Add gmx::isPowerOfTwo function

[alexxy/gromacs.git] / src / gromacs / math / tests / functions.cpp

diff --git a/src/gromacs/math/tests/functions.cpp b/src/gromacs/math/tests/functions.cpp
index b444ee78412448af973b9f75c279a9002f4314c0..939a08da2eb5f5c8fee3575e1c6161cc7cd0466b 100644 (file)
--- a/src/gromacs/math/tests/functions.cpp
+++ b/src/gromacs/math/tests/functions.cpp
@@ -1,7 +1,8 @@
 /*
  * This file is part of the GROMACS molecular simulation package.
  *
- * Copyright (c) 2015,2016,2017,2018,2019, by the GROMACS development team, led by
+ * Copyright (c) 2015,2016,2017,2018,2019 by the GROMACS development team.
+ * Copyright (c) 2021, by the GROMACS development team, led by
  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
  * and including many others, as listed in the AUTHORS file in the
  * top-level source directory and at http://www.gromacs.org.
@@ -356,4 +357,37 @@ TEST(FunctionTest, ErfAndErfInvAreInversesDouble)
     }
 }
 
+template<typename T>
+class FunctionTestIntegerTypes : public ::testing::Test
+{
+};
+
+typedef ::testing::Types<char, unsigned char, int, unsigned int, long, unsigned long> IntegerTypes;
+TYPED_TEST_CASE(FunctionTestIntegerTypes, IntegerTypes);
+
+TYPED_TEST(FunctionTestIntegerTypes, IsPowerOfTwo)
+{
+    if (std::is_signed_v<TypeParam>)
+    {
+        EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(std::numeric_limits<TypeParam>::min()));
+        EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(-16));
+        EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(-3));
+        EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(-2));
+        EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(-1));
+    }
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(0));
+    EXPECT_EQ(true, gmx::isPowerOfTwo<TypeParam>(1));
+    EXPECT_EQ(true, gmx::isPowerOfTwo<TypeParam>(2));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(3));
+    EXPECT_EQ(true, gmx::isPowerOfTwo<TypeParam>(4));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(5));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(6));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(24));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(63));
+    EXPECT_EQ(true, gmx::isPowerOfTwo<TypeParam>(64));
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(66));
+    // Max for any type is always 2^x - 1
+    EXPECT_EQ(false, gmx::isPowerOfTwo<TypeParam>(std::numeric_limits<TypeParam>::max()));
+}
+
 } // namespace