From 1aa2bf82741f2f51fbf0a29ff95e0d017f6962a3 Mon Sep 17 00:00:00 2001
From: Benoit Steiner <benoit.steiner.goog@gmail.com>
Date: Wed, 13 Aug 2014 08:27:58 -0700
Subject: [PATCH] Support for in place evaluation of expressions containing
 slicing and reshaping operations

---
 .../Eigen/CXX11/src/Tensor/TensorMorphing.h   | 30 ++++++++++++++-----
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
index 3b42c8514..2b1b503cf 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
@@ -103,13 +103,14 @@ struct TensorEvaluator<const TensorReshapingOp<NewDimensions, ArgType>, Device>
   { }
 
   typedef typename XprType::Index Index;
+  typedef typename XprType::Scalar Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename XprType::PacketReturnType PacketReturnType;
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
 
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void evalSubExprsIfNeeded() {
-    m_impl.evalSubExprsIfNeeded();
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar* data) {
+    return m_impl.evalSubExprsIfNeeded(data);
   }
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void cleanup() {
     m_impl.cleanup();
@@ -126,6 +127,8 @@ struct TensorEvaluator<const TensorReshapingOp<NewDimensions, ArgType>, Device>
     return m_impl.template packet<LoadMode>(index);
   }
 
+  Scalar* data() const { return NULL; }
+
  protected:
   NewDimensions m_dimensions;
   TensorEvaluator<ArgType, Device> m_impl;
@@ -150,13 +153,14 @@ struct TensorEvaluator<TensorReshapingOp<NewDimensions, ArgType>, Device>
   { }
 
   typedef typename XprType::Index Index;
+  typedef typename XprType::Scalar Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename XprType::PacketReturnType PacketReturnType;
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
 
-    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void evalSubExprsIfNeeded() {
-    m_impl.evalSubExprsIfNeeded();
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar* data) {
+    return m_impl.evalSubExprsIfNeeded(data);
   }
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void cleanup() {
     m_impl.cleanup();
@@ -182,6 +186,8 @@ struct TensorEvaluator<TensorReshapingOp<NewDimensions, ArgType>, Device>
     return m_impl.template packet<LoadMode>(index);
   }
 
+  Scalar* data() const { return NULL; }
+
  private:
   NewDimensions m_dimensions;
   TensorEvaluator<ArgType, Device> m_impl;
@@ -306,14 +312,16 @@ struct TensorEvaluator<const TensorSlicingOp<StartIndices, Sizes, ArgType>, Devi
   }
 
   typedef typename XprType::Index Index;
+  typedef typename XprType::Scalar Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename XprType::PacketReturnType PacketReturnType;
   typedef Sizes Dimensions;
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
 
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void evalSubExprsIfNeeded() {
-    m_impl.evalSubExprsIfNeeded();
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar*) {
+    m_impl.evalSubExprsIfNeeded(NULL);
+    return true;
   }
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void cleanup() {
     m_impl.cleanup();
@@ -366,6 +374,8 @@ struct TensorEvaluator<const TensorSlicingOp<StartIndices, Sizes, ArgType>, Devi
     }
   }
 
+  Scalar* data() const { return NULL; }
+
  private:
   Dimensions m_dimensions;
   array<Index, NumDims> m_outputStrides;
@@ -415,14 +425,16 @@ struct TensorEvaluator<TensorSlicingOp<StartIndices, Sizes, ArgType>, Device>
   }
 
   typedef typename XprType::Index Index;
+  typedef typename XprType::Scalar Scalar;
   typedef typename XprType::CoeffReturnType CoeffReturnType;
   typedef typename XprType::PacketReturnType PacketReturnType;
   typedef Sizes Dimensions;
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
 
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void evalSubExprsIfNeeded() {
-    m_impl.evalSubExprsIfNeeded();
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(Scalar*) {
+    m_impl.evalSubExprsIfNeeded(NULL);
+    return true;
   }
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void cleanup() {
     m_impl.cleanup();
@@ -515,6 +527,8 @@ struct TensorEvaluator<TensorSlicingOp<StartIndices, Sizes, ArgType>, Device>
     }
   }
 
+  Scalar* data() const { return NULL; }
+
  private:
   Dimensions m_dimensions;
   array<Index, NumDims> m_outputStrides;