start adding convolution

src/tensor.cpp

@@ -0,0 +1,46 @@
+#include <boost/range/adaptor/transformed.hpp>
+#include <cassert>
+
+#include "tensor.hpp"
+
+TensorDescriptor::TensorDescriptor() {}
+
+TensorDescriptor::TensorDescriptor(DataType_t t, std::initializer_list<std::size_t> lens)
+    : mLens(lens), mDataType(t)
+{
+    this->CalculateStrides();
+}
+
+TensorDescriptor::TensorDescriptor(DataType_t t,
+                                   std::vector<std::size_t> lens,
+                                   std::vector<std::size_t> strides)
+    : mLens(lens), mStrides(strides), mDataType(t)
+{
+}
+
+void TensorDescriptor::CalculateStrides()
+{
+    mStrides.clear();
+    mStrides.resize(mLens.size(), 0);
+    if(strides.empty())
+        return;
+
+    mStrides.back() = 1;
+    std::partial_sum(
+        mLens.rbegin(), mLens.rend() - 1, mStrides.rbegin() + 1, std::multiplies<std::size_t>());
+}
+
+std::size_t TensorDescriptor::GetDimension() const { return mLens.size(); }
+
+std::size_t TensorDescriptor::GetElementSize() const
+{
+    assert(mLens.size() == mStrides.size());
+    return std::accumulate(
+        mLens.begin(), mLens.end(), std::size_t{1}, std::multiplies<std::size_t>());
+}
+
+std::size_t TensorDescriptor::GetElementSpace() const
+{
+    auto ls = mLens | boost::adaptor::transformed([](auto v) { return v - 1; });
+    return std::inner_product(ls.begin(), ls.end(), mStrides.begin(), std::size_t{0}) + 1;
+}