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/*
* Copyright (C) 2020 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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*/
#include "config.h"
#include <wtf/StdLibExtras.h>
#include <wtf/MathExtras.h>
#include <wtf/RandomNumber.h>
namespace TestWebKitAPI {
template<typename WordType>
void testFindBitInWord()
{
constexpr size_t bitsInWord = sizeof(WordType) * 8;
constexpr size_t numberOfShiftValues = bitsInWord + 1;
constexpr size_t testPermutationsPerShift = 100;
constexpr size_t numberOfTestValues = numberOfShiftValues * testPermutationsPerShift;
uint8_t startIndex[numberOfTestValues];
uint8_t endIndex[numberOfTestValues];
auto initTestValues = [&] () {
// Set some internal and boundary cases.
uint8_t specialCases[] = {
0,
bitsInWord / 2,
bitsInWord - 1,
bitsInWord,
};
constexpr size_t numberOfSpecialCases = sizeof(specialCases) / sizeof(specialCases[0]);
size_t nextTestValue = 0;
for (size_t i = 0; i < numberOfSpecialCases; ++i) {
for (size_t j = 0; j < numberOfSpecialCases; ++j) {
startIndex[nextTestValue] = specialCases[i];
endIndex[nextTestValue++] = specialCases[j];
}
}
// Fill in some random cases.
for (size_t i = nextTestValue; i < numberOfTestValues; ++i) {
startIndex[i] = static_cast<uint8_t>(randomNumber() * bitsInWord);
uint8_t remainingBits = bitsInWord - startIndex[i];
endIndex[i] = static_cast<uint8_t>(randomNumber() * remainingBits) + startIndex[i];
}
};
auto expectedBitInWord = [] (WordType word, size_t& index, size_t endIndex, bool value) -> bool {
word >>= index;
while (index < endIndex) {
if ((word & 1) == static_cast<WordType>(value))
return true;
index++;
word >>= 1;
}
index = endIndex;
return false;
};
auto test = [&] (bool value, size_t shift) {
constexpr uint64_t baseWord = std::numeric_limits<uint64_t>::max();
uint64_t word = (shift < bitsInWord) ? baseWord << shift : 0;
for (size_t i = 0; i < numberOfTestValues; ++i) {
size_t index = startIndex[i];
bool result = findBitInWord(word, index, endIndex[i], value);
size_t expectedIndex = startIndex[i];
bool expectedResult = expectedBitInWord(word, expectedIndex, endIndex[i], value);
ASSERT_EQ(result, expectedResult);
ASSERT_EQ(index, expectedIndex);
}
};
initTestValues();
// Testing find a set bit.
for (size_t i = 0; i < numberOfShiftValues; ++i)
test(true, i);
// Testing find a cleared bit.
for (size_t i = 0; i < numberOfShiftValues; ++i)
test(false, i);
}
TEST(WTF_StdLibExtras, findBitInWord_uint32_t) { testFindBitInWord<uint32_t>(); }
TEST(WTF_StdLibExtras, findBitInWord_uint64_t) { testFindBitInWord<uint64_t>(); }
} // namespace TestWebKitAPI