From 1c4fdad7bd6ffcb6e6f6fbbc00b01585d71062d3 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Wed, 11 Apr 2018 15:24:13 +0200
Subject: [PATCH] bug #1520: workaround some -Wfloat-equal warnings by calling
 std::equal_to

---
 Eigen/src/Core/MathFunctions.h  |  2 +-
 Eigen/src/Core/arch/CUDA/Half.h |  4 ++--
 Eigen/src/Core/util/Meta.h      | 20 ++++++++++++++++++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index 0257b3f4f..6eb974d41 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -471,7 +471,7 @@ namespace std_fallback {
     typedef typename NumTraits<Scalar>::Real RealScalar;
     EIGEN_USING_STD_MATH(log);
     Scalar x1p = RealScalar(1) + x;
-    return ( x1p == Scalar(1) ) ? x : x * ( log(x1p) / (x1p - RealScalar(1)) );
+    return numext::equal_strict(x1p, Scalar(1)) ? x : x * ( log(x1p) / (x1p - RealScalar(1)) );
   }
 }
 
diff --git a/Eigen/src/Core/arch/CUDA/Half.h b/Eigen/src/Core/arch/CUDA/Half.h
index d9b3cb9b1..02ac0c23a 100644
--- a/Eigen/src/Core/arch/CUDA/Half.h
+++ b/Eigen/src/Core/arch/CUDA/Half.h
@@ -238,10 +238,10 @@ EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC half& operator /= (half& a, const half& b)
   return a;
 }
 EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC bool operator == (const half& a, const half& b) {
-  return float(a) == float(b);
+  return numext::equal_strict(float(a),float(b));
 }
 EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC bool operator != (const half& a, const half& b) {
-  return float(a) != float(b);
+  return numext::not_equal_strict(float(a), float(b));
 }
 EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC bool operator < (const half& a, const half& b) {
   return float(a) < float(b);
diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 7f6370755..4e4ea9ab1 100755
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -485,6 +485,26 @@ T div_ceil(const T &a, const T &b)
   return (a+b-1) / b;
 }
 
+// The aim of the following functions is to bypass -Wfloat-equal warnings
+// when we really want a strict equality comparison on floating points.
+template<typename X, typename Y>
+bool equal_strict(const X& x,const Y& y) { return x == y; }
+
+template<>
+bool equal_strict(const float& x,const float& y) { return std::equal_to<float>()(x,y); }
+
+template<>
+bool equal_strict(const double& x,const double& y) { return std::equal_to<double>()(x,y); }
+
+template<typename X, typename Y>
+bool not_equal_strict(const X& x,const Y& y) { return x != y; }
+
+template<>
+bool not_equal_strict(const float& x,const float& y) { return std::not_equal_to<float>()(x,y); }
+
+template<>
+bool not_equal_strict(const double& x,const double& y) { return std::not_equal_to<double>()(x,y); }
+
 } // end namespace numext
 
 } // end namespace Eigen