/* * Copyright (c) 2019, 2020, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ #include "precompiled.hpp" #include "utilities/globalDefinitions.hpp" #include "utilities/powerOfTwo.hpp" #include <limits> #include <type_traits> #include "unittest.hpp" struct StaticTestIsPowerOf2Result { uint64_t _value; int _status; // 0: success, > 0 indicates which failure case constexpr StaticTestIsPowerOf2Result(uint64_t value, int status) : _value(value), _status(status) {} }; // Structure copied from test_is_power_of_2 runtime test (below). template<typename T> static constexpr StaticTestIsPowerOf2Result static_test_is_power_of_2_aux(T v) { using Result = StaticTestIsPowerOf2Result; for ( ; v > 0; v >>= 1) { if (!is_power_of_2(v)) { return Result(v, 1); } else if ((v > 2) && is_power_of_2(T(v - 1))) { return Result(v, 2); } else if ((v > 1) && is_power_of_2(T(v + 1))) { return Result(v, 3); } } return Result(v, 0); } template<typename T> static void static_test_is_power_of_2() { constexpr StaticTestIsPowerOf2Result result = static_test_is_power_of_2_aux(max_power_of_2<T>()); EXPECT_EQ(0, result._status) << "value = " << result._value << ", status = " << result._status; } template <typename T> static void test_is_power_of_2() { EXPECT_FALSE(is_power_of_2(T(0))); EXPECT_FALSE(is_power_of_2(~T(0))); static_assert(!is_power_of_2(T(0)), ""); static_assert(!is_power_of_2(~T(0)), ""); // Should be false regardless of whether T is signed or unsigned. EXPECT_FALSE(is_power_of_2(std::numeric_limits<T>::min())); static_assert(!is_power_of_2(std::numeric_limits<T>::min()), ""); // Test true for (T i = max_power_of_2<T>(); i > 0; i = (i >> 1)) { EXPECT_TRUE(is_power_of_2(i)) << "value = " << T(i); } // Test one less for (T i = max_power_of_2<T>(); i > 2; i = (i >> 1)) { EXPECT_FALSE(is_power_of_2(i - 1)) << "value = " << T(i - 1); } // Test one more for (T i = max_power_of_2<T>(); i > 1; i = (i >> 1)) { EXPECT_FALSE(is_power_of_2(i + 1)) << "value = " << T(i + 1); } static_test_is_power_of_2<T>(); } TEST(power_of_2, is_power_of_2) { test_is_power_of_2<int8_t>(); test_is_power_of_2<int16_t>(); test_is_power_of_2<int32_t>(); test_is_power_of_2<int64_t>(); test_is_power_of_2<int8_t>(); test_is_power_of_2<int16_t>(); test_is_power_of_2<int32_t>(); test_is_power_of_2<int64_t>(); test_is_power_of_2<jint>(); test_is_power_of_2<jlong>(); } TEST(power_of_2, exact_log2) { { uintptr_t j = 1; #ifdef _LP64 for (int i = 0; i < 64; i++, j <<= 1) { #else for (int i = 0; i < 32; i++, j <<= 1) { #endif EXPECT_EQ(i, exact_log2(j)); } } { julong j = 1; for (int i = 0; i < 64; i++, j <<= 1) { EXPECT_EQ(i, exact_log2_long(j)); } } } template <typename T> void round_up_power_of_2() { EXPECT_EQ(round_up_power_of_2(T(1)), T(1)) << "value = " << T(1); EXPECT_EQ(round_up_power_of_2(T(2)), T(2)) << "value = " << T(2); EXPECT_EQ(round_up_power_of_2(T(3)), T(4)) << "value = " << T(3); EXPECT_EQ(round_up_power_of_2(T(4)), T(4)) << "value = " << T(4); EXPECT_EQ(round_up_power_of_2(T(5)), T(8)) << "value = " << T(5); EXPECT_EQ(round_up_power_of_2(T(6)), T(8)) << "value = " << T(6); EXPECT_EQ(round_up_power_of_2(T(7)), T(8)) << "value = " << T(7); EXPECT_EQ(round_up_power_of_2(T(8)), T(8)) << "value = " << T(8); EXPECT_EQ(round_up_power_of_2(T(9)), T(16)) << "value = " << T(9); EXPECT_EQ(round_up_power_of_2(T(10)), T(16)) << "value = " << T(10); T t_max_pow2 = max_power_of_2<T>(); // round_up(any power of two) should return input for (T pow2 = T(1); pow2 < t_max_pow2; pow2 *= 2) { EXPECT_EQ(pow2, round_up_power_of_2(pow2)) << "value = " << pow2; } EXPECT_EQ(round_up_power_of_2(t_max_pow2), t_max_pow2) << "value = " << (t_max_pow2); // For each pow2 gt 2, round_up(pow2 - 1) should return pow2 for (T pow2 = T(4); pow2 < t_max_pow2; pow2 *= 2) { EXPECT_EQ(pow2, round_up_power_of_2(pow2 - 1)) << "value = " << pow2; } EXPECT_EQ(round_up_power_of_2(t_max_pow2 - 1), t_max_pow2) << "value = " << (t_max_pow2 - 1); } TEST(power_of_2, round_up_power_of_2) { round_up_power_of_2<int8_t>(); round_up_power_of_2<int16_t>(); round_up_power_of_2<int32_t>(); round_up_power_of_2<int64_t>(); round_up_power_of_2<uint8_t>(); round_up_power_of_2<uint16_t>(); round_up_power_of_2<uint32_t>(); round_up_power_of_2<uint64_t>(); } template <typename T> void round_down_power_of_2() { EXPECT_EQ(round_down_power_of_2(T(1)), T(1)) << "value = " << T(1); EXPECT_EQ(round_down_power_of_2(T(2)), T(2)) << "value = " << T(2); EXPECT_EQ(round_down_power_of_2(T(3)), T(2)) << "value = " << T(3); EXPECT_EQ(round_down_power_of_2(T(4)), T(4)) << "value = " << T(4); EXPECT_EQ(round_down_power_of_2(T(5)), T(4)) << "value = " << T(5); EXPECT_EQ(round_down_power_of_2(T(6)), T(4)) << "value = " << T(6); EXPECT_EQ(round_down_power_of_2(T(7)), T(4)) << "value = " << T(7); EXPECT_EQ(round_down_power_of_2(T(8)), T(8)) << "value = " << T(8); EXPECT_EQ(round_down_power_of_2(T(9)), T(8)) << "value = " << T(9); EXPECT_EQ(round_down_power_of_2(T(10)), T(8)) << "value = " << T(10); T t_max_pow2 = max_power_of_2<T>(); // For each pow2 >= 2: // - round_down(pow2) should return pow2 // - round_down(pow2 + 1) should return pow2 // - round_down(pow2 - 1) should return pow2 / 2 for (T pow2 = T(2); pow2 < t_max_pow2; pow2 = pow2 * 2) { EXPECT_EQ(pow2, round_down_power_of_2(pow2)) << "value = " << pow2; EXPECT_EQ(pow2, round_down_power_of_2(pow2 + 1)) << "value = " << pow2; EXPECT_EQ(pow2 / 2, round_down_power_of_2(pow2 - 1)) << "value = " << (pow2 / 2); } EXPECT_EQ(round_down_power_of_2(t_max_pow2), t_max_pow2) << "value = " << (t_max_pow2); EXPECT_EQ(round_down_power_of_2(t_max_pow2 + 1), t_max_pow2) << "value = " << (t_max_pow2 + 1); EXPECT_EQ(round_down_power_of_2(t_max_pow2 - 1), t_max_pow2 / 2) << "value = " << (t_max_pow2 - 1); } TEST(power_of_2, round_down_power_of_2) { round_down_power_of_2<int8_t>(); round_down_power_of_2<int16_t>(); round_down_power_of_2<int32_t>(); round_down_power_of_2<int64_t>(); round_down_power_of_2<uint8_t>(); round_down_power_of_2<uint16_t>(); round_down_power_of_2<uint32_t>(); round_down_power_of_2<uint64_t>(); } template <typename T> void next_power_of_2() { EXPECT_EQ(next_power_of_2(T(0)), T(1)) << "value = " << T(0); EXPECT_EQ(next_power_of_2(T(1)), T(2)) << "value = " << T(1); EXPECT_EQ(next_power_of_2(T(2)), T(4)) << "value = " << T(2); EXPECT_EQ(next_power_of_2(T(3)), T(4)) << "value = " << T(3); EXPECT_EQ(next_power_of_2(T(4)), T(8)) << "value = " << T(4); EXPECT_EQ(next_power_of_2(T(5)), T(8)) << "value = " << T(5); EXPECT_EQ(next_power_of_2(T(6)), T(8)) << "value = " << T(6); EXPECT_EQ(next_power_of_2(T(7)), T(8)) << "value = " << T(7); EXPECT_EQ(next_power_of_2(T(8)), T(16)) << "value = " << T(8); EXPECT_EQ(next_power_of_2(T(9)), T(16)) << "value = " << T(9); EXPECT_EQ(next_power_of_2(T(10)), T(16)) << "value = " << T(10); T t_max_pow2 = max_power_of_2<T>(); // next(pow2 - 1) should return pow2 for (T pow2 = T(1); pow2 < t_max_pow2; pow2 = pow2 * 2) { EXPECT_EQ(pow2, next_power_of_2(pow2 - 1)) << "value = " << pow2 - 1; } EXPECT_EQ(next_power_of_2(t_max_pow2 - 1), t_max_pow2) << "value = " << (t_max_pow2 - 1); // next(pow2) should return pow2 * 2 for (T pow2 = T(1); pow2 < t_max_pow2 / 2; pow2 = pow2 * 2) { EXPECT_EQ(pow2 * 2, next_power_of_2(pow2)) << "value = " << pow2; } } TEST(power_of_2, next_power_of_2) { next_power_of_2<int8_t>(); next_power_of_2<int16_t>(); next_power_of_2<int32_t>(); next_power_of_2<int64_t>(); next_power_of_2<uint8_t>(); next_power_of_2<uint16_t>(); next_power_of_2<uint32_t>(); next_power_of_2<uint64_t>(); } TEST(power_of_2, max) { EXPECT_EQ(max_power_of_2<int8_t>(), 0x40); EXPECT_EQ(max_power_of_2<int16_t>(), 0x4000); EXPECT_EQ(max_power_of_2<int32_t>(), 0x40000000); EXPECT_EQ(max_power_of_2<int64_t>(), CONST64(0x4000000000000000)); EXPECT_EQ(max_power_of_2<uint8_t>(), 0x80u); EXPECT_EQ(max_power_of_2<uint16_t>(), 0x8000u); EXPECT_EQ(max_power_of_2<uint32_t>(), 0x80000000u); EXPECT_EQ(max_power_of_2<uint64_t>(), UCONST64(0x8000000000000000)); }