Updates corresponding to the latest round of PR feedback

The major changes are

1. Moving CUDA/PacketMath.h to GPU/PacketMath.h
2. Moving CUDA/MathFunctions.h to GPU/MathFunction.h
3. Moving CUDA/CudaSpecialFunctions.h to GPU/GpuSpecialFunctions.h
    The above three changes effectively enable the Eigen "Packet" layer for the HIP platform

4. Merging the "hip_basic" and "cuda_basic" unit tests into one ("gpu_basic")
5. Updating the "EIGEN_DEVICE_FUNC" marking in some places

The change has been tested on the HIP and CUDA platforms.

10 files changed, 34 insertions, 205 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionBlocking.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionBlocking.h
index a1e292108..8c1af1da8 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionBlocking.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionBlocking.h
@@ -28,6 +28,20 @@ class TensorContractionBlocking {
   typedef typename LhsMapper::Scalar LhsScalar;
   typedef typename RhsMapper::Scalar RhsScalar;
 
+ /*
+   adding EIGEN_DEVICE_FUNC unconditionally to 'TensorContractionBlocking' constructor in `TensorContractionBlocking.h`
+     requires adding EIGEN_DEVICE_FUNC to `computeProductBlockingSizes` in `GeneralBlockPanelKernel.h`
+     which in turn, requires adding EIGEN_DEVICE_FUNC to `evaluateProductBlockingSizesHeuristic` in `GeneralBlockPanelKernel.h`
+     which in turn, requires adding EIGEN_DEVICE_FUNC to `manage_caching_sizes` in `GeneralBlockPanelKernel.h`
+     (else HIPCC will error out)
+
+   However adding EIGEN_DEVICE_FUNC to `manage_caching_sizes` in `GeneralBlockPanelKernel.h`
+   results in NVCC erroring out with the following error
+
+   ../Eigen/src/Core/products/GeneralBlockPanelKernel.h(57): error #2901:
+      dynamic initialization is not supported for function-scope static variables within a __device__/__global__ function
+ */
+ 
   #if !defined(EIGEN_HIPCC)
   EIGEN_DEVICE_FUNC
   #endif
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionGpu.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionGpu.h
index 238754424..a4f92ee44 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionGpu.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionGpu.h
@@ -546,45 +546,6 @@ EigenFloatContractionKernelInternal16x16(const LhsMapper lhs, const RhsMapper rh
     results[i].x = results[i].y = results[i].z = results[i].w = 0;
   }
 
-#if defined(EIGEN_HIPCC)
-
-#define prefetch_lhs(reg, row, col)                            \
-    if (!CHECK_LHS_BOUNDARY) {                                 \
-      if (col < k_size) {                                      \
-          reg.x =lhs(row + 0, col);                            \
-          reg.y =lhs(row + 1, col);                            \
-          reg.z =lhs(row + 2, col);                            \
-          reg.w =lhs(row + 3, col);                            \
-      }                                                        \
-    } else {                                                   \
-      if (col < k_size) {                                      \
-        if (row + 3 < m_size) {                                \
-          reg.x =lhs(row + 0, col);                            \
-          reg.y =lhs(row + 1, col);                            \
-          reg.z =lhs(row + 2, col);                            \
-          reg.w =lhs(row + 3, col);                            \
-        } else if (row + 2 < m_size) {                         \
-          reg.x =lhs(row + 0, col);                            \
-          reg.y =lhs(row + 1, col);                            \
-          reg.z =lhs(row + 2, col);                            \
-        } else if (row + 1 < m_size) {                         \
-          reg.x =lhs(row + 0, col);                            \
-          reg.y =lhs(row + 1, col);                            \
-        } else if (row  < m_size) {                            \
-          reg.x =lhs(row + 0, col);                            \
-        }                                                      \
-      }                                                        \
-    }							       \
-
-#define prefetch_rhs_hipcc(reg, row, col)                  \
-      reg.x =rhs(row + 0, col);				   \
-      reg.y =rhs(row + 1, col);				   \
-      reg.z =rhs(row + 2, col);                            \
-      reg.w =rhs(row + 3, col);                            \
-
-
-#else
-  
 #define prefetch_lhs(reg, row, col)                            \
     if (!CHECK_LHS_BOUNDARY) {                                 \
       if (col < k_size) {                                      \
@@ -607,19 +568,12 @@ EigenFloatContractionKernelInternal16x16(const LhsMapper lhs, const RhsMapper rh
       }                                                        \
     }							       \
 
-#endif
-
   Index lhs_vert = base_m+threadIdx.x*4;
 
   for (Index k = 0; k < k_size; k += 16) {
 
-#if defined(EIGEN_HIPCC)
-    lhs_pf0 = make_float4(0, 0, 0, 0);
-    rhs_pf0 = make_float4(0, 0, 0, 0);
-#else
     lhs_pf0 = internal::pset1<float4>(0);
     rhs_pf0 = internal::pset1<float4>(0);
-#endif
 
     Index lhs_horiz = threadIdx.y+k;
     prefetch_lhs(lhs_pf0, lhs_vert, lhs_horiz)
@@ -630,11 +584,7 @@ EigenFloatContractionKernelInternal16x16(const LhsMapper lhs, const RhsMapper rh
     if (!CHECK_RHS_BOUNDARY) {
       if ((rhs_vert + 3) < k_size) {
         // just CHECK_RHS_BOUNDARY
-#if defined(EIGEN_HIPCC)
-	prefetch_rhs_hipcc(rhs_pf0, rhs_vert, rhs_horiz0)
-#else
         rhs_pf0 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz0);
-#endif
       } else if (rhs_vert + 2 < k_size) {
         // just CHECK_RHS_BOUNDARY
         rhs_pf0.x = rhs(rhs_vert, rhs_horiz0);
@@ -649,11 +599,7 @@ EigenFloatContractionKernelInternal16x16(const LhsMapper lhs, const RhsMapper rh
     } else {
       if (rhs_horiz0 < n_size) {
         if ((rhs_vert + 3) < k_size) {
-#if defined(EIGEN_HIPCC)
-	  prefetch_rhs_hipcc(rhs_pf0, rhs_vert, rhs_horiz0)
-#else
           rhs_pf0 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz0);
-#endif
         } else if ((rhs_vert + 2) < k_size) {
           rhs_pf0.x = rhs(rhs_vert, rhs_horiz0);
           rhs_pf0.y = rhs(rhs_vert + 1, rhs_horiz0);
@@ -753,10 +699,6 @@ EigenFloatContractionKernelInternal16x16(const LhsMapper lhs, const RhsMapper rh
 #undef prefetch_lhs
 #undef add_vals
   
-#if defined(EIGEN_HIPCC)  
-#undef prefetch_rhs_hipcc
-#endif
-  
   Index horiz_base = threadIdx.y*4+base_n;
   if (!CHECK_LHS_BOUNDARY && !CHECK_RHS_BOUNDARY) {
     for (int i = 0; i < 4; i++) {
@@ -845,33 +787,8 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
     results[i].x = results[i].y = results[i].z = results[i].w = 0;
   }
 
-#if defined(EIGEN_HIPCC)
-
-#define prefetch_lhs_hipcc(reg, row, col)                  \
-      reg.x =lhs(row + 0, col);                            \
-      reg.y =lhs(row + 1, col);                            \
-      reg.z =lhs(row + 2, col);                            \
-      reg.w =lhs(row + 3, col);                            
-
-#define prefetch_rhs_hipcc(reg, row, col)                  \
-      reg.x =rhs(row + 0, col);                            \
-      reg.y =rhs(row + 1, col);                            \
-      reg.z =rhs(row + 2, col);                            \
-      reg.w =rhs(row + 3, col);                            
-
-#endif
-
   Index lhs_vert = base_m+threadIdx.x*4+(threadIdx.y%4)*32;
   for (Index k = 0; k < k_size; k += 32) {
-#if defined(EIGEN_HIPCC)
-    lhs_pf0 = make_float4(0, 0, 0, 0);
-    lhs_pf1 = make_float4(0, 0, 0, 0);
-    lhs_pf2 = make_float4(0, 0, 0, 0);
-    lhs_pf3 = make_float4(0, 0, 0, 0);
-
-    rhs_pf0 = make_float4(0, 0, 0, 0);
-    rhs_pf1 = make_float4(0, 0, 0, 0);
-#else  
     lhs_pf0 = internal::pset1<float4>(0);
     lhs_pf1 = internal::pset1<float4>(0);
     lhs_pf2 = internal::pset1<float4>(0);
@@ -879,85 +796,40 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
 
     rhs_pf0 = internal::pset1<float4>(0);
     rhs_pf1 = internal::pset1<float4>(0);
-#endif
 
      if (!CHECK_LHS_BOUNDARY) {
       if ((threadIdx.y/4+k+24) < k_size) {
-#if defined(EIGEN_HIPCC)
-	prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-	prefetch_lhs_hipcc(lhs_pf2, lhs_vert, (threadIdx.y/4+k+16))
-	prefetch_lhs_hipcc(lhs_pf3, lhs_vert, (threadIdx.y/4+k+24))
-#else
         lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
         lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
         lhs_pf2 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+16));
         lhs_pf3 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+24));
-#endif
       } else if ((threadIdx.y/4+k+16) < k_size) {
-#if defined(EIGEN_HIPCC)
-	prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-	prefetch_lhs_hipcc(lhs_pf2, lhs_vert, (threadIdx.y/4+k+16))
-#else
         lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
         lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
         lhs_pf2 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+16));
-#endif
       } else if ((threadIdx.y/4+k+8) < k_size) {
-#if defined(EIGEN_HIPCC)
-	prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-#else
         lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
         lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
-#endif
       } else if ((threadIdx.y/4+k) < k_size) {
-#if defined(EIGEN_HIPCC)
-	prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-#else
         lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
-#endif
       }
     } else {
       // just CHECK_LHS_BOUNDARY
       if (lhs_vert + 3 < m_size) {
         if ((threadIdx.y/4+k+24) < k_size) {
-#if defined(EIGEN_HIPCC)
-	  prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	  prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-	  prefetch_lhs_hipcc(lhs_pf2, lhs_vert, (threadIdx.y/4+k+16))
-	  prefetch_lhs_hipcc(lhs_pf3, lhs_vert, (threadIdx.y/4+k+24))
-#else
           lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
           lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
           lhs_pf2 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+16));
           lhs_pf3 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+24));
-#endif
         } else if ((threadIdx.y/4+k+16) < k_size) {
-#if defined(EIGEN_HIPCC)
-	  prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	  prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-	  prefetch_lhs_hipcc(lhs_pf2, lhs_vert, (threadIdx.y/4+k+16))
-#else
           lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
           lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
           lhs_pf2 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+16));
-#endif
         } else if ((threadIdx.y/4+k+8) < k_size) {
-#if defined(EIGEN_HIPCC)
-	  prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-	  prefetch_lhs_hipcc(lhs_pf1, lhs_vert, (threadIdx.y/4+k+8))
-#else
           lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
           lhs_pf1 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k+8));
-#endif
         } else if ((threadIdx.y/4+k) < k_size) {
-#if defined(EIGEN_HIPCC)
-	  prefetch_lhs_hipcc(lhs_pf0, lhs_vert, (threadIdx.y/4+k))
-#else
           lhs_pf0 =lhs.template loadPacket<Unaligned>(lhs_vert, (threadIdx.y/4+k));
-#endif
         }
       } else if (lhs_vert + 2 < m_size) {
         if ((threadIdx.y/4+k+24) < k_size) {
@@ -1046,13 +918,8 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
     if (!CHECK_RHS_BOUNDARY) {
       if ((rhs_vert + 3) < k_size) {
         // just CHECK_RHS_BOUNDARY
-#if defined(EIGEN_HIPCC)
-	prefetch_rhs_hipcc(rhs_pf0, rhs_vert, rhs_horiz0)
-	prefetch_rhs_hipcc(rhs_pf1, rhs_vert, rhs_horiz1)
-#else	
         rhs_pf0 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz0);
         rhs_pf1 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz1);
-#endif
       } else if (rhs_vert + 2 < k_size) {
         // just CHECK_RHS_BOUNDARY
         rhs_pf0.x = rhs(rhs_vert, rhs_horiz0);
@@ -1074,13 +941,8 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
       if (rhs_horiz1 < n_size) {
         if ((rhs_vert + 3) < k_size) {
           // just CHECK_RHS_BOUNDARY
-#if defined(EIGEN_HIPCC)
-  	  prefetch_rhs_hipcc(rhs_pf0, rhs_vert, rhs_horiz0)
-	  prefetch_rhs_hipcc(rhs_pf1, rhs_vert, rhs_horiz1)
-#else	
           rhs_pf0 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz0);
           rhs_pf1 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz1);
-#endif
         } else if (rhs_vert + 2 < k_size) {
           // just CHECK_RHS_BOUNDARY
           rhs_pf0.x = rhs(rhs_vert, rhs_horiz0);
@@ -1101,11 +963,7 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
       } else if (rhs_horiz0 < n_size) {
         if ((rhs_vert + 3) < k_size) {
           // just CHECK_RHS_BOUNDARY
-#if defined(EIGEN_HIPCC)
-  	  prefetch_rhs_hipcc(rhs_pf0, rhs_vert, rhs_horiz0)
-#else	
           rhs_pf0 = rhs.template loadPacket<Unaligned>(rhs_vert, rhs_horiz0);
-#endif
         } else if ((rhs_vert + 2) < k_size) {
           // just CHECK_RHS_BOUNDARY
           rhs_pf0.x = rhs(rhs_vert, rhs_horiz0);
@@ -1213,11 +1071,6 @@ EigenFloatContractionKernelInternal(const LhsMapper lhs, const RhsMapper rhs,
     __syncthreads();
   } // end loop over k
 
-#if defined(EIGEN_HIPCC)
-#undef prefetch_lhs_hipcc
-#undef prefetch_rhs_hipcc
-#endif
-  
   __syncthreads();
   Index horiz_base = (threadIdx.y/4)*8+base_n;
   if (!CHECK_LHS_BOUNDARY && !CHECK_RHS_BOUNDARY) {
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaDefines.h b/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaDefines.h
index f009ae855..9966955f7 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaDefines.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaDefines.h
@@ -32,8 +32,7 @@
 #define gpuGetDeviceCount hipGetDeviceCount
 #define gpuGetErrorString hipGetErrorString
 #define gpuGetDeviceProperties hipGetDeviceProperties
-// FIXME : use hipStreamDefault instead of 0x00
-#define gpuStreamDefault 0x00
+#define gpuStreamDefault hipStreamDefault
 #define gpuGetDevice hipGetDevice
 #define gpuSetDevice hipSetDevice
 #define gpuMalloc hipMalloc
@@ -47,6 +46,7 @@
 #define gpuSharedMemConfig hipSharedMemConfig
 #define gpuDeviceSetSharedMemConfig hipDeviceSetSharedMemConfig
 #define gpuStreamSynchronize hipStreamSynchronize
+#define gpuDeviceSynchronize hipDeviceSynchronize
 #define gpuMemcpy hipMemcpy
 
 #else
@@ -73,6 +73,7 @@
 #define gpuSharedMemConfig cudaSharedMemConfig
 #define gpuDeviceSetSharedMemConfig cudaDeviceSetSharedMemConfig
 #define gpuStreamSynchronize cudaStreamSynchronize
+#define gpuDeviceSynchronize cudaDeviceSynchronize
 #define gpuMemcpy cudaMemcpy
 
 #endif
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaUndefines.h b/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaUndefines.h
index 9bc0708ed..db394bcbb 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaUndefines.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorGpuHipCudaUndefines.h
@@ -32,6 +32,7 @@
 #undef gpuSharedMemConfig
 #undef gpuDeviceSetSharedMemConfig
 #undef gpuStreamSynchronize
+#undef gpuDeviceSynchronize
 #undef gpuMemcpy
 
 #undef EIGEN_CXX11_TENSOR_GPU_HIP_CUDA_DEFINES_H
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorIndexList.h b/unsupported/Eigen/CXX11/src/Tensor/TensorIndexList.h
index 835efbf72..8810d78cf 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorIndexList.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorIndexList.h
@@ -351,10 +351,7 @@ struct IndexPairList : internal::IndexTuple<FirstType, OtherTypes...> {
 namespace internal {
 
 template<typename FirstType, typename... OtherTypes>
-  #if defined(EIGEN_HIPCC)
-  EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC
-  #endif
-  size_t array_prod(const IndexList<FirstType, OtherTypes...>& sizes) {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE size_t array_prod(const IndexList<FirstType, OtherTypes...>& sizes) {
   size_t result = 1;
   for (int i = 0; i < array_size<IndexList<FirstType, OtherTypes...> >::value; ++i) {
     result *= sizes[i];
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
index 2a979845b..cda49f8fe 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
@@ -859,10 +859,7 @@ struct TensorEvaluator<const TensorStridingSlicingOp<StartIndices, StopIndices,
     return inputIndex;
   }
   
-  #if defined(EIGEN_HIPCC)
-  EIGEN_DEVICE_FUNC
-  #endif
-  static EIGEN_STRONG_INLINE Index clamp(Index value, Index min, Index max) {
+  static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index clamp(Index value, Index min, Index max) {
 #ifndef __SYCL_DEVICE_ONLY__
     return numext::maxi(min, numext::mini(max,value));
 #else
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h b/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
index fdd338b96..ce573d730 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
@@ -497,6 +497,9 @@ struct TensorEvaluator<const TensorReductionOp<Op, Dims, ArgType, MakePointer_>,
 
   EIGEN_STRONG_INLINE
     #if !defined(EIGEN_HIPCC)
+    // Marking this as EIGEN_DEVICE_FUNC for HIPCC requires also doing the same for all the functions
+    // being called within here, which then leads to proliferation of EIGEN_DEVICE_FUNC markings, one
+    // of which will eventually result in an NVCC error
     EIGEN_DEVICE_FUNC
     #endif
     bool evalSubExprsIfNeeded(typename MakePointer_<CoeffReturnType>::Type data) {
@@ -778,17 +781,9 @@ struct TensorEvaluator<const TensorReductionOp<Op, Dims, ArgType, MakePointer_>,
   // Indexed by reduced dimensions.
   array<Index, NumReducedDims> m_reducedDims;
 
-#if defined(EIGEN_HIPCC)
- public:
-#endif
-  
   // Evaluator for the input expression.
   TensorEvaluator<ArgType, Device> m_impl;
 
-#if defined(EIGEN_HIPCC)
- private:
-#endif
-  
   // Operation to apply for computing the reduction.
   Op m_reducer;
 
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorReductionGpu.h b/unsupported/Eigen/CXX11/src/Tensor/TensorReductionGpu.h
index ca854d670..a691e530a 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorReductionGpu.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorReductionGpu.h
@@ -169,7 +169,9 @@ __global__ void FullReductionKernel(Reducer reducer, const Self input, Index num
 #pragma unroll
   for (int offset = warpSize/2; offset > 0; offset /= 2) {
   #if defined(EIGEN_HIPCC)
-    // XXX use std::is_floating_point to determine the type of accum
+    // use std::is_floating_point to determine the type of reduced_val 
+    // This is needed because when Type == double, hipcc will give a "call to __shfl_down is ambguous" error 
+    // and list the float and int versions of __shfl_down as the candidate functions. 
     if (std::is_floating_point<typename Self::CoeffReturnType>::value) {
       reducer.reduce(__shfl_down(static_cast<float>(accum), offset, warpSize), &accum);
     } else {
@@ -238,20 +240,6 @@ __global__ void FullReductionKernelHalfFloat(Reducer reducer, const Self input,
 
   // Initialize the output value if it wasn't initialized by the ReductionInitKernel
 
-#if defined(EIGEN_HIPCC)
-  
-  if (gridDim.x == 1 && first_index == 0) {
-    if (num_coeffs % 2 != 0) {
-      half last = input.m_impl.coeff(num_coeffs-1);
-      *scratch = __halves2half2(last, reducer.initialize());
-    } else {
-      *scratch = reducer.template initializePacket<half2>();
-    }
-    __syncthreads();
-  }
-  
-#else
-  
   if (gridDim.x == 1) {
     if (first_index == 0) {
       if (num_coeffs % 2 != 0) {
@@ -264,8 +252,6 @@ __global__ void FullReductionKernelHalfFloat(Reducer reducer, const Self input,
     __syncthreads();
   }
   
-#endif
-
   half2 accum = reducer.template initializePacket<half2>();
   const Index max_iter = numext::mini<Index>((num_coeffs - first_index) / 2, NumPerThread*BlockSize / 2);
   for (Index i = 0; i < max_iter; i += BlockSize) {
@@ -295,17 +281,6 @@ __global__ void FullReductionKernelHalfFloat(Reducer reducer, const Self input,
     atomicReduce(scratch, accum, reducer);
   }
 
-#if defined(EIGEN_HIPCC)
-  __syncthreads();
-
-  if (gridDim.x == 1 && first_index == 0) {
-    half tmp = __low2half(*scratch);
-    reducer.reduce(__high2half(*scratch), &tmp);
-    *output = tmp;
-  }
-
-#else
-    
   if (gridDim.x == 1) {
     __syncthreads();
     if (first_index == 0) {
@@ -314,8 +289,6 @@ __global__ void FullReductionKernelHalfFloat(Reducer reducer, const Self input,
       *output = tmp;
     }
   }
-
-#endif
 }
 
 template <typename Op>
@@ -485,7 +458,9 @@ __global__ void InnerReductionKernel(Reducer reducer, const Self input, Index nu
 #pragma unroll
       for (int offset = warpSize/2; offset > 0; offset /= 2) {
       #if defined(EIGEN_HIPCC)
-        // XXX use std::is_floating_point to determine the type of reduced_val
+        // use std::is_floating_point to determine the type of reduced_val 
+	// This is needed because when Type == double, hipcc will give a "call to __shfl_down is ambguous" error 
+	// and list the float and int versions of __shfl_down as the candidate functions. 
         if (std::is_floating_point<Type>::value) {
           reducer.reduce(__shfl_down(static_cast<float>(reduced_val), offset), &reduced_val);
         } else {
@@ -847,8 +822,4 @@ struct OuterReducer<Self, Op, GpuDevice> {
 } // end namespace internal
 } // end namespace Eigen
 
-#if defined(EIGEN_HIPCC)
-#undef warpSize
-#endif
-
 #endif // EIGEN_CXX11_TENSOR_TENSOR_REDUCTION_GPU_H
diff --git a/unsupported/Eigen/SpecialFunctions b/unsupported/Eigen/SpecialFunctions
index 9441ba8f5..44fd99b43 100644
--- a/unsupported/Eigen/SpecialFunctions
+++ b/unsupported/Eigen/SpecialFunctions
@@ -53,8 +53,8 @@ namespace Eigen {
 #include "src/SpecialFunctions/SpecialFunctionsFunctors.h"
 #include "src/SpecialFunctions/SpecialFunctionsArrayAPI.h"
 
-#if defined EIGEN_VECTORIZE_CUDA
-  #include "src/SpecialFunctions/arch/CUDA/CudaSpecialFunctions.h"
+#if defined EIGEN_VECTORIZE_GPU
+  #include "src/SpecialFunctions/arch/GPU/GpuSpecialFunctions.h"
 #endif
 
 namespace Eigen {
diff --git a/unsupported/Eigen/src/SpecialFunctions/arch/GPU/GpuSpecialFunctions.h b/unsupported/Eigen/src/SpecialFunctions/arch/GPU/GpuSpecialFunctions.h
index ad011e305..40abcee3a 100644
--- a/unsupported/Eigen/src/SpecialFunctions/arch/GPU/GpuSpecialFunctions.h
+++ b/unsupported/Eigen/src/SpecialFunctions/arch/GPU/GpuSpecialFunctions.h
@@ -7,8 +7,8 @@
 // Public License v. 2.0. If a copy of the MPL was not distributed
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef EIGEN_CUDA_SPECIALFUNCTIONS_H
-#define EIGEN_CUDA_SPECIALFUNCTIONS_H
+#ifndef EIGEN_GPU_SPECIALFUNCTIONS_H
+#define EIGEN_GPU_SPECIALFUNCTIONS_H
 
 namespace Eigen {
 
@@ -223,4 +223,4 @@ pi1e<double2>(const double2& x) {
 
 } // end namespace Eigen
 
-#endif // EIGEN_CUDA_SPECIALFUNCTIONS_H
+#endif // EIGEN_GPU_SPECIALFUNCTIONS_H