Math: benchmark vector dot() and cross().

Have to do some precision improvements, so a baseline is needed. The
debug perf is beyond awful, actually.

src/Magnum/Math/Test/CMakeLists.txt

@@ -68,6 +68,7 @@ corrade_add_test(MathInterpolationBenchmark InterpolationBenchmark.cpp LIBRARIES
 corrade_add_test(MathConfigurationValueTest ConfigurationValueTest.cpp LIBRARIES MagnumMathTestLib)
 corrade_add_test(MathStrictWeakOrderingTest StrictWeakOrderingTest.cpp LIBRARIES MagnumMathTestLib)
 
+corrade_add_test(MathVectorBenchmark VectorBenchmark.cpp LIBRARIES MagnumMathTestLib)
 corrade_add_test(MathMatrixBenchmark MatrixBenchmark.cpp LIBRARIES MagnumMathTestLib)
 
 set_property(TARGET

src/Magnum/Math/Test/VectorBenchmark.cpp

@@ -0,0 +1,154 @@
+/*
+    This file is part of Magnum.
+
+    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
+              Vladimír Vondruš <mosra@centrum.cz>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+
+#include <Corrade/TestSuite/Tester.h>
+
+#include "Magnum/Math/Vector3.h"
+
+namespace Magnum { namespace Math { namespace Test { namespace {
+
+struct VectorBenchmark: Corrade::TestSuite::Tester {
+    explicit VectorBenchmark();
+
+    void dot();
+
+    template<class T> void cross2Baseline();
+    void cross2();
+
+    template<class T> void cross3Baseline();
+    void cross3();
+};
+
+VectorBenchmark::VectorBenchmark() {
+    addBenchmarks({
+        &VectorBenchmark::dot,
+
+        &VectorBenchmark::cross2Baseline<Float>,
+        &VectorBenchmark::cross2Baseline<Double>,
+        &VectorBenchmark::cross2,
+
+        &VectorBenchmark::cross3Baseline<Float>,
+        &VectorBenchmark::cross3Baseline<Double>,
+        &VectorBenchmark::cross3,
+    }, 500);
+}
+
+typedef Math::Constants<Float> Constants;
+typedef Math::Vector2<Float> Vector2;
+typedef Math::Vector3<Float> Vector3;
+
+enum: std::size_t { Repeats = 100000 };
+
+using namespace Literals;
+
+void VectorBenchmark::dot() {
+    Vector3 a{1.3f, -1.1f, 1.0f};
+    Vector3 b{4.5f, 3.2f, 7.3f};
+    CORRADE_COMPARE(Math::dot(a, b), 9.63f);
+
+    CORRADE_BENCHMARK(Repeats) {
+        a.x() = Math::dot(a, b);
+    }
+
+    CORRADE_COMPARE(a, (Vector3{Constants::inf(), -1.1f, 1.0f}));
+}
+
+template<class T> inline T cross2Baseline(const Vector2& v1, const Vector2& v2) {
+    T v1x = T(v1.x()),
+      v1y = T(v1.y());
+    T v2x = T(v2.x()),
+      v2y = T(v2.y());
+    return T(v1x*v2y - v1y*v2x);
+}
+
+template<class T> void VectorBenchmark::cross2Baseline() {
+    setTestCaseTemplateName(TypeTraits<T>::name());
+
+    Vector2 a{1.3f, -1.1f};
+    Vector2 b{4.5f, 3.2f};
+    CORRADE_COMPARE(Test::cross2Baseline<T>(a, b), 9.11f);
+
+    CORRADE_BENCHMARK(Repeats) {
+        a.x() = Test::cross2Baseline<T>(a, b);
+    }
+
+    CORRADE_COMPARE(a, (Vector2{Constants::inf(), -1.1f}));
+}
+
+void VectorBenchmark::cross2() {
+    Vector2 a{1.3f, -1.1f};
+    Vector2 b{4.5f, 3.2f};
+    CORRADE_COMPARE(Math::cross(a, b), 9.11f);
+
+    CORRADE_BENCHMARK(Repeats) {
+        a.x() = Math::cross(a, b);
+    }
+
+    CORRADE_COMPARE(a, (Vector2{Constants::inf(), -1.1f}));
+}
+
+template<class T> inline Vector3 cross3Baseline(const Vector3& v1, const Vector3& v2) {
+    T v1x = T(v1.x()),
+      v1y = T(v1.y()),
+      v1z = T(v1.z());
+    T v2x = T(v2.x()),
+      v2y = T(v2.y()),
+      v2z = T(v2.z());
+    return Vector3(v1y*v2z - v1z*v2y,
+                   v1z*v2x - v1x*v2z,
+                   v1x*v2y - v1y*v2x);
+}
+
+template<class T> void VectorBenchmark::cross3Baseline() {
+    setTestCaseTemplateName(TypeTraits<T>::name());
+
+    Vector3 a{1.3f, -1.1f, 1.0f};
+    Vector3 b{4.5f, 3.2f, 7.3f};
+    CORRADE_COMPARE(Test::cross3Baseline<T>(a, b),
+        (Vector3{-11.23f, -4.99f, 9.11f}));
+
+    CORRADE_BENCHMARK(Repeats) {
+        a = Test::cross3Baseline<T>(a, b);
+    }
+
+    CORRADE_VERIFY(a != a);
+}
+
+void VectorBenchmark::cross3() {
+    Vector3 a{1.3f, -1.1f, 1.0f};
+    Vector3 b{4.5f, 3.2f, 7.3f};
+    CORRADE_COMPARE(Math::cross(a, b),
+        (Vector3{-11.23f, -4.99f, 9.11f}));
+
+    CORRADE_BENCHMARK(Repeats) {
+        a = Math::cross(a, b);
+    }
+
+    CORRADE_VERIFY(a != a);
+}
+
+}}}}
+
+CORRADE_TEST_MAIN(Magnum::Math::Test::VectorBenchmark)