Function bf16_gemm_act_weight_t 

pub fn bf16_gemm_act_weight_t(
    act: u64,
    weight: u64,
    out: u64,
    m: u32,
    n: u32,
    k: u32,
    stream: u64,
) -> Result<()>

Row-major out[M,N] = act[M,K] @ weight[N,K]^T, all BF16.