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

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

File: ds4_metal.m

```c
0 || rows == 0 || (n & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        const uint64_t row_bytes = (uint64_t)n * sizeof(float);
        const uint64_t bytes = row_bytes * rows;
        if (!xbuf || !outbuf ||
            ds4_gpu_tensor_bytes(x) < bytes ||
            ds4_gpu_tensor_bytes(out) < bytes) {
            fprintf(stderr, "ds4: Metal weighted RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (weight_offset > model_size || row_bytes > model_size - weight_offset) {
            fprintf(stderr, "ds4: Metal weighted RMS norm range is outside the mapped model\n");
            return 0;
        }

        uint64_t inner_offset = 0;
        id<MTLBuffer> wbuf = ds4_gpu_wrap_model_range(model_map, model_size, weight_offset, row_bytes, &inner_offset);
        if (!wbuf) return 0;

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_args(n, rows, eps);
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:wbuf offset:(NSUInteger)inner_offset atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:outbuf offset:ds4_gpu_tensor_offset(out) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "weighted RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_qkv_rms_norm_rows_tensor(
        ds4_gpu_tensor       *q_out,
        const ds4_gpu_tensor *q,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                q_weight_offset,
        uint32_t                q_n,
        ds4_gpu_tensor       *kv_out,
        const ds4_gpu_tensor *kv,
        uint64_t                kv_weight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
```

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

File: ds4_metal.m

```c
0 || rows == 0 || (n & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        id<MTLBuffer> outbuf = ds4_gpu_tensor_buffer(out);
        const uint64_t row_bytes = (uint64_t)n * sizeof(float);
        const uint64_t bytes = row_bytes * rows;
        if (!xbuf || !outbuf ||
            ds4_gpu_tensor_bytes(x) < bytes ||
            ds4_gpu_tensor_bytes(out) < bytes) {
            fprintf(stderr, "ds4: Metal weighted RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (weight_offset > model_size || row_bytes > model_size - weight_offset) {
            fprintf(stderr, "ds4: Metal weighted RMS norm range is outside the mapped model\n");
            return 0;
        }

        uint64_t inner_offset = 0;
        id<MTLBuffer> wbuf = ds4_gpu_wrap_model_range(model_map, model_size, weight_offset, row_bytes, &inner_offset);
        if (!wbuf) return 0;

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_args(n, rows, eps);
        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:wbuf offset:(NSUInteger)inner_offset atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:outbuf offset:ds4_gpu_tensor_offset(out) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "weighted RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_qkv_rms_norm_rows_tensor(
        ds4_gpu_tensor       *q_out,
        const ds4_gpu_tensor *q,
        const void             *model_map,
        uint64_t                model_size,
        uint64_t                q_weight_offset,
        uint32_t                q_n,
        ds4_gpu_tensor       *kv_out,
        const ds4_gpu_tensor *kv,
        uint64_t                kv_weight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
t_mapped - t0,
            t_resident - t_mapped,
            t_warm - t_warm0,
            mapped_model_size / 1024.0 / 1024.0,
            page_model_offset / 1024.0 / 1024.0);
    if (!warmed) return 0;
    return 1;
}

static id<MTLBuffer> ds4_gpu_new_transient_buffer(NSUInteger bytes, const char *label) {
    if (bytes == 0) bytes = 1;

    id<MTLBuffer> buffer = [g_device newBufferWithLength:bytes
                                                 options:MTLResourceStorageModeShared];
    if (!buffer) {
        fprintf(stderr, "ds4: failed to allocate Metal transient buffer %s (%llu bytes)\n",
                label ? label : "(unnamed)", (unsigned long long)bytes);
        return nil;
    }
    if (label) buffer.label = [NSString stringWithUTF8String:label];

    /*
     * CPU-filled buffers must survive until their command buffer completes.
     * A local ObjC strong variable is not enough when the encoder function
     * returns before the caller commits the command buffer.
     */
    [g_transient_buffers addObject:buffer];
    return buffer;
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mm_pipeline(
        const char *function_name,
        bool        bc_inp,
        bool        bc_out) {
    NSString *key = [NSString stringWithFormat:@"%s_bci=%d_bco=%d",
                     function_name, bc_inp ? 1 : 0, bc_out ? 1 : 0];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&bc_inp type:MTLDataTypeBool atIndex:700];
    [constants setConstantValue:&bc_out type:MTLDataTypeBool atIndex:701];

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

    error = nil;
    id<MTLComputePipelineState> pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
    if (!pipeline) {
        fprintf(stderr, "ds4: Metal %s pipeline failed: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    [g_pipeline_cache setObject:pipeline forKey:key];
    return pipeline;
}
```

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

File: ds4_metal.m

```c
t_mapped - t0,
            t_resident - t_mapped,
            t_warm - t_warm0,
            mapped_model_size / 1024.0 / 1024.0,
            page_model_offset / 1024.0 / 1024.0);
    if (!warmed) return 0;
    return 1;
}

static id<MTLBuffer> ds4_gpu_new_transient_buffer(NSUInteger bytes, const char *label) {
    if (bytes == 0) bytes = 1;

    id<MTLBuffer> buffer = [g_device newBufferWithLength:bytes
                                                 options:MTLResourceStorageModeShared];
    if (!buffer) {
        fprintf(stderr, "ds4: failed to allocate Metal transient buffer %s (%llu bytes)\n",
                label ? label : "(unnamed)", (unsigned long long)bytes);
        return nil;
    }
    if (label) buffer.label = [NSString stringWithUTF8String:label];

    /*
     * CPU-filled buffers must survive until their command buffer completes.
     * A local ObjC strong variable is not enough when the encoder function
     * returns before the caller commits the command buffer.
     */
    [g_transient_buffers addObject:buffer];
    return buffer;
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mm_pipeline(
        const char *function_name,
        bool        bc_inp,
        bool        bc_out) {
    NSString *key = [NSString stringWithFormat:@"%s_bci=%d_bco=%d",
                     function_name, bc_inp ? 1 : 0, bc_out ? 1 : 0];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&bc_inp type:MTLDataTypeBool atIndex:700];
    [constants setConstantValue:&bc_out type:MTLDataTypeBool atIndex:701];

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

    error = nil;
    id<MTLComputePipelineState> pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
    if (!pipeline) {
        fprintf(stderr, "ds4: Metal %s pipeline failed: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    [g_pipeline_cache setObject:pipeline forKey:key];
    return pipeline;
}
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
t_mapped - t0,
            t_resident - t_mapped,
            t_warm - t_warm0,
            mapped_model_size / 1024.0 / 1024.0,
            page_model_offset / 1024.0 / 1024.0);
    if (!warmed) return 0;
    return 1;
}

static id<MTLBuffer> ds4_gpu_new_transient_buffer(NSUInteger bytes, const char *label) {
    if (bytes == 0) bytes = 1;

    id<MTLBuffer> buffer = [g_device newBufferWithLength:bytes
                                                 options:MTLResourceStorageModeShared];
    if (!buffer) {
        fprintf(stderr, "ds4: failed to allocate Metal transient buffer %s (%llu bytes)\n",
                label ? label : "(unnamed)", (unsigned long long)bytes);
        return nil;
    }
    if (label) buffer.label = [NSString stringWithUTF8String:label];

    /*
     * CPU-filled buffers must survive until their command buffer completes.
     * A local ObjC strong variable is not enough when the encoder function
     * returns before the caller commits the command buffer.
     */
    [g_transient_buffers addObject:buffer];
    return buffer;
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mm_pipeline(
        const char *function_name,
        bool        bc_inp,
        bool        bc_out) {
    NSString *key = [NSString stringWithFormat:@"%s_bci=%d_bco=%d",
                     function_name, bc_inp ? 1 : 0, bc_out ? 1 : 0];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&bc_inp type:MTLDataTypeBool atIndex:700];
    [constants setConstantValue:&bc_out type:MTLDataTypeBool atIndex:701];

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

    error = nil;
    id<MTLComputePipelineState> pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
    if (!pipeline) {
        fprintf(stderr, "ds4: Metal %s pipeline failed: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    [g_pipeline_cache setObject:pipeline forKey:key];
    return pipeline;
}
```

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

File: ds4_metal.m

```c
t_mapped - t0,
            t_resident - t_mapped,
            t_warm - t_warm0,
            mapped_model_size / 1024.0 / 1024.0,
            page_model_offset / 1024.0 / 1024.0);
    if (!warmed) return 0;
    return 1;
}

static id<MTLBuffer> ds4_gpu_new_transient_buffer(NSUInteger bytes, const char *label) {
    if (bytes == 0) bytes = 1;

    id<MTLBuffer> buffer = [g_device newBufferWithLength:bytes
                                                 options:MTLResourceStorageModeShared];
    if (!buffer) {
        fprintf(stderr, "ds4: failed to allocate Metal transient buffer %s (%llu bytes)\n",
                label ? label : "(unnamed)", (unsigned long long)bytes);
        return nil;
    }
    if (label) buffer.label = [NSString stringWithUTF8String:label];

    /*
     * CPU-filled buffers must survive until their command buffer completes.
     * A local ObjC strong variable is not enough when the encoder function
     * returns before the caller commits the command buffer.
     */
    [g_transient_buffers addObject:buffer];
    return buffer;
}

static id<MTLComputePipelineState> ds4_gpu_get_mul_mm_pipeline(
        const char *function_name,
        bool        bc_inp,
        bool        bc_out) {
    NSString *key = [NSString stringWithFormat:@"%s_bci=%d_bco=%d",
                     function_name, bc_inp ? 1 : 0, bc_out ? 1 : 0];
    id<MTLComputePipelineState> cached = [g_pipeline_cache objectForKey:key];
    if (cached) return cached;

    MTLFunctionConstantValues *constants = [[MTLFunctionConstantValues alloc] init];
    [constants setConstantValue:&bc_inp type:MTLDataTypeBool atIndex:700];
    [constants setConstantValue:&bc_out type:MTLDataTypeBool atIndex:701];

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

    error = nil;
    id<MTLComputePipelineState> pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
    if (!pipeline) {
        fprintf(stderr, "ds4: Metal %s pipeline failed: %s\n",
                function_name, [[error localizedDescription] UTF8String]);
        return nil;
    }

    [g_pipeline_cache setObject:pipeline forKey:key];
    return pipeline;
}
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
ight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!q_out || !q || !kv_out || !kv || q_n == 0 || kv_n == 0 || rows == 0 ||
        (q_n & 3u) != 0 || (kv_n & 3u) != 0) {
        return 0;
    }

    @autoreleasepool {
        id<MTLBuffer> qbuf = ds4_gpu_tensor_buffer(q);
        id<MTLBuffer> qoutbuf = ds4_gpu_tensor_buffer(q_out);
        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> kvoutbuf = ds4_gpu_tensor_buffer(kv_out);

        const uint64_t q_row_bytes = (uint64_t)q_n * sizeof(float);
        const uint64_t kv_row_bytes = (uint64_t)kv_n * sizeof(float);
        if (!qbuf || !qoutbuf || !kvbuf || !kvoutbuf ||
            ds4_gpu_tensor_bytes(q) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(q_out) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv) < kv_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv_out) < kv_row_bytes * rows) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (q_weight_offset > model_size || q_row_bytes > model_size - q_weight_offset ||
            kv_weight_offset > model_size || kv_row_bytes > model_size - kv_weight_offset) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm weight range is outside the mapped model\n");
            return 0;
        }

        uint64_t q_inner_offset = 0;
        uint64_t kv_inner_offset = 0;
        id<MTLBuffer> q_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                          q_weight_offset, q_row_bytes,
                                                          &q_inner_offset);
        if (!q_wbuf) return 0;
        id<MTLBuffer> kv_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                           kv_weight_offset, kv_row_bytes,
                                                           &kv_inner_offset);
        if (!kv_wbuf) return 0;

        ds4_gpu_qkv_rms_norm_args args = {
            .q_n = (int32_t)q_n,
            .q_n4 = (int32_t)(q_n / 4u),
            .kv_n = (int32_t)kv_n,
            .kv_n4 = (int32_t)(kv_n / 4u),
            .q_row_stride = q_row_bytes,
            .kv_row_stride = kv_row_bytes,
            .eps = eps,
        };

        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;
```

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

File: ds4_metal.m

```c
ight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!q_out || !q || !kv_out || !kv || q_n == 0 || kv_n == 0 || rows == 0 ||
        (q_n & 3u) != 0 || (kv_n & 3u) != 0) {
        return 0;
    }

    @autoreleasepool {
        id<MTLBuffer> qbuf = ds4_gpu_tensor_buffer(q);
        id<MTLBuffer> qoutbuf = ds4_gpu_tensor_buffer(q_out);
        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> kvoutbuf = ds4_gpu_tensor_buffer(kv_out);

        const uint64_t q_row_bytes = (uint64_t)q_n * sizeof(float);
        const uint64_t kv_row_bytes = (uint64_t)kv_n * sizeof(float);
        if (!qbuf || !qoutbuf || !kvbuf || !kvoutbuf ||
            ds4_gpu_tensor_bytes(q) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(q_out) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv) < kv_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv_out) < kv_row_bytes * rows) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (q_weight_offset > model_size || q_row_bytes > model_size - q_weight_offset ||
            kv_weight_offset > model_size || kv_row_bytes > model_size - kv_weight_offset) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm weight range is outside the mapped model\n");
            return 0;
        }

        uint64_t q_inner_offset = 0;
        uint64_t kv_inner_offset = 0;
        id<MTLBuffer> q_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                          q_weight_offset, q_row_bytes,
                                                          &q_inner_offset);
        if (!q_wbuf) return 0;
        id<MTLBuffer> kv_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                           kv_weight_offset, kv_row_bytes,
                                                           &kv_inner_offset);
        if (!kv_wbuf) return 0;

        ds4_gpu_qkv_rms_norm_args args = {
            .q_n = (int32_t)q_n,
            .q_n4 = (int32_t)(q_n / 4u),
            .kv_n = (int32_t)kv_n,
            .kv_n4 = (int32_t)(kv_n / 4u),
            .q_row_stride = q_row_bytes,
            .kv_row_stride = kv_row_bytes,
            .eps = eps,
        };

        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
ight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!q_out || !q || !kv_out || !kv || q_n == 0 || kv_n == 0 || rows == 0 ||
        (q_n & 3u) != 0 || (kv_n & 3u) != 0) {
        return 0;
    }

    @autoreleasepool {
        id<MTLBuffer> qbuf = ds4_gpu_tensor_buffer(q);
        id<MTLBuffer> qoutbuf = ds4_gpu_tensor_buffer(q_out);
        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> kvoutbuf = ds4_gpu_tensor_buffer(kv_out);

        const uint64_t q_row_bytes = (uint64_t)q_n * sizeof(float);
        const uint64_t kv_row_bytes = (uint64_t)kv_n * sizeof(float);
        if (!qbuf || !qoutbuf || !kvbuf || !kvoutbuf ||
            ds4_gpu_tensor_bytes(q) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(q_out) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv) < kv_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv_out) < kv_row_bytes * rows) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (q_weight_offset > model_size || q_row_bytes > model_size - q_weight_offset ||
            kv_weight_offset > model_size || kv_row_bytes > model_size - kv_weight_offset) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm weight range is outside the mapped model\n");
            return 0;
        }

        uint64_t q_inner_offset = 0;
        uint64_t kv_inner_offset = 0;
        id<MTLBuffer> q_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                          q_weight_offset, q_row_bytes,
                                                          &q_inner_offset);
        if (!q_wbuf) return 0;
        id<MTLBuffer> kv_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                           kv_weight_offset, kv_row_bytes,
                                                           &kv_inner_offset);
        if (!kv_wbuf) return 0;

        ds4_gpu_qkv_rms_norm_args args = {
            .q_n = (int32_t)q_n,
            .q_n4 = (int32_t)(q_n / 4u),
            .kv_n = (int32_t)kv_n,
            .kv_n4 = (int32_t)(kv_n / 4u),
            .q_row_stride = q_row_bytes,
            .kv_row_stride = kv_row_bytes,
            .eps = eps,
        };

        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;
```

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

File: ds4_metal.m

```c
ight_offset,
        uint32_t                kv_n,
        uint32_t                rows,
        float                   eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!q_out || !q || !kv_out || !kv || q_n == 0 || kv_n == 0 || rows == 0 ||
        (q_n & 3u) != 0 || (kv_n & 3u) != 0) {
        return 0;
    }

    @autoreleasepool {
        id<MTLBuffer> qbuf = ds4_gpu_tensor_buffer(q);
        id<MTLBuffer> qoutbuf = ds4_gpu_tensor_buffer(q_out);
        id<MTLBuffer> kvbuf = ds4_gpu_tensor_buffer(kv);
        id<MTLBuffer> kvoutbuf = ds4_gpu_tensor_buffer(kv_out);

        const uint64_t q_row_bytes = (uint64_t)q_n * sizeof(float);
        const uint64_t kv_row_bytes = (uint64_t)kv_n * sizeof(float);
        if (!qbuf || !qoutbuf || !kvbuf || !kvoutbuf ||
            ds4_gpu_tensor_bytes(q) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(q_out) < q_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv) < kv_row_bytes * rows ||
            ds4_gpu_tensor_bytes(kv_out) < kv_row_bytes * rows) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm received undersized activation buffers\n");
            return 0;
        }
        if (q_weight_offset > model_size || q_row_bytes > model_size - q_weight_offset ||
            kv_weight_offset > model_size || kv_row_bytes > model_size - kv_weight_offset) {
            fprintf(stderr, "ds4: Metal fused q/kv RMS norm weight range is outside the mapped model\n");
            return 0;
        }

        uint64_t q_inner_offset = 0;
        uint64_t kv_inner_offset = 0;
        id<MTLBuffer> q_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                          q_weight_offset, q_row_bytes,
                                                          &q_inner_offset);
        if (!q_wbuf) return 0;
        id<MTLBuffer> kv_wbuf = ds4_gpu_wrap_model_range(model_map, model_size,
                                                           kv_weight_offset, kv_row_bytes,
                                                           &kv_inner_offset);
        if (!kv_wbuf) return 0;

        ds4_gpu_qkv_rms_norm_args args = {
            .q_n = (int32_t)q_n,
            .q_n4 = (int32_t)(q_n / 4u),
            .kv_n = (int32_t)kv_n,
            .kv_n4 = (int32_t)(kv_n / 4u),
            .q_row_stride = q_row_bytes,
            .kv_row_stride = kv_row_bytes,
            .eps = eps,
        };

        int owned = 0;
        id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
        if (!cb) return 0;
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
_row_stride = kv_row_bytes,
            .eps = eps,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_qkv_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:qbuf offset:ds4_gpu_tensor_offset(q) atIndex:1];
        [enc setBuffer:q_wbuf offset:(NSUInteger)q_inner_offset atIndex:2];
        [enc setBuffer:qoutbuf offset:ds4_gpu_tensor_offset(q_out) atIndex:3];
        [enc setBuffer:kvbuf offset:ds4_gpu_tensor_offset(kv) atIndex:4];
        [enc setBuffer:kv_wbuf offset:(NSUInteger)kv_inner_offset atIndex:5];
        [enc setBuffer:kvoutbuf offset:ds4_gpu_tensor_offset(kv_out) atIndex:6];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 2, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(q_n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "fused q/kv RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_head_rms_norm_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        float             eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || (head_dim & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal head RMS norm received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_3d_args(head_dim, n_head, n_tok, eps);

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_plain_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
```

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

File: ds4_metal.m

```c
_row_stride = kv_row_bytes,
            .eps = eps,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_qkv_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:qbuf offset:ds4_gpu_tensor_offset(q) atIndex:1];
        [enc setBuffer:q_wbuf offset:(NSUInteger)q_inner_offset atIndex:2];
        [enc setBuffer:qoutbuf offset:ds4_gpu_tensor_offset(q_out) atIndex:3];
        [enc setBuffer:kvbuf offset:ds4_gpu_tensor_offset(kv) atIndex:4];
        [enc setBuffer:kv_wbuf offset:(NSUInteger)kv_inner_offset atIndex:5];
        [enc setBuffer:kvoutbuf offset:ds4_gpu_tensor_offset(kv_out) atIndex:6];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 2, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(q_n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "fused q/kv RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_head_rms_norm_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        float             eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || (head_dim & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal head RMS norm received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_3d_args(head_dim, n_head, n_tok, eps);

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_plain_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
_row_stride = kv_row_bytes,
            .eps = eps,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_qkv_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:qbuf offset:ds4_gpu_tensor_offset(q) atIndex:1];
        [enc setBuffer:q_wbuf offset:(NSUInteger)q_inner_offset atIndex:2];
        [enc setBuffer:qoutbuf offset:ds4_gpu_tensor_offset(q_out) atIndex:3];
        [enc setBuffer:kvbuf offset:ds4_gpu_tensor_offset(kv) atIndex:4];
        [enc setBuffer:kv_wbuf offset:(NSUInteger)kv_inner_offset atIndex:5];
        [enc setBuffer:kvoutbuf offset:ds4_gpu_tensor_offset(kv_out) atIndex:6];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 2, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(q_n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "fused q/kv RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_head_rms_norm_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        float             eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || (head_dim & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal head RMS norm received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_3d_args(head_dim, n_head, n_tok, eps);

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_plain_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
```

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

File: ds4_metal.m

```c
_row_stride = kv_row_bytes,
            .eps = eps,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_qkv_rms_norm_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:qbuf offset:ds4_gpu_tensor_offset(q) atIndex:1];
        [enc setBuffer:q_wbuf offset:(NSUInteger)q_inner_offset atIndex:2];
        [enc setBuffer:qoutbuf offset:ds4_gpu_tensor_offset(q_out) atIndex:3];
        [enc setBuffer:kvbuf offset:ds4_gpu_tensor_offset(kv) atIndex:4];
        [enc setBuffer:kv_wbuf offset:(NSUInteger)kv_inner_offset atIndex:5];
        [enc setBuffer:kvoutbuf offset:ds4_gpu_tensor_offset(kv_out) atIndex:6];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(rows, 2, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_threads(q_n), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "fused q/kv RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_head_rms_norm_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        float             eps) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || (head_dim & 3u) != 0) return 0;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal head RMS norm received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rms_norm_args args = ds4_gpu_make_rms_norm_3d_args(head_dim, n_head, n_tok, eps);

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_rms_norm_plain_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_head, n_tok, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_pipeline_threads(head_dim, g_rms_norm_plain_pipeline), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "head RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_rope_tail_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        uint32_t          n_rot,
        uint32_t          pos0,
        uint32_t          n_ctx_orig,
        bool              inverse,
        float             freq_base,
        float             freq_scale,
        float             ext_factor,
        float             attn_factor,
        float             beta_fast,
        float             beta_slow) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || n_rot > head_dim || (n_rot & 1u) != 0) {
        return 0;
    }
    if (n_rot == 0) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal RoPE received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rope_tail_batch_args args = ds4_gpu_make_rope_tail_args(
            n_tok, n_head, head_dim, n_rot, n_ctx_orig, inverse,
            freq_base, freq_scale, ext_factor, attn_factor, beta_fast, beta_slow);

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

        if (!ds4_gpu_encode_rope_tail_inplace(cb,
                                                xbuf,
                                                ds4_gpu_tensor_offset(x),
                                                &args,
                                                n_tok,
                                                n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
```

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_head, n_tok, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_pipeline_threads(head_dim, g_rms_norm_plain_pipeline), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "head RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_rope_tail_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        uint32_t          n_rot,
        uint32_t          pos0,
        uint32_t          n_ctx_orig,
        bool              inverse,
        float             freq_base,
        float             freq_scale,
        float             ext_factor,
        float             attn_factor,
        float             beta_fast,
        float             beta_slow) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || n_rot > head_dim || (n_rot & 1u) != 0) {
        return 0;
    }
    if (n_rot == 0) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal RoPE received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rope_tail_batch_args args = ds4_gpu_make_rope_tail_args(
            n_tok, n_head, head_dim, n_rot, n_ctx_orig, inverse,
            freq_base, freq_scale, ext_factor, attn_factor, beta_fast, beta_slow);

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

        if (!ds4_gpu_encode_rope_tail_inplace(cb,
                                                xbuf,
                                                ds4_gpu_tensor_offset(x),
                                                &args,
                                                n_tok,
                                                n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_head, n_tok, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_pipeline_threads(head_dim, g_rms_norm_plain_pipeline), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "head RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_rope_tail_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        uint32_t          n_rot,
        uint32_t          pos0,
        uint32_t          n_ctx_orig,
        bool              inverse,
        float             freq_base,
        float             freq_scale,
        float             ext_factor,
        float             attn_factor,
        float             beta_fast,
        float             beta_slow) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || n_rot > head_dim || (n_rot & 1u) != 0) {
        return 0;
    }
    if (n_rot == 0) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal RoPE received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rope_tail_batch_args args = ds4_gpu_make_rope_tail_args(
            n_tok, n_head, head_dim, n_rot, n_ctx_orig, inverse,
            freq_base, freq_scale, ext_factor, attn_factor, beta_fast, beta_slow);

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

        if (!ds4_gpu_encode_rope_tail_inplace(cb,
                                                xbuf,
                                                ds4_gpu_tensor_offset(x),
                                                &args,
                                                n_tok,
                                                n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
```

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

File: ds4_metal.m

```c
ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:3];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:4];
        [enc setThreadgroupMemoryLength:32u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_head, n_tok, 1)
             threadsPerThreadgroup:MTLSizeMake(ds4_gpu_rms_norm_pipeline_threads(head_dim, g_rms_norm_plain_pipeline), 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "head RMS norm")) return 0;
    }

    return 1;
}

int ds4_gpu_rope_tail_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          n_head,
        uint32_t          head_dim,
        uint32_t          n_rot,
        uint32_t          pos0,
        uint32_t          n_ctx_orig,
        bool              inverse,
        float             freq_base,
        float             freq_scale,
        float             ext_factor,
        float             attn_factor,
        float             beta_fast,
        float             beta_slow) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || n_head == 0 || head_dim == 0 || n_rot > head_dim || (n_rot & 1u) != 0) {
        return 0;
    }
    if (n_rot == 0) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * n_head * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal RoPE received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_rope_tail_batch_args args = ds4_gpu_make_rope_tail_args(
            n_tok, n_head, head_dim, n_rot, n_ctx_orig, inverse,
            freq_base, freq_scale, ext_factor, attn_factor, beta_fast, beta_slow);

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

        if (!ds4_gpu_encode_rope_tail_inplace(cb,
                                                xbuf,
                                                ds4_gpu_tensor_offset(x),
                                                &args,
                                                n_tok,
                                                n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
            return 0;
        }

        if (!ds4_gpu_finish_command_buffer(cb, owned, "RoPE tail")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_fp8_kv_quantize_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          head_dim,
        uint32_t          n_rot) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || head_dim == 0 || n_rot > head_dim) return 0;
    if (n_rot == head_dim) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal DSV4 FP8 KV quantize received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_dsv4_fp8_kv_quantize_args args = {
            .ne00 = head_dim,
            .ne01 = n_tok,
            .ne02 = 1,
            .ne03 = 1,
            .nb00 = sizeof(float),
            .nb01 = (uint64_t)head_dim * sizeof(float),
            .nb02 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb03 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb0 = sizeof(float),
            .nb1 = (uint64_t)head_dim * sizeof(float),
            .nb2 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb3 = (uint64_t)n_tok * head_dim * sizeof(float),
            .n_rot = (int32_t)n_rot,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_fp8_kv_quantize_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setThreadgroupMemoryLength:64u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_tok, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(64, 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "DSV4 FP8 KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
```

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

File: ds4_metal.m

```c
n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
            return 0;
        }

        if (!ds4_gpu_finish_command_buffer(cb, owned, "RoPE tail")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_fp8_kv_quantize_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          head_dim,
        uint32_t          n_rot) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || head_dim == 0 || n_rot > head_dim) return 0;
    if (n_rot == head_dim) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal DSV4 FP8 KV quantize received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_dsv4_fp8_kv_quantize_args args = {
            .ne00 = head_dim,
            .ne01 = n_tok,
            .ne02 = 1,
            .ne03 = 1,
            .nb00 = sizeof(float),
            .nb01 = (uint64_t)head_dim * sizeof(float),
            .nb02 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb03 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb0 = sizeof(float),
            .nb1 = (uint64_t)head_dim * sizeof(float),
            .nb2 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb3 = (uint64_t)n_tok * head_dim * sizeof(float),
            .n_rot = (int32_t)n_rot,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_fp8_kv_quantize_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setThreadgroupMemoryLength:64u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_tok, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(64, 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "DSV4 FP8 KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
            return 0;
        }

        if (!ds4_gpu_finish_command_buffer(cb, owned, "RoPE tail")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_fp8_kv_quantize_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          head_dim,
        uint32_t          n_rot) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || head_dim == 0 || n_rot > head_dim) return 0;
    if (n_rot == head_dim) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal DSV4 FP8 KV quantize received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_dsv4_fp8_kv_quantize_args args = {
            .ne00 = head_dim,
            .ne01 = n_tok,
            .ne02 = 1,
            .ne03 = 1,
            .nb00 = sizeof(float),
            .nb01 = (uint64_t)head_dim * sizeof(float),
            .nb02 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb03 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb0 = sizeof(float),
            .nb1 = (uint64_t)head_dim * sizeof(float),
            .nb2 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb3 = (uint64_t)n_tok * head_dim * sizeof(float),
            .n_rot = (int32_t)n_rot,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_fp8_kv_quantize_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setThreadgroupMemoryLength:64u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_tok, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(64, 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "DSV4 FP8 KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
```

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

File: ds4_metal.m

```c
n_head,
                                                head_dim,
                                                pos0,
                                                1)) {
            return 0;
        }

        if (!ds4_gpu_finish_command_buffer(cb, owned, "RoPE tail")) return 0;
    }

    return 1;
}

int ds4_gpu_dsv4_fp8_kv_quantize_tensor(
        ds4_gpu_tensor *x,
        uint32_t          n_tok,
        uint32_t          head_dim,
        uint32_t          n_rot) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!x || n_tok == 0 || head_dim == 0 || n_rot > head_dim) return 0;
    if (n_rot == head_dim) return 1;

    @autoreleasepool {
        id<MTLBuffer> xbuf = ds4_gpu_tensor_buffer(x);
        const uint64_t bytes = (uint64_t)n_tok * head_dim * sizeof(float);
        if (!xbuf || ds4_gpu_tensor_bytes(x) < bytes) {
            fprintf(stderr, "ds4: Metal DSV4 FP8 KV quantize received undersized activation buffer\n");
            return 0;
        }

        ds4_gpu_dsv4_fp8_kv_quantize_args args = {
            .ne00 = head_dim,
            .ne01 = n_tok,
            .ne02 = 1,
            .ne03 = 1,
            .nb00 = sizeof(float),
            .nb01 = (uint64_t)head_dim * sizeof(float),
            .nb02 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb03 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb0 = sizeof(float),
            .nb1 = (uint64_t)head_dim * sizeof(float),
            .nb2 = (uint64_t)n_tok * head_dim * sizeof(float),
            .nb3 = (uint64_t)n_tok * head_dim * sizeof(float),
            .n_rot = (int32_t)n_rot,
        };

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

        id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
        [enc setComputePipelineState:g_dsv4_fp8_kv_quantize_pipeline];
        [enc setBytes:&args length:sizeof(args) atIndex:0];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:1];
        [enc setBuffer:xbuf offset:ds4_gpu_tensor_offset(x) atIndex:2];
        [enc setThreadgroupMemoryLength:64u * sizeof(float) atIndex:0];
        [enc dispatchThreadgroups:MTLSizeMake(n_tok, 1, 1)
             threadsPerThreadgroup:MTLSizeMake(64, 1, 1)];
        ds4_gpu_end_compute_encoder(cb, enc);

        if (!ds4_gpu_finish_command_buffer(cb, owned, "DSV4 FP8 KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
    const NSUInteger nk0 = width ? (NSUInteger)width : 1u;
    const NSUInteger max_threads = g_set_rows_f32_i32_pipeline
        ? (NSUInteger)g_set_rows_f32_i32_pipeline.maxTotalThreadsPerThreadgroup
        : 1024u;

    NSUInteger nth = 32u;
    while (nth < nk0 && nth < max_threads) {
        nth *= 2u;
    }

    NSUInteger nrptg = 1u;
    if (nth > nk0) {
        nrptg = (nth + nk0 - 1u) / nk0;
        nth = nk0;
        if (nrptg * nth > max_threads) {
            nrptg--;
        }
    }

    if (nth > nk0) nth = nk0;
    if (nth == 0u) nth = 1u;
    if (nrptg == 0u) nrptg = 1u;

    *nth_out = nth;
    *nrptg_out = nrptg;
}

static int ds4_gpu_encode_f16_round_copy_for_raw_store(
        id<MTLCommandBuffer>   cb,
        const ds4_gpu_tensor *src,
        uint32_t               n) {
    id<MTLBuffer> srcbuf = ds4_gpu_tensor_buffer(src);
    const uint64_t src_bytes = (uint64_t)n * sizeof(float);
    if (!srcbuf || ds4_gpu_tensor_bytes(src) < src_bytes) {
        fprintf(stderr, "ds4: Metal raw KV store received undersized source buffer\n");
        return 0;
    }
    if (!ds4_gpu_ensure_scratch_buffer(&g_f16_round_scratch_buffer,
                                         &g_f16_round_scratch_bytes,
                                         (NSUInteger)n * sizeof(uint16_t),
                                         "ds4_f16_round_scratch") ||
        !ds4_gpu_ensure_scratch_buffer(&g_raw_store_round_buffer,
                                         &g_raw_store_round_bytes,
                                         (NSUInteger)n * sizeof(float),
                                         "ds4_raw_store_round")) {
        return 0;
    }

    ds4_gpu_cpy_args f32_to_f16 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(float), sizeof(uint16_t));
    ds4_gpu_cpy_args f16_to_f32 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(uint16_t), sizeof(float));
    const NSUInteger nth_f32_f16 = ds4_gpu_cpy_threads(n, g_cpy_f32_f16_pipeline);
    const NSUInteger nth_f16_f32 = ds4_gpu_cpy_threads(n, g_cpy_f16_f32_pipeline);
    const NSUInteger groups_f32_f16 = ((NSUInteger)n + nth_f32_f16 - 1u) / nth_f32_f16;
    const NSUInteger groups_f16_f32 = ((NSUInteger)n + nth_f16_f32 - 1u) / nth_f16_f32;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
```

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

File: ds4_metal.m

```c
KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
    const NSUInteger nk0 = width ? (NSUInteger)width : 1u;
    const NSUInteger max_threads = g_set_rows_f32_i32_pipeline
        ? (NSUInteger)g_set_rows_f32_i32_pipeline.maxTotalThreadsPerThreadgroup
        : 1024u;

    NSUInteger nth = 32u;
    while (nth < nk0 && nth < max_threads) {
        nth *= 2u;
    }

    NSUInteger nrptg = 1u;
    if (nth > nk0) {
        nrptg = (nth + nk0 - 1u) / nk0;
        nth = nk0;
        if (nrptg * nth > max_threads) {
            nrptg--;
        }
    }

    if (nth > nk0) nth = nk0;
    if (nth == 0u) nth = 1u;
    if (nrptg == 0u) nrptg = 1u;

    *nth_out = nth;
    *nrptg_out = nrptg;
}

static int ds4_gpu_encode_f16_round_copy_for_raw_store(
        id<MTLCommandBuffer>   cb,
        const ds4_gpu_tensor *src,
        uint32_t               n) {
    id<MTLBuffer> srcbuf = ds4_gpu_tensor_buffer(src);
    const uint64_t src_bytes = (uint64_t)n * sizeof(float);
    if (!srcbuf || ds4_gpu_tensor_bytes(src) < src_bytes) {
        fprintf(stderr, "ds4: Metal raw KV store received undersized source buffer\n");
        return 0;
    }
    if (!ds4_gpu_ensure_scratch_buffer(&g_f16_round_scratch_buffer,
                                         &g_f16_round_scratch_bytes,
                                         (NSUInteger)n * sizeof(uint16_t),
                                         "ds4_f16_round_scratch") ||
        !ds4_gpu_ensure_scratch_buffer(&g_raw_store_round_buffer,
                                         &g_raw_store_round_bytes,
                                         (NSUInteger)n * sizeof(float),
                                         "ds4_raw_store_round")) {
        return 0;
    }

    ds4_gpu_cpy_args f32_to_f16 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(float), sizeof(uint16_t));
    ds4_gpu_cpy_args f16_to_f32 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(uint16_t), sizeof(float));
    const NSUInteger nth_f32_f16 = ds4_gpu_cpy_threads(n, g_cpy_f32_f16_pipeline);
    const NSUInteger nth_f16_f32 = ds4_gpu_cpy_threads(n, g_cpy_f16_f32_pipeline);
    const NSUInteger groups_f32_f16 = ((NSUInteger)n + nth_f32_f16 - 1u) / nth_f32_f16;
    const NSUInteger groups_f16_f32 = ((NSUInteger)n + nth_f16_f32 - 1u) / nth_f16_f32;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
    const NSUInteger nk0 = width ? (NSUInteger)width : 1u;
    const NSUInteger max_threads = g_set_rows_f32_i32_pipeline
        ? (NSUInteger)g_set_rows_f32_i32_pipeline.maxTotalThreadsPerThreadgroup
        : 1024u;

    NSUInteger nth = 32u;
    while (nth < nk0 && nth < max_threads) {
        nth *= 2u;
    }

    NSUInteger nrptg = 1u;
    if (nth > nk0) {
        nrptg = (nth + nk0 - 1u) / nk0;
        nth = nk0;
        if (nrptg * nth > max_threads) {
            nrptg--;
        }
    }

    if (nth > nk0) nth = nk0;
    if (nth == 0u) nth = 1u;
    if (nrptg == 0u) nrptg = 1u;

    *nth_out = nth;
    *nrptg_out = nrptg;
}

static int ds4_gpu_encode_f16_round_copy_for_raw_store(
        id<MTLCommandBuffer>   cb,
        const ds4_gpu_tensor *src,
        uint32_t               n) {
    id<MTLBuffer> srcbuf = ds4_gpu_tensor_buffer(src);
    const uint64_t src_bytes = (uint64_t)n * sizeof(float);
    if (!srcbuf || ds4_gpu_tensor_bytes(src) < src_bytes) {
        fprintf(stderr, "ds4: Metal raw KV store received undersized source buffer\n");
        return 0;
    }
    if (!ds4_gpu_ensure_scratch_buffer(&g_f16_round_scratch_buffer,
                                         &g_f16_round_scratch_bytes,
                                         (NSUInteger)n * sizeof(uint16_t),
                                         "ds4_f16_round_scratch") ||
        !ds4_gpu_ensure_scratch_buffer(&g_raw_store_round_buffer,
                                         &g_raw_store_round_bytes,
                                         (NSUInteger)n * sizeof(float),
                                         "ds4_raw_store_round")) {
        return 0;
    }

    ds4_gpu_cpy_args f32_to_f16 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(float), sizeof(uint16_t));
    ds4_gpu_cpy_args f16_to_f32 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(uint16_t), sizeof(float));
    const NSUInteger nth_f32_f16 = ds4_gpu_cpy_threads(n, g_cpy_f32_f16_pipeline);
    const NSUInteger nth_f16_f32 = ds4_gpu_cpy_threads(n, g_cpy_f16_f32_pipeline);
    const NSUInteger groups_f32_f16 = ((NSUInteger)n + nth_f32_f16 - 1u) / nth_f32_f16;
    const NSUInteger groups_f16_f32 = ((NSUInteger)n + nth_f16_f32 - 1u) / nth_f16_f32;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
```

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

File: ds4_metal.m

```c
KV quantize")) return 0;
    }

    return 1;
}

static void ds4_gpu_set_rows_thread_shape(
        uint32_t    width,
        NSUInteger *nth_out,
        NSUInteger *nrptg_out) {
    const NSUInteger nk0 = width ? (NSUInteger)width : 1u;
    const NSUInteger max_threads = g_set_rows_f32_i32_pipeline
        ? (NSUInteger)g_set_rows_f32_i32_pipeline.maxTotalThreadsPerThreadgroup
        : 1024u;

    NSUInteger nth = 32u;
    while (nth < nk0 && nth < max_threads) {
        nth *= 2u;
    }

    NSUInteger nrptg = 1u;
    if (nth > nk0) {
        nrptg = (nth + nk0 - 1u) / nk0;
        nth = nk0;
        if (nrptg * nth > max_threads) {
            nrptg--;
        }
    }

    if (nth > nk0) nth = nk0;
    if (nth == 0u) nth = 1u;
    if (nrptg == 0u) nrptg = 1u;

    *nth_out = nth;
    *nrptg_out = nrptg;
}

static int ds4_gpu_encode_f16_round_copy_for_raw_store(
        id<MTLCommandBuffer>   cb,
        const ds4_gpu_tensor *src,
        uint32_t               n) {
    id<MTLBuffer> srcbuf = ds4_gpu_tensor_buffer(src);
    const uint64_t src_bytes = (uint64_t)n * sizeof(float);
    if (!srcbuf || ds4_gpu_tensor_bytes(src) < src_bytes) {
        fprintf(stderr, "ds4: Metal raw KV store received undersized source buffer\n");
        return 0;
    }
    if (!ds4_gpu_ensure_scratch_buffer(&g_f16_round_scratch_buffer,
                                         &g_f16_round_scratch_bytes,
                                         (NSUInteger)n * sizeof(uint16_t),
                                         "ds4_f16_round_scratch") ||
        !ds4_gpu_ensure_scratch_buffer(&g_raw_store_round_buffer,
                                         &g_raw_store_round_bytes,
                                         (NSUInteger)n * sizeof(float),
                                         "ds4_raw_store_round")) {
        return 0;
    }

    ds4_gpu_cpy_args f32_to_f16 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(float), sizeof(uint16_t));
    ds4_gpu_cpy_args f16_to_f32 =
        ds4_gpu_make_cpy_1d_args(n, sizeof(uint16_t), sizeof(float));
    const NSUInteger nth_f32_f16 = ds4_gpu_cpy_threads(n, g_cpy_f32_f16_pipeline);
    const NSUInteger nth_f16_f32 = ds4_gpu_cpy_threads(n, g_cpy_f16_f32_pipeline);
    const NSUInteger groups_f32_f16 = ((NSUInteger)n + nth_f32_f16 - 1u) / nth_f32_f16;
    const NSUInteger groups_f16_f32 = ((NSUInteger)n + nth_f16_f32 - 1u) / nth_f16_f32;

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
puteCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
    [enc setBuffer:srcbuf offset:ds4_gpu_tensor_offset(src) atIndex:1];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f32_f16, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f32_f16, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f16_f32_pipeline];
    [enc setBytes:&f16_to_f32 length:sizeof(f16_to_f32) atIndex:0];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:1];
    [enc setBuffer:g_raw_store_round_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f16_f32, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f16_f32, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_set_rows_f32_i32(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *dst,
        id<MTLBuffer>        srcbuf,
        NSUInteger           src_off,
        const int32_t       *rows,
        uint32_t             n_rows,
        uint32_t             dst_rows,
        uint32_t             width) {
    id<MTLBuffer> dstbuf = ds4_gpu_tensor_buffer(dst);
    const uint64_t dst_bytes = (uint64_t)dst_rows * width * sizeof(float);
    const uint64_t src_bytes = (uint64_t)n_rows * width * sizeof(float);
    if (!dstbuf || !srcbuf || !rows || n_rows == 0 || width == 0 ||
        ds4_gpu_tensor_bytes(dst) < dst_bytes ||
        src_bytes > NSUIntegerMax - src_off) {
        fprintf(stderr, "ds4: Metal DS4 set_rows received invalid buffers\n");
        return 0;
    }

    const uint64_t row_bytes = (uint64_t)width * sizeof(float);
    const uint64_t rows_bytes = (uint64_t)n_rows * sizeof(int32_t);
    ds4_gpu_set_rows_args args = {
        .nk0 = (int32_t)width,
        .ne01 = (int32_t)n_rows,
        .nb01 = row_bytes,
        .nb02 = (uint64_t)n_rows * row_bytes,
        .nb03 = (uint64_t)n_rows * row_bytes,
        .ne11 = 1,
        .ne12 = 1,
        .nb10 = sizeof(int32_t),
        .nb11 = rows_bytes,
        .nb12 = rows_bytes,
        .nb1 = row_bytes,
        .nb2 = (uint64_t)dst_rows * row_bytes,
        .nb3 = (uint64_t)dst_rows * row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
```

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

File: ds4_metal.m

```c
puteCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
    [enc setBuffer:srcbuf offset:ds4_gpu_tensor_offset(src) atIndex:1];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f32_f16, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f32_f16, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f16_f32_pipeline];
    [enc setBytes:&f16_to_f32 length:sizeof(f16_to_f32) atIndex:0];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:1];
    [enc setBuffer:g_raw_store_round_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f16_f32, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f16_f32, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_set_rows_f32_i32(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *dst,
        id<MTLBuffer>        srcbuf,
        NSUInteger           src_off,
        const int32_t       *rows,
        uint32_t             n_rows,
        uint32_t             dst_rows,
        uint32_t             width) {
    id<MTLBuffer> dstbuf = ds4_gpu_tensor_buffer(dst);
    const uint64_t dst_bytes = (uint64_t)dst_rows * width * sizeof(float);
    const uint64_t src_bytes = (uint64_t)n_rows * width * sizeof(float);
    if (!dstbuf || !srcbuf || !rows || n_rows == 0 || width == 0 ||
        ds4_gpu_tensor_bytes(dst) < dst_bytes ||
        src_bytes > NSUIntegerMax - src_off) {
        fprintf(stderr, "ds4: Metal DS4 set_rows received invalid buffers\n");
        return 0;
    }

    const uint64_t row_bytes = (uint64_t)width * sizeof(float);
    const uint64_t rows_bytes = (uint64_t)n_rows * sizeof(int32_t);
    ds4_gpu_set_rows_args args = {
        .nk0 = (int32_t)width,
        .ne01 = (int32_t)n_rows,
        .nb01 = row_bytes,
        .nb02 = (uint64_t)n_rows * row_bytes,
        .nb03 = (uint64_t)n_rows * row_bytes,
        .ne11 = 1,
        .ne12 = 1,
        .nb10 = sizeof(int32_t),
        .nb11 = rows_bytes,
        .nb12 = rows_bytes,
        .nb1 = row_bytes,
        .nb2 = (uint64_t)dst_rows * row_bytes,
        .nb3 = (uint64_t)dst_rows * row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
puteCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
    [enc setBuffer:srcbuf offset:ds4_gpu_tensor_offset(src) atIndex:1];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f32_f16, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f32_f16, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f16_f32_pipeline];
    [enc setBytes:&f16_to_f32 length:sizeof(f16_to_f32) atIndex:0];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:1];
    [enc setBuffer:g_raw_store_round_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f16_f32, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f16_f32, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_set_rows_f32_i32(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *dst,
        id<MTLBuffer>        srcbuf,
        NSUInteger           src_off,
        const int32_t       *rows,
        uint32_t             n_rows,
        uint32_t             dst_rows,
        uint32_t             width) {
    id<MTLBuffer> dstbuf = ds4_gpu_tensor_buffer(dst);
    const uint64_t dst_bytes = (uint64_t)dst_rows * width * sizeof(float);
    const uint64_t src_bytes = (uint64_t)n_rows * width * sizeof(float);
    if (!dstbuf || !srcbuf || !rows || n_rows == 0 || width == 0 ||
        ds4_gpu_tensor_bytes(dst) < dst_bytes ||
        src_bytes > NSUIntegerMax - src_off) {
        fprintf(stderr, "ds4: Metal DS4 set_rows received invalid buffers\n");
        return 0;
    }

    const uint64_t row_bytes = (uint64_t)width * sizeof(float);
    const uint64_t rows_bytes = (uint64_t)n_rows * sizeof(int32_t);
    ds4_gpu_set_rows_args args = {
        .nk0 = (int32_t)width,
        .ne01 = (int32_t)n_rows,
        .nb01 = row_bytes,
        .nb02 = (uint64_t)n_rows * row_bytes,
        .nb03 = (uint64_t)n_rows * row_bytes,
        .ne11 = 1,
        .ne12 = 1,
        .nb10 = sizeof(int32_t),
        .nb11 = rows_bytes,
        .nb12 = rows_bytes,
        .nb1 = row_bytes,
        .nb2 = (uint64_t)dst_rows * row_bytes,
        .nb3 = (uint64_t)dst_rows * row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
```

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

File: ds4_metal.m

```c
puteCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f32_f16_pipeline];
    [enc setBytes:&f32_to_f16 length:sizeof(f32_to_f16) atIndex:0];
    [enc setBuffer:srcbuf offset:ds4_gpu_tensor_offset(src) atIndex:1];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f32_f16, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f32_f16, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_cpy_f16_f32_pipeline];
    [enc setBytes:&f16_to_f32 length:sizeof(f16_to_f32) atIndex:0];
    [enc setBuffer:g_f16_round_scratch_buffer offset:0 atIndex:1];
    [enc setBuffer:g_raw_store_round_buffer offset:0 atIndex:2];
    [enc dispatchThreadgroups:MTLSizeMake(groups_f16_f32, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth_f16_f32, 1, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_set_rows_f32_i32(
        id<MTLCommandBuffer> cb,
        ds4_gpu_tensor    *dst,
        id<MTLBuffer>        srcbuf,
        NSUInteger           src_off,
        const int32_t       *rows,
        uint32_t             n_rows,
        uint32_t             dst_rows,
        uint32_t             width) {
    id<MTLBuffer> dstbuf = ds4_gpu_tensor_buffer(dst);
    const uint64_t dst_bytes = (uint64_t)dst_rows * width * sizeof(float);
    const uint64_t src_bytes = (uint64_t)n_rows * width * sizeof(float);
    if (!dstbuf || !srcbuf || !rows || n_rows == 0 || width == 0 ||
        ds4_gpu_tensor_bytes(dst) < dst_bytes ||
        src_bytes > NSUIntegerMax - src_off) {
        fprintf(stderr, "ds4: Metal DS4 set_rows received invalid buffers\n");
        return 0;
    }

    const uint64_t row_bytes = (uint64_t)width * sizeof(float);
    const uint64_t rows_bytes = (uint64_t)n_rows * sizeof(int32_t);
    ds4_gpu_set_rows_args args = {
        .nk0 = (int32_t)width,
        .ne01 = (int32_t)n_rows,
        .nb01 = row_bytes,
        .nb02 = (uint64_t)n_rows * row_bytes,
        .nb03 = (uint64_t)n_rows * row_bytes,
        .ne11 = 1,
        .ne12 = 1,
        .nb10 = sizeof(int32_t),
        .nb11 = rows_bytes,
        .nb12 = rows_bytes,
        .nb1 = row_bytes,
        .nb2 = (uint64_t)dst_rows * row_bytes,
        .nb3 = (uint64_t)dst_rows * row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
        rowsbuf = ds4_gpu_new_transient_buffer((NSUInteger)rows_bytes, "ds4_set_rows_indices");
        if (!rowsbuf) return 0;
        memcpy([rowsbuf contents], rows, (NSUInteger)rows_bytes);
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_set_rows_f32_i32_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:srcbuf offset:src_off atIndex:1];
    if (rowsbuf) {
        [enc setBuffer:rowsbuf offset:0 atIndex:2];
    } else {
        [enc setBytes:rows length:(NSUInteger)rows_bytes atIndex:2];
    }
    [enc setBuffer:dstbuf offset:ds4_gpu_tensor_offset(dst) atIndex:3];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n_rows + nrptg - 1u) / nrptg, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth, nrptg, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
        NSUInteger           b_off,
        id<MTLBuffer>        out,
        NSUInteger           out_off,
        uint32_t             n) {
    if (!cb || !a || !b || !out || n == 0) return 0;

    const uint64_t row_bytes = (uint64_t)n * sizeof(float);
    ds4_gpu_bin_args args = {
        .ne00 = (int32_t)n,
        .ne01 = 1,
        .ne02 = 1,
        .ne03 = 1,
        .nb00 = sizeof(float),
        .nb01 = row_bytes,
        .nb02 = row_bytes,
        .nb03 = row_bytes,
        .ne10 = (int32_t)n,
        .ne11 = 1,
        .ne12 = 1,
        .ne13 = 1,
        .nb10 = sizeof(float),
        .nb11 = row_bytes,
        .nb12 = row_bytes,
        .nb13 = row_bytes,
        .ne0 = (int32_t)n,
        .ne1 = 1,
        .ne2 = 1,
        .ne3 = 1,
        .nb0 = sizeof(float),
        .nb1 = row_bytes,
        .nb2 = row_bytes,
        .nb3 = row_bytes,
        .offs = 0,
        .o1 = { 0 },
    };

    NSUInteger nth_max = g_add_pipeline.maxTotalThreadsPerThreadgroup;
    if (nth_max > 256u) nth_max = 256u;
    NSUInteger nth = 1u;
    while (2u * nth < (NSUInteger)n && nth < nth_max) {
        nth *= 2u;
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_add_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:a offset:a_off atIndex:1];
```

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

File: ds4_metal.m

```c
row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
        rowsbuf = ds4_gpu_new_transient_buffer((NSUInteger)rows_bytes, "ds4_set_rows_indices");
        if (!rowsbuf) return 0;
        memcpy([rowsbuf contents], rows, (NSUInteger)rows_bytes);
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_set_rows_f32_i32_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:srcbuf offset:src_off atIndex:1];
    if (rowsbuf) {
        [enc setBuffer:rowsbuf offset:0 atIndex:2];
    } else {
        [enc setBytes:rows length:(NSUInteger)rows_bytes atIndex:2];
    }
    [enc setBuffer:dstbuf offset:ds4_gpu_tensor_offset(dst) atIndex:3];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n_rows + nrptg - 1u) / nrptg, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth, nrptg, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
        NSUInteger           b_off,
        id<MTLBuffer>        out,
        NSUInteger           out_off,
        uint32_t             n) {
    if (!cb || !a || !b || !out || n == 0) return 0;

    const uint64_t row_bytes = (uint64_t)n * sizeof(float);
    ds4_gpu_bin_args args = {
        .ne00 = (int32_t)n,
        .ne01 = 1,
        .ne02 = 1,
        .ne03 = 1,
        .nb00 = sizeof(float),
        .nb01 = row_bytes,
        .nb02 = row_bytes,
        .nb03 = row_bytes,
        .ne10 = (int32_t)n,
        .ne11 = 1,
        .ne12 = 1,
        .ne13 = 1,
        .nb10 = sizeof(float),
        .nb11 = row_bytes,
        .nb12 = row_bytes,
        .nb13 = row_bytes,
        .ne0 = (int32_t)n,
        .ne1 = 1,
        .ne2 = 1,
        .ne3 = 1,
        .nb0 = sizeof(float),
        .nb1 = row_bytes,
        .nb2 = row_bytes,
        .nb3 = row_bytes,
        .offs = 0,
        .o1 = { 0 },
    };

    NSUInteger nth_max = g_add_pipeline.maxTotalThreadsPerThreadgroup;
    if (nth_max > 256u) nth_max = 256u;
    NSUInteger nth = 1u;
    while (2u * nth < (NSUInteger)n && nth < nth_max) {
        nth *= 2u;
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_add_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:a offset:a_off atIndex:1];
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
        rowsbuf = ds4_gpu_new_transient_buffer((NSUInteger)rows_bytes, "ds4_set_rows_indices");
        if (!rowsbuf) return 0;
        memcpy([rowsbuf contents], rows, (NSUInteger)rows_bytes);
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_set_rows_f32_i32_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:srcbuf offset:src_off atIndex:1];
    if (rowsbuf) {
        [enc setBuffer:rowsbuf offset:0 atIndex:2];
    } else {
        [enc setBytes:rows length:(NSUInteger)rows_bytes atIndex:2];
    }
    [enc setBuffer:dstbuf offset:ds4_gpu_tensor_offset(dst) atIndex:3];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n_rows + nrptg - 1u) / nrptg, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth, nrptg, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
        NSUInteger           b_off,
        id<MTLBuffer>        out,
        NSUInteger           out_off,
        uint32_t             n) {
    if (!cb || !a || !b || !out || n == 0) return 0;

    const uint64_t row_bytes = (uint64_t)n * sizeof(float);
    ds4_gpu_bin_args args = {
        .ne00 = (int32_t)n,
        .ne01 = 1,
        .ne02 = 1,
        .ne03 = 1,
        .nb00 = sizeof(float),
        .nb01 = row_bytes,
        .nb02 = row_bytes,
        .nb03 = row_bytes,
        .ne10 = (int32_t)n,
        .ne11 = 1,
        .ne12 = 1,
        .ne13 = 1,
        .nb10 = sizeof(float),
        .nb11 = row_bytes,
        .nb12 = row_bytes,
        .nb13 = row_bytes,
        .ne0 = (int32_t)n,
        .ne1 = 1,
        .ne2 = 1,
        .ne3 = 1,
        .nb0 = sizeof(float),
        .nb1 = row_bytes,
        .nb2 = row_bytes,
        .nb3 = row_bytes,
        .offs = 0,
        .o1 = { 0 },
    };

    NSUInteger nth_max = g_add_pipeline.maxTotalThreadsPerThreadgroup;
    if (nth_max > 256u) nth_max = 256u;
    NSUInteger nth = 1u;
    while (2u * nth < (NSUInteger)n && nth < nth_max) {
        nth *= 2u;
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_add_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:a offset:a_off atIndex:1];
```

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

File: ds4_metal.m

```c
row_bytes,
    };

    NSUInteger nth;
    NSUInteger nrptg;
    ds4_gpu_set_rows_thread_shape(width, &nth, &nrptg);

    id<MTLBuffer> rowsbuf = nil;
    if (rows_bytes > 4096u) {
        rowsbuf = ds4_gpu_new_transient_buffer((NSUInteger)rows_bytes, "ds4_set_rows_indices");
        if (!rowsbuf) return 0;
        memcpy([rowsbuf contents], rows, (NSUInteger)rows_bytes);
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_set_rows_f32_i32_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:srcbuf offset:src_off atIndex:1];
    if (rowsbuf) {
        [enc setBuffer:rowsbuf offset:0 atIndex:2];
    } else {
        [enc setBytes:rows length:(NSUInteger)rows_bytes atIndex:2];
    }
    [enc setBuffer:dstbuf offset:ds4_gpu_tensor_offset(dst) atIndex:3];
    [enc dispatchThreadgroups:MTLSizeMake(((NSUInteger)n_rows + nrptg - 1u) / nrptg, 1, 1)
         threadsPerThreadgroup:MTLSizeMake(nth, nrptg, 1)];
    ds4_gpu_end_compute_encoder(cb, enc);

    return 1;
}

static int ds4_gpu_encode_add_f32_1d(
        id<MTLCommandBuffer> cb,
        id<MTLBuffer>        a,
        NSUInteger           a_off,
        id<MTLBuffer>        b,
        NSUInteger           b_off,
        id<MTLBuffer>        out,
        NSUInteger           out_off,
        uint32_t             n) {
    if (!cb || !a || !b || !out || n == 0) return 0;

    const uint64_t row_bytes = (uint64_t)n * sizeof(float);
    ds4_gpu_bin_args args = {
        .ne00 = (int32_t)n,
        .ne01 = 1,
        .ne02 = 1,
        .ne03 = 1,
        .nb00 = sizeof(float),
        .nb01 = row_bytes,
        .nb02 = row_bytes,
        .nb03 = row_bytes,
        .ne10 = (int32_t)n,
        .ne11 = 1,
        .ne12 = 1,
        .ne13 = 1,
        .nb10 = sizeof(float),
        .nb11 = row_bytes,
        .nb12 = row_bytes,
        .nb13 = row_bytes,
        .ne0 = (int32_t)n,
        .ne1 = 1,
        .ne2 = 1,
        .ne3 = 1,
        .nb0 = sizeof(float),
        .nb1 = row_bytes,
        .nb2 = row_bytes,
        .nb3 = row_bytes,
        .offs = 0,
        .o1 = { 0 },
    };

    NSUInteger nth_max = g_add_pipeline.maxTotalThreadsPerThreadgroup;
    if (nth_max > 256u) nth_max = 256u;
    NSUInteger nth = 1u;
    while (2u * nth < (NSUInteger)n && nth < nth_max) {
        nth *= 2u;
    }

    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
    [enc setComputePipelineState:g_add_pipeline];
    [enc setBytes:&args length:sizeof(args) atIndex:0];
    [enc setBuffer:a offset:a_off atIndex:1];
```<｜Assistant｜><think>