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kc3-lang/angle/src/common/bitset_utils_unittest.cpp

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  • Author : Shahbaz Youssefi
    Date : 2019-03-29 00:00:27
    Hash : 90b1865e
    Message : More unittests for BitSet Bug: angleproject:2361 Change-Id: Icca49086d95ddb0d2d50e5ba71ae9b748eeabf3f Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1545203 Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

  • src/common/bitset_utils_unittest.cpp
  • //
    // Copyright 2015 The ANGLE Project Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style license that can be
    // found in the LICENSE file.
    //
    // bitset_utils_unittest:
    //   Tests bitset helpers and custom classes.
    //
    
    #include <gtest/gtest.h>
    
    #include "common/bitset_utils.h"
    
    using namespace angle;
    
    namespace
    {
    class BitSetTest : public testing::Test
    {
      protected:
        BitSet<12> mBits;
    };
    
    TEST_F(BitSetTest, Basic)
    {
        EXPECT_FALSE(mBits.all());
        EXPECT_FALSE(mBits.any());
        EXPECT_TRUE(mBits.none());
        EXPECT_EQ(mBits.count(), 0u);
    
        // Set every bit to 1.
        for (size_t i = 0; i < mBits.size(); ++i)
        {
            mBits.set(i);
    
            EXPECT_EQ(mBits.all(), i + 1 == mBits.size());
            EXPECT_TRUE(mBits.any());
            EXPECT_FALSE(mBits.none());
            EXPECT_EQ(mBits.count(), i + 1);
        }
    
        // Reset every other bit to 0.
        for (size_t i = 0; i < mBits.size(); i += 2)
        {
            mBits.reset(i);
    
            EXPECT_FALSE(mBits.all());
            EXPECT_TRUE(mBits.any());
            EXPECT_FALSE(mBits.none());
            EXPECT_EQ(mBits.count(), mBits.size() - i / 2 - 1);
        }
    
        // Flip all bits.
        for (size_t i = 0; i < mBits.size(); ++i)
        {
            mBits.flip(i);
    
            EXPECT_FALSE(mBits.all());
            EXPECT_TRUE(mBits.any());
            EXPECT_FALSE(mBits.none());
            EXPECT_EQ(mBits.count(), mBits.size() / 2 + (i % 2 == 0));
        }
    
        // Make sure the bit pattern is what we expect at this point.
        for (size_t i = 0; i < mBits.size(); ++i)
        {
            EXPECT_EQ(mBits.test(i), i % 2 == 0);
            EXPECT_EQ(static_cast<bool>(mBits[i]), i % 2 == 0);
        }
    
        // Test that flip, set and reset all bits at once work.
        mBits.flip();
        EXPECT_FALSE(mBits.all());
        EXPECT_TRUE(mBits.any());
        EXPECT_FALSE(mBits.none());
        EXPECT_EQ(mBits.count(), mBits.size() / 2);
    
        mBits.set();
        EXPECT_TRUE(mBits.all());
        EXPECT_TRUE(mBits.any());
        EXPECT_FALSE(mBits.none());
        EXPECT_EQ(mBits.count(), mBits.size());
    
        mBits.reset();
        EXPECT_FALSE(mBits.all());
        EXPECT_FALSE(mBits.any());
        EXPECT_TRUE(mBits.none());
        EXPECT_EQ(mBits.count(), 0u);
    
        // Test that out-of-bound sets don't modify the bitset
        constexpr uint32_t kMask = (1 << 12) - 1;
    
        EXPECT_EQ(mBits.set(12).bits() & ~kMask, 0u);
        EXPECT_EQ(mBits.set(13).bits() & ~kMask, 0u);
        EXPECT_EQ(mBits.flip(12).bits() & ~kMask, 0u);
        EXPECT_EQ(mBits.flip(13).bits() & ~kMask, 0u);
    }
    
    TEST_F(BitSetTest, BitwiseOperators)
    {
        // Use a value that has a 1 in the 12th and 13th bits, to make sure masking to exactly 12 bits
        // does not have an off-by-one error.
        constexpr uint32_t kSelfValue  = 0xF9E4;
        constexpr uint32_t kOtherValue = 0x5C6A;
    
        constexpr uint32_t kMask             = (1 << 12) - 1;
        constexpr uint32_t kSelfMaskedValue  = kSelfValue & kMask;
        constexpr uint32_t kOtherMaskedValue = kOtherValue & kMask;
    
        constexpr uint32_t kShift            = 3;
        constexpr uint32_t kSelfShiftedLeft  = kSelfMaskedValue << kShift & kMask;
        constexpr uint32_t kSelfShiftedRight = kSelfMaskedValue >> kShift & kMask;
    
        mBits |= kSelfValue;
        BitSet<12> other(kOtherValue);
        BitSet<12> anded(kSelfMaskedValue & kOtherMaskedValue);
        BitSet<12> ored(kSelfMaskedValue | kOtherMaskedValue);
        BitSet<12> xored(kSelfMaskedValue ^ kOtherMaskedValue);
    
        EXPECT_EQ(mBits.bits(), kSelfMaskedValue);
        EXPECT_EQ(other.bits(), kOtherMaskedValue);
    
        EXPECT_EQ(mBits & other, anded);
        EXPECT_EQ(mBits | other, ored);
        EXPECT_EQ(mBits ^ other, xored);
    
        EXPECT_NE(mBits, other);
        EXPECT_NE(anded, ored);
        EXPECT_NE(anded, xored);
        EXPECT_NE(ored, xored);
    
        mBits &= other;
        EXPECT_EQ(mBits, anded);
    
        mBits |= ored;
        EXPECT_EQ(mBits, ored);
    
        mBits ^= other;
        mBits ^= anded;
        EXPECT_EQ(mBits, BitSet<12>(kSelfValue));
    
        EXPECT_EQ(mBits << kShift, BitSet<12>(kSelfShiftedLeft));
        EXPECT_EQ(mBits >> kShift, BitSet<12>(kSelfShiftedRight));
    
        mBits <<= kShift;
        EXPECT_EQ(mBits, BitSet<12>(kSelfShiftedLeft));
        EXPECT_EQ(mBits.bits() & ~kMask, 0u);
    
        mBits = BitSet<12>(kSelfValue);
        mBits >>= kShift;
        EXPECT_EQ(mBits, BitSet<12>(kSelfShiftedRight));
        EXPECT_EQ(mBits.bits() & ~kMask, 0u);
    
        mBits |= kSelfMaskedValue;
        EXPECT_EQ(mBits.bits() & ~kMask, 0u);
        mBits ^= kOtherMaskedValue;
        EXPECT_EQ(mBits.bits() & ~kMask, 0u);
    }
    
    class BitSetIteratorTest : public testing::Test
    {
      protected:
        BitSet<40> mStateBits;
    };
    
    // Simple iterator test.
    TEST_F(BitSetIteratorTest, Iterator)
    {
        std::set<size_t> originalValues;
        originalValues.insert(2);
        originalValues.insert(6);
        originalValues.insert(8);
        originalValues.insert(35);
    
        for (size_t value : originalValues)
        {
            mStateBits.set(value);
        }
    
        std::set<size_t> readValues;
        for (size_t bit : mStateBits)
        {
            EXPECT_EQ(1u, originalValues.count(bit));
            EXPECT_EQ(0u, readValues.count(bit));
            readValues.insert(bit);
        }
    
        EXPECT_EQ(originalValues.size(), readValues.size());
    }
    
    // Test an empty iterator.
    TEST_F(BitSetIteratorTest, EmptySet)
    {
        // We don't use the FAIL gtest macro here since it returns immediately,
        // causing an unreachable code warning in MSVS
        bool sawBit = false;
        for (size_t bit : mStateBits)
        {
            sawBit = true;
            ANGLE_UNUSED_VARIABLE(bit);
        }
        EXPECT_FALSE(sawBit);
    }
    
    // Test iterating a result of combining two bitsets.
    TEST_F(BitSetIteratorTest, NonLValueBitset)
    {
        BitSet<40> otherBits;
    
        mStateBits.set(1);
        mStateBits.set(2);
        mStateBits.set(3);
        mStateBits.set(4);
    
        otherBits.set(0);
        otherBits.set(1);
        otherBits.set(3);
        otherBits.set(5);
    
        std::set<size_t> seenBits;
    
        angle::BitSet<40> maskedBits = (mStateBits & otherBits);
        for (size_t bit : maskedBits)
        {
            EXPECT_EQ(0u, seenBits.count(bit));
            seenBits.insert(bit);
            EXPECT_TRUE(mStateBits[bit]);
            EXPECT_TRUE(otherBits[bit]);
        }
    
        EXPECT_EQ((mStateBits & otherBits).count(), seenBits.size());
    }
    
    // Test bit assignments.
    TEST_F(BitSetIteratorTest, BitAssignment)
    {
        std::set<size_t> originalValues;
        originalValues.insert(2);
        originalValues.insert(6);
        originalValues.insert(8);
        originalValues.insert(35);
    
        for (size_t value : originalValues)
        {
            (mStateBits[value] = false) = true;
        }
    
        for (size_t value : originalValues)
        {
            EXPECT_TRUE(mStateBits.test(value));
        }
    }
    
    // Tests adding bits to the iterator during iteration.
    TEST_F(BitSetIteratorTest, SetLaterBit)
    {
        std::set<size_t> expectedValues = {1, 3, 5, 7, 9};
        mStateBits.set(1);
    
        std::set<size_t> actualValues;
    
        for (auto iter = mStateBits.begin(), end = mStateBits.end(); iter != end; ++iter)
        {
            if (*iter == 1)
            {
                iter.setLaterBit(3);
                iter.setLaterBit(5);
                iter.setLaterBit(7);
                iter.setLaterBit(9);
            }
    
            actualValues.insert(*iter);
        }
    
        EXPECT_EQ(expectedValues, actualValues);
    }
    
    // Tests removing bits from the iterator during iteration.
    TEST_F(BitSetIteratorTest, ResetLaterBit)
    {
        std::set<size_t> expectedValues = {1, 3, 5, 7, 9};
    
        for (size_t index = 1; index <= 9; ++index)
            mStateBits.set(index);
    
        std::set<size_t> actualValues;
    
        for (auto iter = mStateBits.begin(), end = mStateBits.end(); iter != end; ++iter)
        {
            if (*iter == 1)
            {
                iter.resetLaterBit(2);
                iter.resetLaterBit(4);
                iter.resetLaterBit(6);
                iter.resetLaterBit(8);
            }
    
            actualValues.insert(*iter);
        }
    
        EXPECT_EQ(expectedValues, actualValues);
    }
    }  // anonymous namespace