add global batch normalization

mindspore/nn/layer/normalization.py

@@ -27,14 +27,6 @@ from mindspore.communication import management
 from mindspore._checkparam import check_int_positive
 from ..cell import Cell
 
-class _GlobalBNHelper(Cell):
-    def __init__(self, group):
-        super(_GlobalBNHelper, self).__init__()
-        self.group = group
-        self.reduce = P.AllReduce(P.ReduceOp.SUM, group=self.group).add_prim_attr('fusion', 1)
-    def construct(self, x):
-        x = self.reduce(x)
-        return x
 
 class _BatchNorm(Cell):
     """Batch Normalization base class."""