Fix issue relating to serialization of reducer (#282)

include/tvm/ir.h

@@ -108,6 +108,7 @@ struct Reduce : public ExprNode<Reduce> {
 
   void VisitAttrs(AttrVisitor* v) final {
     v->Visit("dtype", &type);
+    v->Visit("combiner", &combiner);
     v->Visit("source", &source);
     v->Visit("axis", &axis);
     v->Visit("condition", &condition);

src/lang/ir.cc

@@ -97,6 +97,7 @@ Expr Reduce::make(CommReducer combiner, Array<Expr> source,
   return Expr(n);
 }
 
+TVM_REGISTER_NODE_TYPE(CommReducerNode);
 TVM_REGISTER_NODE_TYPE(Reduce);
 TVM_REGISTER_NODE_TYPE(AttrStmt);
 

tests/python/unittest/test_lang_reflection.py

@@ -24,7 +24,16 @@ def test_make_node():
     assert AA.op == A.op
     assert AA.value_index == A.value_index
 
+def test_make_sum():
+    A = tvm.placeholder((2, 10), name='A')
+    k = tvm.reduce_axis((0,10), "k")
+    B = tvm.compute((2,), lambda i: tvm.sum(A[i, k], axis=k), name="B")
+    json_str = tvm.save_json(B)
+    BB = tvm.load_json(json_str)
+    assert B.op.body[0].combiner.handle.value  != 0
+    assert BB.op.body[0].combiner.handle.value != 0
 
 if __name__ == "__main__":
     test_make_node()
     test_const_saveload_json()
+    test_make_sum()