fn main() {
    println("=== GPU TEST ===")
    let status = use_gpu()
    println(status)
    println(gpu_status())

    // Test GPU matmul
    let a = t_randn(512, 512)
    let b = t_randn(512, 512)

    let t0 = timestamp()
    let c = matmul(a, b)
    let t1 = timestamp()
    println("GPU matmul 512x512: done")

    // Verify it produced output
    let s = tensor_sum(c)
    println("Sum: " + s)
    println("=== GPU TEST PASSED ===")
}
