reshape (#2342)

src/operator/reshape-inl.h

@@ -27,6 +27,18 @@ enum ReshapeOpOutputs {kOut};
 
 
 struct ShapeInfo {
+  inline size_t ndim() const {
+    return info.size();
+  }
+
+  inline size_t Size() const {
+    size_t sz = 1;
+    for (size_t i = 0; i < info.size(); ++i) {
+      sz *= info[i];
+    }
+    return sz;
+  }
+
   std::vector<int> info;
 };
 
@@ -40,9 +52,18 @@ inline std::istream &operator>>(std::istream &is, ShapeInfo &shape) {
       return is;
     }
   }
-
   int idx;
   std::vector<int> tmp;
+  // deal with empty case
+  // safe to remove after stop using target_shape
+  size_t pos = is.tellg();
+  char ch = is.get();
+  if (ch == ')') {
+    shape.info = tmp;
+    return is;
+  }
+  is.seekg(pos);
+  // finish deal
   while (is >> idx) {
     tmp.push_back(idx);
     char ch;
@@ -90,8 +111,9 @@ struct ReshapeParam : public dmlc::Parameter<ReshapeParam> {
   bool keep_highest;
   ShapeInfo shape;
   DMLC_DECLARE_PARAMETER(ReshapeParam) {
+    int tmp[] = {0, 0};
     DMLC_DECLARE_FIELD(target_shape)
-    .set_default(TShape())
+    .set_default(TShape(tmp, tmp + 2))
     .describe("(Deprecated! Use shape instead.) Target new shape. One and only one dim can be 0, "
               "in which case it will be inferred from the rest of dims");
     DMLC_DECLARE_FIELD(keep_highest).set_default(false)
@@ -180,7 +202,7 @@ class ReshapeProp : public OperatorProperty {
              param_.shape.info.size() > 0, true) << "targe_shape or shape must be present.";
     const TShape &dshape = in_shape->at(reshape_enum::kData);
     if (dshape.ndim() == 0) return false;
-    if (param_.target_shape.ndim() == 0) {
+    if (param_.shape.ndim() != 0) {
       std::vector<int> tmp;
       int src_idx = 0;
       int neg_idx = -1;

tests/python/unittest/test_operator.py

@@ -889,6 +889,8 @@ def test_reshape():
     def test_reshape_new(src_shape, shape_args, dst_shape):
         net = mx.sym.Variable("data")
         net = mx.sym.Reshape(net, shape=shape_args)
+        js = net.tojson()
+        net = mx.sym.load_json(js)
         _, output_shape, __ = net.infer_shape(data=src_shape)
         assert output_shape[0] == dst_shape, \
             'Src Shape = %s, Shape Arguments = %s, Dst Shape = %s, Output Shape = %s' \
@@ -919,6 +921,8 @@ def test_reshape_new(src_shape, shape_args, dst_shape):
     # Test old api
     net = mx.sym.Variable("data")
     net = mx.sym.Reshape(net, target_shape=(2, 0))
+    js = net.tojson()
+    net = mx.sym.load_json(js)
     _, output_shape, __ = net.infer_shape(data=(2, 3, 5, 5))
     assert(output_shape[0] == (2, 75))