1 files changed, 118 insertions, 0 deletions
diff --git a/src/armnnUtils/Permute.cpp b/src/armnnUtils/Permute.cpp
new file mode 100644
index 0000000000..58e58583fc
--- /dev/null
+++ b/src/armnnUtils/Permute.cpp
@@ -0,0 +1,118 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+
+#include "Permute.hpp"
+
+#include <armnn/Tensor.hpp>
+
+#include <cassert>
+
+namespace
+{
+
+class PermuteLoop
+{
+public:
+    using size_type = unsigned int;
+
+    PermuteLoop(const armnn::TensorShape& dstShape, const armnn::PermutationVector& mappings)
+        : m_DstShape(dstShape)
+    {
+        assert(dstShape.GetNumDimensions() == mappings.GetSize());
+
+        const size_type numDims = dstShape.GetNumDimensions();
+
+        size_type srcStride = 1U;
+        size_type dstStride = 1U;
+
+        for (size_type i = numDims - 1U, k = 0U; k < numDims; ++k, --i)
+        {
+            m_SrcStrides[mappings[i]] = srcStride;
+            m_DstStrides[i] = dstStride;
+
+            srcStride *= dstShape[mappings[i]];
+            dstStride *= dstShape[i];
+        }
+    }
+
+    template <typename T>
+    void Unroll(const T* srcData, T* dstData)
+    {
+        const T* const srcEnd = srcData + m_DstShape.GetNumElements();
+        T* const       dstEnd = dstData + m_DstShape.GetNumElements();
+        Unroll(0, srcData, dstData, srcEnd, dstEnd);
+    }
+
+private:
+    template <typename T>
+    void Unroll(size_type dimension, const T* srcData, T* dstData, const T* srcEnd, T* dstEnd)
+    {
+        assert(srcData < srcEnd);
+        assert(dstData < dstEnd);
+
+        if (dimension >= m_DstShape.GetNumDimensions())
+        {
+            *dstData = *srcData;
+        }
+        else
+        {
+            for (size_type i = 0; i < m_DstShape[dimension]; i++)
+            {
+                Unroll(dimension + 1, srcData, dstData, srcEnd, dstEnd);
+
+                srcData += m_SrcStrides[dimension];
+                dstData += m_DstStrides[dimension];
+            }
+        }
+    }
+
+    armnn::TensorShape m_DstShape;
+    std::array<size_type, armnn::MaxNumOfTensorDimensions> m_SrcStrides;
+    std::array<size_type, armnn::MaxNumOfTensorDimensions> m_DstStrides;
+};
+
+} // namespace
+
+namespace armnnUtils
+{
+
+armnn::TensorShape Permuted(const armnn::TensorShape& srcShape, const armnn::PermutationVector& mappings)
+{
+    assert(srcShape.GetNumDimensions() == mappings.GetSize());
+
+    const unsigned int numDims = mappings.GetSize();
+    unsigned int outDims[armnn::MaxNumOfTensorDimensions];
+
+    for (unsigned int i = 0U; i < numDims; ++i)
+    {
+        outDims[mappings[i]] = srcShape[i];
+    }
+
+    armnn::TensorShape permutedShape(numDims, outDims);
+    return permutedShape;
+}
+
+armnn::TensorInfo Permuted(const armnn::TensorInfo& info, const armnn::PermutationVector& mappings)
+{
+    armnn::TensorInfo outInfo(info);
+    outInfo.SetShape(Permuted(info.GetShape(), mappings));
+    return outInfo;
+}
+
+template <typename T>
+void Permute(const armnn::TensorShape& dstShape, const armnn::PermutationVector& mappings, const T* src, T* dst)
+{
+    PermuteLoop(dstShape, mappings).Unroll(src, dst);
+}
+
+// Instantiate for types
+template void Permute(const armnn::TensorShape& dstShape, const armnn::PermutationVector& mappings,
+                      const float* src, float* dst);
+template void Permute(const armnn::TensorShape& dstShape, const armnn::PermutationVector& mappings,
+                      const uint8_t* src, uint8_t* dst);
+template void Permute(const armnn::TensorShape& dstShape, const armnn::PermutationVector& mappings,
+                      const int32_t* src, int32_t* dst);
+
+} // namespace armnnUtils