Fix split bug in static mode (#45906)

* fix split bug in static mode

* modify code style

* modify code style

* add unit test for split

paddle/phi/infermeta/unary.cc

@@ -3205,10 +3205,14 @@ void SplitInferMeta(const MetaTensor& x,
   // fill out dims with -1
   if ((sections.FromTensor() && !config.is_runtime) || axis_value == -1 ||
       (axis_value >= 0 && x.dims().at(axis_value) <= 0)) {
-    std::vector<phi::DDim> out_dims(
+    std::vector<phi::DDim> out_dims;
+    if ((sections.FromTensor() && !config.is_runtime) || axis_value == -1) {
+      out_dims = std::vector<phi::DDim>(
           sections_data.size(),
           phi::make_ddim(std::vector<int>(x.dims().size(), -1)));
-
+    } else {
+      out_dims = std::vector<phi::DDim>(sections_data.size(), x.dims());
+    }
     for (size_t i = 0; i < sections_data.size(); ++i) {
       if (axis_value != 0) {
         // Only pass LoD when not spliting along the first dim.
@@ -3293,9 +3297,13 @@ void SplitWithNumInferMeta(const MetaTensor& x,
   int axis_value = GetSplitAxisValue(x, axis, config);
   // fill out dims with -1
   if (axis_value == -1 || (axis_value >= 0 && x.dims().at(axis_value) <= 0)) {
-    std::vector<phi::DDim> out_dims(
+    std::vector<phi::DDim> out_dims;
+    if (axis_value == -1) {
+      out_dims = std::vector<phi::DDim>(
           num, phi::make_ddim(std::vector<int>(x.dims().size(), -1)));
-
+    } else {
+      out_dims = std::vector<phi::DDim>(num, x.dims());
+    }
     for (int i = 0; i < num; ++i) {
       if (axis_value != 0) {
         // Only pass LoD when not spliting along the first dim.

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

@@ -441,6 +441,21 @@ class API_TestSplit5(unittest.TestCase):
                 np.testing.assert_allclose(ex_out, re, rtol=1e-05)
 
 
+class API_TestSplit6(unittest.TestCase):
+
+    def test_out(self):
+        with fluid.program_guard(fluid.Program(), fluid.Program()):
+            data = fluid.layers.data('data', shape=[-1, 10], dtype='float64')
+            x0, x1 = paddle.split(data, num_or_sections=[1, 1], axis=0)
+            place = fluid.CPUPlace()
+            exe = fluid.Executor(place)
+            input1 = np.random.random([2, 10]).astype('float64')
+            r0, r1 = exe.run(feed={"data": input1}, fetch_list=[x0, x1])
+            ex_x0, ex_x1 = np.split(input1, (1, ), axis=0)
+            np.testing.assert_allclose(ex_x0, r0, rtol=1e-05)
+            np.testing.assert_allclose(ex_x1, r1, rtol=1e-05)
+
+
 class API_TestDygraphFluidSplit(unittest.TestCase):
 
     def test_out1(self):