add device index (#1489)

Author: faaany

bitsandbytes/nn/modules.py

@@ -660,9 +660,9 @@ def cpu(self):
         self.SCB = SCB
         return self
 
-    def xpu(self):
+    def xpu(self, device):
         # we store the 8-bit rows-major weight
-        B = self.data.contiguous().to(torch.float16).xpu()
+        B = self.data.contiguous().to(torch.float16).xpu(device)
         CB, CBt, SCB, SCBt, coo_tensorB = bnb.functional.double_quant(B)
         if CBt is not None:
             del CBt
@@ -700,11 +700,11 @@ def to(self, *args, **kwargs):
                 return self.cpu()
         elif device.type == "xpu":
             if self.data.dtype == torch.int8:
-                self.data = self.data.contiguous().xpu()
+                self.data = self.data.contiguous().xpu(device)
                 self.CB = self.data
                 return self
             else:
-                return self.xpu()
+                return self.xpu(device)
         else:
             new_param = Int8Params(
                 super().to(device=device, dtype=dtype, non_blocking=non_blocking),