Function w8a8_act_quant 

pub fn w8a8_act_quant(
    gpu: &dyn GpuBackend,
    kernels: &W8a8Kernels,
    scale: W8a8Scale,
    x: DevicePtr,
    ldx: u32,
    rows: usize,
    k: u32,
    scratch: &W8a8Scratch,
    stream: u64,
) -> Result<()>

2026-09-28: Quantize rows rows of the BF16 activation x ([rows, ldx], the first k columns) into scratch for scale’s layout.