Fixed wrong condition in cat op (#2546)

Signed-off-by: majing <Jing1.Ma@intel.com>

Author: majing921201

csrc/gpu/aten/operators/CatImpl.cpp

@@ -336,7 +336,7 @@ static void cat(
   bool hasSkippedInput = false;
   Tensor notSkippedTensor; // non-owning reference
   auto should_skip = [](const Tensor& t) {
-    return !t.defined() && t.dim() == 1;
+    return t.numel() == 0 && t.dim() == 1;
   };
   int nDims = 0;
 

tests/gpu/examples/test_cat_array.py

@@ -131,3 +131,17 @@ def test_cat_multi_device(self, dtype=torch.float):
         x_xpu2 = x_cpu2.clone().to("xpu:1")
         res_xpu = torch.cat((x_xpu1, x_xpu2))
         self.assertEqual(res_cpu, res_xpu.cpu())
+
+    def test_cat_size0_tensor(self):
+        output1_cpu = torch.cat((torch.tensor([],device='cpu'), torch.tensor([1],device='cpu')), dim=0)
+        output2_cpu = torch.cat((torch.tensor([],device='cpu'), torch.tensor([1,2],device='cpu')), dim=0)
+        output3_cpu = torch.cat((torch.tensor([],device='cpu'), torch.tensor([[1,2],[3,4]],device='cpu')), dim=0)
+        output4_cpu = torch.cat((torch.tensor([],device='cpu'), torch.tensor([[[1]],[[2]]],device='cpu')), dim=0)
+        output1_xpu = torch.cat((torch.tensor([],device='xpu'), torch.tensor([1],device='xpu')), dim=0)
+        output2_xpu = torch.cat((torch.tensor([],device='xpu'), torch.tensor([1,2],device='xpu')), dim=0)
+        output3_xpu = torch.cat((torch.tensor([],device='xpu'), torch.tensor([[1,2],[3,4]],device='xpu')), dim=0)
+        output4_xpu = torch.cat((torch.tensor([],device='xpu'), torch.tensor([[[1]],[[2]]],device='xpu')), dim=0)
+        self.assertEqual(output1_cpu, output1_xpu.cpu())
+        self.assertEqual(output2_cpu, output2_xpu.cpu())
+        self.assertEqual(output3_cpu, output3_xpu.cpu())
+        self.assertEqual(output4_cpu, output4_xpu.cpu())