fix grad and add value assertion

paddle/phi/kernels/gpu/argsort_grad_kernel.cu

@@ -150,7 +150,7 @@ void ArgsortGradKernel(const Context& dev_ctx,
   int64_t size = in_grad->numel();
 
   if (rank == 0) {
-    phi::funcs::set_constant(dev_ctx, in_grad, 1.0);
+    phi::Copy<Context>(dev_ctx, out_grad, dev_ctx.GetPlace(), false, in_grad);
     return;
   }
 

paddle/phi/kernels/xpu/argsort_grad_kernel.cc

@@ -43,7 +43,7 @@ void ArgsortGradKernel(const Context& dev_ctx,
   if (out_grad.numel() == 0) return;
 
   if (rank == 0) {
-    phi::funcs::set_constant(dev_ctx, in_grad, 1.0);
+    phi::Copy<Context>(dev_ctx, out_grad, dev_ctx.GetPlace(), false, in_grad);
     return;
   }
 

python/paddle/fluid/tests/unittests/test_zero_dim_tensor.py

@@ -868,10 +868,14 @@ class TestSundryAPI(unittest.TestCase):
 
         self.assertEqual(out1.shape, [])
         self.assertEqual(out2.shape, [])
+        self.assertEqual(out1.numpy(), x1.numpy())
+        self.assertEqual(out2.numpy(), x2.numpy())
         self.assertEqual(out1.grad.shape, [])
         self.assertEqual(out2.grad.shape, [])
         self.assertEqual(x1.grad.shape, [])
         self.assertEqual(x2.grad.shape, [])
+        self.assertEqual(x1.grad.numpy(), 1)
+        self.assertEqual(x2.grad.numpy(), 1)
 
     def test_argsort(self):
         x1 = paddle.rand([])
@@ -886,10 +890,14 @@ class TestSundryAPI(unittest.TestCase):
 
         self.assertEqual(out1.shape, [])
         self.assertEqual(out2.shape, [])
+        self.assertEqual(out1.numpy(), 0)
+        self.assertEqual(out2.numpy(), 0)
         self.assertEqual(out1.grad.shape, [])
         self.assertEqual(out2.grad.shape, [])
         self.assertEqual(x1.grad.shape, [])
         self.assertEqual(x2.grad.shape, [])
+        self.assertEqual(x1.grad.numpy(), 0)
+        self.assertEqual(x2.grad.numpy(), 0)
 
 
 class TestSundryAPIStatic(unittest.TestCase):

python/paddle/fluid/tests/unittests/xpu/test_zero_dim_tensor_xpu.py

@@ -659,10 +659,14 @@ class TestSundryAPI(unittest.TestCase):
 
         self.assertEqual(out1.shape, [])
         self.assertEqual(out2.shape, [])
+        self.assertEqual(out1.numpy(), x1.numpy())
+        self.assertEqual(out2.numpy(), x2.numpy())
         self.assertEqual(out1.grad.shape, [])
         self.assertEqual(out2.grad.shape, [])
         self.assertEqual(x1.grad.shape, [])
         self.assertEqual(x2.grad.shape, [])
+        self.assertEqual(x1.grad.numpy(), 1)
+        self.assertEqual(x2.grad.numpy(), 1)
 
     def test_argsort(self):
         x1 = paddle.rand([])