed_mv_pipeline(down_type);
        id<MTLComputePipelineState> gate_mm_pipeline = nil;
        id<MTLComputePipelineState> down_mm_pipeline = nil;
        if (gate_nr0 == 0 || down_nr0 == 0 || !gate_mv_pipeline || !down_mv_pipeline) {
            fprintf(stderr, "ds4: unsupported Metal routed batch MoE quant types gate=%u down=%u\n",
                    gate_type, down_type);
            return 0;
        }

        ds4_gpu_mul_mv_id_args gate_args =
            ds4_gpu_make_mul_mv_id_args(expert_in_dim, expert_mid_dim, 256,
                                          gate_row_bytes, gate_expert_bytes,
                                          1, n_expert, n_tokens, gate_nr0);
        ds4_gpu_mul_mv_id_args down_args =
            ds4_gpu_make_mul_mv_id_args(expert_mid_dim, out_dim, 256,
                                          down_row_bytes, down_expert_bytes,
                                          n_expert, n_expert, n_tokens, down_nr0);
        const bool use_mm_id = n_tokens >= 32u && ds4_gpu_mul_mm_id_map0_name(n_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
```<｜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
_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
         * layer-major pass.  For that shape the prefill expert-major GEMM path
         * is too large, but the decode pair kernels are exactly the right
         * primitive: they read the same activation once and compute routed
         * gate/up together for every selected expert row.  Keep this limited to
         * tiny batches so ordinary prefill keeps using the higher-throughput
         * grouped matmul path.
         */
        const bool use_tiny_pair_mv =
            !g_quality_mode &&
            n_tokens <= 4u &&
            !use_mm_id &&
            ((gate_type == DS4_METAL_TENSOR_IQ2_XXS && g_moe_mul_mv_id_iq2_xxs_pair_pipeline) ||
             (gate_type == DS4_METAL_TENSOR_Q4_K && g_moe_mul_mv_id_q4_k_pair_pipeline));
        ds4_gpu_mul_mm_id_map_args gate_map_args = { 0 };
        ds4_gpu_mul_mm_id_args gate_mm_args = { 0 };
        ds4_gpu_mul_mm_id_args down_mm_args = { 0 };
        id<MTLComputePipelineState> map_pipeline = nil;
        /*
         * The grouped routed-MoE matmul loads activation tiles as half before
         * using SIMD-group MMA.  Store the SwiGLU/route-weight intermediate in
         * that same precision so the down projection avoids a large F32 mid
         * write/read.  --quality or DS4_METAL_MOE_MID_F32 keeps the older F32
         * intermediate for isolated diagnostics.
         */
        const bool request_mid_f16 =
            !g_quality_mode && getenv("DS4_METAL_MOE_MID_F32") == NULL;
        if (use_mm_id) {
            gate_map_args =
                ds4_gpu_make_mul_mm_id_map_args(expert_in_dim, 256, 1, n_expert, n_tokens);
            gate_mm_args =
                ds4_gpu_make_mul_mm_id_args(expert_in_dim, expert_mid_dim, 256,
                                              gate_row_bytes, gate_expert_bytes,
                                              1, n_expert, n_tokens);
            down_mm_args =
                ds4_gpu_make_mul_mm_id_args_src1_size(expert_mid_dim, out_dim, 256,
                                                        down_row_bytes, down_expert_bytes,
                                                        n_expert, n_expert, n_tokens,
                                                        request_mid_f16 ? sizeof(uint16_t) : sizeof(float));

            map_pipeline = ds4_gpu_get_pipeline(ds4_gpu_mul_mm_id_map0_name(n_expert));
```

<｜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
_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
         * layer-major pass.  For that shape the prefill expert-major GEMM path
         * is too large, but the decode pair kernels are exactly the right
         * primitive: they read the same activation once and compute routed
         * gate/up together for every selected expert row.  Keep this limited to
         * tiny batches so ordinary prefill keeps using the higher-throughput
         * grouped matmul path.
         */
        const bool use_tiny_pair_mv =
            !g_quality_mode &&
            n_tokens <= 4u &&
            !use_mm_id &&
            ((gate_type == DS4_METAL_TENSOR_IQ2_XXS && g_moe_mul_mv_id_iq2_xxs_pair_pipeline) ||
             (gate_type == DS4_METAL_TENSOR_Q4_K && g_moe_mul_mv_id_q4_k_pair_pipeline));
        ds4_gpu_mul_mm_id_map_args gate_map_args = { 0 };
        ds4_gpu_mul_mm_id_args gate_mm_args = { 0 };
        ds4_gpu_mul_mm_id_args down_mm_args = { 0 };
        id<MTLComputePipelineState> map_pipeline = nil;
        /*
         * The grouped routed-MoE matmul loads activation tiles as half before
         * using SIMD-group MMA.  Store the SwiGLU/route-weight intermediate in
         * that same precision so the down projection avoids a large F32 mid
         * write/read.  --quality or DS4_METAL_MOE_MID_F32 keeps the older F32
         * intermediate for isolated diagnostics.
         */
        const bool request_mid_f16 =
            !g_quality_mode && getenv("DS4_METAL_MOE_MID_F32") == NULL;
        if (use_mm_id) {
            gate_map_args =
                ds4_gpu_make_mul_mm_id_map_args(expert_in_dim, 256, 1, n_expert, n_tokens);
            gate_mm_args =
                ds4_gpu_make_mul_mm_id_args(expert_in_dim, expert_mid_dim, 256,
                                              gate_row_bytes, gate_expert_bytes,
                                              1, n_expert, n_tokens);
            down_mm_args =
                ds4_gpu_make_mul_mm_id_args_src1_size(expert_mid_dim, out_dim, 256,
                                                        down_row_bytes, down_expert_bytes,
                                                        n_expert, n_expert, n_tokens,
                                                        request_mid_f16 ? sizeof(uint16_t) : sizeof(float));

            map_pipeline = ds4_gpu_get_pipeline(ds4_gpu_mul_mm_id_map0_name(n_expert));
```<｜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
_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
         * layer-major pass.  For that shape the prefill expert-major GEMM path
         * is too large, but the decode pair kernels are exactly the right
         * primitive: they read the same activation once and compute routed
         * gate/up together for every selected expert row.  Keep this limited to
         * tiny batches so ordinary prefill keeps using the higher-throughput
         * grouped matmul path.
         */
        const bool use_tiny_pair_mv =
            !g_quality_mode &&
            n_tokens <= 4u &&
            !use_mm_id &&
            ((gate_type == DS4_METAL_TENSOR_IQ2_XXS && g_moe_mul_mv_id_iq2_xxs_pair_pipeline) ||
             (gate_type == DS4_METAL_TENSOR_Q4_K && g_moe_mul_mv_id_q4_k_pair_pipeline));
        ds4_gpu_mul_mm_id_map_args gate_map_args = { 0 };
        ds4_gpu_mul_mm_id_args gate_mm_args = { 0 };
        ds4_gpu_mul_mm_id_args down_mm_args = { 0 };
        id<MTLComputePipelineState> map_pipeline = nil;
        /*
         * The grouped routed-MoE matmul loads activation tiles as half before
         * using SIMD-group MMA.  Store the SwiGLU/route-weight intermediate in
         * that same precision so the down projection avoids a large F32 mid
         * write/read.  --quality or DS4_METAL_MOE_MID_F32 keeps the older F32
         * intermediate for isolated diagnostics.
         */
        const bool request_mid_f16 =
            !g_quality_mode && getenv("DS4_METAL_MOE_MID_F32") == NULL;
        if (use_mm_id) {
            gate_map_args =
                ds4_gpu_make_mul_mm_id_map_args(expert_in_dim, 256, 1, n_expert, n_tokens);
            gate_mm_args =
                ds4_gpu_make_mul_mm_id_args(expert_in_dim, expert_mid_dim, 256,
                                              gate_row_bytes, gate_expert_bytes,
                                              1, n_expert, n_tokens);
            down_mm_args =
                ds4_gpu_make_mul_mm_id_args_src1_size(expert_mid_dim, out_dim, 256,
                                                        down_row_bytes, down_expert_bytes,
                                                        n_expert, n_expert, n_tokens,
                                                        request_mid_f16 ? sizeof(uint16_t) : sizeof(float));

            map_pipeline = ds4_gpu_get_pipeline(ds4_gpu_mul_mm_id_map0_name(n_expert));
```

<｜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
_expert) != NULL;
        /*
         * MTP verification is neither normal decode nor large prefill: the
         * target model must verify a tiny suffix (usually 2 tokens) in one
         * layer-major pass.  For that shape the prefill expert-major GEMM path
         * is too large, but the decode pair kernels are exactly the right
         * primitive: they read the same activation once and compute routed
         * gate/up together for every selected expert row.  Keep this limited to
         * tiny batches so ordinary prefill keeps using the higher-throughput
         * grouped matmul path.
         */
        const bool use_tiny_pair_mv =
            !g_quality_mode &&
            n_tokens <= 4u &&
            !use_mm_id &&
            ((gate_type == DS4_METAL_TENSOR_IQ2_XXS && g_moe_mul_mv_id_iq2_xxs_pair_pipeline) ||
             (gate_type == DS4_METAL_TENSOR_Q4_K && g_moe_mul_mv_id_q4_k_pair_pipeline));
        ds4_gpu_mul_mm_id_map_args gate_map_args = { 0 };
        ds4_gpu_mul_mm_id_args gate_mm_args = { 0 };
        ds4_gpu_mul_mm_id_args down_mm_args = { 0 };
        id<MTLComputePipelineState> map_pipeline = nil;
        /*
         * The grouped routed-MoE matmul loads activation tiles as half before
         * using SIMD-group MMA.  Store the SwiGLU/route-weight intermediate in
         * that same precision so the down projection avoids a large F32 mid
         * write/read.  --quality or DS4_METAL_MOE_MID_F32 keeps the older F32
         * intermediate for isolated diagnostics.
         */
        const bool request_mid_f16 =
            !g_quality_mode && getenv("DS4_METAL_MOE_MID_F32") == NULL;
        if (use_mm_id) {
            gate_map_args =
                ds4_gpu_make_mul_mm_id_map_args(expert_in_dim, 256, 1, n_expert, n_tokens);
            gate_mm_args =
                ds4_gpu_make_mul_mm_id_args(expert_in_dim, expert_mid_dim, 256,
                                              gate_row_bytes, gate_expert_bytes,
                                              1, n_expert, n_tokens);
            down_mm_args =
                ds4_gpu_make_mul_mm_id_args_src1_size(expert_mid_dim, out_dim, 256,
                                                        down_row_bytes, down_expert_bytes,
                                                        n_expert, n_expert, n_tokens,
                                                        request_mid_f16 ? sizeof(uint16_t) : sizeof(float));

            map_pipeline = ds4_gpu_get_pipeline(ds4_gpu_mul_mm_id_map0_name(n_expert));
```<｜Assistant｜><think>