From cb9f3685d351dc39200638c0b48891d730976656 Mon Sep 17 00:00:00 2001
From: Jitse Niesen <jitse@maths.leeds.ac.uk>
Date: Thu, 5 Jul 2012 11:09:42 +0100
Subject: [PATCH] Move implementation of coeff() &c to Matrix/Array evaluator.

---
 Eigen/src/Core/CoreEvaluators.h | 81 +++++++++++++++++++++++++--------
 1 file changed, 63 insertions(+), 18 deletions(-)

diff --git a/Eigen/src/Core/CoreEvaluators.h b/Eigen/src/Core/CoreEvaluators.h
index 906df2af7..2a6099dd1 100644
--- a/Eigen/src/Core/CoreEvaluators.h
+++ b/Eigen/src/Core/CoreEvaluators.h
@@ -169,7 +169,19 @@ struct evaluator_impl<PlainObjectBase<Derived> >
 {
   typedef PlainObjectBase<Derived> PlainObjectType;
 
-  evaluator_impl(const PlainObjectType& m) : m_plainObject(m) {}
+  evaluator_impl(void) 
+  { }
+
+  evaluator_impl(const PlainObjectType& m) 
+  { 
+    init(m);
+  }
+
+  void init(const PlainObjectType& m)
+  {
+    m_data = m.data();
+    m_outerStride = m.outerStride();
+  }
 
   typedef typename PlainObjectType::Index Index;
   typedef typename PlainObjectType::Scalar Scalar;
@@ -177,52 +189,71 @@ struct evaluator_impl<PlainObjectBase<Derived> >
   typedef typename PlainObjectType::PacketScalar PacketScalar;
   typedef typename PlainObjectType::PacketReturnType PacketReturnType;
 
-  CoeffReturnType coeff(Index i, Index j) const
+  enum {
+    IsRowMajor = PlainObjectType::IsRowMajor,
+  };
+
+  CoeffReturnType coeff(Index row, Index col) const
   {
-    return m_plainObject.coeff(i, j);
+    if (IsRowMajor)
+      return m_data[row * m_outerStride + col];
+    else
+      return m_data[row + col * m_outerStride];
   }
 
   CoeffReturnType coeff(Index index) const
   {
-    return m_plainObject.coeff(index);
+    return m_data[index];
   }
 
-  Scalar& coeffRef(Index i, Index j)
+  Scalar& coeffRef(Index row, Index col)
   {
-    return m_plainObject.const_cast_derived().coeffRef(i, j);
+    if (IsRowMajor)
+      return const_cast<Scalar*>(m_data)[row * m_outerStride + col];
+    else
+      return const_cast<Scalar*>(m_data)[row + col * m_outerStride];
   }
 
   Scalar& coeffRef(Index index)
   {
-    return m_plainObject.const_cast_derived().coeffRef(index);
+    return const_cast<Scalar*>(m_data)[index];
   }
 
   template<int LoadMode> 
   PacketReturnType packet(Index row, Index col) const
   {
-    return m_plainObject.template packet<LoadMode>(row, col);
+    if (IsRowMajor)
+      return ploadt<PacketScalar, LoadMode>(m_data + row * m_outerStride + col);
+    else
+      return ploadt<PacketScalar, LoadMode>(m_data + row + col * m_outerStride);
   }
 
   template<int LoadMode> 
   PacketReturnType packet(Index index) const
   {
-    return m_plainObject.template packet<LoadMode>(index);
+    return ploadt<PacketScalar, LoadMode>(m_data + index);
   }
 
   template<int StoreMode> 
   void writePacket(Index row, Index col, const PacketScalar& x)
   {
-    m_plainObject.const_cast_derived().template writePacket<StoreMode>(row, col, x);
+    if (IsRowMajor)
+      return pstoret<Scalar, PacketScalar, StoreMode>
+	            (const_cast<Scalar*>(m_data) + row * m_outerStride + col, x);
+    else
+      return pstoret<Scalar, PacketScalar, StoreMode>
+                    (const_cast<Scalar*>(m_data) + row + col * m_outerStride, x);
   }
 
   template<int StoreMode> 
   void writePacket(Index index, const PacketScalar& x)
   {
-    m_plainObject.const_cast_derived().template writePacket<StoreMode>(index, x);
+    return pstoret<Scalar, PacketScalar, StoreMode>(const_cast<Scalar*>(m_data) + index, x);
   }
 
 protected:
-  const PlainObjectType &m_plainObject;
+  const Scalar *m_data;
+  Index m_outerStride;
 };
 
 template<typename Scalar, int Rows, int Cols, int Options, int MaxRows, int MaxCols>
@@ -231,6 +262,9 @@ struct evaluator_impl<Matrix<Scalar, Rows, Cols, Options, MaxRows, MaxCols> >
 {
   typedef Matrix<Scalar, Rows, Cols, Options, MaxRows, MaxCols> XprType;
 
+  evaluator_impl(void) 
+  { }
+
   evaluator_impl(const XprType& m) 
     : evaluator_impl<PlainObjectBase<XprType> >(m) 
   { }
@@ -242,6 +276,9 @@ struct evaluator_impl<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> >
 {
   typedef Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> XprType;
 
+  evaluator_impl(void) 
+  { }
+
   evaluator_impl(const XprType& m) 
     : evaluator_impl<PlainObjectBase<XprType> >(m) 
   { }
@@ -295,17 +332,25 @@ struct evaluator_impl<EvalToTemp<ArgType> >
   typedef evaluator_impl<PlainObject> BaseType;
 
   evaluator_impl(const XprType& xpr) 
-    : BaseType(m_result)
   { 
-    noalias_copy_using_evaluator(m_result, xpr.arg());
-  };
+    init(xpr.arg());
+  }
 
-  // this constructor is used when nesting an EvalTo evaluator in another evaluator
+  // This constructor is used when nesting an EvalTo evaluator in another evaluator
   evaluator_impl(const ArgType& arg) 
-    : BaseType(m_result)
   { 
+    init(arg);
+  }
+
+protected:
+  void init(const ArgType& arg) 
+  {
+    // We can only initialize the base class evaluator after m_result is initialized.
+    // TODO: Redesign to get rid of inheritance, so that we can remove default c'tors in
+    //       PlainObject, Matrix and Array evaluators.
     noalias_copy_using_evaluator(m_result, arg);
-  };
+    BaseType::init(m_result);
+  }
 
 protected:
   PlainObject m_result;