Fix arange_mps_out for empty tensor (#245)

* Fix arange_mps_out for empty tensor

* Address PR comments

Author: DenisVieriu97

aten/src/ATen/native/mps/operations/RangeFactories.mm

@@ -87,6 +87,11 @@
       }
       result.resize_({size});
     }
+
+    if (result.numel() == 0) {
+      return;
+    }
+
     bool is_contiguous = result.is_contiguous();
     Tensor r = !is_contiguous ? at::empty_like(result, LEGACY_CONTIGUOUS_MEMORY_FORMAT) : result;
     using namespace mps;

test/test_mps.py

@@ -5564,6 +5564,14 @@ def test_arange(self):
         self.assertEqual(np.arange(1, 2, .3, dtype=np.float32), torch.arange(1, 2, .3, device='mps'))
         self.assertEqual(np.arange(6.3, dtype=np.float32), torch.arange(6.3, device='mps'))
 
+    def test_arange_empty(self):
+        out_mps = torch.tensor([], device="mps")
+        out_cpu = torch.tensor([], device="cpu")
+
+        y_mps = torch.arange(0, 0, 1, out=out_mps)
+        y_cpu = torch.arange(0, 0, 1, out=out_cpu)
+        self.assertEqual(y_mps, y_cpu)
+
     # Test softmax
     def test_softmax(self):
         def helper(shape, dim, channels_last=False):