Function w4a16_t_via_fp8_ldmab 

pub fn w4a16_t_via_fp8_ldmab(
    gpu: &dyn GpuBackend,
    input: DevicePtr,
    weight: &QuantizedWeight,
    output: DevicePtr,
    m: u32,
    n: u32,
    k: u32,
    stream: u64,
) -> Result<()>

2026-09-28: w4a16_gemm_t_m128’s product on the multistage FP8 GEMM: the transposed NVFP4 weight ([K/2, N] codes, [K/16, N] E4M3 scales, scalar weight_scale_2) is dequantized to E4M3 [N, K] with that kernel’s arithmetic (fp8_predequant_nvfp4_t), then fp8_act_ldmab_gemm runs. Bit-identical to w4a16_gemm_t_m128 (kbench w4a16_bench.cu, nine shapes). k must be a multiple of 32.