Math: added function fma().

src/Math/Functions.h

@@ -280,6 +280,22 @@ template<std::size_t size, class T, class U> inline Vector<size, T> lerp(const V
 }
 #endif
 
+/**
+@brief Fused multiply-add
+
+Computes and returns @f$ ab + c @f$.
+*/
+#ifdef DOXYGEN_GENERATING_OUTPUT
+template<class T> inline T fma(const T& a, const T& b, const T& c);
+#else
+template<class T> inline typename std::enable_if<std::is_arithmetic<T>::value, T>::type fma(T a, T b, T c) {
+    return std::fma(a, b, c);
+}
+template<std::size_t size, class T> inline Vector<size, T> fma(const Vector<size, T>& a, const Vector<size, T>& b, const Vector<size, T>& c) {
+    return a*b + c;
+}
+#endif
+
 /**
 @brief Normalize integral value
 

src/Math/Test/FunctionsTest.cpp

@@ -41,6 +41,7 @@ class FunctionsTest: public Corrade::TestSuite::Tester {
         void sqrtInverted();
         void clamp();
         void lerp();
+        void fma();
         void normalizeUnsigned();
         void normalizeSigned();
         void denormalizeUnsigned();
@@ -74,6 +75,7 @@ FunctionsTest::FunctionsTest() {
               &FunctionsTest::sqrtInverted,
               &FunctionsTest::clamp,
               &FunctionsTest::lerp,
+              &FunctionsTest::fma,
               &FunctionsTest::normalizeUnsigned,
               &FunctionsTest::normalizeSigned,
               &FunctionsTest::denormalizeUnsigned,
@@ -148,6 +150,14 @@ void FunctionsTest::lerp() {
     CORRADE_COMPARE(Math::lerp(c, d, 0.25f), Vector3ub(4, 96, 56));
 }
 
+void FunctionsTest::fma() {
+    CORRADE_COMPARE(Math::fma(2.0f, 3.0f, 0.75f), 6.75f);
+    CORRADE_COMPARE(Math::fma(Vector3( 2.0f,  1.5f,  0.5f),
+                              Vector3( 3.0f,  2.0f, -1.0f),
+                              Vector3(0.75f, 0.25f,  0.1f)),
+                              Vector3(6.75f, 3.25f, -0.4f));
+}
+
 void FunctionsTest::normalizeUnsigned() {
     CORRADE_COMPARE((Math::normalize<Float, UnsignedByte>(0)), 0.0f);
     CORRADE_COMPARE((Math::normalize<Float, UnsignedByte>(255)), 1.0f);