add a conj_product functor and optimize dot products

3 files changed, 25 insertions, 2 deletions

diff --git a/Eigen/src/Core/Dot.h b/Eigen/src/Core/Dot.h
index 8eaa62185..9fc2fb60e 100644
--- a/Eigen/src/Core/Dot.h
+++ b/Eigen/src/Core/Dot.h
@@ -41,7 +41,7 @@ struct ei_dot_nocheck
 {
   static inline typename ei_traits<T>::Scalar run(const MatrixBase<T>& a, const MatrixBase<U>& b)
   {
-    return a.conjugate().cwiseProduct(b).sum();
+    return a.template binaryExpr<ei_scalar_conj_product_op<typename ei_traits<T>::Scalar> >(b).sum();
   }
 };
 
@@ -50,7 +50,7 @@ struct ei_dot_nocheck<T, U, true>
 {
   static inline typename ei_traits<T>::Scalar run(const MatrixBase<T>& a, const MatrixBase<U>& b)
   {
-    return a.adjoint().cwiseProduct(b).sum();
+    return a.transpose().template binaryExpr<ei_scalar_conj_product_op<typename ei_traits<T>::Scalar> >(b).sum();
   }
 };
 
diff --git a/Eigen/src/Core/Functors.h b/Eigen/src/Core/Functors.h
index 103833447..ac5aa67c4 100644
--- a/Eigen/src/Core/Functors.h
+++ b/Eigen/src/Core/Functors.h
@@ -74,6 +74,28 @@ struct ei_functor_traits<ei_scalar_product_op<Scalar> > {
 };
 
 /** \internal
+  * \brief Template functor to compute the conjugate product of two scalars
+  *
+  * This is a short cut for ei_conj(x) * y which is needed for optimization purpose
+  */
+template<typename Scalar> struct ei_scalar_conj_product_op {
+  enum { Conj = NumTraits<Scalar>::IsComplex };
+  EIGEN_EMPTY_STRUCT_CTOR(ei_scalar_conj_product_op)
+  EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const
+  { return ei_conj_helper<Scalar,Scalar,Conj,false>().pmul(a,b); }
+  template<typename PacketScalar>
+  EIGEN_STRONG_INLINE const PacketScalar packetOp(const PacketScalar& a, const PacketScalar& b) const
+  { return ei_conj_helper<PacketScalar,PacketScalar,Conj,false>().pmul(a,b); }
+};
+template<typename Scalar>
+struct ei_functor_traits<ei_scalar_conj_product_op<Scalar> > {
+  enum {
+    Cost = NumTraits<Scalar>::MulCost,
+    PacketAccess = ei_packet_traits<Scalar>::HasMul
+  };
+};
+
+/** \internal
   * \brief Template functor to compute the min of two scalars
   *
   * \sa class CwiseBinaryOp, MatrixBase::cwiseMin, class VectorwiseOp, MatrixBase::minCoeff()
diff --git a/Eigen/src/Core/util/ForwardDeclarations.h b/Eigen/src/Core/util/ForwardDeclarations.h
index a757bef76..310ffa4b3 100644
--- a/Eigen/src/Core/util/ForwardDeclarations.h
+++ b/Eigen/src/Core/util/ForwardDeclarations.h
@@ -113,6 +113,7 @@ template<typename LhsScalar, typename RhsScalar, bool ConjLhs, bool ConjRhs> str
 template<typename Scalar> struct ei_scalar_sum_op;
 template<typename Scalar> struct ei_scalar_difference_op;
 template<typename Scalar> struct ei_scalar_product_op;
+template<typename Scalar> struct ei_scalar_conj_product_op;
 template<typename Scalar> struct ei_scalar_quotient_op;
 template<typename Scalar> struct ei_scalar_opposite_op;
 template<typename Scalar> struct ei_scalar_conjugate_op;