192 changes: 57 additions & 135 deletions libc/src/__support/UInt.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,20 +43,13 @@ struct BigInt {
static_assert(is_integral_v<WordType> && is_unsigned_v<WordType>,
"WordType must be unsigned integer.");

using word_type = WordType;
LIBC_INLINE_VAR static constexpr bool SIGNED = Signed;
LIBC_INLINE_VAR static constexpr size_t BITS = Bits;
LIBC_INLINE_VAR
static constexpr size_t WORD_SIZE = sizeof(WordType) * CHAR_BIT;

static_assert(Bits > 0 && Bits % WORD_SIZE == 0,
"Number of bits in BigInt should be a multiple of WORD_SIZE.");

LIBC_INLINE_VAR static constexpr size_t WORD_COUNT = Bits / WORD_SIZE;

using unsigned_type = BigInt<BITS, false, word_type>;
using signed_type = BigInt<BITS, true, word_type>;

cpp::array<WordType, WORD_COUNT> val{};

LIBC_INLINE constexpr BigInt() = default;
Expand Down Expand Up @@ -586,33 +579,19 @@ struct BigInt {
return *this;
}

// TODO: remove and use cpp::countl_zero below.
[[nodiscard]] LIBC_INLINE constexpr int clz() const {
constexpr int word_digits = cpp::numeric_limits<word_type>::digits;
int leading_zeroes = 0;
for (auto i = val.size(); i > 0;) {
--i;
const int zeroes = countl_zero(val[i]);
leading_zeroes += zeroes;
if (zeroes != word_digits)
LIBC_INLINE constexpr uint64_t clz() {
uint64_t leading_zeroes = 0;
for (size_t i = WORD_COUNT; i > 0; --i) {
if (val[i - 1] == 0) {
leading_zeroes += WORD_SIZE;
} else {
leading_zeroes += countl_zero(val[i - 1]);
break;
}
}
return leading_zeroes;
}

// TODO: remove and use cpp::countr_zero below.
[[nodiscard]] LIBC_INLINE constexpr int ctz() const {
constexpr int word_digits = cpp::numeric_limits<word_type>::digits;
int trailing_zeroes = 0;
for (auto word : val) {
const int zeroes = countr_zero(word);
trailing_zeroes += zeroes;
if (zeroes != word_digits)
break;
}
return trailing_zeroes;
}

LIBC_INLINE constexpr void shift_left(size_t s) {
if constexpr (Bits == WORD_SIZE) {
// Use native types if possible.
Expand Down Expand Up @@ -937,121 +916,64 @@ template <> class numeric_limits<Int<128>> {
LIBC_INLINE_VAR static constexpr int digits = 128;
};

// type traits to determine whether a T is a cpp::BigInt.
template <typename T> struct is_big_int : cpp::false_type {};

// Provides is_integral of U/Int<128>, U/Int<192>, U/Int<256>.
template <size_t Bits, bool Signed, typename T>
struct is_big_int<BigInt<Bits, Signed, T>> : cpp::true_type {};

template <class T>
LIBC_INLINE_VAR constexpr bool is_big_int_v = is_big_int<T>::value;

// Specialization of cpp::bit_cast ('bit.h') from T to BigInt.
template <typename To, typename From>
LIBC_INLINE constexpr cpp::enable_if_t<
(sizeof(To) == sizeof(From)) && cpp::is_trivially_copyable<To>::value &&
cpp::is_trivially_copyable<From>::value && is_big_int<To>::value,
To>
bit_cast(const From &from) {
To out;
using Storage = decltype(out.val);
out.val = cpp::bit_cast<Storage>(from);
return out;
}
struct is_integral<BigInt<Bits, Signed, T>> : cpp::true_type {};

// Specialization of cpp::bit_cast ('bit.h') from BigInt to T.
template <typename To, size_t Bits>
LIBC_INLINE constexpr cpp::enable_if_t<
sizeof(To) == sizeof(UInt<Bits>) &&
cpp::is_trivially_constructible<To>::value &&
cpp::is_trivially_copyable<To>::value &&
cpp::is_trivially_copyable<UInt<Bits>>::value,
To>
bit_cast(const UInt<Bits> &from) {
return cpp::bit_cast<To>(from.val);
}

// Specialization of cpp::has_single_bit ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, bool>
has_single_bit(T value) {
int bits = 0;
for (auto word : value.val) {
if (word == 0)
continue;
bits += count_ones(word);
if (bits > 1)
return false;
}
return bits == 1;
}

// Specialization of cpp::countr_zero ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, int>
countr_zero(const T &value) {
return value.ctz();
}
// Provides is_unsigned of UInt<128>, UInt<192>, UInt<256>.
template <size_t Bits, bool Signed, typename T>
struct is_unsigned<BigInt<Bits, Signed, T>> : cpp::bool_constant<!Signed> {};

// Specialization of cpp::countl_zero ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, int>
countl_zero(const T &value) {
return value.clz();
}
template <size_t Bits, bool Signed, typename T>
struct make_unsigned<BigInt<Bits, Signed, T>>
: type_identity<BigInt<Bits, false, T>> {};

// Specialization of cpp::countl_one ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, int>
countl_one(T value) {
// TODO : Implement a faster version not involving operator~.
return cpp::countl_zero<T>(~value);
}
template <size_t Bits, bool Signed, typename T>
struct make_signed<BigInt<Bits, Signed, T>>
: type_identity<BigInt<Bits, true, T>> {};

// Specialization of cpp::countr_one ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, int>
countr_one(T value) {
// TODO : Implement a faster version not involving operator~.
return cpp::countr_zero<T>(~value);
}
namespace internal {
template <typename T> struct is_custom_uint : cpp::false_type {};

// Specialization of cpp::bit_width ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, int>
bit_width(T value) {
return cpp::numeric_limits<T>::digits - cpp::countl_zero(value);
}
template <size_t Bits, bool Signed, typename T>
struct is_custom_uint<BigInt<Bits, Signed, T>> : cpp::true_type {};
} // namespace internal

// Forward-declare rotr so that rotl can use it.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, T>
rotr(T value, int rotate);

// Specialization of cpp::rotl ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, T>
rotl(T value, int rotate) {
constexpr unsigned N = cpp::numeric_limits<T>::digits;
rotate = rotate % N;
if (!rotate)
return value;
if (rotate < 0)
return cpp::rotr<T>(value, -rotate);
return (value << rotate) | (value >> (N - rotate));
// bit_cast to UInt
// Note: The standard scheme for SFINAE selection is to have exactly one
// function instanciation valid at a time. This is usually done by having a
// predicate in one function and the negated predicate in the other one.
// e.g.
// template<typename = cpp::enable_if_t< is_custom_uint<To>::value == true> ...
// template<typename = cpp::enable_if_t< is_custom_uint<To>::value == false> ...
//
// Unfortunately this would make the default 'cpp::bit_cast' aware of
// 'is_custom_uint' (or any other customization). To prevent exposing all
// customizations in the original function, we create a different function with
// four 'typename's instead of three - otherwise it would be considered as a
// redeclaration of the same function leading to "error: template parameter
// redefines default argument".
template <typename To, typename From,
typename = cpp::enable_if_t<sizeof(To) == sizeof(From) &&
cpp::is_trivially_copyable<To>::value &&
cpp::is_trivially_copyable<From>::value>,
typename = cpp::enable_if_t<internal::is_custom_uint<To>::value>>
LIBC_INLINE constexpr To bit_cast(const From &from) {
To out;
using Storage = decltype(out.val);
out.val = cpp::bit_cast<Storage>(from);
return out;
}

// Specialization of cpp::rotr ('bit.h') for BigInt.
template <typename T>
[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_big_int_v<T>, T>
rotr(T value, int rotate) {
constexpr unsigned N = cpp::numeric_limits<T>::digits;
rotate = rotate % N;
if (!rotate)
return value;
if (rotate < 0)
return cpp::rotl<T>(value, -rotate);
return (value >> rotate) | (value << (N - rotate));
// bit_cast from UInt
template <
typename To, size_t Bits,
typename = cpp::enable_if_t<sizeof(To) == sizeof(UInt<Bits>) &&
cpp::is_trivially_constructible<To>::value &&
cpp::is_trivially_copyable<To>::value &&
cpp::is_trivially_copyable<UInt<Bits>>::value>>
LIBC_INLINE constexpr To bit_cast(const UInt<Bits> &from) {
return cpp::bit_cast<To>(from.val);
}

} // namespace LIBC_NAMESPACE::cpp
Expand Down
2 changes: 1 addition & 1 deletion libc/src/__support/float_to_string.h
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Original file line number Diff line number Diff line change
Expand Up @@ -713,7 +713,7 @@ template <> class FloatToString<long double> {
float_as_fixed.shift_left(SHIFT_AMOUNT);

// If there are still digits above the decimal point, handle those.
if (float_as_fixed.clz() < static_cast<int>(EXTRA_INT_WIDTH)) {
if (float_as_fixed.clz() < EXTRA_INT_WIDTH) {
cpp::UInt<EXTRA_INT_WIDTH> above_decimal_point =
float_as_fixed >> FLOAT_AS_INT_WIDTH;

Expand Down
19 changes: 3 additions & 16 deletions libc/src/__support/integer_to_string.h
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Original file line number Diff line number Diff line change
Expand Up @@ -67,7 +67,6 @@
#include "src/__support/CPP/span.h"
#include "src/__support/CPP/string_view.h"
#include "src/__support/CPP/type_traits.h"
#include "src/__support/UInt.h" // is_big_int
#include "src/__support/common.h"

namespace LIBC_NAMESPACE {
Expand Down Expand Up @@ -150,18 +149,6 @@ template <bool forward> class StringBufferWriterImpl {
using StringBufferWriter = StringBufferWriterImpl<true>;
using BackwardStringBufferWriter = StringBufferWriterImpl<false>;

template <typename T, class = void> struct IntegerWriterUnsigned {};

template <typename T>
struct IntegerWriterUnsigned<T, cpp::enable_if_t<cpp::is_integral_v<T>>> {
using type = cpp::make_unsigned_t<T>;
};

template <typename T>
struct IntegerWriterUnsigned<T, cpp::enable_if_t<cpp::is_big_int_v<T>>> {
using type = typename T::unsigned_type;
};

} // namespace details

namespace radix {
Expand All @@ -176,7 +163,7 @@ template <size_t radix> using Custom = details::Fmt<radix>;

// See file header for documentation.
template <typename T, typename Fmt = radix::Dec> class IntegerToString {
static_assert(cpp::is_integral_v<T> || cpp::is_big_int_v<T>);
static_assert(cpp::is_integral_v<T>);

LIBC_INLINE static constexpr size_t compute_buffer_size() {
constexpr auto MAX_DIGITS = []() -> size_t {
Expand Down Expand Up @@ -221,8 +208,8 @@ template <typename T, typename Fmt = radix::Dec> class IntegerToString {

// An internal stateless structure that handles the number formatting logic.
struct IntegerWriter {
static_assert(cpp::is_integral_v<T> || cpp::is_big_int_v<T>);
using UNSIGNED_T = typename details::IntegerWriterUnsigned<T>::type;
static_assert(cpp::is_integral_v<T>);
using UNSIGNED_T = cpp::make_unsigned_t<T>;

LIBC_INLINE static char digit_char(uint8_t digit) {
if (digit < 10)
Expand Down
1 change: 0 additions & 1 deletion libc/test/UnitTest/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -74,7 +74,6 @@ add_unittest_framework_library(
libc.src.__support.CPP.type_traits
libc.src.__support.fixed_point.fx_rep
libc.src.__support.OSUtil.osutil
libc.src.__support.uint
libc.src.__support.uint128
)

Expand Down
10 changes: 5 additions & 5 deletions libc/test/UnitTest/LibcTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -38,8 +38,7 @@ TestLogger &operator<<(TestLogger &logger, Location Loc) {
// When the value is UInt128, __uint128_t or wider, show its hexadecimal
// digits.
template <typename T>
cpp::enable_if_t<(cpp::is_integral_v<T> && (sizeof(T) > sizeof(uint64_t))) ||
cpp::is_big_int_v<T>,
cpp::enable_if_t<cpp::is_integral_v<T> && (sizeof(T) > sizeof(uint64_t)),
cpp::string>
describeValue(T Value) {
static_assert(sizeof(T) % 8 == 0, "Unsupported size of UInt");
Expand All @@ -48,10 +47,11 @@ describeValue(T Value) {
}

// When the value is of a standard integral type, just display it as normal.
template <typename T>
cpp::enable_if_t<cpp::is_integral_v<T> && (sizeof(T) <= sizeof(uint64_t)),
template <typename ValType>
cpp::enable_if_t<cpp::is_integral_v<ValType> &&
sizeof(ValType) <= sizeof(uint64_t),
cpp::string>
describeValue(T Value) {
describeValue(ValType Value) {
return cpp::to_string(Value);
}

Expand Down
1 change: 0 additions & 1 deletion libc/test/UnitTest/LibcTest.h
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Original file line number Diff line number Diff line change
Expand Up @@ -127,7 +127,6 @@ class Test {
// of type promotion.
template <typename ValType,
cpp::enable_if_t<cpp::is_integral_v<ValType> ||
cpp::is_big_int_v<ValType> ||
cpp::is_fixed_point_v<ValType>,
int> = 0>
bool test(TestCond Cond, ValType LHS, ValType RHS, const char *LHSStr,
Expand Down
8 changes: 3 additions & 5 deletions libc/test/UnitTest/TestLogger.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@
#include "src/__support/CPP/string.h"
#include "src/__support/CPP/string_view.h"
#include "src/__support/OSUtil/io.h" // write_to_stderr
#include "src/__support/UInt.h" // is_big_int
#include "src/__support/UInt128.h"

#include <stdint.h>
Expand Down Expand Up @@ -48,9 +47,8 @@ template <> TestLogger &TestLogger::operator<<(void *addr) {
}

template <typename T> TestLogger &TestLogger::operator<<(T t) {
if constexpr (cpp::is_big_int_v<T> ||
(cpp::is_integral_v<T> && cpp::is_unsigned_v<T> &&
(sizeof(T) > sizeof(uint64_t)))) {
if constexpr (cpp::is_integral_v<T> && cpp::is_unsigned_v<T> &&
sizeof(T) > sizeof(uint64_t)) {
static_assert(sizeof(T) % 8 == 0, "Unsupported size of UInt");
const IntegerToString<T, radix::Hex::WithPrefix> buffer(t);
return *this << buffer.view();
Expand All @@ -70,7 +68,7 @@ template TestLogger &TestLogger::operator<< <unsigned short>(unsigned short);
template TestLogger &TestLogger::operator<< <unsigned int>(unsigned int);
template TestLogger &TestLogger::operator<< <unsigned long>(unsigned long);
template TestLogger &
TestLogger::operator<< <unsigned long long>(unsigned long long);
TestLogger::operator<< <unsigned long long>(unsigned long long);

#ifdef __SIZEOF_INT128__
template TestLogger &TestLogger::operator<< <__uint128_t>(__uint128_t);
Expand Down
49 changes: 13 additions & 36 deletions libc/test/src/__support/CPP/bit_test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -12,44 +12,21 @@

#include <stdint.h>

#include <iostream>

namespace LIBC_NAMESPACE::cpp {

using UnsignedTypesNoBigInt = testing::TypeList<
#if defined(__SIZEOF_INT128__)
__uint128_t,
#endif
unsigned char, unsigned short, unsigned int, unsigned long,
unsigned long long>;

using UnsignedTypes = testing::TypeList<
using UnsignedTypes =
testing::TypeList<unsigned char, unsigned short, unsigned int,
unsigned long, unsigned long long,
#if defined(__SIZEOF_INT128__)
__uint128_t,
__uint128_t,
#endif
unsigned char, unsigned short, unsigned int, unsigned long,
unsigned long long, cpp::UInt<128>>;
cpp::UInt<128>>;

TYPED_TEST(LlvmLibcBitTest, HasSingleBit, UnsignedTypes) {
constexpr auto ZERO = T(0);
constexpr auto ALL_ONES = T(~ZERO);
EXPECT_FALSE(has_single_bit<T>(ZERO));
EXPECT_FALSE(has_single_bit<T>(ALL_ONES));

EXPECT_FALSE(has_single_bit<T>(T(0)));
EXPECT_FALSE(has_single_bit<T>(~T(0)));
for (T value = 1; value; value <<= 1)
EXPECT_TRUE(has_single_bit<T>(value));

// We test that if two bits are set has_single_bit returns false.
// We do this by setting the highest or lowest bit depending or where the
// current bit is. This is a bit convoluted but it helps catch a bug on BigInt
// where we have to work on an element-by-element basis.
constexpr auto MIDPOINT = T(ALL_ONES / 2);
constexpr auto LSB = T(1);
constexpr auto MSB = T(~(ALL_ONES >> 1));
for (T value = 1; value; value <<= 1) {
auto two_bits_value = value | ((value <= MIDPOINT) ? MSB : LSB);
EXPECT_FALSE(has_single_bit<T>(two_bits_value));
}
}

TYPED_TEST(LlvmLibcBitTest, CountLZero, UnsignedTypes) {
Expand Down Expand Up @@ -229,39 +206,39 @@ TEST(LlvmLibcBitTest, Rotr) {
rotr<uint64_t>(0x12345678deadbeefULL, -19));
}

TYPED_TEST(LlvmLibcBitTest, FirstLeadingZero, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, FirstLeadingZero, UnsignedTypes) {
EXPECT_EQ(first_leading_zero<T>(cpp::numeric_limits<T>::max()), 0);
for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(first_leading_zero<T>(~(T(1) << i)),
cpp::numeric_limits<T>::digits - i);
}

TYPED_TEST(LlvmLibcBitTest, FirstLeadingOne, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, FirstLeadingOne, UnsignedTypes) {
EXPECT_EQ(first_leading_one<T>(static_cast<T>(0)), 0);
for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(first_leading_one<T>(T(1) << i),
cpp::numeric_limits<T>::digits - i);
}

TYPED_TEST(LlvmLibcBitTest, FirstTrailingZero, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, FirstTrailingZero, UnsignedTypes) {
EXPECT_EQ(first_trailing_zero<T>(cpp::numeric_limits<T>::max()), 0);
for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(first_trailing_zero<T>(~(T(1) << i)), i + 1);
}

TYPED_TEST(LlvmLibcBitTest, FirstTrailingOne, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, FirstTrailingOne, UnsignedTypes) {
EXPECT_EQ(first_trailing_one<T>(cpp::numeric_limits<T>::max()), 0);
for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(first_trailing_one<T>(T(1) << i), i + 1);
}

TYPED_TEST(LlvmLibcBitTest, CountZeros, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, CountZeros, UnsignedTypes) {
EXPECT_EQ(count_zeros(T(0)), cpp::numeric_limits<T>::digits);
for (int i = 0; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(count_zeros<T>(cpp::numeric_limits<T>::max() >> i), i);
}

TYPED_TEST(LlvmLibcBitTest, CountOnes, UnsignedTypesNoBigInt) {
TYPED_TEST(LlvmLibcBitTest, CountOnes, UnsignedTypes) {
EXPECT_EQ(count_ones(T(0)), 0);
for (int i = 0; i != cpp::numeric_limits<T>::digits; ++i)
EXPECT_EQ(count_ones<T>(cpp::numeric_limits<T>::max() >> i),
Expand Down
1 change: 0 additions & 1 deletion utils/bazel/llvm-project-overlay/libc/BUILD.bazel
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Original file line number Diff line number Diff line change
Expand Up @@ -507,7 +507,6 @@ libc_support_library(
":__support_cpp_span",
":__support_cpp_string_view",
":__support_cpp_type_traits",
":__support_uint",
],
)

Expand Down
1 change: 0 additions & 1 deletion utils/bazel/llvm-project-overlay/libc/test/UnitTest/BUILD.bazel
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@ libc_support_library(
"//libc:__support_cpp_string",
"//libc:__support_cpp_string_view",
"//libc:__support_osutil_io",
"//libc:__support_uint",
"//libc:__support_uint128",
],
)
Expand Down