// Copyright 2021 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "src/tint/utils/math.h"

#include "gtest/gtest.h"

namespace tint::utils {
namespace {

TEST(MathTests, RoundUp) {
    EXPECT_EQ(RoundUp(1, 0), 0);
    EXPECT_EQ(RoundUp(1, 1), 1);
    EXPECT_EQ(RoundUp(1, 2), 2);

    EXPECT_EQ(RoundUp(1, 1), 1);
    EXPECT_EQ(RoundUp(2, 1), 2);
    EXPECT_EQ(RoundUp(3, 1), 3);
    EXPECT_EQ(RoundUp(4, 1), 4);

    EXPECT_EQ(RoundUp(1, 2), 2);
    EXPECT_EQ(RoundUp(2, 2), 2);
    EXPECT_EQ(RoundUp(3, 2), 3);
    EXPECT_EQ(RoundUp(4, 2), 4);

    EXPECT_EQ(RoundUp(1, 3), 3);
    EXPECT_EQ(RoundUp(2, 3), 4);
    EXPECT_EQ(RoundUp(3, 3), 3);
    EXPECT_EQ(RoundUp(4, 3), 4);

    EXPECT_EQ(RoundUp(1, 4), 4);
    EXPECT_EQ(RoundUp(2, 4), 4);
    EXPECT_EQ(RoundUp(3, 4), 6);
    EXPECT_EQ(RoundUp(4, 4), 4);
}

TEST(MathTests, IsPowerOfTwo) {
    EXPECT_EQ(IsPowerOfTwo(1), true);
    EXPECT_EQ(IsPowerOfTwo(2), true);
    EXPECT_EQ(IsPowerOfTwo(3), false);
    EXPECT_EQ(IsPowerOfTwo(4), true);
    EXPECT_EQ(IsPowerOfTwo(5), false);
    EXPECT_EQ(IsPowerOfTwo(6), false);
    EXPECT_EQ(IsPowerOfTwo(7), false);
    EXPECT_EQ(IsPowerOfTwo(8), true);
    EXPECT_EQ(IsPowerOfTwo(9), false);
}

TEST(MathTests, Log2) {
    EXPECT_EQ(Log2(1), 0u);
    EXPECT_EQ(Log2(2), 1u);
    EXPECT_EQ(Log2(3), 1u);
    EXPECT_EQ(Log2(4), 2u);
    EXPECT_EQ(Log2(5), 2u);
    EXPECT_EQ(Log2(6), 2u);
    EXPECT_EQ(Log2(7), 2u);
    EXPECT_EQ(Log2(8), 3u);
    EXPECT_EQ(Log2(9), 3u);
    EXPECT_EQ(Log2(0x7fffffffu), 30u);
    EXPECT_EQ(Log2(0x80000000u), 31u);
    EXPECT_EQ(Log2(0x80000001u), 31u);
    EXPECT_EQ(Log2(0x7fffffffffffffffu), 62u);
    EXPECT_EQ(Log2(0x8000000000000000u), 63u);

    static_assert(Log2(1) == 0u);
    static_assert(Log2(2) == 1u);
    static_assert(Log2(3) == 1u);
    static_assert(Log2(4) == 2u);
    static_assert(Log2(5) == 2u);
    static_assert(Log2(6) == 2u);
    static_assert(Log2(7) == 2u);
    static_assert(Log2(8) == 3u);
    static_assert(Log2(9) == 3u);
    static_assert(Log2(0x7fffffffu) == 30u);
    static_assert(Log2(0x80000000u) == 31u);
    static_assert(Log2(0x80000001u) == 31u);
    static_assert(Log2(0x7fffffffffffffffu) == 62u);
    static_assert(Log2(0x8000000000000000u) == 63u);
}

TEST(MathTests, NextPowerOfTwo) {
    EXPECT_EQ(NextPowerOfTwo(0), 1u);
    EXPECT_EQ(NextPowerOfTwo(1), 1u);
    EXPECT_EQ(NextPowerOfTwo(2), 2u);
    EXPECT_EQ(NextPowerOfTwo(3), 4u);
    EXPECT_EQ(NextPowerOfTwo(4), 4u);
    EXPECT_EQ(NextPowerOfTwo(5), 8u);
    EXPECT_EQ(NextPowerOfTwo(6), 8u);
    EXPECT_EQ(NextPowerOfTwo(7), 8u);
    EXPECT_EQ(NextPowerOfTwo(8), 8u);
    EXPECT_EQ(NextPowerOfTwo(9), 16u);
    EXPECT_EQ(NextPowerOfTwo(0x7fffffffu), 0x80000000u);
    EXPECT_EQ(NextPowerOfTwo(0x80000000u), 0x80000000u);
    EXPECT_EQ(NextPowerOfTwo(0x80000001u), 0x100000000u);
    EXPECT_EQ(NextPowerOfTwo(0x7fffffffffffffffu), 0x8000000000000000u);

    static_assert(NextPowerOfTwo(0) == 1u);
    static_assert(NextPowerOfTwo(1) == 1u);
    static_assert(NextPowerOfTwo(2) == 2u);
    static_assert(NextPowerOfTwo(3) == 4u);
    static_assert(NextPowerOfTwo(4) == 4u);
    static_assert(NextPowerOfTwo(5) == 8u);
    static_assert(NextPowerOfTwo(6) == 8u);
    static_assert(NextPowerOfTwo(7) == 8u);
    static_assert(NextPowerOfTwo(8) == 8u);
    static_assert(NextPowerOfTwo(9) == 16u);
    static_assert(NextPowerOfTwo(0x7fffffffu) == 0x80000000u);
    static_assert(NextPowerOfTwo(0x80000000u) == 0x80000000u);
    static_assert(NextPowerOfTwo(0x80000001u) == 0x100000000u);
    static_assert(NextPowerOfTwo(0x7fffffffffffffffu) == 0x8000000000000000u);
}

TEST(MathTests, MaxAlignOf) {
    EXPECT_EQ(MaxAlignOf(0u), 1u);
    EXPECT_EQ(MaxAlignOf(1u), 1u);
    EXPECT_EQ(MaxAlignOf(2u), 2u);
    EXPECT_EQ(MaxAlignOf(3u), 1u);
    EXPECT_EQ(MaxAlignOf(4u), 4u);
    EXPECT_EQ(MaxAlignOf(5u), 1u);
    EXPECT_EQ(MaxAlignOf(6u), 2u);
    EXPECT_EQ(MaxAlignOf(7u), 1u);
    EXPECT_EQ(MaxAlignOf(8u), 8u);
    EXPECT_EQ(MaxAlignOf(9u), 1u);
    EXPECT_EQ(MaxAlignOf(10u), 2u);
    EXPECT_EQ(MaxAlignOf(11u), 1u);
    EXPECT_EQ(MaxAlignOf(12u), 4u);
    EXPECT_EQ(MaxAlignOf(13u), 1u);
    EXPECT_EQ(MaxAlignOf(14u), 2u);
    EXPECT_EQ(MaxAlignOf(15u), 1u);
    EXPECT_EQ(MaxAlignOf(16u), 16u);
}

}  // namespace
}  // namespace tint::utils