!8675 support allreduce prod

From: @yao_yf
Reviewed-by: @stsuteng,@kisnwang
Signed-off-by: @stsuteng

mindspore/ops/_grad/grad_comm_ops.py

@@ -37,11 +37,18 @@ def get_bprop_all_reduce(self):
     equal = P.Equal()
     cast = P.Cast()
     mul = P.Mul()
+    div = P.RealDiv()
     dtype = P.DType()
 
     if self.op == ReduceOp.PROD:
-        raise RuntimeError("The bprop of ReduceOp.PROD is not supported yet.")
-    if self.op == ReduceOp.SUM:
+
+        def bprop(x, out, dout):
+            dy1 = mul(dout, out)
+            dy2 = all_reduce_grad(dy1)
+            dx = div(dy2, x)
+            return (dx,)
+
+    elif self.op == ReduceOp.SUM:
 
         def bprop(x, out, dout):
             if F.issubclass_(F.typeof(dout), mstype.tensor):

mindspore/ops/operations/comm_ops.py

@@ -95,8 +95,6 @@ class AllReduce(PrimitiveWithInfer):
     def __init__(self, op=ReduceOp.SUM, group=GlobalComm.WORLD_COMM_GROUP):
         if not isinstance(op, type(ReduceOp.SUM)):
             raise TypeError("The operation of AllReduce should be str.")
-        if op == ReduceOp.PROD:
-            raise RuntimeError("The operation of AllReduce 'prod' is not supported yet.")
         if not isinstance(_get_group(group), str):
             raise TypeError("The group of AllReduce should be str.")
         self.op = op

tests/ut/python/communication/test_comm.py

@@ -159,6 +159,7 @@ def test_allreduce():
     run_allreduce(ReduceOp.SUM)
     run_allreduce(ReduceOp.MAX)
     run_allreduce(ReduceOp.MIN)
+    run_allreduce(ReduceOp.PROD)
 
 
 def test_allgather():