diff --git a/Eigen/src/Core/DeviceWrapper.h b/Eigen/src/Core/DeviceWrapper.h
index 3ae8256..75fc8e7 100644
--- a/Eigen/src/Core/DeviceWrapper.h
+++ b/Eigen/src/Core/DeviceWrapper.h
@@ -66,7 +66,7 @@
   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void run(DstXprType& dst, const SrcXprType& src, const Functor& func,
                                                         Device&) {
     Base::run(dst, src, func);
-  };
+  }
 };
 
 // specialization for coeffcient-wise assignment
diff --git a/Eigen/src/Core/StlIterators.h b/Eigen/src/Core/StlIterators.h
index 25d4575..4576cc0 100644
--- a/Eigen/src/Core/StlIterators.h
+++ b/Eigen/src/Core/StlIterators.h
@@ -325,7 +325,7 @@
  public:
   typedef Index difference_type;
   typedef typename XprType::Scalar value_type;
-#if EIGEN_CPLUSPLUS >= 202002L
+#if EIGEN_COMP_CXXVER >= 20 && defined(__cpp_lib_concepts) && __cpp_lib_concepts >= 202002L
   typedef std::conditional_t<XprType::InnerStrideAtCompileTime == 1, std::contiguous_iterator_tag,
                              std::random_access_iterator_tag>
       iterator_category;
diff --git a/Eigen/src/Core/functors/AssignmentFunctors.h b/Eigen/src/Core/functors/AssignmentFunctors.h
index 3687bb2..7edcc60 100644
--- a/Eigen/src/Core/functors/AssignmentFunctors.h
+++ b/Eigen/src/Core/functors/AssignmentFunctors.h
@@ -27,7 +27,7 @@
 
   template <int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const {
-    internal::pstoret<DstScalar, Packet, Alignment>(a, b);
+    pstoret<DstScalar, Packet, Alignment>(a, b);
   }
 };
 
@@ -36,7 +36,7 @@
 struct assign_op<DstScalar, void> {};
 
 template <typename DstScalar, typename SrcScalar>
-struct functor_traits<assign_op<DstScalar, SrcScalar> > {
+struct functor_traits<assign_op<DstScalar, SrcScalar>> {
   enum {
     Cost = NumTraits<DstScalar>::ReadCost,
     PacketAccess = is_same<DstScalar, SrcScalar>::value && packet_traits<DstScalar>::Vectorizable &&
@@ -45,88 +45,70 @@
 };
 
 /** \internal
- * \brief Template functor for scalar/packet assignment with addition
+ * \brief Template functor for scalar/packet compound assignment
  *
  */
-template <typename DstScalar, typename SrcScalar>
-struct add_assign_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a += b; }
+template <typename DstScalar, typename SrcScalar, typename Func>
+struct compound_assign_op {
+  using traits = functor_traits<compound_assign_op<DstScalar, SrcScalar, Func>>;
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr void assignCoeff(DstScalar& a, const SrcScalar& b) const {
+    assign_op<DstScalar, DstScalar>().assignCoeff(a, Func().operator()(a, b));
+  }
 
   template <int Alignment, typename Packet>
   EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const {
-    internal::pstoret<DstScalar, Packet, Alignment>(a, internal::padd(internal::ploadt<Packet, Alignment>(a), b));
+    assign_op<DstScalar, DstScalar>().template assignPacket<Alignment, Packet>(
+        a, Func().packetOp(ploadt<Packet, Alignment>(a), b));
   }
 };
-template <typename DstScalar, typename SrcScalar>
-struct functor_traits<add_assign_op<DstScalar, SrcScalar> > {
+
+template <typename DstScalar, typename SrcScalar, typename Func>
+struct functor_traits<compound_assign_op<DstScalar, SrcScalar, Func>> {
   enum {
-    Cost = NumTraits<DstScalar>::ReadCost + NumTraits<DstScalar>::AddCost,
-    PacketAccess = is_same<DstScalar, SrcScalar>::value && packet_traits<DstScalar>::HasAdd
+    Cost = int(functor_traits<assign_op<DstScalar, DstScalar>>::Cost) + int(functor_traits<Func>::Cost),
+    PacketAccess = functor_traits<assign_op<DstScalar, DstScalar>>::PacketAccess && functor_traits<Func>::PacketAccess
   };
 };
 
 /** \internal
+ * \brief Template functor for scalar/packet assignment with addition
+ *
+ */
+template <typename DstScalar, typename SrcScalar = DstScalar>
+struct add_assign_op : compound_assign_op<DstScalar, SrcScalar, scalar_sum_op<DstScalar, SrcScalar>> {};
+
+template <typename DstScalar, typename SrcScalar>
+struct functor_traits<add_assign_op<DstScalar, SrcScalar>> : add_assign_op<DstScalar, SrcScalar>::traits {};
+
+/** \internal
  * \brief Template functor for scalar/packet assignment with subtraction
  *
  */
-template <typename DstScalar, typename SrcScalar>
-struct sub_assign_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a -= b; }
+template <typename DstScalar, typename SrcScalar = DstScalar>
+struct sub_assign_op : compound_assign_op<DstScalar, SrcScalar, scalar_difference_op<DstScalar, SrcScalar>> {};
 
-  template <int Alignment, typename Packet>
-  EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const {
-    internal::pstoret<DstScalar, Packet, Alignment>(a, internal::psub(internal::ploadt<Packet, Alignment>(a), b));
-  }
-};
 template <typename DstScalar, typename SrcScalar>
-struct functor_traits<sub_assign_op<DstScalar, SrcScalar> > {
-  enum {
-    Cost = NumTraits<DstScalar>::ReadCost + NumTraits<DstScalar>::AddCost,
-    PacketAccess = is_same<DstScalar, SrcScalar>::value && packet_traits<DstScalar>::HasSub
-  };
-};
+struct functor_traits<sub_assign_op<DstScalar, SrcScalar>> : sub_assign_op<DstScalar, SrcScalar>::traits {};
 
 /** \internal
  * \brief Template functor for scalar/packet assignment with multiplication
  *
  */
 template <typename DstScalar, typename SrcScalar = DstScalar>
-struct mul_assign_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a *= b; }
+struct mul_assign_op : compound_assign_op<DstScalar, SrcScalar, scalar_product_op<DstScalar, SrcScalar>> {};
 
-  template <int Alignment, typename Packet>
-  EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const {
-    internal::pstoret<DstScalar, Packet, Alignment>(a, internal::pmul(internal::ploadt<Packet, Alignment>(a), b));
-  }
-};
 template <typename DstScalar, typename SrcScalar>
-struct functor_traits<mul_assign_op<DstScalar, SrcScalar> > {
-  enum {
-    Cost = NumTraits<DstScalar>::ReadCost + NumTraits<DstScalar>::MulCost,
-    PacketAccess = is_same<DstScalar, SrcScalar>::value && packet_traits<DstScalar>::HasMul
-  };
-};
+struct functor_traits<mul_assign_op<DstScalar, SrcScalar>> : mul_assign_op<DstScalar, SrcScalar>::traits {};
 
 /** \internal
- * \brief Template functor for scalar/packet assignment with diviving
+ * \brief Template functor for scalar/packet assignment with dividing
  *
  */
 template <typename DstScalar, typename SrcScalar = DstScalar>
-struct div_assign_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void assignCoeff(DstScalar& a, const SrcScalar& b) const { a /= b; }
+struct div_assign_op : compound_assign_op<DstScalar, SrcScalar, scalar_quotient_op<DstScalar, SrcScalar>> {};
 
-  template <int Alignment, typename Packet>
-  EIGEN_STRONG_INLINE void assignPacket(DstScalar* a, const Packet& b) const {
-    internal::pstoret<DstScalar, Packet, Alignment>(a, internal::pdiv(internal::ploadt<Packet, Alignment>(a), b));
-  }
-};
 template <typename DstScalar, typename SrcScalar>
-struct functor_traits<div_assign_op<DstScalar, SrcScalar> > {
-  enum {
-    Cost = NumTraits<DstScalar>::ReadCost + NumTraits<DstScalar>::MulCost,
-    PacketAccess = is_same<DstScalar, SrcScalar>::value && packet_traits<DstScalar>::HasDiv
-  };
-};
+struct functor_traits<div_assign_op<DstScalar, SrcScalar>> : div_assign_op<DstScalar, SrcScalar>::traits {};
 
 /** \internal
  * \brief Template functor for scalar/packet assignment with swapping
@@ -158,7 +140,7 @@
   }
 };
 template <typename Scalar>
-struct functor_traits<swap_assign_op<Scalar> > {
+struct functor_traits<swap_assign_op<Scalar>> {
   enum {
     Cost = 3 * NumTraits<Scalar>::ReadCost,
     PacketAccess =
diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index 97cf4f3..0facd26 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -1316,7 +1316,8 @@
  * This wraps C++20's std::construct_at, using placement new instead if it is not available.
  */
 
-#if EIGEN_COMP_CXXVER >= 20
+#if EIGEN_COMP_CXXVER >= 20 && defined(__cpp_lib_constexpr_dynamic_alloc) && \
+    __cpp_lib_constexpr_dynamic_alloc >= 201907L
 using std::construct_at;
 #else
 template <class T, class... Args>
diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 39a117e..40604f8 100644
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -220,7 +220,7 @@
  *
  * Post C++17: Uses std::void_t
  */
-#if EIGEN_COMP_CXXVER >= 17
+#if EIGEN_COMP_CXXVER >= 17 && defined(__cpp_lib_void_t) && __cpp_lib_void_t >= 201411L
 using std::void_t;
 #else
 template <typename...>
@@ -338,7 +338,16 @@
  *
  * For C++20, this function just forwards to `std::ssize`, or any ADL discoverable `ssize` function.
  */
-#if EIGEN_COMP_CXXVER < 20 || EIGEN_GNUC_STRICT_LESS_THAN(10, 0, 0)
+#if EIGEN_COMP_CXXVER >= 20 && defined(__cpp_lib_ssize) && __cpp_lib_ssize >= 201902L
+
+template <typename T>
+EIGEN_CONSTEXPR auto index_list_size(T&& x) {
+  using std::ssize;
+  return ssize(std::forward<T>(x));
+}
+
+#else
+
 template <typename T>
 EIGEN_CONSTEXPR auto index_list_size(const T& x) {
   using R = std::common_type_t<std::ptrdiff_t, std::make_signed_t<decltype(x.size())>>;
@@ -349,13 +358,7 @@
 EIGEN_CONSTEXPR std::ptrdiff_t index_list_size(const T (&)[N]) {
   return N;
 }
-#else
-template <typename T>
-EIGEN_CONSTEXPR auto index_list_size(T&& x) {
-  using std::ssize;
-  return ssize(std::forward<T>(x));
-}
-#endif  // EIGEN_COMP_CXXVER
+#endif
 
 /** \internal
  * Convenient struct to get the result type of a nullary, unary, binary, or
@@ -745,7 +748,7 @@
 inline constexpr bool check_implication(bool a, bool b) { return !a || b; }
 
 /// \internal Provide fallback for std::is_constant_evaluated for pre-C++20.
-#if EIGEN_COMP_CXXVER >= 20
+#if EIGEN_COMP_CXXVER >= 20 && defined(__cpp_lib_is_constant_evaluated) && __cpp_lib_is_constant_evaluated >= 201811L
 using std::is_constant_evaluated;
 #else
 constexpr bool is_constant_evaluated() { return false; }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 3a67ab1..813cc53 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -384,7 +384,7 @@
 endif()
 
 # boost MP unit test
-find_package(Boost 1.53.0)
+find_package(Boost 1.53.0 CONFIG)
 if(Boost_FOUND)
   include_directories(${Boost_INCLUDE_DIRS})
   ei_add_test(boostmultiprec "" "${Boost_LIBRARIES}")
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
index 288d79f..99e7304 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
@@ -932,7 +932,7 @@
         kernel(m, n, k, use_thread_local);
       } else {
         eigen_assert(!use_thread_local);
-        device_.enqueueNoNotification([this, m, n, k, use_thread_local]() { 
+        device_.enqueue([this, m, n, k, use_thread_local]() { 
             kernel(m, n, k, use_thread_local); 
           });
       }
@@ -982,7 +982,7 @@
       } else {
         while (end - start > 1) {
           Index mid = (start + end) / 2;
-          device_.enqueueNoNotification([this, mid, end, k, rhs]() { 
+          device_.enqueue([this, mid, end, k, rhs]() { 
               enqueue_packing_helper(mid, end, k, rhs);
             });
           end = mid;
@@ -1000,7 +1000,7 @@
                           (k > 0 || std::this_thread::get_id() == created_by_thread_id_);
 
         if (pack_async) {
-          device_.enqueueNoNotification([this, start, end, k, rhs]() { 
+          device_.enqueue([this, start, end, k, rhs]() { 
               enqueue_packing_helper(start, end, k, rhs);
             });
         } else {
@@ -1264,7 +1264,7 @@
     void eval(Barrier& barrier, Index start_block_idx, Index end_block_idx) {
       while (end_block_idx - start_block_idx > 1) {
         Index mid_block_idx = (start_block_idx + end_block_idx) / 2;
-        evaluator->m_device.enqueueNoNotification([this, &barrier, mid_block_idx, end_block_idx]() {
+        evaluator->m_device.enqueue([this, &barrier, mid_block_idx, end_block_idx]() {
           eval<Alignment>(barrier, mid_block_idx, end_block_idx);
         });
         end_block_idx = mid_block_idx;
@@ -1282,7 +1282,7 @@
     void evalAsync(Index start_block_idx, Index end_block_idx) {
       while (end_block_idx - start_block_idx > 1) {
         Index mid_block_idx = (start_block_idx + end_block_idx) / 2;
-        evaluator->m_device.enqueueNoNotification(
+        evaluator->m_device.enqueue(
             [this, mid_block_idx, end_block_idx]() { 
               evalAsync<Alignment>(mid_block_idx, end_block_idx);
             });
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
index c95c8f2..3320990 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
@@ -15,35 +15,6 @@
 
 namespace Eigen {
 
-// Runs an arbitrary function and then calls Notify() on the passed in
-// Notification.
-template <typename Function, typename... Args>
-struct FunctionWrapperWithNotification {
-  static void run(Notification* n, Function f, Args... args) {
-    f(args...);
-    if (n) {
-      n->Notify();
-    }
-  }
-};
-
-template <typename Function, typename... Args>
-struct FunctionWrapperWithBarrier {
-  static void run(Barrier* b, Function f, Args... args) {
-    f(args...);
-    if (b) {
-      b->Notify();
-    }
-  }
-};
-
-template <typename SyncType>
-static EIGEN_STRONG_INLINE void wait_until_ready(SyncType* n) {
-  if (n) {
-    n->Wait();
-  }
-}
-
 // An abstract interface to a device specific memory allocator.
 class Allocator {
  public:
@@ -98,8 +69,9 @@
       Barrier barrier(static_cast<int>(num_threads - 1));
       // Launch the last 3 blocks on worker threads.
       for (size_t i = 1; i < num_threads; ++i) {
-        enqueue_with_barrier(&barrier, [n, i, src_ptr, dst_ptr, blocksize] {
+        pool_->Schedule([n, i, src_ptr, dst_ptr, blocksize, &barrier] {
           ::memcpy(dst_ptr + i * blocksize, src_ptr + i * blocksize, numext::mini(blocksize, n - (i * blocksize)));
+          barrier.Notify();
         });
       }
       // Launch the first block on the main thread.
@@ -140,24 +112,22 @@
     return 1;
   }
 
-  template <class Function, class... Args>
-  EIGEN_STRONG_INLINE Notification* enqueue(Function&& f, Args&&... args) const {
-    Notification* n = new Notification();
-    pool_->Schedule(
-        std::bind(&FunctionWrapperWithNotification<Function, Args...>::run, n, std::forward<Function>(f), args...));
-    return n;
-  }
-
-  template <class Function, class... Args>
-  EIGEN_STRONG_INLINE void enqueue_with_barrier(Barrier* b, Function&& f, Args&&... args) const {
-    pool_->Schedule(
-        std::bind(&FunctionWrapperWithBarrier<Function, Args...>::run, b, std::forward<Function>(f), args...));
-  }
-
+  // TODO(rmlarsen): Remove this deprecated interface when all users have been converted.
   template <class Function, class... Args>
   EIGEN_STRONG_INLINE void enqueueNoNotification(Function&& f, Args&&... args) const {
+    enqueue(std::forward<Function>(f), std::forward<Args>(args)...);
+  }
+
+  template <class Function, class... Args>
+  EIGEN_STRONG_INLINE void enqueue(Function&& f, Args&&... args) const {
+#if EIGEN_COMP_CXXVER >= 20
+    if constexpr (sizeof...(args) > 0) {
+      auto run_f = [f = std::forward<Function>(f), ... args = std::forward<Args>(args)]() { f(args...); };
+#else
     if (sizeof...(args) > 0) {
-      pool_->Schedule(std::bind(std::forward<Function>(f), args...));
+      auto run_f = [f = std::forward<Function>(f), &args...]() { f(args...); };
+#endif
+      pool_->Schedule(std::move(run_f));
     } else {
       pool_->Schedule(std::forward<Function>(f));
     }
@@ -191,27 +161,14 @@
     // Division code rounds mid to block_size, so we are guaranteed to get
     // block_count leaves that do actual computations.
     Barrier barrier(static_cast<unsigned int>(block.count));
-    std::function<void(Index, Index)> handleRange;
-    handleRange = [this, block, &handleRange, &barrier, &f](Index firstIdx, Index lastIdx) {
-      while (lastIdx - firstIdx > block.size) {
-        // Split into halves and schedule the second half on a different thread.
-        const Index midIdx = firstIdx + numext::div_ceil((lastIdx - firstIdx) / 2, block.size) * block.size;
-        pool_->Schedule([=, &handleRange]() { handleRange(midIdx, lastIdx); });
-        lastIdx = midIdx;
-      }
-      // Single block or less, execute directly.
-      f(firstIdx, lastIdx);
-      barrier.Notify();
-    };
-
     if (block.count <= numThreads()) {
       // Avoid a thread hop by running the root of the tree and one block on the
       // main thread.
-      handleRange(0, n);
+      handleRange(0, n, block.size, &barrier, pool_, f);
     } else {
       // Execute the root in the thread pool to avoid running work on more than
       // numThreads() threads.
-      pool_->Schedule([=, &handleRange]() { handleRange(0, n); });
+      pool_->Schedule([this, n, &block, &barrier, &f]() { handleRange(0, n, block.size, &barrier, pool_, f); });
     }
 
     barrier.Wait();
@@ -287,6 +244,19 @@
  private:
   typedef TensorCostModel<ThreadPoolDevice> CostModel;
 
+  static void handleRange(Index firstIdx, Index lastIdx, Index granularity, Barrier* barrier, ThreadPoolInterface* pool,
+                          const std::function<void(Index, Index)>& f) {
+    while (lastIdx - firstIdx > granularity) {
+      // Split into halves and schedule the second half on a different thread.
+      const Index midIdx = firstIdx + numext::div_ceil((lastIdx - firstIdx) / 2, granularity) * granularity;
+      pool->Schedule([=, &f]() { handleRange(midIdx, lastIdx, granularity, barrier, pool, f); });
+      lastIdx = midIdx;
+    }
+    // Single block or less, execute directly.
+    f(firstIdx, lastIdx);
+    barrier->Notify();
+  }
+
   // For parallelForAsync we must keep passed in closures on the heap, and
   // delete them only after `done` callback finished.
   struct ParallelForAsyncContext {
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorExecutor.h b/unsupported/Eigen/CXX11/src/Tensor/TensorExecutor.h
index b1da1a5..da33210 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorExecutor.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorExecutor.h
@@ -352,7 +352,7 @@
         TensorBlockDesc desc(0, tiling.block_mapper.blockDimensions());
         evaluator.evalBlock(desc, scratch);
       } else {
-        device.parallelFor(tiling.block_mapper.blockCount(), tiling.cost, eval_block);
+        device.parallelFor(tiling.block_mapper.blockCount(), tiling.cost, std::move(eval_block));
       }
     }
     evaluator.cleanup();
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h b/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
index 62c54e3..9bbf945 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h
@@ -357,17 +357,6 @@
 };
 
 #ifdef EIGEN_USE_THREADS
-// Multithreaded full reducers
-template <typename Self, typename Op,
-          bool Vectorizable = (Self::InputPacketAccess && Self::ReducerTraits::PacketAccess)>
-struct FullReducerShard {
-  static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void run(const Self& self, typename Self::Index firstIndex,
-                                                        typename Self::Index numValuesToReduce, Op& reducer,
-                                                        typename Self::CoeffReturnType* output) {
-    *output = InnerMostDimReducer<Self, Op, Vectorizable>::reduce(self, firstIndex, numValuesToReduce, reducer);
-  }
-};
-
 // Multithreaded full reducer
 template <typename Self, typename Op, bool Vectorizable>
 struct FullReducer<Self, Op, ThreadPoolDevice, Vectorizable> {
@@ -397,8 +386,11 @@
     Barrier barrier(internal::convert_index<unsigned int>(numblocks));
     MaxSizeVector<typename Self::CoeffReturnType> shards(numblocks, reducer.initialize());
     for (Index i = 0; i < numblocks; ++i) {
-      device.enqueue_with_barrier(&barrier, &FullReducerShard<Self, Op, Vectorizable>::run, self, i * blocksize,
-                                  blocksize, reducer, &shards[i]);
+      auto run_shard = [i, blocksize, &self, &barrier, &shards, &reducer](){
+        shards[i] = InnerMostDimReducer<Self, Op, Vectorizable>::reduce(self, i * blocksize, blocksize, reducer);
+        barrier.Notify();
+      };
+      device.enqueue(std::move(run_shard));
     }
     typename Self::CoeffReturnType finalShard;
     if (numblocks * blocksize < num_coeffs) {
@@ -888,10 +880,6 @@
   friend struct internal::InnerMostDimPreserver;
   template <typename S, typename O, typename D, bool V>
   friend struct internal::FullReducer;
-#ifdef EIGEN_USE_THREADS
-  template <typename S, typename O, bool V>
-  friend struct internal::FullReducerShard;
-#endif
 #if defined(EIGEN_USE_GPU) && (defined(EIGEN_GPUCC))
   template <int B, int N, typename S, typename R, typename I_>
   KERNEL_FRIEND void internal::FullReductionKernel(R, const S, I_, typename S::CoeffReturnType*, unsigned int*);
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorVolumePatch.h b/unsupported/Eigen/CXX11/src/Tensor/TensorVolumePatch.h
index ce712e2..cf69fef 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorVolumePatch.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorVolumePatch.h
@@ -448,8 +448,11 @@
     eigen_assert(otherIndex == indices[1] / m_fastOtherStride);
 
     // Find the offset of the element wrt the location of the first element.
-    const Index patchOffsets[2] = {(indices[0] - patchIndex * m_patchStride) / m_fastOutputDepth,
-                                   (indices[1] - patchIndex * m_patchStride) / m_fastOutputDepth};
+    Index first_entry = (indices[0] - patchIndex * m_patchStride) / m_fastOutputDepth;
+    Index second_entry = PacketSize == 1 ? first_entry : 
+                        (indices[1] - patchIndex * m_patchStride) / m_fastOutputDepth;
+
+    const Index patchOffsets[2] = {first_entry, second_entry};
 
     const Index patch3DIndex =
         (NumDims == 5) ? patchIndex : (indices[0] - otherIndex * m_otherStride) / m_fastPatchStride;