Function argmax_bf16_batch 

pub fn argmax_bf16_batch(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    logits: DevicePtr,
    out: DevicePtr,
    vocab_size: u32,
    n_rows: u32,
    row_stride: u32,
    stream: u64,
) -> Result<()>

2026-09-25: argmax_bf16 for n_rows rows row_stride apart, one block per row. Each block runs the per-row body of argmax_bf16 (argmax_bf16.cu), so a row’s index equals what argmax_bf16 returns for it.