Function nvfp4_silu_mul_quant 

pub fn nvfp4_silu_mul_quant(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    gate: DevicePtr,
    up: DevicePtr,
    out_y: DevicePtr,
    gate_scale: f32,
    up_scale: f32,
    m: u32,
    k: u32,
    stream: u64,
) -> Result<()>

2026-09-25: silu(gate * gate_scale) * (up * up_scale) quantized straight to block_fp4_mmq in out_y for the down GEMM, without writing a BF16 intermediate. k is the intermediate width, padded to 256. The kernel applies no clamp.