From f40484677c23368068c0ff75ae7910b5ca72461e Mon Sep 17 00:00:00 2001
From: Minghao Liu <tommliu96@gmail.com>
Date: Fri, 28 Feb 2020 04:27:15 +0000
Subject: [PATCH] ffi_bincount

---
 python/mxnet/ndarray/numpy/_op.py        |  6 +--
 src/api/operator/numpy/np_bincount_op.cc | 56 ++++++++++++++++++++++++
 src/operator/numpy/np_bincount_op-inl.h  |  8 ++++
 3 files changed, 65 insertions(+), 5 deletions(-)
 create mode 100644 src/api/operator/numpy/np_bincount_op.cc

diff --git a/python/mxnet/ndarray/numpy/_op.py b/python/mxnet/ndarray/numpy/_op.py
index 242931862988..d465057dd726 100644
--- a/python/mxnet/ndarray/numpy/_op.py
+++ b/python/mxnet/ndarray/numpy/_op.py
@@ -7341,13 +7341,9 @@ def bincount(x, weights=None, minlength=0):
     >>> np.bincount(x,  weights=w)
     array([ 0.3,  0.7,  1.1])
     """
-    if not isinstance(x, NDArray):
-        raise TypeError("Input data should be NDarray")
     if minlength < 0:
         raise ValueError("Minlength value should greater than 0")
-    if weights is None:
-        return _npi.bincount(x, minlength=minlength, has_weights=False)
-    return _npi.bincount(x, weights=weights, minlength=minlength, has_weights=True)
+    return _api_internal.bincount(x, weights, minlength)
 
 
 @set_module('mxnet.ndarray.numpy')
diff --git a/src/api/operator/numpy/np_bincount_op.cc b/src/api/operator/numpy/np_bincount_op.cc
new file mode 100644
index 000000000000..4baebdeb8223
--- /dev/null
+++ b/src/api/operator/numpy/np_bincount_op.cc
@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*!
+ * \file np_bincount_op.cc
+ * \brief Implementation of the API of functions in src/operator/numpy/np_bincount_op.cc
+ */
+#include "../utils.h"
+#include "../../../operator/numpy/np_bincount_op-inl.h"
+
+namespace mxnet {
+
+MXNET_REGISTER_API("_npi.bincount")
+.set_body([](runtime::MXNetArgs args, runtime::MXNetRetValue* ret) {
+  using namespace runtime;
+  const nnvm::Op* op = Op::Get("_npi_bincount");
+  nnvm::NodeAttrs attrs;
+  op::NumpyBincountParam param;
+
+  int num_outputs = 0;
+  if (args[1].type_code() == kNull) {
+    param.minlength = args[2].operator int64_t();
+    param.has_weights = false;
+    NDArray* inputs[] = {args[0].operator mxnet::NDArray*()};
+    attrs.parsed = param; //  remove std::move() ci error trivially-copyable type
+    attrs.op = op;
+    auto ndoutputs = Invoke<op::NumpyBincountParam>(op, &attrs, 1, inputs, &num_outputs, nullptr);
+    *ret = reinterpret_cast<mxnet::NDArray*>(ndoutputs[0]);
+  } else {
+    param.minlength = args[2].operator int64_t();
+    param.has_weights = true;
+    NDArray* inputs[] = {args[0].operator mxnet::NDArray*(), args[1].operator mxnet::NDArray*()};
+    attrs.parsed = param; //  remove std::move() ci error trivially-copyable type
+    attrs.op = op;
+    auto ndoutputs = Invoke<op::NumpyBincountParam>(op, &attrs, 2, inputs, &num_outputs, nullptr);
+    *ret = reinterpret_cast<mxnet::NDArray*>(ndoutputs[0]);
+    }
+});
+
+}  // namespace mxnet
diff --git a/src/operator/numpy/np_bincount_op-inl.h b/src/operator/numpy/np_bincount_op-inl.h
index 254ea8fdec22..a2e758f36059 100644
--- a/src/operator/numpy/np_bincount_op-inl.h
+++ b/src/operator/numpy/np_bincount_op-inl.h
@@ -28,6 +28,7 @@
 #include <mxnet/operator_util.h>
 #include <utility>
 #include <vector>
+#include <string>
 #include "../mshadow_op.h"
 #include "../mxnet_op.h"
 #include "../operator_common.h"
@@ -50,6 +51,13 @@ struct NumpyBincountParam : public dmlc::Parameter<NumpyBincountParam> {
     .set_default(false)
     .describe("Determine whether Bincount has weights.");
   }
+  void SetAttrDict(std::unordered_map<std::string, std::string>* dict) {
+    std::ostringstream minlength_s, has_weights_s;
+    minlength_s << minlength;
+    has_weights_s << has_weights;
+    (*dict)["minlength"] = minlength_s.str();
+    (*dict)["has_weights"] = has_weights_s.str();
+  }
 };
 
 inline bool NumpyBincountType(const nnvm::NodeAttrs& attrs,