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AK: Make truncating UFixedBigInts constexpr

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Also add some tests and shift tests while we're at it.
This commit is contained in:
davidot 2022-10-10 02:30:29 +02:00 • committed by Linus Groh
parent 66d07a452f
commit bf6d4a5cbf
2 changed files with 16 additions and 1 deletions
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2
AK/UFixedBigInt.h
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@ -87,7 +87,7 @@ public:
} }
template<Unsigned U> template<Unsigned U>
requires(sizeof(T) >= sizeof(U)) explicit operator U() const requires(sizeof(T) >= sizeof(U)) constexpr explicit operator U() const
{ {
return static_cast<U>(m_low); return static_cast<U>(m_low);
} }

15
Tests/AK/TestUFixedBigInt.cpp
View file

@ -88,6 +88,21 @@ TEST_CASE(div_mod)
} }
} }
TEST_CASE(shifts)
{
u128 val { 0x1234ULL };
EXPECT_EQ(val << 1u, u128(0x2468ull));
EXPECT_EQ(val << 4u, u128(0x12340ull));
EXPECT_EQ(val << 64u, u128(0ull, 0x1234ull));
}
TEST_CASE(constexpr_truncae)
{
static constexpr u256 wide = u256(u128 { 0x8a4b08d32f8b8e48ULL, 0x8459322f67b8e26dULL }, u128 { 0xeea82af4312d1931ULL, 0x654fb5cfe82dbd58ULL });
static constexpr u64 val = static_cast<u64>(wide);
EXPECT_EQ(val, 0x8a4b08d32f8b8e48ULL);
}
TEST_CASE(mod_hardcoded) TEST_CASE(mod_hardcoded)
{ {
EXPECT_EQ(u256(u128 { 0x8a4b08d32f8b8e48ULL, 0x8459322f67b8e26dULL }, u128 { 0xeea82af4312d1931ULL, 0x654fb5cfe82dbd58ULL }) % u256(u128 { 0x40a58652868d5d66ULL, 0x81d674bf7d6d6861ULL }, u128 { 0xa8314900e6188a82ULL, 0xc273ca947237b4aaULL }), u256(u128 { 0x8a4b08d32f8b8e48ULL, 0x8459322f67b8e26dULL }, u128 { 0xeea82af4312d1931ULL, 0x654fb5cfe82dbd58ULL })); EXPECT_EQ(u256(u128 { 0x8a4b08d32f8b8e48ULL, 0x8459322f67b8e26dULL }, u128 { 0xeea82af4312d1931ULL, 0x654fb5cfe82dbd58ULL }) % u256(u128 { 0x40a58652868d5d66ULL, 0x81d674bf7d6d6861ULL }, u128 { 0xa8314900e6188a82ULL, 0xc273ca947237b4aaULL }), u256(u128 { 0x8a4b08d32f8b8e48ULL, 0x8459322f67b8e26dULL }, u128 { 0xeea82af4312d1931ULL, 0x654fb5cfe82dbd58ULL }));