Function compare_ggml_vs_nchw

tests/test_debug_encoder.cpp:34–52

Compare C++ ggml tensor (dumped as [C, W, H]) vs Python NCHW [1, C, H, W] ggml stores: flat[c + w*C + h*C*W] Python NCHW: flat[c*H*W + h*W + w] These differ! Need transposition.

// Python NCHW: flat[c*H*W + h*W + w]
// These differ! Need transposition.
static compare_result compare_ggml_vs_nchw(const ref_tensor_f32& cpp,
                                            const ref_tensor_f32& ref) {
    if (cpp.shape.size() < 3 || ref.data.empty()) {
        compare_result r;
        r.max_diff = 999.0f;
        return r;
    }
    int C = cpp.shape[0], W = cpp.shape[1], H = cpp.shape[2];

    // Transpose ggml → NCHW
    std::vector<float> transposed(C * W * H);
    for (int c = 0; c < C; ++c)
        for (int h = 0; h < H; ++h)
            for (int w = 0; w < W; ++w)
                transposed[c * H * W + h * W + w] = cpp.data[c + w * C + h * C * W];

    return compare_tensors(transposed.data(), ref.data.data(),
                           std::min((int)transposed.size(), ref.numel()));
}

static void print_result(const char* name, const compare_result& r, float atol) {
    const char* status = (r.max_diff < atol) ? "[PASS]" : "[FAIL]";