Function dense_gemm_prefill 

pub fn dense_gemm_prefill(
    gpu: &dyn GpuBackend,
    fallback_kernel: KernelHandle,
    pipelined_kernel: KernelHandle,
    input: DevicePtr,
    weight: &DenseWeight,
    output: DevicePtr,
    m: u32,
    n: u32,
    k: u32,
    stream: u64,
) -> Result<()>

2026-09-25: Dense BF16 prefill GEMM: dense_gemm_bf16_pipelined when pipelined_kernel is loaded, otherwise dense_gemm with fallback_kernel.