[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
] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_topk_mask_scatter"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_topk_mask_scatter_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_topk_mask_scatter_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_indexer_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_indexer_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_indexer_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_sinkhorn"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_sinkhorn_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_sinkhorn_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_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｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4_metal.m

```c
] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_topk_mask_scatter"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_topk_mask_scatter_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_topk_mask_scatter_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_indexer_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_indexer_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_indexer_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_sinkhorn"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_sinkhorn_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_sinkhorn_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_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
] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_topk_mask_scatter"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_topk_mask_scatter_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_topk_mask_scatter_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_indexer_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_indexer_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_indexer_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_sinkhorn"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_sinkhorn_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_sinkhorn_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_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｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4_metal.m

```c
] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_topk_mask_scatter"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_topk_mask_scatter_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_topk_mask_scatter_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_topk_mask_scatter pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_indexer_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_dsv4_indexer_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_dsv4_indexer_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_indexer_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_sinkhorn"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_sinkhorn_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_sinkhorn_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_sinkhorn pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_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]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_metal.m

```c
return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum_norm4"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_norm_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_norm_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sigmoid_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sigmoid_op = 102;
        bool unary_cnt = false;
        [unary_sigmoid_constants setConstantValue:&unary_sigmoid_op type:MTLDataTypeShort atIndex:1200];
        [unary_sigmoid_constants setConstantValue:&unary_cnt        type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sigmoid_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```

<｜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
return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum_norm4"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_norm_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_norm_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sigmoid_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sigmoid_op = 102;
        bool unary_cnt = false;
        [unary_sigmoid_constants setConstantValue:&unary_sigmoid_op type:MTLDataTypeShort atIndex:1200];
        [unary_sigmoid_constants setConstantValue:&unary_cnt        type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sigmoid_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```<｜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
return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum_norm4"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_norm_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_norm_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sigmoid_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sigmoid_op = 102;
        bool unary_cnt = false;
        [unary_sigmoid_constants setConstantValue:&unary_sigmoid_op type:MTLDataTypeShort atIndex:1200];
        [unary_sigmoid_constants setConstantValue:&unary_cnt        type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sigmoid_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```

<｜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
return 0;
        }
        g_hc_split_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_split_weighted_sum_norm4"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_split_weighted_sum_norm_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_split_weighted_sum_norm_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_split_weighted_sum_norm4 pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_weighted_sum"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_weighted_sum_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_weighted_sum_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_weighted_sum pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sigmoid_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sigmoid_op = 102;
        bool unary_cnt = false;
        [unary_sigmoid_constants setConstantValue:&unary_sigmoid_op type:MTLDataTypeShort atIndex:1200];
        [unary_sigmoid_constants setConstantValue:&unary_cnt        type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sigmoid_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```<｜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
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sigmoid_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sigmoid_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_silu_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_silu_op = 106;
        [unary_silu_constants setConstantValue:&unary_silu_op type:MTLDataTypeShort atIndex:1200];
        [unary_silu_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_silu_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_silu_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_silu_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_softplus_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_softplus_op = 115;
        [unary_softplus_constants setConstantValue:&unary_softplus_op type:MTLDataTypeShort atIndex:1200];
        [unary_softplus_constants setConstantValue:&unary_cnt         type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_softplus_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```

<｜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
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sigmoid_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sigmoid_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_silu_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_silu_op = 106;
        [unary_silu_constants setConstantValue:&unary_silu_op type:MTLDataTypeShort atIndex:1200];
        [unary_silu_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_silu_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_silu_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_silu_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_softplus_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_softplus_op = 115;
        [unary_softplus_constants setConstantValue:&unary_softplus_op type:MTLDataTypeShort atIndex:1200];
        [unary_softplus_constants setConstantValue:&unary_cnt         type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_softplus_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```<｜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
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sigmoid_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sigmoid_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_silu_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_silu_op = 106;
        [unary_silu_constants setConstantValue:&unary_silu_op type:MTLDataTypeShort atIndex:1200];
        [unary_silu_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_silu_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_silu_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_silu_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_softplus_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_softplus_op = 115;
        [unary_softplus_constants setConstantValue:&unary_softplus_op type:MTLDataTypeShort atIndex:1200];
        [unary_softplus_constants setConstantValue:&unary_cnt         type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_softplus_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```

<｜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
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sigmoid_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sigmoid_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sigmoid pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_silu_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_silu_op = 106;
        [unary_silu_constants setConstantValue:&unary_silu_op type:MTLDataTypeShort atIndex:1200];
        [unary_silu_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_silu_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_silu_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_silu_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 silu pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_softplus_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_softplus_op = 115;
        [unary_softplus_constants setConstantValue:&unary_softplus_op type:MTLDataTypeShort atIndex:1200];
        [unary_softplus_constants setConstantValue:&unary_cnt         type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_softplus_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
```<｜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
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_softplus_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_softplus_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sqrt_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sqrt_op = 14;
        [unary_sqrt_constants setConstantValue:&unary_sqrt_op type:MTLDataTypeShort atIndex:1200];
        [unary_sqrt_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sqrt_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sqrt_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sqrt_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_clamp_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_clamp_op = 12;
        [unary_clamp_constants setConstantValue:&unary_clamp_op type:MTLDataTypeShort atIndex:1200];
        [unary_clamp_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32"
                           constantValues:unary_clamp_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
```

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

File: ds4_metal.m

```c
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_softplus_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_softplus_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sqrt_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sqrt_op = 14;
        [unary_sqrt_constants setConstantValue:&unary_sqrt_op type:MTLDataTypeShort atIndex:1200];
        [unary_sqrt_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sqrt_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sqrt_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sqrt_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_clamp_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_clamp_op = 12;
        [unary_clamp_constants setConstantValue:&unary_clamp_op type:MTLDataTypeShort atIndex:1200];
        [unary_clamp_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32"
                           constantValues:unary_clamp_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_softplus_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_softplus_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sqrt_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sqrt_op = 14;
        [unary_sqrt_constants setConstantValue:&unary_sqrt_op type:MTLDataTypeShort atIndex:1200];
        [unary_sqrt_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sqrt_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sqrt_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sqrt_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_clamp_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_clamp_op = 12;
        [unary_clamp_constants setConstantValue:&unary_clamp_op type:MTLDataTypeShort atIndex:1200];
        [unary_clamp_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32"
                           constantValues:unary_clamp_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
```

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

File: ds4_metal.m

```c
if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_softplus_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_softplus_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 softplus pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_sqrt_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_sqrt_op = 14;
        [unary_sqrt_constants setConstantValue:&unary_sqrt_op type:MTLDataTypeShort atIndex:1200];
        [unary_sqrt_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_sqrt_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_sqrt_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_sqrt_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 sqrt pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_clamp_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_clamp_op = 12;
        [unary_clamp_constants setConstantValue:&unary_clamp_op type:MTLDataTypeShort atIndex:1200];
        [unary_clamp_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32"
                           constantValues:unary_clamp_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_clamp_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_clamp_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_scale_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_scale_op = 10;
        [unary_scale_constants setConstantValue:&unary_scale_op type:MTLDataTypeShort atIndex:1200];
        [unary_scale_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_scale_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_scale_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_scale_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_fill_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_fill_op = 11;
        [unary_fill_constants setConstantValue:&unary_fill_op type:MTLDataTypeShort atIndex:1200];
        [unary_fill_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
```

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

File: ds4_metal.m

```c
fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_clamp_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_clamp_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_scale_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_scale_op = 10;
        [unary_scale_constants setConstantValue:&unary_scale_op type:MTLDataTypeShort atIndex:1200];
        [unary_scale_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_scale_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_scale_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_scale_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_fill_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_fill_op = 11;
        [unary_fill_constants setConstantValue:&unary_fill_op type:MTLDataTypeShort atIndex:1200];
        [unary_fill_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
```<｜Assistant｜></think>


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

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

File: ds4_metal.m

```c
fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_clamp_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_clamp_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_scale_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_scale_op = 10;
        [unary_scale_constants setConstantValue:&unary_scale_op type:MTLDataTypeShort atIndex:1200];
        [unary_scale_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_scale_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_scale_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_scale_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_fill_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_fill_op = 11;
        [unary_fill_constants setConstantValue:&unary_fill_op type:MTLDataTypeShort atIndex:1200];
        [unary_fill_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
```

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

File: ds4_metal.m

```c
fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_clamp_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_clamp_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32 clamp pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_scale_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_scale_op = 10;
        [unary_scale_constants setConstantValue:&unary_scale_op type:MTLDataTypeShort atIndex:1200];
        [unary_scale_constants setConstantValue:&unary_cnt      type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_scale_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_scale_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_scale_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 scale pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        MTLFunctionConstantValues *unary_fill_constants = [[MTLFunctionConstantValues alloc] init];
        int16_t unary_fill_op = 11;
        [unary_fill_constants setConstantValue:&unary_fill_op type:MTLDataTypeShort atIndex:1200];
        [unary_fill_constants setConstantValue:&unary_cnt     type:MTLDataTypeBool  atIndex:1201];

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f32_f32_4"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
```<｜Assistant｜><think>


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

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

File: ds4_metal.m

```c
Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f16_f16"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_f16_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_f16_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_expand"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_expand_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_expand_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_dsv4_indexer_score_one_direct_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexer_score_one_direct");
        g_dsv4_compressor_store_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_compressor_store_one");
        g_dsv4_sort_i32_rows_asc_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
```

<｜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
Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f16_f16"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_f16_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_f16_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_expand"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_expand_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_expand_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_dsv4_indexer_score_one_direct_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexer_score_one_direct");
        g_dsv4_compressor_store_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_compressor_store_one");
        g_dsv4_sort_i32_rows_asc_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
```<｜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
Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f16_f16"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_f16_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_f16_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_expand"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_expand_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_expand_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_dsv4_indexer_score_one_direct_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexer_score_one_direct");
        g_dsv4_compressor_store_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_compressor_store_one");
        g_dsv4_sort_i32_rows_asc_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
```

<｜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
Metal kernel_unary_f32_f32_4 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f32_f32_4 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        error = nil;
        fn = [library newFunctionWithName:@"kernel_unary_f16_f16"
                           constantValues:unary_fill_constants
                                    error:&error];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill function not found: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_unary_fill_f16_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_unary_fill_f16_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_unary_f16_f16 fill pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        fn = [library newFunctionWithName:@"kernel_dsv4_hc_expand"];
        if (!fn) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand function not found\n");
            g_queue = nil;
            g_device = nil;
            return 0;
        }
        g_hc_expand_pipeline = [g_device newComputePipelineStateWithFunction:fn error:&error];
        if (!g_hc_expand_pipeline) {
            fprintf(stderr, "ds4: Metal kernel_dsv4_hc_expand pipeline failed: %s\n",
                    [[error localizedDescription] UTF8String]);
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_dsv4_indexer_score_one_direct_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexer_score_one_direct");
        g_dsv4_compressor_store_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_compressor_store_one");
        g_dsv4_sort_i32_rows_asc_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
```<｜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
pu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
        g_dsv4_indexed_attention_heads8_rb4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8_rb4");
        g_dsv4_softplus_sqrt_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_softplus_sqrt_f32_4");
        g_dsv4_router_finalize_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_finalize_one");
        g_dsv4_router_weights_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_weights_one");
        g_dsv4_hc_expand4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_hc_expand4");
        if (!g_dsv4_indexer_score_one_direct_pipeline ||
            !g_dsv4_compressor_store_one_pipeline ||
            !g_dsv4_sort_i32_rows_asc_pipeline ||
            !g_dsv4_indexed_attention_heads8_pipeline ||
            !g_dsv4_indexed_attention_heads8_rb4_pipeline ||
            !g_dsv4_softplus_sqrt_pipeline ||
            !g_dsv4_router_finalize_one_pipeline ||
            !g_dsv4_router_weights_one_pipeline ||
            !g_dsv4_hc_expand4_pipeline) {
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_initialized = 1;
    }

    return 1;
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc(uint64_t bytes) {
    if (!g_initialized && !ds4_gpu_init()) return NULL;
    if (bytes == 0 || bytes > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *tensor = [DS4MetalTensor new];
        tensor.buffer = [g_device newBufferWithLength:(NSUInteger)bytes
                                              options:MTLResourceStorageModeShared];
        if (!tensor.buffer) {
            return NULL;
        }
        tensor.offset = 0;
        tensor.bytes = bytes;
        tensor.owner = 1;
        g_tensor_alloc_live_bytes += bytes;
        if (g_tensor_alloc_live_bytes > g_tensor_alloc_peak_bytes) {
            g_tensor_alloc_peak_bytes = g_tensor_alloc_live_bytes;
        }
        if (ds4_gpu_trace_allocs()) {
            fprintf(stderr,
                    "ds4: Metal tensor alloc %.3f MiB live %.3f MiB peak %.3f MiB\n",
                    (double)bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}
```

<｜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
pu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
        g_dsv4_indexed_attention_heads8_rb4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8_rb4");
        g_dsv4_softplus_sqrt_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_softplus_sqrt_f32_4");
        g_dsv4_router_finalize_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_finalize_one");
        g_dsv4_router_weights_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_weights_one");
        g_dsv4_hc_expand4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_hc_expand4");
        if (!g_dsv4_indexer_score_one_direct_pipeline ||
            !g_dsv4_compressor_store_one_pipeline ||
            !g_dsv4_sort_i32_rows_asc_pipeline ||
            !g_dsv4_indexed_attention_heads8_pipeline ||
            !g_dsv4_indexed_attention_heads8_rb4_pipeline ||
            !g_dsv4_softplus_sqrt_pipeline ||
            !g_dsv4_router_finalize_one_pipeline ||
            !g_dsv4_router_weights_one_pipeline ||
            !g_dsv4_hc_expand4_pipeline) {
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_initialized = 1;
    }

    return 1;
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc(uint64_t bytes) {
    if (!g_initialized && !ds4_gpu_init()) return NULL;
    if (bytes == 0 || bytes > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *tensor = [DS4MetalTensor new];
        tensor.buffer = [g_device newBufferWithLength:(NSUInteger)bytes
                                              options:MTLResourceStorageModeShared];
        if (!tensor.buffer) {
            return NULL;
        }
        tensor.offset = 0;
        tensor.bytes = bytes;
        tensor.owner = 1;
        g_tensor_alloc_live_bytes += bytes;
        if (g_tensor_alloc_live_bytes > g_tensor_alloc_peak_bytes) {
            g_tensor_alloc_peak_bytes = g_tensor_alloc_live_bytes;
        }
        if (ds4_gpu_trace_allocs()) {
            fprintf(stderr,
                    "ds4: Metal tensor alloc %.3f MiB live %.3f MiB peak %.3f MiB\n",
                    (double)bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}
```<｜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
pu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
        g_dsv4_indexed_attention_heads8_rb4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8_rb4");
        g_dsv4_softplus_sqrt_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_softplus_sqrt_f32_4");
        g_dsv4_router_finalize_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_finalize_one");
        g_dsv4_router_weights_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_weights_one");
        g_dsv4_hc_expand4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_hc_expand4");
        if (!g_dsv4_indexer_score_one_direct_pipeline ||
            !g_dsv4_compressor_store_one_pipeline ||
            !g_dsv4_sort_i32_rows_asc_pipeline ||
            !g_dsv4_indexed_attention_heads8_pipeline ||
            !g_dsv4_indexed_attention_heads8_rb4_pipeline ||
            !g_dsv4_softplus_sqrt_pipeline ||
            !g_dsv4_router_finalize_one_pipeline ||
            !g_dsv4_router_weights_one_pipeline ||
            !g_dsv4_hc_expand4_pipeline) {
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_initialized = 1;
    }

    return 1;
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc(uint64_t bytes) {
    if (!g_initialized && !ds4_gpu_init()) return NULL;
    if (bytes == 0 || bytes > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *tensor = [DS4MetalTensor new];
        tensor.buffer = [g_device newBufferWithLength:(NSUInteger)bytes
                                              options:MTLResourceStorageModeShared];
        if (!tensor.buffer) {
            return NULL;
        }
        tensor.offset = 0;
        tensor.bytes = bytes;
        tensor.owner = 1;
        g_tensor_alloc_live_bytes += bytes;
        if (g_tensor_alloc_live_bytes > g_tensor_alloc_peak_bytes) {
            g_tensor_alloc_peak_bytes = g_tensor_alloc_live_bytes;
        }
        if (ds4_gpu_trace_allocs()) {
            fprintf(stderr,
                    "ds4: Metal tensor alloc %.3f MiB live %.3f MiB peak %.3f MiB\n",
                    (double)bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}
```

<｜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
pu_get_pipeline("kernel_dsv4_sort_i32_rows_asc");
        g_dsv4_indexed_attention_heads8_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8");
        g_dsv4_indexed_attention_heads8_rb4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_indexed_mixed_attention_heads8_rb4");
        g_dsv4_softplus_sqrt_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_softplus_sqrt_f32_4");
        g_dsv4_router_finalize_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_finalize_one");
        g_dsv4_router_weights_one_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_router_weights_one");
        g_dsv4_hc_expand4_pipeline =
            ds4_gpu_get_pipeline("kernel_dsv4_hc_expand4");
        if (!g_dsv4_indexer_score_one_direct_pipeline ||
            !g_dsv4_compressor_store_one_pipeline ||
            !g_dsv4_sort_i32_rows_asc_pipeline ||
            !g_dsv4_indexed_attention_heads8_pipeline ||
            !g_dsv4_indexed_attention_heads8_rb4_pipeline ||
            !g_dsv4_softplus_sqrt_pipeline ||
            !g_dsv4_router_finalize_one_pipeline ||
            !g_dsv4_router_weights_one_pipeline ||
            !g_dsv4_hc_expand4_pipeline) {
            g_queue = nil;
            g_device = nil;
            return 0;
        }

        g_initialized = 1;
    }

    return 1;
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc(uint64_t bytes) {
    if (!g_initialized && !ds4_gpu_init()) return NULL;
    if (bytes == 0 || bytes > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *tensor = [DS4MetalTensor new];
        tensor.buffer = [g_device newBufferWithLength:(NSUInteger)bytes
                                              options:MTLResourceStorageModeShared];
        if (!tensor.buffer) {
            return NULL;
        }
        tensor.offset = 0;
        tensor.bytes = bytes;
        tensor.owner = 1;
        g_tensor_alloc_live_bytes += bytes;
        if (g_tensor_alloc_live_bytes > g_tensor_alloc_peak_bytes) {
            g_tensor_alloc_peak_bytes = g_tensor_alloc_live_bytes;
        }
        if (ds4_gpu_trace_allocs()) {
            fprintf(stderr,
                    "ds4: Metal tensor alloc %.3f MiB live %.3f MiB peak %.3f MiB\n",
                    (double)bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}
```<｜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
bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc_managed(uint64_t bytes) {
    return ds4_gpu_tensor_alloc(bytes);
}

int ds4_gpu_should_use_managed_kv_cache(uint64_t kv_cache_bytes, uint64_t context_bytes) {
    (void)kv_cache_bytes;
    (void)context_bytes;
    return 0;
}

ds4_gpu_tensor *ds4_gpu_tensor_view(const ds4_gpu_tensor *base, uint64_t offset, uint64_t bytes) {
    if (!base) return NULL;
    const DS4MetalTensor *base_obj = ds4_gpu_tensor_const_obj(base);
    if (offset > base_obj.bytes || bytes > base_obj.bytes - offset) return NULL;
    if (base_obj.offset > UINT64_MAX - offset) return NULL;
    const uint64_t absolute_offset = base_obj.offset + offset;
    if (absolute_offset > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *view = [DS4MetalTensor new];
        view.buffer = base_obj.buffer;
        view.offset = absolute_offset;
        view.bytes = bytes;
        view.owner = 0;
        return (__bridge_retained ds4_gpu_tensor *)view;
    }
}

void ds4_gpu_tensor_free(ds4_gpu_tensor *tensor) {
    if (!tensor) return;
    @autoreleasepool {
        DS4MetalTensor *obj = (__bridge_transfer DS4MetalTensor *)tensor;
        if (obj.owner) {
            if (obj.bytes <= g_tensor_alloc_live_bytes) {
                g_tensor_alloc_live_bytes -= obj.bytes;
            } else {
                g_tensor_alloc_live_bytes = 0;
            }
            if (ds4_gpu_trace_allocs()) {
                fprintf(stderr,
                        "ds4: Metal tensor free %.3f MiB live %.3f MiB peak %.3f MiB\n",
                        (double)obj.bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
            }
        }
        obj.buffer = nil;
        obj.offset = 0;
        obj.bytes = 0;
        obj.owner = 0;
    }
}

uint64_t ds4_gpu_tensor_bytes(const ds4_gpu_tensor *tensor) {
    if (!tensor) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    return obj.bytes;
}

void *ds4_gpu_tensor_contents(ds4_gpu_tensor *tensor) {
    if (!tensor) return NULL;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
```

<｜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
bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc_managed(uint64_t bytes) {
    return ds4_gpu_tensor_alloc(bytes);
}

int ds4_gpu_should_use_managed_kv_cache(uint64_t kv_cache_bytes, uint64_t context_bytes) {
    (void)kv_cache_bytes;
    (void)context_bytes;
    return 0;
}

ds4_gpu_tensor *ds4_gpu_tensor_view(const ds4_gpu_tensor *base, uint64_t offset, uint64_t bytes) {
    if (!base) return NULL;
    const DS4MetalTensor *base_obj = ds4_gpu_tensor_const_obj(base);
    if (offset > base_obj.bytes || bytes > base_obj.bytes - offset) return NULL;
    if (base_obj.offset > UINT64_MAX - offset) return NULL;
    const uint64_t absolute_offset = base_obj.offset + offset;
    if (absolute_offset > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *view = [DS4MetalTensor new];
        view.buffer = base_obj.buffer;
        view.offset = absolute_offset;
        view.bytes = bytes;
        view.owner = 0;
        return (__bridge_retained ds4_gpu_tensor *)view;
    }
}

void ds4_gpu_tensor_free(ds4_gpu_tensor *tensor) {
    if (!tensor) return;
    @autoreleasepool {
        DS4MetalTensor *obj = (__bridge_transfer DS4MetalTensor *)tensor;
        if (obj.owner) {
            if (obj.bytes <= g_tensor_alloc_live_bytes) {
                g_tensor_alloc_live_bytes -= obj.bytes;
            } else {
                g_tensor_alloc_live_bytes = 0;
            }
            if (ds4_gpu_trace_allocs()) {
                fprintf(stderr,
                        "ds4: Metal tensor free %.3f MiB live %.3f MiB peak %.3f MiB\n",
                        (double)obj.bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
            }
        }
        obj.buffer = nil;
        obj.offset = 0;
        obj.bytes = 0;
        obj.owner = 0;
    }
}

uint64_t ds4_gpu_tensor_bytes(const ds4_gpu_tensor *tensor) {
    if (!tensor) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    return obj.bytes;
}

void *ds4_gpu_tensor_contents(ds4_gpu_tensor *tensor) {
    if (!tensor) return NULL;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
```<｜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
bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc_managed(uint64_t bytes) {
    return ds4_gpu_tensor_alloc(bytes);
}

int ds4_gpu_should_use_managed_kv_cache(uint64_t kv_cache_bytes, uint64_t context_bytes) {
    (void)kv_cache_bytes;
    (void)context_bytes;
    return 0;
}

ds4_gpu_tensor *ds4_gpu_tensor_view(const ds4_gpu_tensor *base, uint64_t offset, uint64_t bytes) {
    if (!base) return NULL;
    const DS4MetalTensor *base_obj = ds4_gpu_tensor_const_obj(base);
    if (offset > base_obj.bytes || bytes > base_obj.bytes - offset) return NULL;
    if (base_obj.offset > UINT64_MAX - offset) return NULL;
    const uint64_t absolute_offset = base_obj.offset + offset;
    if (absolute_offset > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *view = [DS4MetalTensor new];
        view.buffer = base_obj.buffer;
        view.offset = absolute_offset;
        view.bytes = bytes;
        view.owner = 0;
        return (__bridge_retained ds4_gpu_tensor *)view;
    }
}

void ds4_gpu_tensor_free(ds4_gpu_tensor *tensor) {
    if (!tensor) return;
    @autoreleasepool {
        DS4MetalTensor *obj = (__bridge_transfer DS4MetalTensor *)tensor;
        if (obj.owner) {
            if (obj.bytes <= g_tensor_alloc_live_bytes) {
                g_tensor_alloc_live_bytes -= obj.bytes;
            } else {
                g_tensor_alloc_live_bytes = 0;
            }
            if (ds4_gpu_trace_allocs()) {
                fprintf(stderr,
                        "ds4: Metal tensor free %.3f MiB live %.3f MiB peak %.3f MiB\n",
                        (double)obj.bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
            }
        }
        obj.buffer = nil;
        obj.offset = 0;
        obj.bytes = 0;
        obj.owner = 0;
    }
}

uint64_t ds4_gpu_tensor_bytes(const ds4_gpu_tensor *tensor) {
    if (!tensor) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    return obj.bytes;
}

void *ds4_gpu_tensor_contents(ds4_gpu_tensor *tensor) {
    if (!tensor) return NULL;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
```

<｜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
bytes / (1024.0 * 1024.0),
                    (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
        }
        return (__bridge_retained ds4_gpu_tensor *)tensor;
    }
}

ds4_gpu_tensor *ds4_gpu_tensor_alloc_managed(uint64_t bytes) {
    return ds4_gpu_tensor_alloc(bytes);
}

int ds4_gpu_should_use_managed_kv_cache(uint64_t kv_cache_bytes, uint64_t context_bytes) {
    (void)kv_cache_bytes;
    (void)context_bytes;
    return 0;
}

ds4_gpu_tensor *ds4_gpu_tensor_view(const ds4_gpu_tensor *base, uint64_t offset, uint64_t bytes) {
    if (!base) return NULL;
    const DS4MetalTensor *base_obj = ds4_gpu_tensor_const_obj(base);
    if (offset > base_obj.bytes || bytes > base_obj.bytes - offset) return NULL;
    if (base_obj.offset > UINT64_MAX - offset) return NULL;
    const uint64_t absolute_offset = base_obj.offset + offset;
    if (absolute_offset > (uint64_t)NSUIntegerMax) return NULL;

    @autoreleasepool {
        DS4MetalTensor *view = [DS4MetalTensor new];
        view.buffer = base_obj.buffer;
        view.offset = absolute_offset;
        view.bytes = bytes;
        view.owner = 0;
        return (__bridge_retained ds4_gpu_tensor *)view;
    }
}

void ds4_gpu_tensor_free(ds4_gpu_tensor *tensor) {
    if (!tensor) return;
    @autoreleasepool {
        DS4MetalTensor *obj = (__bridge_transfer DS4MetalTensor *)tensor;
        if (obj.owner) {
            if (obj.bytes <= g_tensor_alloc_live_bytes) {
                g_tensor_alloc_live_bytes -= obj.bytes;
            } else {
                g_tensor_alloc_live_bytes = 0;
            }
            if (ds4_gpu_trace_allocs()) {
                fprintf(stderr,
                        "ds4: Metal tensor free %.3f MiB live %.3f MiB peak %.3f MiB\n",
                        (double)obj.bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_live_bytes / (1024.0 * 1024.0),
                        (double)g_tensor_alloc_peak_bytes / (1024.0 * 1024.0));
            }
        }
        obj.buffer = nil;
        obj.offset = 0;
        obj.bytes = 0;
        obj.owner = 0;
    }
}

uint64_t ds4_gpu_tensor_bytes(const ds4_gpu_tensor *tensor) {
    if (!tensor) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    return obj.bytes;
}

void *ds4_gpu_tensor_contents(ds4_gpu_tensor *tensor) {
    if (!tensor) return NULL;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
```<｜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
r *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
    if (!tensor || count > ds4_gpu_tensor_bytes(tensor) / sizeof(float)) return 0;
    float *p = ds4_gpu_tensor_contents(tensor);
    if (!p && count != 0) return 0;
    for (uint64_t i = 0; i < count; i++) p[i] = value;
    return 1;
}

int ds4_gpu_tensor_write(ds4_gpu_tensor *tensor, uint64_t offset, const void *data, uint64_t bytes) {
    if (!tensor || (!data && bytes != 0)) return 0;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    if (offset > obj.bytes || bytes > obj.bytes - offset) return 0;
    if (bytes != 0) {
        memcpy((uint8_t *)[obj.buffer contents] + obj.offset + offset, data, (size_t)bytes);
    }
    return 1;
}

int ds4_gpu_tensor_read(const ds4_gpu_tensor *tensor, uint64_t offset, void *data, uint64_t bytes) {
    if (!tensor || (!data && bytes != 0)) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    if (offset > obj.bytes || bytes > obj.bytes - offset) return 0;
    if (bytes != 0) {
        memcpy(data, (const uint8_t *)[obj.buffer contents] + obj.offset + offset, (size_t)bytes);
    }
    return 1;
}

int ds4_gpu_tensor_copy(ds4_gpu_tensor *dst, uint64_t dst_offset,
                          const ds4_gpu_tensor *src, uint64_t src_offset,
                          uint64_t bytes) {
    if (!dst || !src) return 0;
    if (!g_initialized && !ds4_gpu_init()) return 0;
    DS4MetalTensor *d = ds4_gpu_tensor_obj(dst);
    const DS4MetalTensor *s = ds4_gpu_tensor_const_obj(src);
    if (dst_offset > d.bytes || bytes > d.bytes - dst_offset) return 0;
    if (src_offset > s.bytes || bytes > s.bytes - src_offset) return 0;
    if (bytes == 0) return 1;
    if (!g_batch_cb) return 0;

    ds4_gpu_close_batch_encoder();
    id<MTLBlitCommandEncoder> blit = [g_batch_cb blitCommandEncoder];
    if (!blit) return 0;
    [blit copyFromBuffer:s.buffer
            sourceOffset:(NSUInteger)(s.offset + src_offset)
                toBuffer:d.buffer
       destinationOffset:(NSUInteger)(d.offset + dst_offset)
                    size:(NSUInteger)bytes];
    [blit endEncoding];
    return 1;
}

int ds4_gpu_begin_commands(void) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (g_batch_cb) return 0;
    g_batch_cb = [g_queue commandBuffer];
    return g_batch_cb != nil;
}

int ds4_gpu_flush_commands(void) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!g_batch_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
r *obj = ds4_gpu_tensor_obj(tensor);
    return (uint8_t *)[obj.buffer contents] + obj.offset;
}

int ds4_gpu_tensor_fill_f32(ds4_gpu_tensor *tensor, float value, uint64_t count) {
    if (!tensor || count > ds4_gpu_tensor_bytes(tensor) / sizeof(float)) return 0;
    float *p = ds4_gpu_tensor_contents(tensor);
    if (!p && count != 0) return 0;
    for (uint64_t i = 0; i < count; i++) p[i] = value;
    return 1;
}

int ds4_gpu_tensor_write(ds4_gpu_tensor *tensor, uint64_t offset, const void *data, uint64_t bytes) {
    if (!tensor || (!data && bytes != 0)) return 0;
    DS4MetalTensor *obj = ds4_gpu_tensor_obj(tensor);
    if (offset > obj.bytes || bytes > obj.bytes - offset) return 0;
    if (bytes != 0) {
        memcpy((uint8_t *)[obj.buffer contents] + obj.offset + offset, data, (size_t)bytes);
    }
    return 1;
}

int ds4_gpu_tensor_read(const ds4_gpu_tensor *tensor, uint64_t offset, void *data, uint64_t bytes) {
    if (!tensor || (!data && bytes != 0)) return 0;
    const DS4MetalTensor *obj = ds4_gpu_tensor_const_obj(tensor);
    if (offset > obj.bytes || bytes > obj.bytes - offset) return 0;
    if (bytes != 0) {
        memcpy(data, (const uint8_t *)[obj.buffer contents] + obj.offset + offset, (size_t)bytes);
    }
    return 1;
}

int ds4_gpu_tensor_copy(ds4_gpu_tensor *dst, uint64_t dst_offset,
                          const ds4_gpu_tensor *src, uint64_t src_offset,
                          uint64_t bytes) {
    if (!dst || !src) return 0;
    if (!g_initialized && !ds4_gpu_init()) return 0;
    DS4MetalTensor *d = ds4_gpu_tensor_obj(dst);
    const DS4MetalTensor *s = ds4_gpu_tensor_const_obj(src);
    if (dst_offset > d.bytes || bytes > d.bytes - dst_offset) return 0;
    if (src_offset > s.bytes || bytes > s.bytes - src_offset) return 0;
    if (bytes == 0) return 1;
    if (!g_batch_cb) return 0;

    ds4_gpu_close_batch_encoder();
    id<MTLBlitCommandEncoder> blit = [g_batch_cb blitCommandEncoder];
    if (!blit) return 0;
    [blit copyFromBuffer:s.buffer
            sourceOffset:(NSUInteger)(s.offset + src_offset)
                toBuffer:d.buffer
       destinationOffset:(NSUInteger)(d.offset + dst_offset)
                    size:(NSUInteger)bytes];
    [blit endEncoding];
    return 1;
}

int ds4_gpu_begin_commands(void) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (g_batch_cb) return 0;
    g_batch_cb = [g_queue commandBuffer];
    return g_batch_cb != nil;
}

int ds4_gpu_flush_commands(void) {
    if (!g_initialized && !ds4_gpu_init()) return 0;
    if (!g_batch_cb) return 0;
```<｜Assistant｜></think>