Function run_win_roundtrip

tests/test_metal_win.cpp:21–67

Run a graph: build win_part -> win_unpart on the given backend. Returns the final output as a flat float vector.

// Run a graph: build win_part -> win_unpart on the given backend.
// Returns the final output as a flat float vector.
static std::vector<float> run_win_roundtrip(ggml_backend_t backend,
                                            const std::vector<float>& input,
                                            int C, int W, int H, int WS) {
    // Graph context
    size_t ctx_size = ggml_tensor_overhead() * 16 + ggml_graph_overhead();
    struct ggml_init_params params = {ctx_size, nullptr, true};
    struct ggml_context* ctx = ggml_init(params);

    // Input tensor: [C, W, H, 1]
    auto* inp = ggml_new_tensor_3d(ctx, GGML_TYPE_F32, C, W, H);
    ggml_set_name(inp, "input");
    ggml_set_input(inp);

    // win_part: [C, W, H, 1] -> [C, WS, WS, np]
    auto* parted = ggml_win_part(ctx, inp, WS);
    ggml_set_name(parted, "parted");

    // win_unpart: [C, WS, WS, np] -> [C, W, H, 1]
    auto* unparted = ggml_win_unpart(ctx, parted, W, H, WS);
    ggml_set_name(unparted, "unparted");
    ggml_set_output(unparted);

    // Build graph
    auto* graph = ggml_new_graph(ctx);
    ggml_build_forward_expand(graph, unparted);

    // Allocate
    auto* galloc = ggml_gallocr_new(ggml_backend_get_default_buffer_type(backend));
    if (!ggml_gallocr_reserve(galloc, graph) || !ggml_gallocr_alloc_graph(galloc, graph)) {
        fprintf(stderr, "FAIL: gallocr_alloc_graph failed\n");
        exit(1);
    }

    // Set input data
    ggml_backend_tensor_set(inp, input.data(), 0, input.size() * sizeof(float));

    // Compute
    ggml_backend_graph_compute(backend, graph);

    // Read output
    std::vector<float> output(C * W * H);
    ggml_backend_tensor_get(unparted, output.data(), 0, output.size() * sizeof(float));

    ggml_gallocr_free(galloc);
    ggml_free(ctx);
    return output;
}

// Run win_part only (no roundtrip) — compare intermediate output.
static std::vector<float> run_win_part_only(ggml_backend_t backend,