[Unittest] Add NCNN tensorslice unittest and fix tensorslice.cpp bugs. (open-mmlab#115)

* add tensorslice unittest

* reply code review

* fix lint

* fix typo

Author: hanrui1sensetime

backend_ops/ncnn/ops/tensorslice/tensorslice.cpp

@@ -53,12 +53,17 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
   size_t elemsize = bottom_blob.elemsize;
   const int* start_ptr = starts;
   const int* end_ptr = ends;
-  const float* axes_ptr = axes;
+  const int* axes_ptr = axes;
   const int* step_ptr = steps;
   if (starts.w > dims || ends.w > dims) {
     fprintf(stderr, "start/end attributes shape error!\n");
     return -100;
   }
+  if (axes.w != 1) {
+    fprintf(stderr,
+            "axes.w must be 1 because any of multiaxes slice is regarded as "
+            "multi-staged onnx slice in pytorch2onnx.");
+  }
   if (dims == 1) {
     for (int i = 0; i < axes.w; i++) {
       int positive_axis = axes_ptr[i] < 0 ? dims + axes_ptr[i] : axes_ptr[i];
@@ -106,6 +111,8 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
       int start = start_ptr[i];
       int end = end_ptr[i];
       int dim_shape = get_shape_by_axes(bottom_blob, positive_axis, dims);
+      int dim_shape_test =
+          get_shape_by_axes(bottom_blob, positive_axis, dims - 1);
       if (dim_shape < 0) {
         return -1;
       }
@@ -127,6 +134,7 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
         return -100;
       }
       active_indice[positive_axis - 1] = temp_indice;
+      active_indice[positive_axis - 1].resize(temp_indice.size());
     }
     top_blob.create((int)active_indice[1].size(), (int)active_indice[0].size(),
                     elemsize, opt.blob_allocator);
@@ -138,6 +146,7 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
     }
     return 0;
   }
+
   if (dims == 3) {
     std::vector<std::vector<int> > active_indice;
     std::vector<int> indices;
@@ -177,7 +186,8 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
         fprintf(stderr, "step should not be 0!\n");
         return -100;
       }
-      active_indice[positive_axis] = temp_indice;
+      active_indice[positive_axis - 1] = temp_indice;
+      active_indice[positive_axis - 1].resize(temp_indice.size());
     }
     top_blob.create((int)active_indice[2].size(), (int)active_indice[1].size(),
                     (int)active_indice[0].size(), elemsize, opt.blob_allocator);
@@ -192,6 +202,7 @@ int TensorSlice::forward(const Mat& bottom_blob, Mat& top_blob,
     }
     return 0;
   }
+
   return 0;
 }
 

tests/test_ops/test_ops.py

@@ -545,3 +545,38 @@ def test_constantofshape(backend,
     ncnn_outputs = ncnn_model(dict(zip(input_names, [input.float()])))
     ncnn_outputs = [ncnn_outputs[name] for name in output_names]
     assert_allclose(model_outputs, ncnn_outputs, tolerate_small_mismatch)
+
+
+@pytest.mark.parametrize('backend', [TEST_NCNN])
+@pytest.mark.parametrize('dim', [1, 2, 3])
+def test_tensorslice(backend, dim, input_list=None, save_dir=None):
+    backend.check_env()
+
+    if input_list is None:
+        input = torch.rand((8, 12, 17)[-dim:]).unsqueeze(0)
+    else:
+        input = input_list[0]
+        assert input.dim() == dim + 1, f'input.dim() must equal to \
+            dim + 1, expected: {dim + 1}, got: {input.dim()}'
+
+    assert input.shape[0] == 1, (f'ncnn batch must be 1, \
+        but got {input.shape[0]}')
+    cfg = dict()
+    register_extra_symbolics(cfg=cfg, backend=backend.backend_name, opset=11)
+
+    def tensorslice_function(inputs):
+        if dim == 1:
+            return inputs[:, 2:17:7]
+        if dim == 2:
+            return inputs[:, 3:12:4, 2:15:3]
+        if dim == 3:
+            return inputs[:, 0:8:2, 2:12:4, 2:17:7]
+
+    wrapped_model = WrapFunction(tensorslice_function)
+
+    backend.run_and_validate(
+        wrapped_model, [input.float()],
+        'tensorslice',
+        input_names=['inputs'],
+        output_names=['outputs'],
+        save_dir=save_dir)