1 files changed, 120 insertions, 0 deletions
diff --git a/reference_model/src/ops/scatter_gather.cc b/reference_model/src/ops/scatter_gather.cc
new file mode 100644
index 0000000..c54204a
--- /dev/null
+++ b/reference_model/src/ops/scatter_gather.cc
@@ -0,0 +1,120 @@
+
+// Copyright (c) 2020, ARM Limited.
+//
+//    Licensed 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.
+
+#include "scatter_gather.h"
+#include "quant_util.h"
+
+using namespace TosaReference;
+using namespace Eigen;
+using namespace tosa;
+
+template <int InRank, int IndexRank, DType Dtype>
+OpGather<InRank, IndexRank, Dtype>::OpGather(TosaAttributeBase* attribute_, TosaQuantInfoBase* qinfo_, uint64_t id_)
+    : GraphNode(Op_GATHER, id_)
+{
+    setRequiredOperands(2, 1);
+    setRequiredRank(1, 6);
+
+    INIT_ATTRIBUTE(Axis);
+}
+
+template <int InRank, int IndexRank, DType Dtype>
+OpGather<InRank, IndexRank, Dtype>::~OpGather()
+{
+    if (attribute)
+        delete attribute;
+}
+
+template <int InRank, int IndexRank, DType Dtype>
+int OpGather<InRank, IndexRank, Dtype>::checkTensorAttributes()
+{
+    if (validateRequiredOperands())
+        return 1;
+
+    if (validateRequiredRank(inputs[0]) || validateRequiredRank(inputs[1]) || validateRequiredRank(outputs[0]))
+    {
+        return 1;
+    }
+
+    // output and input must be the same types
+    if (inputs[0]->matchType(*outputs[0]))
+    {
+        printNodeValidationError("Failure to match input and output type");
+        return 1;
+    }
+
+    in    = dynamic_cast<TosaReference::TensorTemplate<TIn>*>(inputs[0]);
+    index = dynamic_cast<TosaReference::TensorTemplate<TIndex>*>(inputs[1]);
+    out   = dynamic_cast<TosaReference::TensorTemplate<TOut>*>(outputs[0]);
+
+    ASSERT_MEM(in && index && out);
+
+    return 0;
+}
+
+template <int InRank, int IndexRank, DType Dtype>
+int OpGather<InRank, IndexRank, Dtype>::eval()
+{
+    int axis = attribute->axis();
+
+    // calculate size left and right to axis
+    int left_size = 1;
+    for (int i = 0; i < axis; ++i)
+    {
+        left_size *= in->getShape()[i];
+    }
+
+    int right_size = 1;
+    for (int i = axis + 1; i < in->getRank(); ++i)
+    {
+        right_size *= in->getShape()[i];
+    }
+
+    InEigenType* input_data   = in->getTensor().data();
+    int32_t* index_data       = index->getTensor().data();
+    OutEigenType* output_data = out->getTensor().data();
+
+    int32_t axis_size   = in->getShape()[axis];
+    int32_t index_count = index->getElementCount();
+
+    // sanity check if index is valid
+    // need to check until this point since index is not known until runtime
+    for (size_t i = 0; i < index->getElementCount(); i++)
+    {
+        if (index_data[i] >= axis_size)
+        {
+            FATAL_ERROR_NODE("OpGather: index[%lu]=%i can't exceed axis_size=%i", i, index_data[i], axis_size);
+        }
+    }
+
+    // Eigen stores tensor in column-major
+    // so we iterate through dimension right to axis and the index array
+    // do memory copy with size of left size each time
+    for (int right = 0; right < right_size; ++right)
+    {
+        for (int i = 0; i < index_count; ++i)
+        {
+            std::memcpy(output_data + (right * index_count + i) * left_size,
+                        input_data + (right * axis_size + index_data[i]) * left_size, sizeof(InEigenType) * left_size);
+        }
+    }
+
+    return GraphNode::eval();
+}
+
+// template explicit instantiation
+DEF_INSTANTIATE_GATHER(OpGather, AINT8);
+DEF_INSTANTIATE_GATHER(OpGather, INT16);
+DEF_INSTANTIATE_GATHER(OpGather, INT32);