SwinIR: use prefer_half

extensions-builtin/SwinIR/scripts/swinir_model.py

 import logging
 import sys
 
+import torch
 from PIL import Image
 
 from modules import devices, modelloader, script_callbacks, shared, upscaler_utils
@@ -69,7 +70,7 @@ class UpscalerSwinIR(Upscaler):
         model_descriptor = modelloader.load_spandrel_model(
             filename,
             device=self._get_device(),
-            dtype=devices.dtype,
+            prefer_half=(devices.dtype == torch.float16),
             expected_architecture="SwinIR",
         )
         if getattr(shared.opts, 'SWIN_torch_compile', False):