From 8e5da71466591cc24352782b08dc78ddb94f0717 Mon Sep 17 00:00:00 2001
From: Christoph Hertzberg <chtz@informatik.uni-bremen.de>
Date: Fri, 13 Dec 2019 22:46:40 +0100
Subject: [PATCH] Resolve double-promotion warnings when compiling with clang.
 `sin` was calling `sin(double)` instead of `std::sin(float)`

---
 Eigen/src/Core/MathFunctions.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index dadf2cba2..dde329007 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -540,8 +540,11 @@ struct expm1_impl<std::complex<RealScalar> > {
     //          = exp(x) * cos(y) - 1.
     //          = expm1(x) + exp(x) * (cos(y) - 1)
     //          = expm1(x) + exp(x) * (2 * sin(y / 2) ** 2)
-    RealScalar erm1 = std_fallback::expm1(xr);
+
+    // TODO better use numext::expm1 and numext::sin (but that would require forward declarations or moving this specialization down).
+    RealScalar erm1 = expm1_impl<RealScalar>::run(xr);
     RealScalar er = erm1 + RealScalar(1.);
+    EIGEN_USING_STD_MATH(sin);
     RealScalar sin2 = sin(xi / RealScalar(2.));
     sin2 = sin2 * sin2;
     RealScalar s = sin(xi);