Fix: ensure FP4 LUT on CUDA before index op

single_shot_inference.py

@@ -54,8 +54,8 @@ def dequant_nvfp4_weight(
     high_sign = (high >> 3).bool()
     high_idx = (high & 0x07).long()
     
-    # LUT lookup
-    lut = FP4_LUT.to(device=weight.device)
+    # LUT lookup (ensure LUT on same device as weight)
+    lut = FP4_LUT.to(device=weight.device, dtype=torch.float32)
     low_f = lut[low_idx] * torch.where(low_sign, -1.0, 1.0)
     high_f = lut[high_idx] * torch.where(high_sign, -1.0, 1.0)