Eigen cost model part 1. This implements a basic recursive framework to estimate the cost of evaluating tensor expressions.

1 files changed, 13 insertions, 0 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h b/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
index b7c13f67f..ccaa757d1 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorFunctors.h
@@ -594,6 +594,8 @@ template <> class UniformRandomGenerator<std::complex<double> > {
 template <typename Scalar>
 struct functor_traits<UniformRandomGenerator<Scalar> > {
   enum {
+    // Rough estimate.
+    Cost = 100 * NumTraits<Scalar>::MulCost,
     PacketAccess = UniformRandomGenerator<Scalar>::PacketAccess
   };
 };
@@ -774,6 +776,8 @@ template <typename T> class NormalRandomGenerator {
 template <typename Scalar>
 struct functor_traits<NormalRandomGenerator<Scalar> > {
   enum {
+    // Rough estimate.
+    Cost = 100 * NumTraits<Scalar>::MulCost,
     PacketAccess = NormalRandomGenerator<Scalar>::PacketAccess
   };
 };
@@ -807,6 +811,15 @@ class GaussianGenerator {
   array<T, NumDims> m_two_sigmas;
 };
 
+template <typename T, typename Index, size_t NumDims>
+struct functor_traits<GaussianGenerator<T, Index, NumDims> > {
+  enum {
+    Cost = NumDims * (2 * NumTraits<T>::AddCost + NumTraits<T>::MulCost +
+                      functor_traits<scalar_quotient_op<T, T> >::Cost) +
+           functor_traits<scalar_exp_op<T> >::Cost,
+    PacketAccess = GaussianGenerator<T, Index, NumDims>::PacketAccess
+  };
+};
 
 } // end namespace internal
 } // end namespace Eigen