From 9ca57b4a966da601d7d61d7c95ddb55147fc35b1 Mon Sep 17 00:00:00 2001
From: Sam Skalicky <samskalicky@gmail.com>
Date: Wed, 21 Oct 2020 04:38:26 +0000
Subject: [PATCH] backport #19393 to v1.x

---
 python/mxnet/gluon/block.py     | 2 +-
 python/mxnet/gluon/parameter.py | 9 ++++++---
 src/c_api/c_api.cc              | 2 +-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/python/mxnet/gluon/block.py b/python/mxnet/gluon/block.py
index a89d4bc13f13..765790c1a0da 100644
--- a/python/mxnet/gluon/block.py
+++ b/python/mxnet/gluon/block.py
@@ -1072,7 +1072,7 @@ def _build_cache(self, *args):
                                            'added to the parameter dicts.\n'
                                            'Please check the backend.')
 
-                    param = Parameter(name)
+                    param = Parameter(name, dtype=param_data.dtype)
                     param._var_name = name
                     serialization_name = name  # HybridBlock.export
                     param._load_init(param_data, args[0].context)
diff --git a/python/mxnet/gluon/parameter.py b/python/mxnet/gluon/parameter.py
index 6f66947d2c10..26d061a703fe 100644
--- a/python/mxnet/gluon/parameter.py
+++ b/python/mxnet/gluon/parameter.py
@@ -400,10 +400,13 @@ def _reduce(self):
         ctx = context.cpu()
         if self._stype == 'default':
             block = self.list_data()
-            if is_np_array():
-                data = sum([w.copyto(ctx) for w in block]) / len(block)
+            if len(block) > 1:
+                if is_np_array():
+                    data = sum([w.copyto(ctx) for w in block]) / len(block)
+                else:
+                    data = ndarray.add_n(*(w.copyto(ctx) for w in block)) / len(block)
             else:
-                data = ndarray.add_n(*(w.copyto(ctx) for w in block)) / len(block)
+                data = self.data().copyto(ctx)
         else:
             # fetch all rows for 'row_sparse' param
             all_row_ids = ndarray.arange(0, self.shape[0], dtype='int64', ctx=ctx)
diff --git a/src/c_api/c_api.cc b/src/c_api/c_api.cc
index 36678636391c..3c793dd01c7f 100644
--- a/src/c_api/c_api.cc
+++ b/src/c_api/c_api.cc
@@ -1417,7 +1417,7 @@ void registerPasses(void *lib, int verbose, mxnet::ext::msgSize_t msgSize,
       // this temp workspace holds memory allocated by custom library via OpResource
       auto ndarray_alloc = [&](const mxnet::TShape &shape, Context ctx, int dtype,
                                std::string name, bool isArg) {
-        NDArray* arr = new NDArray(shape, ctx, dtype);
+        NDArray* arr = new NDArray(shape, ctx, false, dtype);
         if (isArg) {
           new_args.push_back(arr);
           new_arg_names.push_back(name);