From ed1962b464119395d23fa7deeb9b7e77b0c05d18 Mon Sep 17 00:00:00 2001
From: Benoit Steiner <benoit.steiner.goog@gmail.com>
Date: Fri, 6 Nov 2015 09:18:43 -0800
Subject: [PATCH] Reimplement the tensor comparison operators by using the
 scalar_cmp_op functors. This makes them more cuda friendly.

---
 Eigen/src/Core/functors/BinaryFunctors.h        | 8 ++++++++
 Eigen/src/Core/util/Constants.h                 | 4 +++-
 unsupported/Eigen/CXX11/src/Tensor/TensorBase.h | 8 ++++----
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/Eigen/src/Core/functors/BinaryFunctors.h b/Eigen/src/Core/functors/BinaryFunctors.h
index cc0e80a33..f77066910 100644
--- a/Eigen/src/Core/functors/BinaryFunctors.h
+++ b/Eigen/src/Core/functors/BinaryFunctors.h
@@ -186,6 +186,14 @@ template<typename Scalar> struct scalar_cmp_op<Scalar, cmp_LE> {
   EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const Scalar& a, const Scalar& b) const {return a<=b;}
 };
+template<typename Scalar> struct scalar_cmp_op<Scalar, cmp_GT> {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const Scalar& a, const Scalar& b) const {return a>b;}
+};
+template<typename Scalar> struct scalar_cmp_op<Scalar, cmp_GE> {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const Scalar& a, const Scalar& b) const {return a>=b;}
+};
 template<typename Scalar> struct scalar_cmp_op<Scalar, cmp_UNORD> {
   EIGEN_EMPTY_STRUCT_CTOR(scalar_cmp_op)
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE bool operator()(const Scalar& a, const Scalar& b) const {return !(a<=b || b<=a);}
diff --git a/Eigen/src/Core/util/Constants.h b/Eigen/src/Core/util/Constants.h
index c35077af6..28852c8c3 100644
--- a/Eigen/src/Core/util/Constants.h
+++ b/Eigen/src/Core/util/Constants.h
@@ -531,7 +531,9 @@ enum ComparisonName {
   cmp_LT = 1,
   cmp_LE = 2,
   cmp_UNORD = 3,
-  cmp_NEQ = 4
+  cmp_NEQ = 4,
+  cmp_GT = 5,
+  cmp_GE = 6
 };
 } // end namespace internal
 
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorBase.h b/unsupported/Eigen/CXX11/src/Tensor/TensorBase.h
index ceced984b..906687436 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorBase.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorBase.h
@@ -257,12 +257,12 @@ class TensorBase<Derived, ReadOnlyAccessors>
     template<typename OtherDerived> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     const TensorCwiseBinaryOp<std::less<Scalar>, const Derived, const OtherDerived>
     operator<(const OtherDerived& other) const {
-      return binaryExpr(other.derived(), std::less<Scalar>());
+      return binaryExpr(other.derived(), internal::scalar_cmp_op<Scalar, internal::cmp_LT>());
     }
     template<typename OtherDerived> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     const TensorCwiseBinaryOp<std::less_equal<Scalar>, const Derived, const OtherDerived>
     operator<=(const OtherDerived& other) const {
-      return binaryExpr(other.derived(), std::less_equal<Scalar>());
+      return binaryExpr(other.derived(), internal::scalar_cmp_op<Scalar, internal::cmp_LE>());
     }
     template<typename OtherDerived> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     const TensorCwiseBinaryOp<std::greater<Scalar>, const Derived, const OtherDerived>
@@ -278,12 +278,12 @@ class TensorBase<Derived, ReadOnlyAccessors>
     template<typename OtherDerived> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     const TensorCwiseBinaryOp<std::equal_to<Scalar>, const Derived, const OtherDerived>
     operator==(const OtherDerived& other) const {
-      return binaryExpr(other.derived(), std::equal_to<Scalar>());
+      return binaryExpr(other.derived(), internal::scalar_cmp_op<Scalar, internal::cmp_EQ>());
     }
     template<typename OtherDerived> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
     const TensorCwiseBinaryOp<std::not_equal_to<Scalar>, const Derived, const OtherDerived>
     operator!=(const OtherDerived& other) const {
-      return binaryExpr(other.derived(), std::not_equal_to<Scalar>());
+      return binaryExpr(other.derived(), internal::scalar_cmp_op<Scalar, internal::cmp_NEQ>());
     }
 
     // comparisons and tests for Scalars