[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, 23 insertions, 8 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorScan.h b/unsupported/Eigen/CXX11/src/Tensor/TensorScan.h
index 64f10d0a4..44156126d 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorScan.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorScan.h
@@ -86,12 +86,15 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
 
   typedef TensorScanOp<Op, ArgType> XprType;
   typedef typename XprType::Index Index;
+  typedef const ArgType ChildType;
   static const int NumDims = internal::array_size<typename TensorEvaluator<ArgType, Device>::Dimensions>::value;
   typedef DSizes<Index, NumDims> Dimensions;
   typedef typename internal::remove_const<typename XprType::Scalar>::type Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename PacketType<CoeffReturnType, Device>::type PacketReturnType;
   typedef TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> Self;
+  typedef StorageMemory<Scalar, Device> Storage;
+  typedef typename Storage::Type EvaluatorPointerType;
 
   enum {
     IsAligned = false,
@@ -110,7 +113,7 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
         m_exclusive(op.exclusive()),
         m_accumulator(op.accumulator()),
         m_size(m_impl.dimensions()[op.axis()]),
-        m_stride(1),
+        m_stride(1), m_consume_dim(op.axis()),
         m_output(NULL) {
 
     // Accumulating a scalar isn't supported.
@@ -142,6 +145,10 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
     return m_stride;
   }
 
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Index& consume_dim() const {
+    return m_consume_dim;
+  }
+
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Index& size() const {
     return m_size;
   }
@@ -162,7 +169,7 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
     return m_device;
   }
 
-  EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar* data) {
+  EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(EvaluatorPointerType data) {
     m_impl.evalSubExprsIfNeeded(NULL);
     ScanLauncher<Self, Op, Device> launcher;
     if (data) {
@@ -171,7 +178,7 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
     }
 
     const Index total_size = internal::array_prod(dimensions());
-    m_output = static_cast<CoeffReturnType*>(m_device.allocate(total_size * sizeof(Scalar)));
+    m_output = static_cast<EvaluatorPointerType>(m_device.get((Scalar*) m_device.allocate_temp(total_size * sizeof(Scalar))));
     launcher(*this, m_output);
     return true;
   }
@@ -181,7 +188,7 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
     return internal::ploadt<PacketReturnType, LoadMode>(m_output + index);
   }
 
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE typename Eigen::internal::traits<XprType>::PointerType data() const
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EvaluatorPointerType data() const
   {
     return m_output;
   }
@@ -196,21 +203,29 @@ struct TensorEvaluator<const TensorScanOp<Op, ArgType>, Device> {
   }
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void cleanup() {
-    if (m_output != NULL) {
-      m_device.deallocate(m_output);
+    if (m_output) {
+      m_device.deallocate_temp(m_output);
       m_output = NULL;
     }
     m_impl.cleanup();
   }
 
+#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_impl.bind(cgh);
+    m_output.bind(cgh);
+  }
+#endif
 protected:
   TensorEvaluator<ArgType, Device> m_impl;
-  const Device& m_device;
+  const Device EIGEN_DEVICE_REF m_device;
   const bool m_exclusive;
   Op m_accumulator;
   const Index m_size;
   Index m_stride;
-  CoeffReturnType* m_output;
+  Index m_consume_dim;
+  EvaluatorPointerType m_output;
 };
 
 // CPU implementation of scan