[SYCL] This PR adds the minimum modifications to the Eigen unsupported module required to run it on devices supporting SYCL.

* Abstracting the pointer type so that both SYCL memory and pointer can be captured.
* Converting SYCL virtual pointer to SYCL device memory in Eigen evaluator class.
* Binding SYCL placeholder accessor to command group handler by using bind method in Eigen evaluator node.
* Adding SYCL macro for controlling loop unrolling.
* Modifying the TensorDeviceSycl.h and SYCL executor method to adopt the above changes.

1 files changed, 17 insertions, 8 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorConcatenation.h b/unsupported/Eigen/CXX11/src/Tensor/TensorConcatenation.h
index 3863ee8c3..292a1bae1 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorConcatenation.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorConcatenation.h
@@ -119,6 +119,8 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
   typedef typename XprType::Scalar Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename PacketType<CoeffReturnType, Device>::type PacketReturnType;
+  typedef StorageMemory<CoeffReturnType, Device> Storage;
+  typedef typename Storage::Type EvaluatorPointerType;
   enum {
     IsAligned = false,
     PacketAccess = TensorEvaluator<LeftArgType, Device>::PacketAccess & TensorEvaluator<RightArgType, Device>::PacketAccess,
@@ -181,7 +183,7 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
 
   // TODO(phli): Add short-circuit memcpy evaluation if underlying data are linear?
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar* /*data*/)
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(EvaluatorPointerType)
   {
     m_leftImpl.evalSubExprsIfNeeded(NULL);
     m_rightImpl.evalSubExprsIfNeeded(NULL);
@@ -219,11 +221,13 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
       Index left_index;
       if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
         left_index = subs[0];
+        EIGEN_UNROLL_LOOP
         for (int i = 1; i < NumDims; ++i) {
           left_index += (subs[i] % left_dims[i]) * m_leftStrides[i];
         }
       } else {
         left_index = subs[NumDims - 1];
+        EIGEN_UNROLL_LOOP
         for (int i = NumDims - 2; i >= 0; --i) {
           left_index += (subs[i] % left_dims[i]) * m_leftStrides[i];
         }
@@ -235,11 +239,13 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
       Index right_index;
       if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
         right_index = subs[0];
+        EIGEN_UNROLL_LOOP
         for (int i = 1; i < NumDims; ++i) {
           right_index += (subs[i] % right_dims[i]) * m_rightStrides[i];
         }
       } else {
         right_index = subs[NumDims - 1];
+        EIGEN_UNROLL_LOOP
         for (int i = NumDims - 2; i >= 0; --i) {
           right_index += (subs[i] % right_dims[i]) * m_rightStrides[i];
         }
@@ -257,6 +263,7 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
     eigen_assert(index + packetSize - 1 < dimensions().TotalSize());
 
     EIGEN_ALIGN_MAX CoeffReturnType values[packetSize];
+    EIGEN_UNROLL_LOOP
     for (int i = 0; i < packetSize; ++i) {
       values[i] = coeff(index+i);
     }
@@ -279,13 +286,15 @@ struct TensorEvaluator<const TensorConcatenationOp<Axis, LeftArgType, RightArgTy
            TensorOpCost(0, 0, compute_cost);
   }
 
-  EIGEN_DEVICE_FUNC typename Eigen::internal::traits<XprType>::PointerType data() const { return NULL; }
-  /// required by sycl in order to extract the accessor
-  const TensorEvaluator<LeftArgType, Device>& left_impl() const { return m_leftImpl; }
-  /// required by sycl in order to extract the accessor
-  const TensorEvaluator<RightArgType, Device>& right_impl() const { return m_rightImpl; }
-  /// required by sycl in order to extract the accessor
-  const Axis& axis() const { return m_axis; }
+  EIGEN_DEVICE_FUNC EvaluatorPointerType data() const { return NULL; }
+  
+  #ifdef EIGEN_USE_SYCL
+  // binding placeholder accessors to a command group handler for SYCL
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void bind(cl::sycl::handler &cgh) const {
+    m_leftImpl.bind(cgh);
+    m_rightImpl.bind(cgh);
+  }
+  #endif
 
   protected:
     Dimensions m_dimensions;