From 95b1cdbbfed628a49fd00c4ab18fd0e4f59b8e9f Mon Sep 17 00:00:00 2001
From: Christophe Riccio <christophe.riccio@unity3d.com>
Date: Wed, 6 Nov 2019 10:56:44 +0100
Subject: [PATCH] Added fma implementation based on std::fma #969

---
 glm/detail/func_common.inl | 14 +++++++++-----
 readme.md                  |  1 +
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/glm/detail/func_common.inl b/glm/detail/func_common.inl
index 85b9ae73..8a7681c4 100644
--- a/glm/detail/func_common.inl
+++ b/glm/detail/func_common.inl
@@ -737,11 +737,15 @@ namespace detail
 		return reinterpret_cast<vec<L, float, Q>&>(const_cast<vec<L, uint, Q>&>(v));
 	}
 
-	template<typename genType>
-	GLM_FUNC_QUALIFIER genType fma(genType const& a, genType const& b, genType const& c)
-	{
-		return a * b + c;
-	}
+#	if GLM_HAS_CXX11_STL
+		using std::fma;
+#	else
+		template<typename genType>
+		GLM_FUNC_QUALIFIER genType fma(genType const& a, genType const& b, genType const& c)
+		{
+			return a * b + c;
+		}
+#	endif
 
 	template<typename genType>
 	GLM_FUNC_QUALIFIER genType frexp(genType x, int& exp)
diff --git a/readme.md b/readme.md
index 8440d5f5..f038fad2 100644
--- a/readme.md
+++ b/readme.md
@@ -57,6 +57,7 @@ glm::mat4 camera(float Translate, glm::vec2 const& Rotate)
 #### Improvements:
 - Improved Neon support with more functions optimized #950
 - Added CMake GLM interface #963
+- Added fma implementation based on std::fma #969
 
 #### Fixes:
 - Fixed equal ULP variation when using negative sign #965