bug #1520: workaround some -Wfloat-equal warnings by calling std::equal_to

3 files changed, 25 insertions, 5 deletions

diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index 84f9d0cd5..ac1b7a6a1 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -473,11 +473,11 @@ namespace std_fallback {
 
     EIGEN_USING_STD_MATH(exp);
     Scalar u = exp(x);
-    if (u == Scalar(1)) {
+    if (numext::equal_strict(u, Scalar(1))) {
       return x;
     }
     Scalar um1 = u - RealScalar(1);
-    if (um1 == Scalar(-1)) {
+    if (numext::equal_strict(um1, Scalar(-1))) {
       return RealScalar(-1);
     }
 
@@ -519,7 +519,7 @@ 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 2bb3d0d9b..c10550050 100644
--- a/Eigen/src/Core/arch/CUDA/Half.h
+++ b/Eigen/src/Core/arch/CUDA/Half.h
@@ -299,10 +299,10 @@ 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 998b8921a..e7729fdc8 100755
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -543,6 +543,26 @@ 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