resurrect expression evaluators

1 files changed, 682 insertions, 0 deletions

diff --git a/Eigen/src/Core/AssignEvaluator.h b/Eigen/src/Core/AssignEvaluator.h
new file mode 100644
index 000000000..006a87d47
--- /dev/null
+++ b/Eigen/src/Core/AssignEvaluator.h
@@ -0,0 +1,682 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Benoit Jacob <jacob.benoit.1@gmail.com>
+// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
+// Copyright (C) 2011 Jitse Niesen <jitse@maths.leeds.ac.uk>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_ASSIGN_EVALUATOR_H
+#define EIGEN_ASSIGN_EVALUATOR_H
+
+// This implementation is based on Assign.h
+
+namespace internal {
+  
+/***************************************************************************
+* Part 1 : the logic deciding a strategy for traversal and unrolling       *
+***************************************************************************/
+
+// copy_using_evaluator_traits is based on assign_traits
+// (actually, it's identical)
+
+template <typename Derived, typename OtherDerived>
+struct copy_using_evaluator_traits
+{
+public:
+  enum {
+    DstIsAligned = Derived::Flags & AlignedBit,
+    DstHasDirectAccess = Derived::Flags & DirectAccessBit,
+    SrcIsAligned = OtherDerived::Flags & AlignedBit,
+    JointAlignment = bool(DstIsAligned) && bool(SrcIsAligned) ? Aligned : Unaligned
+  };
+
+private:
+  enum {
+    InnerSize = int(Derived::IsVectorAtCompileTime) ? int(Derived::SizeAtCompileTime)
+              : int(Derived::Flags)&RowMajorBit ? int(Derived::ColsAtCompileTime)
+              : int(Derived::RowsAtCompileTime),
+    InnerMaxSize = int(Derived::IsVectorAtCompileTime) ? int(Derived::MaxSizeAtCompileTime)
+              : int(Derived::Flags)&RowMajorBit ? int(Derived::MaxColsAtCompileTime)
+              : int(Derived::MaxRowsAtCompileTime),
+    MaxSizeAtCompileTime = Derived::SizeAtCompileTime,
+    PacketSize = packet_traits<typename Derived::Scalar>::size
+  };
+
+  enum {
+    StorageOrdersAgree = (int(Derived::IsRowMajor) == int(OtherDerived::IsRowMajor)),
+    MightVectorize = StorageOrdersAgree
+                  && (int(Derived::Flags) & int(OtherDerived::Flags) & ActualPacketAccessBit),
+    MayInnerVectorize  = MightVectorize && int(InnerSize)!=Dynamic && int(InnerSize)%int(PacketSize)==0
+                       && int(DstIsAligned) && int(SrcIsAligned),
+    MayLinearize = StorageOrdersAgree && (int(Derived::Flags) & int(OtherDerived::Flags) & LinearAccessBit),
+    MayLinearVectorize = MightVectorize && MayLinearize && DstHasDirectAccess
+                       && (DstIsAligned || MaxSizeAtCompileTime == Dynamic),
+      /* If the destination isn't aligned, we have to do runtime checks and we don't unroll,
+         so it's only good for large enough sizes. */
+    MaySliceVectorize  = MightVectorize && DstHasDirectAccess
+                       && (int(InnerMaxSize)==Dynamic || int(InnerMaxSize)>=3*PacketSize)
+      /* slice vectorization can be slow, so we only want it if the slices are big, which is
+         indicated by InnerMaxSize rather than InnerSize, think of the case of a dynamic block
+         in a fixed-size matrix */
+  };
+
+public:
+  enum {
+    Traversal = int(MayInnerVectorize)  ? int(InnerVectorizedTraversal)
+              : int(MayLinearVectorize) ? int(LinearVectorizedTraversal)
+              : int(MaySliceVectorize)  ? int(SliceVectorizedTraversal)
+              : int(MayLinearize)       ? int(LinearTraversal)
+                                        : int(DefaultTraversal),
+    Vectorized = int(Traversal) == InnerVectorizedTraversal
+              || int(Traversal) == LinearVectorizedTraversal
+              || int(Traversal) == SliceVectorizedTraversal
+  };
+
+private:
+  enum {
+    UnrollingLimit      = EIGEN_UNROLLING_LIMIT * (Vectorized ? int(PacketSize) : 1),
+    MayUnrollCompletely = int(Derived::SizeAtCompileTime) != Dynamic
+                       && int(OtherDerived::CoeffReadCost) != Dynamic
+                       && int(Derived::SizeAtCompileTime) * int(OtherDerived::CoeffReadCost) <= int(UnrollingLimit),
+    MayUnrollInner      = int(InnerSize) != Dynamic
+                       && int(OtherDerived::CoeffReadCost) != Dynamic
+                       && int(InnerSize) * int(OtherDerived::CoeffReadCost) <= int(UnrollingLimit)
+  };
+
+public:
+  enum {
+    Unrolling = (int(Traversal) == int(InnerVectorizedTraversal) || int(Traversal) == int(DefaultTraversal))
+                ? (
+ 		    int(MayUnrollCompletely) ? int(CompleteUnrolling)
+                  : int(MayUnrollInner)      ? int(InnerUnrolling)
+                                             : int(NoUnrolling)
+                  )
+              : int(Traversal) == int(LinearVectorizedTraversal)
+                ? ( bool(MayUnrollCompletely) && bool(DstIsAligned) ? int(CompleteUnrolling) 
+                                                                    : int(NoUnrolling) )
+              : int(Traversal) == int(LinearTraversal)
+                ? ( bool(MayUnrollCompletely) ? int(CompleteUnrolling) 
+                                              : int(NoUnrolling) )
+              : int(NoUnrolling)
+  };
+
+#ifdef EIGEN_DEBUG_ASSIGN
+  static void debug()
+  {
+    EIGEN_DEBUG_VAR(DstIsAligned)
+    EIGEN_DEBUG_VAR(SrcIsAligned)
+    EIGEN_DEBUG_VAR(JointAlignment)
+    EIGEN_DEBUG_VAR(InnerSize)
+    EIGEN_DEBUG_VAR(InnerMaxSize)
+    EIGEN_DEBUG_VAR(PacketSize)
+    EIGEN_DEBUG_VAR(StorageOrdersAgree)
+    EIGEN_DEBUG_VAR(MightVectorize)
+    EIGEN_DEBUG_VAR(MayLinearize)
+    EIGEN_DEBUG_VAR(MayInnerVectorize)
+    EIGEN_DEBUG_VAR(MayLinearVectorize)
+    EIGEN_DEBUG_VAR(MaySliceVectorize)
+    EIGEN_DEBUG_VAR(Traversal)
+    EIGEN_DEBUG_VAR(UnrollingLimit)
+    EIGEN_DEBUG_VAR(MayUnrollCompletely)
+    EIGEN_DEBUG_VAR(MayUnrollInner)
+    EIGEN_DEBUG_VAR(Unrolling)
+  }
+#endif
+};
+
+/***************************************************************************
+* Part 2 : meta-unrollers
+***************************************************************************/
+
+/************************
+*** Default traversal ***
+************************/
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Index, int Stop>
+struct copy_using_evaluator_DefaultTraversal_CompleteUnrolling
+{
+  typedef typename DstEvaluatorType::XprType DstXprType;
+  
+  enum {
+    outer = Index / DstXprType::InnerSizeAtCompileTime,
+    inner = Index % DstXprType::InnerSizeAtCompileTime
+  };
+
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType &dstEvaluator, 
+				      SrcEvaluatorType &srcEvaluator)
+  {
+    dstEvaluator.copyCoeffByOuterInner(outer, inner, srcEvaluator);
+    copy_using_evaluator_DefaultTraversal_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, Index+1, Stop>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Stop>
+struct copy_using_evaluator_DefaultTraversal_CompleteUnrolling<DstEvaluatorType, SrcEvaluatorType, Stop, Stop>
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType&, SrcEvaluatorType&) { }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Index, int Stop>
+struct copy_using_evaluator_DefaultTraversal_InnerUnrolling
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType &dstEvaluator, 
+				      SrcEvaluatorType &srcEvaluator, 
+				      int outer)
+  {
+    dstEvaluator.copyCoeffByOuterInner(outer, Index, srcEvaluator);
+    copy_using_evaluator_DefaultTraversal_InnerUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, Index+1, Stop>
+      ::run(dstEvaluator, srcEvaluator, outer);
+  }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Stop>
+struct copy_using_evaluator_DefaultTraversal_InnerUnrolling<DstEvaluatorType, SrcEvaluatorType, Stop, Stop>
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType&, SrcEvaluatorType&, int) { }
+};
+
+/***********************
+*** Linear traversal ***
+***********************/
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Index, int Stop>
+struct copy_using_evaluator_LinearTraversal_CompleteUnrolling
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType &dstEvaluator, 
+				      SrcEvaluatorType &srcEvaluator)
+  {
+    dstEvaluator.copyCoeff(Index, srcEvaluator);
+    copy_using_evaluator_LinearTraversal_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, Index+1, Stop>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Stop>
+struct copy_using_evaluator_LinearTraversal_CompleteUnrolling<DstEvaluatorType, SrcEvaluatorType, Stop, Stop>
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType&, SrcEvaluatorType&) { }
+};
+
+/**************************
+*** Inner vectorization ***
+**************************/
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Index, int Stop>
+struct copy_using_evaluator_innervec_CompleteUnrolling
+{
+  typedef typename DstEvaluatorType::XprType DstXprType;
+  typedef typename SrcEvaluatorType::XprType SrcXprType;
+
+  enum {
+    outer = Index / DstXprType::InnerSizeAtCompileTime,
+    inner = Index % DstXprType::InnerSizeAtCompileTime,
+    JointAlignment = copy_using_evaluator_traits<DstXprType,SrcXprType>::JointAlignment
+  };
+
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType &dstEvaluator, 
+				      SrcEvaluatorType &srcEvaluator)
+  {
+    dstEvaluator.template copyPacketByOuterInner<Aligned, JointAlignment>(outer, inner, srcEvaluator);
+    enum { NextIndex = Index + packet_traits<typename DstXprType::Scalar>::size };
+    copy_using_evaluator_innervec_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, NextIndex, Stop>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Stop>
+struct copy_using_evaluator_innervec_CompleteUnrolling<DstEvaluatorType, SrcEvaluatorType, Stop, Stop>
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType&, SrcEvaluatorType&) { }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Index, int Stop>
+struct copy_using_evaluator_innervec_InnerUnrolling
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType &dstEvaluator, 
+				      SrcEvaluatorType &srcEvaluator, 
+				      int outer)
+  {
+    dstEvaluator.template copyPacketByOuterInner<Aligned, Aligned>(outer, Index, srcEvaluator);
+    typedef typename DstEvaluatorType::XprType DstXprType;
+    enum { NextIndex = Index + packet_traits<typename DstXprType::Scalar>::size };
+    copy_using_evaluator_innervec_InnerUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, NextIndex, Stop>
+      ::run(dstEvaluator, srcEvaluator, outer);
+  }
+};
+
+template<typename DstEvaluatorType, typename SrcEvaluatorType, int Stop>
+struct copy_using_evaluator_innervec_InnerUnrolling<DstEvaluatorType, SrcEvaluatorType, Stop, Stop>
+{
+  EIGEN_STRONG_INLINE static void run(DstEvaluatorType&, SrcEvaluatorType&, int) { }
+};
+
+/***************************************************************************
+* Part 3 : implementation of all cases
+***************************************************************************/
+
+// copy_using_evaluator_impl is based on assign_impl
+
+template<typename DstXprType, typename SrcXprType,
+         int Traversal = copy_using_evaluator_traits<DstXprType, SrcXprType>::Traversal,
+         int Unrolling = copy_using_evaluator_traits<DstXprType, SrcXprType>::Unrolling>
+struct copy_using_evaluator_impl;
+
+/************************
+*** Default traversal ***
+************************/
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, DefaultTraversal, NoUnrolling>
+{
+  static void run(DstXprType& dst, const SrcXprType& src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+    typedef typename DstXprType::Index Index;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    for(Index outer = 0; outer < dst.outerSize(); ++outer) {
+      for(Index inner = 0; inner < dst.innerSize(); ++inner) {
+	dstEvaluator.copyCoeffByOuterInner(outer, inner, srcEvaluator);
+      }
+    }
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, DefaultTraversal, CompleteUnrolling>
+{
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    copy_using_evaluator_DefaultTraversal_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, 0, DstXprType::SizeAtCompileTime>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, DefaultTraversal, InnerUnrolling>
+{
+  typedef typename DstXprType::Index Index;
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    const Index outerSize = dst.outerSize();
+    for(Index outer = 0; outer < outerSize; ++outer)
+      copy_using_evaluator_DefaultTraversal_InnerUnrolling
+	<DstEvaluatorType, SrcEvaluatorType, 0, DstXprType::InnerSizeAtCompileTime>
+        ::run(dstEvaluator, srcEvaluator, outer);
+  }
+};
+
+/***************************
+*** Linear vectorization ***
+***************************/
+
+template <bool IsAligned = false>
+struct unaligned_copy_using_evaluator_impl
+{
+  // if IsAligned = true, then do nothing
+  template <typename SrcEvaluatorType, typename DstEvaluatorType>
+  static EIGEN_STRONG_INLINE void run(const SrcEvaluatorType&, DstEvaluatorType&, 
+				      typename SrcEvaluatorType::Index, typename SrcEvaluatorType::Index) {}
+};
+
+template <>
+struct unaligned_copy_using_evaluator_impl<false>
+{
+  // MSVC must not inline this functions. If it does, it fails to optimize the
+  // packet access path.
+#ifdef _MSC_VER
+  template <typename DstEvaluatorType, typename SrcEvaluatorType>
+  static EIGEN_DONT_INLINE void run(DstEvaluatorType &dstEvaluator, 
+				    const SrcEvaluatorType &srcEvaluator, 
+				    typename DstEvaluatorType::Index start, 
+				    typename DstEvaluatorType::Index end)
+#else
+  template <typename DstEvaluatorType, typename SrcEvaluatorType>
+  static EIGEN_STRONG_INLINE void run(DstEvaluatorType &dstEvaluator, 
+				      const SrcEvaluatorType &srcEvaluator, 
+				      typename DstEvaluatorType::Index start, 
+				      typename DstEvaluatorType::Index end)
+#endif
+  {
+    for (typename DstEvaluatorType::Index index = start; index < end; ++index)
+      dstEvaluator.copyCoeff(index, srcEvaluator);
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, LinearVectorizedTraversal, NoUnrolling>
+{
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+    typedef typename DstXprType::Index Index;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    const Index size = dst.size();
+    typedef packet_traits<typename DstXprType::Scalar> PacketTraits;
+    enum {
+      packetSize = PacketTraits::size,
+      dstIsAligned = int(copy_using_evaluator_traits<DstXprType,SrcXprType>::DstIsAligned),
+      dstAlignment = PacketTraits::AlignedOnScalar ? Aligned : dstIsAligned,
+      srcAlignment = copy_using_evaluator_traits<DstXprType,SrcXprType>::JointAlignment
+    };
+    const Index alignedStart = dstIsAligned ? 0 : first_aligned(&dstEvaluator.coeffRef(0), size);
+    const Index alignedEnd = alignedStart + ((size-alignedStart)/packetSize)*packetSize;
+
+    unaligned_copy_using_evaluator_impl<dstIsAligned!=0>::run(dstEvaluator, srcEvaluator, 0, alignedStart);
+
+    for(Index index = alignedStart; index < alignedEnd; index += packetSize)
+    {
+      dstEvaluator.template copyPacket<dstAlignment, srcAlignment>(index, srcEvaluator);
+    }
+
+    unaligned_copy_using_evaluator_impl<>::run(dstEvaluator, srcEvaluator, alignedEnd, size);
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, LinearVectorizedTraversal, CompleteUnrolling>
+{
+  typedef typename DstXprType::Index Index;
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    enum { size = DstXprType::SizeAtCompileTime,
+           packetSize = packet_traits<typename DstXprType::Scalar>::size,
+           alignedSize = (size/packetSize)*packetSize };
+
+    copy_using_evaluator_innervec_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, 0, alignedSize>
+      ::run(dstEvaluator, srcEvaluator);
+    copy_using_evaluator_DefaultTraversal_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, alignedSize, size>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+/**************************
+*** Inner vectorization ***
+**************************/
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, InnerVectorizedTraversal, NoUnrolling>
+{
+  inline static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+    typedef typename DstXprType::Index Index;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    const Index innerSize = dst.innerSize();
+    const Index outerSize = dst.outerSize();
+    const Index packetSize = packet_traits<typename DstXprType::Scalar>::size;
+    for(Index outer = 0; outer < outerSize; ++outer)
+      for(Index inner = 0; inner < innerSize; inner+=packetSize) {
+	dstEvaluator.template copyPacketByOuterInner<Aligned, Aligned>(outer, inner, srcEvaluator);
+      }
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, InnerVectorizedTraversal, CompleteUnrolling>
+{
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    copy_using_evaluator_innervec_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, 0, DstXprType::SizeAtCompileTime>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, InnerVectorizedTraversal, InnerUnrolling>
+{
+  typedef typename DstXprType::Index Index;
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    const Index outerSize = dst.outerSize();
+    for(Index outer = 0; outer < outerSize; ++outer)
+      copy_using_evaluator_innervec_InnerUnrolling
+	<DstEvaluatorType, SrcEvaluatorType, 0, DstXprType::InnerSizeAtCompileTime>
+        ::run(dstEvaluator, srcEvaluator, outer);
+  }
+};
+
+/***********************
+*** Linear traversal ***
+***********************/
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, LinearTraversal, NoUnrolling>
+{
+  inline static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+    typedef typename DstXprType::Index Index;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    const Index size = dst.size();
+    for(Index i = 0; i < size; ++i)
+      dstEvaluator.copyCoeff(i, srcEvaluator);
+  }
+};
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, LinearTraversal, CompleteUnrolling>
+{
+  EIGEN_STRONG_INLINE static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    copy_using_evaluator_LinearTraversal_CompleteUnrolling
+      <DstEvaluatorType, SrcEvaluatorType, 0, DstXprType::SizeAtCompileTime>
+      ::run(dstEvaluator, srcEvaluator);
+  }
+};
+
+/**************************
+*** Slice vectorization ***
+***************************/
+
+template<typename DstXprType, typename SrcXprType>
+struct copy_using_evaluator_impl<DstXprType, SrcXprType, SliceVectorizedTraversal, NoUnrolling>
+{
+  inline static void run(DstXprType &dst, const SrcXprType &src)
+  {
+    typedef typename evaluator<DstXprType>::type DstEvaluatorType;
+    typedef typename evaluator<SrcXprType>::type SrcEvaluatorType;
+    typedef typename DstXprType::Index Index;
+
+    DstEvaluatorType dstEvaluator(dst);
+    SrcEvaluatorType srcEvaluator(src);
+
+    typedef packet_traits<typename DstXprType::Scalar> PacketTraits;
+    enum {
+      packetSize = PacketTraits::size,
+      alignable = PacketTraits::AlignedOnScalar,
+      dstAlignment = alignable ? Aligned : int(copy_using_evaluator_traits<DstXprType,SrcXprType>::DstIsAligned) ,
+      srcAlignment = copy_using_evaluator_traits<DstXprType,SrcXprType>::JointAlignment
+    };
+    const Index packetAlignedMask = packetSize - 1;
+    const Index innerSize = dst.innerSize();
+    const Index outerSize = dst.outerSize();
+    const Index alignedStep = alignable ? (packetSize - dst.outerStride() % packetSize) & packetAlignedMask : 0;
+    Index alignedStart = ((!alignable) || copy_using_evaluator_traits<DstXprType,SrcXprType>::DstIsAligned) ? 0
+                       : first_aligned(&dstEvaluator.coeffRef(0,0), innerSize);
+
+    for(Index outer = 0; outer < outerSize; ++outer)
+    {
+      const Index alignedEnd = alignedStart + ((innerSize-alignedStart) & ~packetAlignedMask);
+      // do the non-vectorizable part of the assignment
+      for(Index inner = 0; inner<alignedStart ; ++inner) {
+        dstEvaluator.copyCoeffByOuterInner(outer, inner, srcEvaluator);
+      }
+
+      // do the vectorizable part of the assignment
+      for(Index inner = alignedStart; inner<alignedEnd; inner+=packetSize) {
+        dstEvaluator.template copyPacketByOuterInner<dstAlignment, srcAlignment>(outer, inner, srcEvaluator);
+      }
+
+      // do the non-vectorizable part of the assignment
+      for(Index inner = alignedEnd; inner<innerSize ; ++inner) {
+        dstEvaluator.copyCoeffByOuterInner(outer, inner, srcEvaluator);
+      }
+
+      alignedStart = std::min<Index>((alignedStart+alignedStep)%packetSize, innerSize);
+    }
+  }
+};
+
+/***************************************************************************
+* Part 4 : Entry points
+***************************************************************************/
+
+// Based on DenseBase::LazyAssign()
+
+template<typename DstXprType, typename SrcXprType>
+const DstXprType& copy_using_evaluator(const DstXprType& dst, const SrcXprType& src)
+{
+#ifdef EIGEN_DEBUG_ASSIGN
+  internal::copy_using_evaluator_traits<DstXprType, SrcXprType>::debug();
+#endif
+  copy_using_evaluator_impl<DstXprType, SrcXprType>::run(const_cast<DstXprType&>(dst), src);
+  return dst;
+}
+
+// Based on DenseBase::swap()
+// TODO: Chech whether we need to do something special for swapping two
+//       Arrays or Matrices.
+
+template<typename DstXprType, typename SrcXprType>
+void swap_using_evaluator(const DstXprType& dst, const SrcXprType& src)
+{
+  copy_using_evaluator(SwapWrapper<DstXprType>(const_cast<DstXprType&>(dst)), src);
+}
+
+// Based on MatrixBase::operator+= (in CwiseBinaryOp.h)
+template<typename DstXprType, typename SrcXprType>
+void add_assign_using_evaluator(const MatrixBase<DstXprType>& dst, const MatrixBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_sum_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+// Based on ArrayBase::operator+=
+template<typename DstXprType, typename SrcXprType>
+void add_assign_using_evaluator(const ArrayBase<DstXprType>& dst, const ArrayBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_sum_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+// TODO: Add add_assign_using_evaluator for EigenBase ?
+
+template<typename DstXprType, typename SrcXprType>
+void subtract_assign_using_evaluator(const MatrixBase<DstXprType>& dst, const MatrixBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_difference_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+template<typename DstXprType, typename SrcXprType>
+void subtract_assign_using_evaluator(const ArrayBase<DstXprType>& dst, const ArrayBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_difference_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+template<typename DstXprType, typename SrcXprType>
+void multiply_assign_using_evaluator(const ArrayBase<DstXprType>& dst, const ArrayBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_product_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+template<typename DstXprType, typename SrcXprType>
+void divide_assign_using_evaluator(const ArrayBase<DstXprType>& dst, const ArrayBase<SrcXprType>& src)
+{
+  typedef typename DstXprType::Scalar Scalar;
+  SelfCwiseBinaryOp<internal::scalar_quotient_op<Scalar>, DstXprType, SrcXprType> tmp(dst.const_cast_derived());
+  copy_using_evaluator(tmp, src.derived());
+}
+
+
+} // namespace internal
+
+#endif // EIGEN_ASSIGN_EVALUATOR_H