[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: metal/moe.metal

```metal
e half  *mid_row  = (device half  *)(mid  + (uint64_t)row * args.mid_row_stride);
    device const float *w  = (device const float *)(weights + (uint64_t)row * args.weight_stride);
    const float route_weight = w[0];
    const float c = args.clamp_value;

    for (uint i = tid; i < args.width; i += ntg) {
        float g = gate_row[i];
        float u = up_row[i];
        if (c > 1.0e-6f) {
            g = min(g, c);
            u = clamp(u, -c, c);
            if (args.write_clamped != 0) {
                gate_row[i] = g;
                up_row[i] = u;
            }
        }
        const float silu = g / (1.0f + exp(-g));
        mid_row[i] = (half)(silu * u * route_weight);
    }
}

template <typename type4x4>
void dequantize_q2_K(device const block_q2_K *xb, short il, thread type4x4 & reg) {
    const float d = xb->d;
    const float min = xb->dmin;
    device const uint8_t * q = (device const uint8_t *)xb->qs;
    float dl, ml;
    uint8_t sc = xb->scales[il];

    q = q + 32*(il/8) + 16*(il&1);
    il = (il/2)%4;

    half  coef = il>1 ? (il>2 ? 1/64.h : 1/16.h) : (il>0 ? 1/4.h : 1.h);
    uchar mask = il>1 ? (il>2 ? 192    : 48)     : (il>0 ? 12    : 3);
    dl = d * (sc & 0xF) * coef, ml = min * (sc >> 4);
    for (int i = 0; i < 16; ++i) {
        reg[i/4][i%4] = dl * (q[i] & mask) - ml;
    }
}

static inline uchar2 get_scale_min_k4_just2(int j, int k, device const uchar * q) {
    return j < 4 ? uchar2{uchar(q[j+0+k] & 63), uchar(q[j+4+k] & 63)}
                 : uchar2{uchar((q[j+4+k] & 0xF) | ((q[j-4+k] & 0xc0) >> 2)),
                          uchar((q[j+4+k] >> 4) | ((q[j-0+k] & 0xc0) >> 2))};
}

template <typename type4x4>
void dequantize_q4_K(device const block_q4_K *xb, short il, thread type4x4 &reg) {
    device const uchar *q = xb->qs;

    short is = (il / 4) * 2;
    q = q + (il / 4) * 32 + 16 * (il & 1);
    il = il & 3;
    const uchar2 sc = get_scale_min_k4_just2(is, il / 2, xb->scales);
    const float d = il < 2 ? xb->d : xb->d / 16.h;
    const float min = xb->dmin;
    const float dl = d * sc[0];
    const float ml = min * sc[1];

    const ushort mask = il < 2 ? 0x0F : 0xF0;
    for (int i = 0; i < 16; ++i) {
        reg[i / 4][i % 4] = dl * (q[i] & mask) - ml;
    }
}

template <typename type4x4>
void dequantize_iq2_xxs(device const block_iq2_xxs * xb, short il, thread type4x4 & reg) {
    const float d = xb->d;
    const int ib32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
```

<｜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: metal/moe.metal

```metal
e half  *mid_row  = (device half  *)(mid  + (uint64_t)row * args.mid_row_stride);
    device const float *w  = (device const float *)(weights + (uint64_t)row * args.weight_stride);
    const float route_weight = w[0];
    const float c = args.clamp_value;

    for (uint i = tid; i < args.width; i += ntg) {
        float g = gate_row[i];
        float u = up_row[i];
        if (c > 1.0e-6f) {
            g = min(g, c);
            u = clamp(u, -c, c);
            if (args.write_clamped != 0) {
                gate_row[i] = g;
                up_row[i] = u;
            }
        }
        const float silu = g / (1.0f + exp(-g));
        mid_row[i] = (half)(silu * u * route_weight);
    }
}

template <typename type4x4>
void dequantize_q2_K(device const block_q2_K *xb, short il, thread type4x4 & reg) {
    const float d = xb->d;
    const float min = xb->dmin;
    device const uint8_t * q = (device const uint8_t *)xb->qs;
    float dl, ml;
    uint8_t sc = xb->scales[il];

    q = q + 32*(il/8) + 16*(il&1);
    il = (il/2)%4;

    half  coef = il>1 ? (il>2 ? 1/64.h : 1/16.h) : (il>0 ? 1/4.h : 1.h);
    uchar mask = il>1 ? (il>2 ? 192    : 48)     : (il>0 ? 12    : 3);
    dl = d * (sc & 0xF) * coef, ml = min * (sc >> 4);
    for (int i = 0; i < 16; ++i) {
        reg[i/4][i%4] = dl * (q[i] & mask) - ml;
    }
}

static inline uchar2 get_scale_min_k4_just2(int j, int k, device const uchar * q) {
    return j < 4 ? uchar2{uchar(q[j+0+k] & 63), uchar(q[j+4+k] & 63)}
                 : uchar2{uchar((q[j+4+k] & 0xF) | ((q[j-4+k] & 0xc0) >> 2)),
                          uchar((q[j+4+k] >> 4) | ((q[j-0+k] & 0xc0) >> 2))};
}

template <typename type4x4>
void dequantize_q4_K(device const block_q4_K *xb, short il, thread type4x4 &reg) {
    device const uchar *q = xb->qs;

    short is = (il / 4) * 2;
    q = q + (il / 4) * 32 + 16 * (il & 1);
    il = il & 3;
    const uchar2 sc = get_scale_min_k4_just2(is, il / 2, xb->scales);
    const float d = il < 2 ? xb->d : xb->d / 16.h;
    const float min = xb->dmin;
    const float dl = d * sc[0];
    const float ml = min * sc[1];

    const ushort mask = il < 2 ? 0x0F : 0xF0;
    for (int i = 0; i < 16; ++i) {
        reg[i / 4][i % 4] = dl * (q[i] & mask) - ml;
    }
}

template <typename type4x4>
void dequantize_iq2_xxs(device const block_iq2_xxs * xb, short il, thread type4x4 & reg) {
    const float d = xb->d;
    const int ib32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
```<｜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: metal/moe.metal

```metal
b32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
    thread const uint8_t * aux8 = (thread const uint8_t *)&aux32_g;
    const float dl = d * (0.5f + (aux32_s >> 28)) * 0.25f;
    constant uint8_t * grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+0]);
    uint8_t signs = ksigns_iq2xs[(aux32_s >> 14*il) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
    grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+1]);
    signs = ksigns_iq2xs[(aux32_s >> (14*il+7)) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[2+i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
}

struct ds4_metal_args_mul_mv_id {
    int32_t  nei0;
    int32_t  nei1;
    uint64_t nbi1;
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    int32_t  ne10;
    int32_t  ne11;
    int32_t  ne12;
    int32_t  ne13;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne0;
    int32_t  ne1;
    uint64_t nb1;
    int32_t  nr0;
};

struct ds4_metal_args_mul_mm_id_map0 {
    int32_t  ne02;
    int32_t  ne10;
    int32_t  ne11;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne21;
    int32_t  ne20;
    uint64_t nb21;
};

struct ds4_metal_args_mul_mm_id {
    int32_t  ne00;
    int32_t  ne02;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne11;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    uint64_t nb13;
    int32_t  ne20;
    int32_t  ne21;
    int32_t  ne0;
    int32_t  ne1;
    int16_t  r2;
    int16_t  r3;
};

template<int nr0, typename args_t>
void kernel_mul_mv_q2_K_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;
```

<｜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: metal/moe.metal

```metal
b32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
    thread const uint8_t * aux8 = (thread const uint8_t *)&aux32_g;
    const float dl = d * (0.5f + (aux32_s >> 28)) * 0.25f;
    constant uint8_t * grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+0]);
    uint8_t signs = ksigns_iq2xs[(aux32_s >> 14*il) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
    grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+1]);
    signs = ksigns_iq2xs[(aux32_s >> (14*il+7)) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[2+i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
}

struct ds4_metal_args_mul_mv_id {
    int32_t  nei0;
    int32_t  nei1;
    uint64_t nbi1;
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    int32_t  ne10;
    int32_t  ne11;
    int32_t  ne12;
    int32_t  ne13;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne0;
    int32_t  ne1;
    uint64_t nb1;
    int32_t  nr0;
};

struct ds4_metal_args_mul_mm_id_map0 {
    int32_t  ne02;
    int32_t  ne10;
    int32_t  ne11;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne21;
    int32_t  ne20;
    uint64_t nb21;
};

struct ds4_metal_args_mul_mm_id {
    int32_t  ne00;
    int32_t  ne02;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne11;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    uint64_t nb13;
    int32_t  ne20;
    int32_t  ne21;
    int32_t  ne0;
    int32_t  ne1;
    int16_t  r2;
    int16_t  r3;
};

template<int nr0, typename args_t>
void kernel_mul_mv_q2_K_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;
```<｜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: metal/moe.metal

```metal
b32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
    thread const uint8_t * aux8 = (thread const uint8_t *)&aux32_g;
    const float dl = d * (0.5f + (aux32_s >> 28)) * 0.25f;
    constant uint8_t * grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+0]);
    uint8_t signs = ksigns_iq2xs[(aux32_s >> 14*il) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
    grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+1]);
    signs = ksigns_iq2xs[(aux32_s >> (14*il+7)) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[2+i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
}

struct ds4_metal_args_mul_mv_id {
    int32_t  nei0;
    int32_t  nei1;
    uint64_t nbi1;
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    int32_t  ne10;
    int32_t  ne11;
    int32_t  ne12;
    int32_t  ne13;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne0;
    int32_t  ne1;
    uint64_t nb1;
    int32_t  nr0;
};

struct ds4_metal_args_mul_mm_id_map0 {
    int32_t  ne02;
    int32_t  ne10;
    int32_t  ne11;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne21;
    int32_t  ne20;
    uint64_t nb21;
};

struct ds4_metal_args_mul_mm_id {
    int32_t  ne00;
    int32_t  ne02;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne11;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    uint64_t nb13;
    int32_t  ne20;
    int32_t  ne21;
    int32_t  ne0;
    int32_t  ne1;
    int16_t  r2;
    int16_t  r3;
};

template<int nr0, typename args_t>
void kernel_mul_mv_q2_K_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;
```

<｜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: metal/moe.metal

```metal
b32 = il/2;
    il = il%2;
    device const uint16_t * q2 = xb->qs + 4*ib32;
    const uint32_t aux32_g = q2[0] | (q2[1] << 16);
    const uint32_t aux32_s = q2[2] | (q2[3] << 16);
    thread const uint8_t * aux8 = (thread const uint8_t *)&aux32_g;
    const float dl = d * (0.5f + (aux32_s >> 28)) * 0.25f;
    constant uint8_t * grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+0]);
    uint8_t signs = ksigns_iq2xs[(aux32_s >> 14*il) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
    grid = (constant uint8_t *)(iq2xxs_grid + aux8[2*il+1]);
    signs = ksigns_iq2xs[(aux32_s >> (14*il+7)) & 127];
    for (int i = 0; i < 8; ++i) {
        reg[2+i/4][i%4] = dl * grid[i] * (signs & kmask_iq2xs[i] ? -1.f : 1.f);
    }
}

struct ds4_metal_args_mul_mv_id {
    int32_t  nei0;
    int32_t  nei1;
    uint64_t nbi1;
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    int32_t  ne10;
    int32_t  ne11;
    int32_t  ne12;
    int32_t  ne13;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne0;
    int32_t  ne1;
    uint64_t nb1;
    int32_t  nr0;
};

struct ds4_metal_args_mul_mm_id_map0 {
    int32_t  ne02;
    int32_t  ne10;
    int32_t  ne11;
    uint64_t nb11;
    uint64_t nb12;
    int32_t  ne21;
    int32_t  ne20;
    uint64_t nb21;
};

struct ds4_metal_args_mul_mm_id {
    int32_t  ne00;
    int32_t  ne02;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne11;
    uint64_t nb10;
    uint64_t nb11;
    uint64_t nb12;
    uint64_t nb13;
    int32_t  ne20;
    int32_t  ne21;
    int32_t  ne0;
    int32_t  ne1;
    int16_t  r2;
    int16_t  r3;
};

template<int nr0, typename args_t>
void kernel_mul_mv_q2_K_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;
```<｜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: metal/moe.metal

```metal
t0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_q2_K * x = (device const block_q2_K *) (src0 + offset0);
    device const float      * y = (device const float      *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const short ix = tiisg/8;  // 0...3
    const short it = tiisg%8;  // 0...7
    const short iq = it/4;     // 0 or 1
    const short ir = it%4;     // 0...3
    const short is = (8*ir)/16;// 0 or 1

    device const float * y4 = y + ix * QK_K + 128 * iq + 8 * ir;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};
        for (short i = 0; i < 8; ++i) {
            yl[i+ 0] = y4[i+ 0]; sumy[0] += yl[i+ 0];
            yl[i+ 8] = y4[i+32]; sumy[1] += yl[i+ 8];
            yl[i+16] = y4[i+64]; sumy[2] += yl[i+16];
            yl[i+24] = y4[i+96]; sumy[3] += yl[i+24];
        }

        device const uint8_t  * sc = (device const uint8_t  *)x[ib].scales + 8*iq + is;
        device const uint16_t * qs = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half     * dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};
            for (int i = 0; i < 8; i += 2) {
                acc1[0] += yl[i+ 0] * (qs[i/2] & 0x0003);
                acc2[0] += yl[i+ 1] * (qs[i/2] & 0x0300);
                acc1[1] += yl[i+ 8] * (qs[i/2] & 0x000c);
                acc2[1] += yl[i+ 9] * (qs[i/2] & 0x0c00);
                acc1[2] += yl[i+16] * (qs[i/2] & 0x0030);
                acc2[2] += yl[i+17] * (qs[i/2] & 0x3000);
                acc1[3] += yl[i+24] * (qs[i/2] & 0x00c0);
                acc2[3] += yl[i+25] * (qs[i/2] & 0xc000);
            }
            float dall = dh[0];
            float dmin = dh[1] * 1.f/16.f;
            sumf[row] += dall * ((acc1[0] + 1.f/256.f * acc2[0]) * (sc[0] & 0xF) * 1.f/ 1.f +
                                 (acc1[1] + 1.f/256.f * acc2[1]) * (sc[2] & 0xF) * 1.f/ 4.f +
                                 (acc1[2] + 1.f/256.f * acc2[2]) * (sc[4] & 0xF) * 1.f/16.f +
                                 (acc1[3] + 1.f/256.f * acc2[3]) * (sc[6] & 0xF) * 1.f/64.f) -
                         dmin * (sumy[0] * (sc[0] & 0xF0) + sumy[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }
```

<｜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: metal/moe.metal

```metal
t0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_q2_K * x = (device const block_q2_K *) (src0 + offset0);
    device const float      * y = (device const float      *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const short ix = tiisg/8;  // 0...3
    const short it = tiisg%8;  // 0...7
    const short iq = it/4;     // 0 or 1
    const short ir = it%4;     // 0...3
    const short is = (8*ir)/16;// 0 or 1

    device const float * y4 = y + ix * QK_K + 128 * iq + 8 * ir;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};
        for (short i = 0; i < 8; ++i) {
            yl[i+ 0] = y4[i+ 0]; sumy[0] += yl[i+ 0];
            yl[i+ 8] = y4[i+32]; sumy[1] += yl[i+ 8];
            yl[i+16] = y4[i+64]; sumy[2] += yl[i+16];
            yl[i+24] = y4[i+96]; sumy[3] += yl[i+24];
        }

        device const uint8_t  * sc = (device const uint8_t  *)x[ib].scales + 8*iq + is;
        device const uint16_t * qs = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half     * dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};
            for (int i = 0; i < 8; i += 2) {
                acc1[0] += yl[i+ 0] * (qs[i/2] & 0x0003);
                acc2[0] += yl[i+ 1] * (qs[i/2] & 0x0300);
                acc1[1] += yl[i+ 8] * (qs[i/2] & 0x000c);
                acc2[1] += yl[i+ 9] * (qs[i/2] & 0x0c00);
                acc1[2] += yl[i+16] * (qs[i/2] & 0x0030);
                acc2[2] += yl[i+17] * (qs[i/2] & 0x3000);
                acc1[3] += yl[i+24] * (qs[i/2] & 0x00c0);
                acc2[3] += yl[i+25] * (qs[i/2] & 0xc000);
            }
            float dall = dh[0];
            float dmin = dh[1] * 1.f/16.f;
            sumf[row] += dall * ((acc1[0] + 1.f/256.f * acc2[0]) * (sc[0] & 0xF) * 1.f/ 1.f +
                                 (acc1[1] + 1.f/256.f * acc2[1]) * (sc[2] & 0xF) * 1.f/ 4.f +
                                 (acc1[2] + 1.f/256.f * acc2[2]) * (sc[4] & 0xF) * 1.f/16.f +
                                 (acc1[3] + 1.f/256.f * acc2[3]) * (sc[6] & 0xF) * 1.f/64.f) -
                         dmin * (sumy[0] * (sc[0] & 0xF0) + sumy[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }
```<｜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: metal/moe.metal

```metal
t0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_q2_K * x = (device const block_q2_K *) (src0 + offset0);
    device const float      * y = (device const float      *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const short ix = tiisg/8;  // 0...3
    const short it = tiisg%8;  // 0...7
    const short iq = it/4;     // 0 or 1
    const short ir = it%4;     // 0...3
    const short is = (8*ir)/16;// 0 or 1

    device const float * y4 = y + ix * QK_K + 128 * iq + 8 * ir;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};
        for (short i = 0; i < 8; ++i) {
            yl[i+ 0] = y4[i+ 0]; sumy[0] += yl[i+ 0];
            yl[i+ 8] = y4[i+32]; sumy[1] += yl[i+ 8];
            yl[i+16] = y4[i+64]; sumy[2] += yl[i+16];
            yl[i+24] = y4[i+96]; sumy[3] += yl[i+24];
        }

        device const uint8_t  * sc = (device const uint8_t  *)x[ib].scales + 8*iq + is;
        device const uint16_t * qs = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half     * dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};
            for (int i = 0; i < 8; i += 2) {
                acc1[0] += yl[i+ 0] * (qs[i/2] & 0x0003);
                acc2[0] += yl[i+ 1] * (qs[i/2] & 0x0300);
                acc1[1] += yl[i+ 8] * (qs[i/2] & 0x000c);
                acc2[1] += yl[i+ 9] * (qs[i/2] & 0x0c00);
                acc1[2] += yl[i+16] * (qs[i/2] & 0x0030);
                acc2[2] += yl[i+17] * (qs[i/2] & 0x3000);
                acc1[3] += yl[i+24] * (qs[i/2] & 0x00c0);
                acc2[3] += yl[i+25] * (qs[i/2] & 0xc000);
            }
            float dall = dh[0];
            float dmin = dh[1] * 1.f/16.f;
            sumf[row] += dall * ((acc1[0] + 1.f/256.f * acc2[0]) * (sc[0] & 0xF) * 1.f/ 1.f +
                                 (acc1[1] + 1.f/256.f * acc2[1]) * (sc[2] & 0xF) * 1.f/ 4.f +
                                 (acc1[2] + 1.f/256.f * acc2[2]) * (sc[4] & 0xF) * 1.f/16.f +
                                 (acc1[3] + 1.f/256.f * acc2[3]) * (sc[6] & 0xF) * 1.f/64.f) -
                         dmin * (sumy[0] * (sc[0] & 0xF0) + sumy[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }
```

<｜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: metal/moe.metal

```metal
t0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_q2_K * x = (device const block_q2_K *) (src0 + offset0);
    device const float      * y = (device const float      *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const short ix = tiisg/8;  // 0...3
    const short it = tiisg%8;  // 0...7
    const short iq = it/4;     // 0 or 1
    const short ir = it%4;     // 0...3
    const short is = (8*ir)/16;// 0 or 1

    device const float * y4 = y + ix * QK_K + 128 * iq + 8 * ir;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};
        for (short i = 0; i < 8; ++i) {
            yl[i+ 0] = y4[i+ 0]; sumy[0] += yl[i+ 0];
            yl[i+ 8] = y4[i+32]; sumy[1] += yl[i+ 8];
            yl[i+16] = y4[i+64]; sumy[2] += yl[i+16];
            yl[i+24] = y4[i+96]; sumy[3] += yl[i+24];
        }

        device const uint8_t  * sc = (device const uint8_t  *)x[ib].scales + 8*iq + is;
        device const uint16_t * qs = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half     * dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};
            for (int i = 0; i < 8; i += 2) {
                acc1[0] += yl[i+ 0] * (qs[i/2] & 0x0003);
                acc2[0] += yl[i+ 1] * (qs[i/2] & 0x0300);
                acc1[1] += yl[i+ 8] * (qs[i/2] & 0x000c);
                acc2[1] += yl[i+ 9] * (qs[i/2] & 0x0c00);
                acc1[2] += yl[i+16] * (qs[i/2] & 0x0030);
                acc2[2] += yl[i+17] * (qs[i/2] & 0x3000);
                acc1[3] += yl[i+24] * (qs[i/2] & 0x00c0);
                acc2[3] += yl[i+25] * (qs[i/2] & 0xc000);
            }
            float dall = dh[0];
            float dmin = dh[1] * 1.f/16.f;
            sumf[row] += dall * ((acc1[0] + 1.f/256.f * acc2[0]) * (sc[0] & 0xF) * 1.f/ 1.f +
                                 (acc1[1] + 1.f/256.f * acc2[1]) * (sc[2] & 0xF) * 1.f/ 4.f +
                                 (acc1[2] + 1.f/256.f * acc2[2]) * (sc[4] & 0xF) * 1.f/16.f +
                                 (acc1[3] + 1.f/256.f * acc2[3]) * (sc[6] & 0xF) * 1.f/64.f) -
                         dmin * (sumy[0] * (sc[0] & 0xF0) + sumy[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }
```<｜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: metal/moe.metal

```metal
y[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }

        y4 += 4 * QK_K;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }
}

template<int nr0, typename args_t>
void kernel_mul_mv_q4_K_f32_impl(
        args_t args,
        device const char *src0,
        device const char *src1,
        device       char *dst,
        threadgroup  char *shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    constexpr uint16_t kmask1 = 0x3f3f;
    constexpr uint16_t kmask2 = 0x0f0f;
    constexpr uint16_t kmask3 = 0xc0c0;

    const short ix = tiisg / 8;
    const short it = tiisg % 8;
    const short iq = it / 4;
    const short ir = it % 4;

    const int nb = args.ne00 / QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im % args.ne12;
    const uint i13 = im / args.ne12;

    const uint64_t offset0 = first_row * args.nb01 + (i12 / args.r2) * args.nb02 + (i13 / args.r3) * args.nb03;
    const uint64_t offset1 = r1 * args.nb11 + i12 * args.nb12 + i13 * args.nb13;

    device const block_q4_K *x = (device const block_q4_K *)(src0 + offset0);
    device const float *y = (device const float *)(src1 + offset1);

    float yl[16];
    float yh[16];
    float sumf[nr0] = {0.f};

    device const float *y4 = y + ix * QK_K + 64 * iq + 8 * ir;

    uint16_t sc16[4];
    thread const uint8_t *sc8 = (thread const uint8_t *)sc16;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};

        for (short i = 0; i < 8; ++i) {
            yl[i + 0] = y4[i +   0]; sumy[0] += yl[i + 0];
            yl[i + 8] = y4[i +  32]; sumy[1] += yl[i + 8];
            yh[i + 0] = y4[i + 128]; sumy[2] += yh[i + 0];
            yh[i + 8] = y4[i + 160]; sumy[3] += yh[i + 8];
        }

        device const uint16_t *sc = (device const uint16_t *)x[ib].scales + iq;
        device const uint16_t *q1 = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
```

<｜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: metal/moe.metal

```metal
y[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }

        y4 += 4 * QK_K;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }
}

template<int nr0, typename args_t>
void kernel_mul_mv_q4_K_f32_impl(
        args_t args,
        device const char *src0,
        device const char *src1,
        device       char *dst,
        threadgroup  char *shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    constexpr uint16_t kmask1 = 0x3f3f;
    constexpr uint16_t kmask2 = 0x0f0f;
    constexpr uint16_t kmask3 = 0xc0c0;

    const short ix = tiisg / 8;
    const short it = tiisg % 8;
    const short iq = it / 4;
    const short ir = it % 4;

    const int nb = args.ne00 / QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im % args.ne12;
    const uint i13 = im / args.ne12;

    const uint64_t offset0 = first_row * args.nb01 + (i12 / args.r2) * args.nb02 + (i13 / args.r3) * args.nb03;
    const uint64_t offset1 = r1 * args.nb11 + i12 * args.nb12 + i13 * args.nb13;

    device const block_q4_K *x = (device const block_q4_K *)(src0 + offset0);
    device const float *y = (device const float *)(src1 + offset1);

    float yl[16];
    float yh[16];
    float sumf[nr0] = {0.f};

    device const float *y4 = y + ix * QK_K + 64 * iq + 8 * ir;

    uint16_t sc16[4];
    thread const uint8_t *sc8 = (thread const uint8_t *)sc16;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};

        for (short i = 0; i < 8; ++i) {
            yl[i + 0] = y4[i +   0]; sumy[0] += yl[i + 0];
            yl[i + 8] = y4[i +  32]; sumy[1] += yl[i + 8];
            yh[i + 0] = y4[i + 128]; sumy[2] += yh[i + 0];
            yh[i + 8] = y4[i + 160]; sumy[3] += yh[i + 8];
        }

        device const uint16_t *sc = (device const uint16_t *)x[ib].scales + iq;
        device const uint16_t *q1 = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
```<｜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: metal/moe.metal

```metal
y[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }

        y4 += 4 * QK_K;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }
}

template<int nr0, typename args_t>
void kernel_mul_mv_q4_K_f32_impl(
        args_t args,
        device const char *src0,
        device const char *src1,
        device       char *dst,
        threadgroup  char *shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    constexpr uint16_t kmask1 = 0x3f3f;
    constexpr uint16_t kmask2 = 0x0f0f;
    constexpr uint16_t kmask3 = 0xc0c0;

    const short ix = tiisg / 8;
    const short it = tiisg % 8;
    const short iq = it / 4;
    const short ir = it % 4;

    const int nb = args.ne00 / QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im % args.ne12;
    const uint i13 = im / args.ne12;

    const uint64_t offset0 = first_row * args.nb01 + (i12 / args.r2) * args.nb02 + (i13 / args.r3) * args.nb03;
    const uint64_t offset1 = r1 * args.nb11 + i12 * args.nb12 + i13 * args.nb13;

    device const block_q4_K *x = (device const block_q4_K *)(src0 + offset0);
    device const float *y = (device const float *)(src1 + offset1);

    float yl[16];
    float yh[16];
    float sumf[nr0] = {0.f};

    device const float *y4 = y + ix * QK_K + 64 * iq + 8 * ir;

    uint16_t sc16[4];
    thread const uint8_t *sc8 = (thread const uint8_t *)sc16;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};

        for (short i = 0; i < 8; ++i) {
            yl[i + 0] = y4[i +   0]; sumy[0] += yl[i + 0];
            yl[i + 8] = y4[i +  32]; sumy[1] += yl[i + 8];
            yh[i + 0] = y4[i + 128]; sumy[2] += yh[i + 0];
            yh[i + 8] = y4[i + 160]; sumy[3] += yh[i + 8];
        }

        device const uint16_t *sc = (device const uint16_t *)x[ib].scales + iq;
        device const uint16_t *q1 = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
```

<｜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: metal/moe.metal

```metal
y[1] * (sc[2] & 0xF0) + sumy[2] * (sc[4] & 0xF0) + sumy[3] * (sc[6] & 0xF0));

            qs += args.nb01/2;
            sc += args.nb01;
            dh += args.nb01/2;
        }

        y4 += 4 * QK_K;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }
}

template<int nr0, typename args_t>
void kernel_mul_mv_q4_K_f32_impl(
        args_t args,
        device const char *src0,
        device const char *src1,
        device       char *dst,
        threadgroup  char *shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    constexpr uint16_t kmask1 = 0x3f3f;
    constexpr uint16_t kmask2 = 0x0f0f;
    constexpr uint16_t kmask3 = 0xc0c0;

    const short ix = tiisg / 8;
    const short it = tiisg % 8;
    const short iq = it / 4;
    const short ir = it % 4;

    const int nb = args.ne00 / QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im % args.ne12;
    const uint i13 = im / args.ne12;

    const uint64_t offset0 = first_row * args.nb01 + (i12 / args.r2) * args.nb02 + (i13 / args.r3) * args.nb03;
    const uint64_t offset1 = r1 * args.nb11 + i12 * args.nb12 + i13 * args.nb13;

    device const block_q4_K *x = (device const block_q4_K *)(src0 + offset0);
    device const float *y = (device const float *)(src1 + offset1);

    float yl[16];
    float yh[16];
    float sumf[nr0] = {0.f};

    device const float *y4 = y + ix * QK_K + 64 * iq + 8 * ir;

    uint16_t sc16[4];
    thread const uint8_t *sc8 = (thread const uint8_t *)sc16;

    for (int ib = ix; ib < nb; ib += 4) {
        float4 sumy = {0.f, 0.f, 0.f, 0.f};

        for (short i = 0; i < 8; ++i) {
            yl[i + 0] = y4[i +   0]; sumy[0] += yl[i + 0];
            yl[i + 8] = y4[i +  32]; sumy[1] += yl[i + 8];
            yh[i + 0] = y4[i + 128]; sumy[2] += yh[i + 0];
            yh[i + 8] = y4[i + 160]; sumy[3] += yh[i + 8];
        }

        device const uint16_t *sc = (device const uint16_t *)x[ib].scales + iq;
        device const uint16_t *q1 = (device const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
```<｜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: metal/moe.metal

```metal
evice const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
            sc16[1] = sc[2] & kmask1;
            sc16[2] = ((sc[4] >> 0) & kmask2) | ((sc[0] & kmask3) >> 2);
            sc16[3] = ((sc[4] >> 4) & kmask2) | ((sc[2] & kmask3) >> 2);

            device const uint16_t *q2 = q1 + 32;

            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};

            FOR_UNROLL (short i = 0; i < 4; ++i) {
                acc1[0] += yl[2 * i + 0] * (q1[i] & 0x000F);
                acc1[1] += yl[2 * i + 1] * (q1[i] & 0x0F00);
                acc1[2] += yl[2 * i + 8] * (q1[i] & 0x00F0);
                acc1[3] += yl[2 * i + 9] * (q1[i] & 0xF000);
                acc2[0] += yh[2 * i + 0] * (q2[i] & 0x000F);
                acc2[1] += yh[2 * i + 1] * (q2[i] & 0x0F00);
                acc2[2] += yh[2 * i + 8] * (q2[i] & 0x00F0);
                acc2[3] += yh[2 * i + 9] * (q2[i] & 0xF000);
            }

            sumf[row] += dh[0] * ((acc1[0] + 1.f / 256.f * acc1[1]) * sc8[0] +
                                  (acc1[2] + 1.f / 256.f * acc1[3]) * sc8[1] * 1.f / 16.f +
                                  (acc2[0] + 1.f / 256.f * acc2[1]) * sc8[4] +
                                  (acc2[2] + 1.f / 256.f * acc2[3]) * sc8[5] * 1.f / 16.f) -
                         dh[1] * (sumy[0] * sc8[2] + sumy[1] * sc8[3] + sumy[2] * sc8[6] + sumy[3] * sc8[7]);

            q1 += args.nb01 / 2;
            sc += args.nb01 / 2;
            dh += args.nb01 / 2;
        }

        y4 += 4 * QK_K;
    }

    device float *dst_f32 = (device float *)dst + (uint64_t)im * args.ne0 * args.ne1 + (uint64_t)r1 * args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }

    (void)shmem;
}

template<int nr0, typename args_t>
void kernel_mul_mv_iq2_xxs_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;
```

<｜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: metal/moe.metal

```metal
evice const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
            sc16[1] = sc[2] & kmask1;
            sc16[2] = ((sc[4] >> 0) & kmask2) | ((sc[0] & kmask3) >> 2);
            sc16[3] = ((sc[4] >> 4) & kmask2) | ((sc[2] & kmask3) >> 2);

            device const uint16_t *q2 = q1 + 32;

            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};

            FOR_UNROLL (short i = 0; i < 4; ++i) {
                acc1[0] += yl[2 * i + 0] * (q1[i] & 0x000F);
                acc1[1] += yl[2 * i + 1] * (q1[i] & 0x0F00);
                acc1[2] += yl[2 * i + 8] * (q1[i] & 0x00F0);
                acc1[3] += yl[2 * i + 9] * (q1[i] & 0xF000);
                acc2[0] += yh[2 * i + 0] * (q2[i] & 0x000F);
                acc2[1] += yh[2 * i + 1] * (q2[i] & 0x0F00);
                acc2[2] += yh[2 * i + 8] * (q2[i] & 0x00F0);
                acc2[3] += yh[2 * i + 9] * (q2[i] & 0xF000);
            }

            sumf[row] += dh[0] * ((acc1[0] + 1.f / 256.f * acc1[1]) * sc8[0] +
                                  (acc1[2] + 1.f / 256.f * acc1[3]) * sc8[1] * 1.f / 16.f +
                                  (acc2[0] + 1.f / 256.f * acc2[1]) * sc8[4] +
                                  (acc2[2] + 1.f / 256.f * acc2[3]) * sc8[5] * 1.f / 16.f) -
                         dh[1] * (sumy[0] * sc8[2] + sumy[1] * sc8[3] + sumy[2] * sc8[6] + sumy[3] * sc8[7]);

            q1 += args.nb01 / 2;
            sc += args.nb01 / 2;
            dh += args.nb01 / 2;
        }

        y4 += 4 * QK_K;
    }

    device float *dst_f32 = (device float *)dst + (uint64_t)im * args.ne0 * args.ne1 + (uint64_t)r1 * args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }

    (void)shmem;
}

template<int nr0, typename args_t>
void kernel_mul_mv_iq2_xxs_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;
```<｜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: metal/moe.metal

```metal
evice const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
            sc16[1] = sc[2] & kmask1;
            sc16[2] = ((sc[4] >> 0) & kmask2) | ((sc[0] & kmask3) >> 2);
            sc16[3] = ((sc[4] >> 4) & kmask2) | ((sc[2] & kmask3) >> 2);

            device const uint16_t *q2 = q1 + 32;

            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};

            FOR_UNROLL (short i = 0; i < 4; ++i) {
                acc1[0] += yl[2 * i + 0] * (q1[i] & 0x000F);
                acc1[1] += yl[2 * i + 1] * (q1[i] & 0x0F00);
                acc1[2] += yl[2 * i + 8] * (q1[i] & 0x00F0);
                acc1[3] += yl[2 * i + 9] * (q1[i] & 0xF000);
                acc2[0] += yh[2 * i + 0] * (q2[i] & 0x000F);
                acc2[1] += yh[2 * i + 1] * (q2[i] & 0x0F00);
                acc2[2] += yh[2 * i + 8] * (q2[i] & 0x00F0);
                acc2[3] += yh[2 * i + 9] * (q2[i] & 0xF000);
            }

            sumf[row] += dh[0] * ((acc1[0] + 1.f / 256.f * acc1[1]) * sc8[0] +
                                  (acc1[2] + 1.f / 256.f * acc1[3]) * sc8[1] * 1.f / 16.f +
                                  (acc2[0] + 1.f / 256.f * acc2[1]) * sc8[4] +
                                  (acc2[2] + 1.f / 256.f * acc2[3]) * sc8[5] * 1.f / 16.f) -
                         dh[1] * (sumy[0] * sc8[2] + sumy[1] * sc8[3] + sumy[2] * sc8[6] + sumy[3] * sc8[7]);

            q1 += args.nb01 / 2;
            sc += args.nb01 / 2;
            dh += args.nb01 / 2;
        }

        y4 += 4 * QK_K;
    }

    device float *dst_f32 = (device float *)dst + (uint64_t)im * args.ne0 * args.ne1 + (uint64_t)r1 * args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }

    (void)shmem;
}

template<int nr0, typename args_t>
void kernel_mul_mv_iq2_xxs_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;
```

<｜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: metal/moe.metal

```metal
evice const uint16_t *)x[ib].qs + 16 * iq + 4 * ir;
        device const half *dh = &x[ib].d;

        for (short row = 0; row < nr0; row++) {
            sc16[0] = sc[0] & kmask1;
            sc16[1] = sc[2] & kmask1;
            sc16[2] = ((sc[4] >> 0) & kmask2) | ((sc[0] & kmask3) >> 2);
            sc16[3] = ((sc[4] >> 4) & kmask2) | ((sc[2] & kmask3) >> 2);

            device const uint16_t *q2 = q1 + 32;

            float4 acc1 = {0.f, 0.f, 0.f, 0.f};
            float4 acc2 = {0.f, 0.f, 0.f, 0.f};

            FOR_UNROLL (short i = 0; i < 4; ++i) {
                acc1[0] += yl[2 * i + 0] * (q1[i] & 0x000F);
                acc1[1] += yl[2 * i + 1] * (q1[i] & 0x0F00);
                acc1[2] += yl[2 * i + 8] * (q1[i] & 0x00F0);
                acc1[3] += yl[2 * i + 9] * (q1[i] & 0xF000);
                acc2[0] += yh[2 * i + 0] * (q2[i] & 0x000F);
                acc2[1] += yh[2 * i + 1] * (q2[i] & 0x0F00);
                acc2[2] += yh[2 * i + 8] * (q2[i] & 0x00F0);
                acc2[3] += yh[2 * i + 9] * (q2[i] & 0xF000);
            }

            sumf[row] += dh[0] * ((acc1[0] + 1.f / 256.f * acc1[1]) * sc8[0] +
                                  (acc1[2] + 1.f / 256.f * acc1[3]) * sc8[1] * 1.f / 16.f +
                                  (acc2[0] + 1.f / 256.f * acc2[1]) * sc8[4] +
                                  (acc2[2] + 1.f / 256.f * acc2[3]) * sc8[5] * 1.f / 16.f) -
                         dh[1] * (sumy[0] * sc8[2] + sumy[1] * sc8[3] + sumy[2] * sc8[6] + sumy[3] * sc8[7]);

            q1 += args.nb01 / 2;
            sc += args.nb01 / 2;
            dh += args.nb01 / 2;
        }

        y4 += 4 * QK_K;
    }

    device float *dst_f32 = (device float *)dst + (uint64_t)im * args.ne0 * args.ne1 + (uint64_t)r1 * args.ne0;

    for (int row = 0; row < nr0 && first_row + row < args.ne0; ++row) {
        float sum_all = simd_sum(sumf[row]);
        if (tiisg == 0) {
            dst_f32[first_row + row] = sum_all;
        }
    }

    (void)shmem;
}

template<int nr0, typename args_t>
void kernel_mul_mv_iq2_xxs_f32_impl(
        args_t args,
        device const char * src0,
        device const char * src1,
        device       char * dst,
        threadgroup  char * shmem,
        uint3  tgpig,
        ushort tiisg,
        ushort sgitg) {
    const short NSG = FC_mul_mv_nsg;

    const int nb = args.ne00/QK_K;

    const int r0 = tgpig.x;
    const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;
```<｜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: metal/moe.metal

```metal
const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_iq2_xxs * x = (device const block_iq2_xxs *) (src0 + offset0);
    device const float         * y = (device const float         *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const int nb32 = nb * (QK_K / 32);

    threadgroup uint64_t * svalues = (threadgroup uint64_t *)(shmem);
    threadgroup uint8_t  * ssigns  = (threadgroup uint8_t  *)(svalues + 256);
    {
        int nval = 4;
        int pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) svalues[pos + i] = ds4_metal_iq2xxs_grid[pos + i];
        nval = 2;
        pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) ssigns[pos+i] = ds4_metal_ksigns_iq2xs[pos+i];
        threadgroup_barrier(mem_flags::mem_threadgroup);
    }

    const int ix = tiisg;

    device const float * y4 = y + 32 * ix;

    for (int ib32 = ix; ib32 < nb32; ib32 += 32) {
        for (short i = 0; i < 32; ++i) {
            yl[i] = y4[i];
        }

        const int ibl = ib32 / (QK_K / 32);
        const int ib  = ib32 % (QK_K / 32);

        device const block_iq2_xxs * xr = x + ibl;
        device const uint16_t * q2 = xr->qs + 4 * ib;
        device const half * dh = &xr->d;

        for (short row = 0; row < nr0; row++) {
            const float db = dh[0];
            device const uint8_t * aux8 = (device const uint8_t *)q2;
            const uint32_t aux32 = q2[2] | (q2[3] << 16);
            const float d = db * (0.5f + (aux32 >> 28));

            float sum = 0;
            for (short l = 0; l < 4; ++l) {
                const threadgroup uint8_t * grid = (const threadgroup uint8_t *)(svalues + aux8[l]);
                const uint8_t signs = ssigns[(aux32 >> 7*l) & 127];
                for (short j = 0; j < 8; ++j) {
                    sum += yl[8*l + j] * grid[j] * (signs & ds4_metal_kmask_iq2xs[j] ? -1.f : 1.f);
                }
            }
            sumf[row] += d * sum;

            dh += args.nb01/2;
            q2 += args.nb01/2;
        }

        y4 += 32 * 32;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;
```

<｜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: metal/moe.metal

```metal
const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_iq2_xxs * x = (device const block_iq2_xxs *) (src0 + offset0);
    device const float         * y = (device const float         *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const int nb32 = nb * (QK_K / 32);

    threadgroup uint64_t * svalues = (threadgroup uint64_t *)(shmem);
    threadgroup uint8_t  * ssigns  = (threadgroup uint8_t  *)(svalues + 256);
    {
        int nval = 4;
        int pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) svalues[pos + i] = ds4_metal_iq2xxs_grid[pos + i];
        nval = 2;
        pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) ssigns[pos+i] = ds4_metal_ksigns_iq2xs[pos+i];
        threadgroup_barrier(mem_flags::mem_threadgroup);
    }

    const int ix = tiisg;

    device const float * y4 = y + 32 * ix;

    for (int ib32 = ix; ib32 < nb32; ib32 += 32) {
        for (short i = 0; i < 32; ++i) {
            yl[i] = y4[i];
        }

        const int ibl = ib32 / (QK_K / 32);
        const int ib  = ib32 % (QK_K / 32);

        device const block_iq2_xxs * xr = x + ibl;
        device const uint16_t * q2 = xr->qs + 4 * ib;
        device const half * dh = &xr->d;

        for (short row = 0; row < nr0; row++) {
            const float db = dh[0];
            device const uint8_t * aux8 = (device const uint8_t *)q2;
            const uint32_t aux32 = q2[2] | (q2[3] << 16);
            const float d = db * (0.5f + (aux32 >> 28));

            float sum = 0;
            for (short l = 0; l < 4; ++l) {
                const threadgroup uint8_t * grid = (const threadgroup uint8_t *)(svalues + aux8[l]);
                const uint8_t signs = ssigns[(aux32 >> 7*l) & 127];
                for (short j = 0; j < 8; ++j) {
                    sum += yl[8*l + j] * grid[j] * (signs & ds4_metal_kmask_iq2xs[j] ? -1.f : 1.f);
                }
            }
            sumf[row] += d * sum;

            dh += args.nb01/2;
            q2 += args.nb01/2;
        }

        y4 += 32 * 32;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;
```<｜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: metal/moe.metal

```metal
const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_iq2_xxs * x = (device const block_iq2_xxs *) (src0 + offset0);
    device const float         * y = (device const float         *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const int nb32 = nb * (QK_K / 32);

    threadgroup uint64_t * svalues = (threadgroup uint64_t *)(shmem);
    threadgroup uint8_t  * ssigns  = (threadgroup uint8_t  *)(svalues + 256);
    {
        int nval = 4;
        int pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) svalues[pos + i] = ds4_metal_iq2xxs_grid[pos + i];
        nval = 2;
        pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) ssigns[pos+i] = ds4_metal_ksigns_iq2xs[pos+i];
        threadgroup_barrier(mem_flags::mem_threadgroup);
    }

    const int ix = tiisg;

    device const float * y4 = y + 32 * ix;

    for (int ib32 = ix; ib32 < nb32; ib32 += 32) {
        for (short i = 0; i < 32; ++i) {
            yl[i] = y4[i];
        }

        const int ibl = ib32 / (QK_K / 32);
        const int ib  = ib32 % (QK_K / 32);

        device const block_iq2_xxs * xr = x + ibl;
        device const uint16_t * q2 = xr->qs + 4 * ib;
        device const half * dh = &xr->d;

        for (short row = 0; row < nr0; row++) {
            const float db = dh[0];
            device const uint8_t * aux8 = (device const uint8_t *)q2;
            const uint32_t aux32 = q2[2] | (q2[3] << 16);
            const float d = db * (0.5f + (aux32 >> 28));

            float sum = 0;
            for (short l = 0; l < 4; ++l) {
                const threadgroup uint8_t * grid = (const threadgroup uint8_t *)(svalues + aux8[l]);
                const uint8_t signs = ssigns[(aux32 >> 7*l) & 127];
                for (short j = 0; j < 8; ++j) {
                    sum += yl[8*l + j] * grid[j] * (signs & ds4_metal_kmask_iq2xs[j] ? -1.f : 1.f);
                }
            }
            sumf[row] += d * sum;

            dh += args.nb01/2;
            q2 += args.nb01/2;
        }

        y4 += 32 * 32;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;
```

<｜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: metal/moe.metal

```metal
const int r1 = tgpig.y;
    const int im = tgpig.z;

    const int first_row = (r0 * NSG + sgitg) * nr0;

    const uint i12 = im%args.ne12;
    const uint i13 = im/args.ne12;

    const uint64_t offset0 = first_row*args.nb01 + (i12/args.r2)*args.nb02 + (i13/args.r3)*args.nb03;
    const uint64_t offset1 =        r1*args.nb11 + (i12        )*args.nb12 + (i13        )*args.nb13;

    device const block_iq2_xxs * x = (device const block_iq2_xxs *) (src0 + offset0);
    device const float         * y = (device const float         *) (src1 + offset1);

    float yl[32];
    float sumf[nr0]={0.f};

    const int nb32 = nb * (QK_K / 32);

    threadgroup uint64_t * svalues = (threadgroup uint64_t *)(shmem);
    threadgroup uint8_t  * ssigns  = (threadgroup uint8_t  *)(svalues + 256);
    {
        int nval = 4;
        int pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) svalues[pos + i] = ds4_metal_iq2xxs_grid[pos + i];
        nval = 2;
        pos  = (32*sgitg + tiisg)*nval;
        for (int i = 0; i < nval; ++i) ssigns[pos+i] = ds4_metal_ksigns_iq2xs[pos+i];
        threadgroup_barrier(mem_flags::mem_threadgroup);
    }

    const int ix = tiisg;

    device const float * y4 = y + 32 * ix;

    for (int ib32 = ix; ib32 < nb32; ib32 += 32) {
        for (short i = 0; i < 32; ++i) {
            yl[i] = y4[i];
        }

        const int ibl = ib32 / (QK_K / 32);
        const int ib  = ib32 % (QK_K / 32);

        device const block_iq2_xxs * xr = x + ibl;
        device const uint16_t * q2 = xr->qs + 4 * ib;
        device const half * dh = &xr->d;

        for (short row = 0; row < nr0; row++) {
            const float db = dh[0];
            device const uint8_t * aux8 = (device const uint8_t *)q2;
            const uint32_t aux32 = q2[2] | (q2[3] << 16);
            const float d = db * (0.5f + (aux32 >> 28));

            float sum = 0;
            for (short l = 0; l < 4; ++l) {
                const threadgroup uint8_t * grid = (const threadgroup uint8_t *)(svalues + aux8[l]);
                const uint8_t signs = ssigns[(aux32 >> 7*l) & 127];
                for (short j = 0; j < 8; ++j) {
                    sum += yl[8*l + j] * grid[j] * (signs & ds4_metal_kmask_iq2xs[j] ? -1.f : 1.f);
                }
            }
            sumf[row] += d * sum;

            dh += args.nb01/2;
            q2 += args.nb01/2;
        }

        y4 += 32 * 32;
    }

    device float * dst_f32 = (device float *) dst + (uint64_t)im*args.ne0*args.ne1 + (uint64_t)r1*args.ne0;
```<｜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: metal/norm.metal

```metal
struct ds4_metal_args_norm {
    int32_t  ne00;
    int32_t  ne00_t;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
    float    eps;
    int32_t  nef1[3];
    int32_t  nef2[3];
    int32_t  nef3[3];
    uint64_t nbf1[3];
    uint64_t nbf2[3];
    uint64_t nbf3[3];
};

// RMSNorm over one activation row, optionally fusing the learned weight
// multiply. DS4 calls this before attention, before the FFN, and for plain
// diagnostics that need normalized but unweighted rows.
template <typename T, short F>
kernel void kernel_rms_norm_fuse_impl(
        constant ds4_metal_args_norm & args,
        device const char * src0,
        device const char * src1_0,
        device const char * src1_1,
        device       char * dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const int i01 = tgpig.x;
    const int i02 = tgpig.y;
    const int i03 = tgpig.z;

    device const T * x = (device const T *) (src0 + i03*args.nbf3[0] + i02*args.nbf2[0] + i01*args.nbf1[0]);

    device const T * f0 = (device const T *) (src1_0 + (i03%args.nef3[1])*args.nbf3[1] + (i02%args.nef2[1])*args.nbf2[1] + (i01%args.nef1[1])*args.nbf1[1]);
    device const T * f1 = (device const T *) (src1_1 + (i03%args.nef3[2])*args.nbf3[2] + (i02%args.nef2[2])*args.nbf2[2] + (i01%args.nef1[2])*args.nbf1[2]);

    float sumf = 0.0f;

    // parallel sum
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        sumf += dot(x[i00], x[i00]);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float mean  = sumf/args.ne00;
    const float scale = 1.0f/sqrt(mean + args.eps);

    device T * y = (device T *) (dst + i03*args.nb3 + i02*args.nb2 + i01*args.nb1);
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        if (F == 1) {
            y[i00] = (x[i00]*scale);
        }
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}
```

<｜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: metal/norm.metal

```metal
struct ds4_metal_args_norm {
    int32_t  ne00;
    int32_t  ne00_t;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
    float    eps;
    int32_t  nef1[3];
    int32_t  nef2[3];
    int32_t  nef3[3];
    uint64_t nbf1[3];
    uint64_t nbf2[3];
    uint64_t nbf3[3];
};

// RMSNorm over one activation row, optionally fusing the learned weight
// multiply. DS4 calls this before attention, before the FFN, and for plain
// diagnostics that need normalized but unweighted rows.
template <typename T, short F>
kernel void kernel_rms_norm_fuse_impl(
        constant ds4_metal_args_norm & args,
        device const char * src0,
        device const char * src1_0,
        device const char * src1_1,
        device       char * dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const int i01 = tgpig.x;
    const int i02 = tgpig.y;
    const int i03 = tgpig.z;

    device const T * x = (device const T *) (src0 + i03*args.nbf3[0] + i02*args.nbf2[0] + i01*args.nbf1[0]);

    device const T * f0 = (device const T *) (src1_0 + (i03%args.nef3[1])*args.nbf3[1] + (i02%args.nef2[1])*args.nbf2[1] + (i01%args.nef1[1])*args.nbf1[1]);
    device const T * f1 = (device const T *) (src1_1 + (i03%args.nef3[2])*args.nbf3[2] + (i02%args.nef2[2])*args.nbf2[2] + (i01%args.nef1[2])*args.nbf1[2]);

    float sumf = 0.0f;

    // parallel sum
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        sumf += dot(x[i00], x[i00]);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float mean  = sumf/args.ne00;
    const float scale = 1.0f/sqrt(mean + args.eps);

    device T * y = (device T *) (dst + i03*args.nb3 + i02*args.nb2 + i01*args.nb1);
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        if (F == 1) {
            y[i00] = (x[i00]*scale);
        }
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}
```<｜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: metal/norm.metal

```metal
struct ds4_metal_args_norm {
    int32_t  ne00;
    int32_t  ne00_t;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
    float    eps;
    int32_t  nef1[3];
    int32_t  nef2[3];
    int32_t  nef3[3];
    uint64_t nbf1[3];
    uint64_t nbf2[3];
    uint64_t nbf3[3];
};

// RMSNorm over one activation row, optionally fusing the learned weight
// multiply. DS4 calls this before attention, before the FFN, and for plain
// diagnostics that need normalized but unweighted rows.
template <typename T, short F>
kernel void kernel_rms_norm_fuse_impl(
        constant ds4_metal_args_norm & args,
        device const char * src0,
        device const char * src1_0,
        device const char * src1_1,
        device       char * dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const int i01 = tgpig.x;
    const int i02 = tgpig.y;
    const int i03 = tgpig.z;

    device const T * x = (device const T *) (src0 + i03*args.nbf3[0] + i02*args.nbf2[0] + i01*args.nbf1[0]);

    device const T * f0 = (device const T *) (src1_0 + (i03%args.nef3[1])*args.nbf3[1] + (i02%args.nef2[1])*args.nbf2[1] + (i01%args.nef1[1])*args.nbf1[1]);
    device const T * f1 = (device const T *) (src1_1 + (i03%args.nef3[2])*args.nbf3[2] + (i02%args.nef2[2])*args.nbf2[2] + (i01%args.nef1[2])*args.nbf1[2]);

    float sumf = 0.0f;

    // parallel sum
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        sumf += dot(x[i00], x[i00]);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float mean  = sumf/args.ne00;
    const float scale = 1.0f/sqrt(mean + args.eps);

    device T * y = (device T *) (dst + i03*args.nb3 + i02*args.nb2 + i01*args.nb1);
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        if (F == 1) {
            y[i00] = (x[i00]*scale);
        }
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}
```

<｜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: metal/norm.metal

```metal
struct ds4_metal_args_norm {
    int32_t  ne00;
    int32_t  ne00_t;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
    float    eps;
    int32_t  nef1[3];
    int32_t  nef2[3];
    int32_t  nef3[3];
    uint64_t nbf1[3];
    uint64_t nbf2[3];
    uint64_t nbf3[3];
};

// RMSNorm over one activation row, optionally fusing the learned weight
// multiply. DS4 calls this before attention, before the FFN, and for plain
// diagnostics that need normalized but unweighted rows.
template <typename T, short F>
kernel void kernel_rms_norm_fuse_impl(
        constant ds4_metal_args_norm & args,
        device const char * src0,
        device const char * src1_0,
        device const char * src1_1,
        device       char * dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const int i01 = tgpig.x;
    const int i02 = tgpig.y;
    const int i03 = tgpig.z;

    device const T * x = (device const T *) (src0 + i03*args.nbf3[0] + i02*args.nbf2[0] + i01*args.nbf1[0]);

    device const T * f0 = (device const T *) (src1_0 + (i03%args.nef3[1])*args.nbf3[1] + (i02%args.nef2[1])*args.nbf2[1] + (i01%args.nef1[1])*args.nbf1[1]);
    device const T * f1 = (device const T *) (src1_1 + (i03%args.nef3[2])*args.nbf3[2] + (i02%args.nef2[2])*args.nbf2[2] + (i01%args.nef1[2])*args.nbf1[2]);

    float sumf = 0.0f;

    // parallel sum
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        sumf += dot(x[i00], x[i00]);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float mean  = sumf/args.ne00;
    const float scale = 1.0f/sqrt(mean + args.eps);

    device T * y = (device T *) (dst + i03*args.nb3 + i02*args.nb2 + i01*args.nb1);
    for (int i00 = tpitg.x; i00 < args.ne00_t; i00 += ntg.x) {
        if (F == 1) {
            y[i00] = (x[i00]*scale);
        }
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}
```<｜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: metal/norm.metal

```metal
}
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}

typedef decltype(kernel_rms_norm_fuse_impl<float4, 1>) kernel_rms_norm_fuse_t;

// Host-visible RMSNorm variants: plain norm and norm multiplied by weight.
template [[host_name("kernel_rms_norm_f32_4")]]     kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 1>;
template [[host_name("kernel_rms_norm_mul_f32_4")]] kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 2>;

struct ds4_metal_args_qkv_rms_norm {
    int32_t  q_n;
    int32_t  q_n4;
    int32_t  kv_n;
    int32_t  kv_n4;
    uint64_t q_row_stride;
    uint64_t kv_row_stride;
    float    eps;
};

// Normalizes DS4's q-lora row and KV row in one dispatch.  The two reductions
// deliberately mirror kernel_rms_norm_mul_f32_4: Q uses the full 256-thread
// row shape for 1024 floats, while KV only has work in the first 128 lanes for
// its 512 floats.  This keeps the q/kv normalization math aligned with the
// standalone kernels while removing one tiny launch from the attention setup.
kernel void kernel_dsv4_qkv_rms_norm_f32_4(
        constant ds4_metal_args_qkv_rms_norm & args,
        device const float4 * q_src,
        device const float4 * q_weight,
        device       float4 * q_dst,
        device const float4 * kv_src,
        device const float4 * kv_weight,
        device       float4 * kv_dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3 ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const uint row = tgpig.x;
    const bool kv_task = tgpig.y != 0;
    const int n = kv_task ? args.kv_n : args.q_n;
    const int n4 = kv_task ? args.kv_n4 : args.q_n4;
    const uint64_t row_stride4 = (kv_task ? args.kv_row_stride : args.q_row_stride) / sizeof(float4);

    device const float4 * x = kv_task ? kv_src + row * row_stride4 : q_src + row * row_stride4;
    device const float4 * w = kv_task ? kv_weight : q_weight;
    device       float4 * y = kv_task ? kv_dst + row * row_stride4 : q_dst + row * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);
```

<｜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: metal/norm.metal

```metal
}
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}

typedef decltype(kernel_rms_norm_fuse_impl<float4, 1>) kernel_rms_norm_fuse_t;

// Host-visible RMSNorm variants: plain norm and norm multiplied by weight.
template [[host_name("kernel_rms_norm_f32_4")]]     kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 1>;
template [[host_name("kernel_rms_norm_mul_f32_4")]] kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 2>;

struct ds4_metal_args_qkv_rms_norm {
    int32_t  q_n;
    int32_t  q_n4;
    int32_t  kv_n;
    int32_t  kv_n4;
    uint64_t q_row_stride;
    uint64_t kv_row_stride;
    float    eps;
};

// Normalizes DS4's q-lora row and KV row in one dispatch.  The two reductions
// deliberately mirror kernel_rms_norm_mul_f32_4: Q uses the full 256-thread
// row shape for 1024 floats, while KV only has work in the first 128 lanes for
// its 512 floats.  This keeps the q/kv normalization math aligned with the
// standalone kernels while removing one tiny launch from the attention setup.
kernel void kernel_dsv4_qkv_rms_norm_f32_4(
        constant ds4_metal_args_qkv_rms_norm & args,
        device const float4 * q_src,
        device const float4 * q_weight,
        device       float4 * q_dst,
        device const float4 * kv_src,
        device const float4 * kv_weight,
        device       float4 * kv_dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3 ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const uint row = tgpig.x;
    const bool kv_task = tgpig.y != 0;
    const int n = kv_task ? args.kv_n : args.q_n;
    const int n4 = kv_task ? args.kv_n4 : args.q_n4;
    const uint64_t row_stride4 = (kv_task ? args.kv_row_stride : args.q_row_stride) / sizeof(float4);

    device const float4 * x = kv_task ? kv_src + row * row_stride4 : q_src + row * row_stride4;
    device const float4 * w = kv_task ? kv_weight : q_weight;
    device       float4 * y = kv_task ? kv_dst + row * row_stride4 : q_dst + row * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);
```<｜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: metal/norm.metal

```metal
}
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}

typedef decltype(kernel_rms_norm_fuse_impl<float4, 1>) kernel_rms_norm_fuse_t;

// Host-visible RMSNorm variants: plain norm and norm multiplied by weight.
template [[host_name("kernel_rms_norm_f32_4")]]     kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 1>;
template [[host_name("kernel_rms_norm_mul_f32_4")]] kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 2>;

struct ds4_metal_args_qkv_rms_norm {
    int32_t  q_n;
    int32_t  q_n4;
    int32_t  kv_n;
    int32_t  kv_n4;
    uint64_t q_row_stride;
    uint64_t kv_row_stride;
    float    eps;
};

// Normalizes DS4's q-lora row and KV row in one dispatch.  The two reductions
// deliberately mirror kernel_rms_norm_mul_f32_4: Q uses the full 256-thread
// row shape for 1024 floats, while KV only has work in the first 128 lanes for
// its 512 floats.  This keeps the q/kv normalization math aligned with the
// standalone kernels while removing one tiny launch from the attention setup.
kernel void kernel_dsv4_qkv_rms_norm_f32_4(
        constant ds4_metal_args_qkv_rms_norm & args,
        device const float4 * q_src,
        device const float4 * q_weight,
        device       float4 * q_dst,
        device const float4 * kv_src,
        device const float4 * kv_weight,
        device       float4 * kv_dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3 ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const uint row = tgpig.x;
    const bool kv_task = tgpig.y != 0;
    const int n = kv_task ? args.kv_n : args.q_n;
    const int n4 = kv_task ? args.kv_n4 : args.q_n4;
    const uint64_t row_stride4 = (kv_task ? args.kv_row_stride : args.q_row_stride) / sizeof(float4);

    device const float4 * x = kv_task ? kv_src + row * row_stride4 : q_src + row * row_stride4;
    device const float4 * w = kv_task ? kv_weight : q_weight;
    device       float4 * y = kv_task ? kv_dst + row * row_stride4 : q_dst + row * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);
```

<｜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: metal/norm.metal

```metal
}
        if (F == 2) {
            y[i00] = (x[i00]*scale)*f0[i00];
        }
        if (F == 3) {
            y[i00] = (x[i00]*scale)*f0[i00] + f1[i00];
        }
    }
}

typedef decltype(kernel_rms_norm_fuse_impl<float4, 1>) kernel_rms_norm_fuse_t;

// Host-visible RMSNorm variants: plain norm and norm multiplied by weight.
template [[host_name("kernel_rms_norm_f32_4")]]     kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 1>;
template [[host_name("kernel_rms_norm_mul_f32_4")]] kernel kernel_rms_norm_fuse_t kernel_rms_norm_fuse_impl<float4, 2>;

struct ds4_metal_args_qkv_rms_norm {
    int32_t  q_n;
    int32_t  q_n4;
    int32_t  kv_n;
    int32_t  kv_n4;
    uint64_t q_row_stride;
    uint64_t kv_row_stride;
    float    eps;
};

// Normalizes DS4's q-lora row and KV row in one dispatch.  The two reductions
// deliberately mirror kernel_rms_norm_mul_f32_4: Q uses the full 256-thread
// row shape for 1024 floats, while KV only has work in the first 128 lanes for
// its 512 floats.  This keeps the q/kv normalization math aligned with the
// standalone kernels while removing one tiny launch from the attention setup.
kernel void kernel_dsv4_qkv_rms_norm_f32_4(
        constant ds4_metal_args_qkv_rms_norm & args,
        device const float4 * q_src,
        device const float4 * q_weight,
        device       float4 * q_dst,
        device const float4 * kv_src,
        device const float4 * kv_weight,
        device       float4 * kv_dst,
        threadgroup float * shmem_f32 [[threadgroup(0)]],
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort  sgitg[[simdgroup_index_in_threadgroup]],
        ushort  tiisg[[thread_index_in_simdgroup]],
        ushort3 ntg[[threads_per_threadgroup]]) {
    if (sgitg == 0) {
        shmem_f32[tiisg] = 0.0f;
    }

    const uint row = tgpig.x;
    const bool kv_task = tgpig.y != 0;
    const int n = kv_task ? args.kv_n : args.q_n;
    const int n4 = kv_task ? args.kv_n4 : args.q_n4;
    const uint64_t row_stride4 = (kv_task ? args.kv_row_stride : args.q_row_stride) / sizeof(float4);

    device const float4 * x = kv_task ? kv_src + row * row_stride4 : q_src + row * row_stride4;
    device const float4 * w = kv_task ? kv_weight : q_weight;
    device       float4 * y = kv_task ? kv_dst + row * row_stride4 : q_dst + row * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);
```<｜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: metal/norm.metal

```metal
w * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float scale = rsqrt(sumf / float(n) + args.eps);

    for (int i = tpitg.x; i < n4; i += ntg.x) {
        y[i] = (x[i] * scale) * w[i];
    }
}
```

<｜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: metal/norm.metal

```metal
w * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float scale = rsqrt(sumf / float(n) + args.eps);

    for (int i = tpitg.x; i < n4; i += ntg.x) {
        y[i] = (x[i] * scale) * w[i];
    }
}
```<｜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: metal/norm.metal

```metal
w * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float scale = rsqrt(sumf / float(n) + args.eps);

    for (int i = tpitg.x; i < n4; i += ntg.x) {
        y[i] = (x[i] * scale) * w[i];
    }
}
```

<｜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: metal/norm.metal

```metal
w * row_stride4;

    float sumf = 0.0f;
    for (int i = tpitg.x; i < n4; i += ntg.x) {
        const float4 v = x[i];
        sumf += dot(v, v);
    }
    sumf = simd_sum(sumf);

    threadgroup_barrier(mem_flags::mem_threadgroup);

    if (tiisg == 0) {
        shmem_f32[sgitg] = sumf;
    }

    threadgroup_barrier(mem_flags::mem_threadgroup);

    sumf = shmem_f32[tiisg];
    sumf = simd_sum(sumf);

    const float scale = rsqrt(sumf / float(n) + args.eps);

    for (int i = tpitg.x; i < n4; i += ntg.x) {
        y[i] = (x[i] * scale) * w[i];
    }
}
```<｜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: metal/repeat.metal

```metal
// DS4 Metal repeat kernel used for HC embedding expansion.

struct ds4_metal_args_repeat {
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    int32_t  ne03;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne0;
    int32_t  ne1;
    int32_t  ne2;
    int32_t  ne3;
    uint64_t nb0;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
};

// Repeats a source row into the HC channel dimension. DS4 uses this when the
// token embedding has to become an HC activation block before layer 0.
template<typename T>
kernel void kernel_repeat(
        constant ds4_metal_args_repeat & args,
        device const char * src0,
        device       char * dst,
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    const int i3 = tgpig.z;
    const int i2 = tgpig.y;
    const int i1 = tgpig.x;

    const int i03 = i3%args.ne03;
    const int i02 = i2%args.ne02;
    const int i01 = i1%args.ne01;

    device const char * src0_ptr = src0 + i03*args.nb03 + i02*args.nb02 + i01*args.nb01;
    device       char * dst_ptr  = dst  +  i3*args.nb3  +  i2*args.nb2  +  i1*args.nb1;

    for (int i0 = tpitg.x; i0 < args.ne0; i0 += ntg.x) {
        const int i00 = i0%args.ne00;
        *((device T *)(dst_ptr + i0*args.nb0)) = *((device T *)(src0_ptr + i00*args.nb00));
    }
}

typedef decltype(kernel_repeat<float>) kernel_repeat_t;

// Host-visible F32 repeat used for HC expansion of embeddings.
template [[host_name("kernel_repeat_f32")]] kernel kernel_repeat_t kernel_repeat<float>;
```

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

File: metal/repeat.metal

```metal
// DS4 Metal repeat kernel used for HC embedding expansion.

struct ds4_metal_args_repeat {
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    int32_t  ne03;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne0;
    int32_t  ne1;
    int32_t  ne2;
    int32_t  ne3;
    uint64_t nb0;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
};

// Repeats a source row into the HC channel dimension. DS4 uses this when the
// token embedding has to become an HC activation block before layer 0.
template<typename T>
kernel void kernel_repeat(
        constant ds4_metal_args_repeat & args,
        device const char * src0,
        device       char * dst,
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    const int i3 = tgpig.z;
    const int i2 = tgpig.y;
    const int i1 = tgpig.x;

    const int i03 = i3%args.ne03;
    const int i02 = i2%args.ne02;
    const int i01 = i1%args.ne01;

    device const char * src0_ptr = src0 + i03*args.nb03 + i02*args.nb02 + i01*args.nb01;
    device       char * dst_ptr  = dst  +  i3*args.nb3  +  i2*args.nb2  +  i1*args.nb1;

    for (int i0 = tpitg.x; i0 < args.ne0; i0 += ntg.x) {
        const int i00 = i0%args.ne00;
        *((device T *)(dst_ptr + i0*args.nb0)) = *((device T *)(src0_ptr + i00*args.nb00));
    }
}

typedef decltype(kernel_repeat<float>) kernel_repeat_t;

// Host-visible F32 repeat used for HC expansion of embeddings.
template [[host_name("kernel_repeat_f32")]] kernel kernel_repeat_t kernel_repeat<float>;
```<｜Assistant｜></think>


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

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

File: metal/repeat.metal

```metal
// DS4 Metal repeat kernel used for HC embedding expansion.

struct ds4_metal_args_repeat {
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    int32_t  ne03;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne0;
    int32_t  ne1;
    int32_t  ne2;
    int32_t  ne3;
    uint64_t nb0;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
};

// Repeats a source row into the HC channel dimension. DS4 uses this when the
// token embedding has to become an HC activation block before layer 0.
template<typename T>
kernel void kernel_repeat(
        constant ds4_metal_args_repeat & args,
        device const char * src0,
        device       char * dst,
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    const int i3 = tgpig.z;
    const int i2 = tgpig.y;
    const int i1 = tgpig.x;

    const int i03 = i3%args.ne03;
    const int i02 = i2%args.ne02;
    const int i01 = i1%args.ne01;

    device const char * src0_ptr = src0 + i03*args.nb03 + i02*args.nb02 + i01*args.nb01;
    device       char * dst_ptr  = dst  +  i3*args.nb3  +  i2*args.nb2  +  i1*args.nb1;

    for (int i0 = tpitg.x; i0 < args.ne0; i0 += ntg.x) {
        const int i00 = i0%args.ne00;
        *((device T *)(dst_ptr + i0*args.nb0)) = *((device T *)(src0_ptr + i00*args.nb00));
    }
}

typedef decltype(kernel_repeat<float>) kernel_repeat_t;

// Host-visible F32 repeat used for HC expansion of embeddings.
template [[host_name("kernel_repeat_f32")]] kernel kernel_repeat_t kernel_repeat<float>;
```

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

File: metal/repeat.metal

```metal
// DS4 Metal repeat kernel used for HC embedding expansion.

struct ds4_metal_args_repeat {
    int32_t  ne00;
    int32_t  ne01;
    int32_t  ne02;
    int32_t  ne03;
    uint64_t nb00;
    uint64_t nb01;
    uint64_t nb02;
    uint64_t nb03;
    int32_t  ne0;
    int32_t  ne1;
    int32_t  ne2;
    int32_t  ne3;
    uint64_t nb0;
    uint64_t nb1;
    uint64_t nb2;
    uint64_t nb3;
};

// Repeats a source row into the HC channel dimension. DS4 uses this when the
// token embedding has to become an HC activation block before layer 0.
template<typename T>
kernel void kernel_repeat(
        constant ds4_metal_args_repeat & args,
        device const char * src0,
        device       char * dst,
        uint3   tgpig[[threadgroup_position_in_grid]],
        ushort3 tpitg[[thread_position_in_threadgroup]],
        ushort3   ntg[[threads_per_threadgroup]]) {
    const int i3 = tgpig.z;
    const int i2 = tgpig.y;
    const int i1 = tgpig.x;

    const int i03 = i3%args.ne03;
    const int i02 = i2%args.ne02;
    const int i01 = i1%args.ne01;

    device const char * src0_ptr = src0 + i03*args.nb03 + i02*args.nb02 + i01*args.nb01;
    device       char * dst_ptr  = dst  +  i3*args.nb3  +  i2*args.nb2  +  i1*args.nb1;

    for (int i0 = tpitg.x; i0 < args.ne0; i0 += ntg.x) {
        const int i00 = i0%args.ne00;
        *((device T *)(dst_ptr + i0*args.nb0)) = *((device T *)(src0_ptr + i00*args.nb00));
    }
}

typedef decltype(kernel_repeat<float>) kernel_repeat_t;

// Host-visible F32 repeat used for HC expansion of embeddings.
template [[host_name("kernel_repeat_f32")]] kernel kernel_repeat_t kernel_repeat<float>;
```<｜Assistant｜><think>