tvl-depot/absl/numeric/int128_no_intrinsic.inc
Abseil Team 2103fd9acd Export of internal Abseil changes
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d447fdcb801036cf08197eece193a5a706661120 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the need for static function holding help message. This decreases the cost of ABSL_FLAG abstraction by 120 bytes under clang.

PiperOrigin-RevId: 281107806

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0aa6b91189f0e8b2381438c33465673a7ae02487 by Derek Mauro <dmauro@google.com>:

Disable the weak symbol CCTZ extension in the time test_util
on MinGW, which does not support it.

PiperOrigin-RevId: 280719769

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67322c41c3e776eb541de90fa4526bdb49422eb6 by Abseil Team <absl-team@google.com>:

Tune PeriodicSampler implementation (for internal-use only)

PiperOrigin-RevId: 280708943

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3a48c346340c7ed03816645cd327e1ff07729aa4 by Abseil Team <absl-team@google.com>:

Clean up public headers not to have warnings for "-Wcomma"

PiperOrigin-RevId: 280695373

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981acd1ef3b13a83a84f04f11c8931f4ed4451c9 by Matthew Brown <matthewbr@google.com>:

Release absl::int128.

PiperOrigin-RevId: 280690817

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d30fae9d2ec30b81322d2eb5afe7e13e45b4b422 by Derek Mauro <dmauro@google.com>:

Fix -Wundef warnings in random platform detection

PiperOrigin-RevId: 280669598
GitOrigin-RevId: d447fdcb801036cf08197eece193a5a706661120
Change-Id: Ie5e10e567c54b7de211833607689f233d4ddf734
2019-11-19 10:27:57 -05:00

308 lines
9.9 KiB
C++

//
// Copyright 2017 The Abseil 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
//
// https://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.
// This file contains :int128 implementation details that depend on internal
// representation when ABSL_HAVE_INTRINSIC_INT128 is *not* defined. This file
// is included by int128.h and relies on ABSL_INTERNAL_WCHAR_T being defined.
constexpr uint64_t Int128Low64(int128 v) { return v.lo_; }
constexpr int64_t Int128High64(int128 v) { return v.hi_; }
#if defined(ABSL_IS_LITTLE_ENDIAN)
constexpr int128::int128(int64_t high, uint64_t low) :
lo_(low), hi_(high) {}
constexpr int128::int128(int v)
: lo_{static_cast<uint64_t>(v)}, hi_{v < 0 ? ~int64_t{0} : 0} {}
constexpr int128::int128(long v) // NOLINT(runtime/int)
: lo_{static_cast<uint64_t>(v)}, hi_{v < 0 ? ~int64_t{0} : 0} {}
constexpr int128::int128(long long v) // NOLINT(runtime/int)
: lo_{static_cast<uint64_t>(v)}, hi_{v < 0 ? ~int64_t{0} : 0} {}
constexpr int128::int128(unsigned int v) : lo_{v}, hi_{0} {}
// NOLINTNEXTLINE(runtime/int)
constexpr int128::int128(unsigned long v) : lo_{v}, hi_{0} {}
// NOLINTNEXTLINE(runtime/int)
constexpr int128::int128(unsigned long long v) : lo_{v}, hi_{0} {}
constexpr int128::int128(uint128 v)
: lo_{Uint128Low64(v)}, hi_{static_cast<int64_t>(Uint128High64(v))} {}
#elif defined(ABSL_IS_BIG_ENDIAN)
constexpr int128::int128(int64_t high, uint64_t low) :
hi_{high}, lo_{low} {}
constexpr int128::int128(int v)
: hi_{v < 0 ? ~int64_t{0} : 0}, lo_{static_cast<uint64_t>(v)} {}
constexpr int128::int128(long v) // NOLINT(runtime/int)
: hi_{v < 0 ? ~int64_t{0} : 0}, lo_{static_cast<uint64_t>(v)} {}
constexpr int128::int128(long long v) // NOLINT(runtime/int)
: hi_{v < 0 ? ~int64_t{0} : 0}, lo_{static_cast<uint64_t>(v)} {}
constexpr int128::int128(unsigned int v) : hi_{0}, lo_{v} {}
// NOLINTNEXTLINE(runtime/int)
constexpr int128::int128(unsigned long v) : hi_{0}, lo_{v} {}
// NOLINTNEXTLINE(runtime/int)
constexpr int128::int128(unsigned long long v) : hi_{0}, lo_{v} {}
constexpr int128::int128(uint128 v)
: hi_{static_cast<int64_t>(Uint128High64(v))}, lo_{Uint128Low64(v)} {}
#else // byte order
#error "Unsupported byte order: must be little-endian or big-endian."
#endif // byte order
constexpr int128::operator bool() const { return lo_ || hi_; }
constexpr int128::operator char() const {
// NOLINTNEXTLINE(runtime/int)
return static_cast<char>(static_cast<long long>(*this));
}
constexpr int128::operator signed char() const {
// NOLINTNEXTLINE(runtime/int)
return static_cast<signed char>(static_cast<long long>(*this));
}
constexpr int128::operator unsigned char() const {
return static_cast<unsigned char>(lo_);
}
constexpr int128::operator char16_t() const {
return static_cast<char16_t>(lo_);
}
constexpr int128::operator char32_t() const {
return static_cast<char32_t>(lo_);
}
constexpr int128::operator ABSL_INTERNAL_WCHAR_T() const {
// NOLINTNEXTLINE(runtime/int)
return static_cast<ABSL_INTERNAL_WCHAR_T>(static_cast<long long>(*this));
}
constexpr int128::operator short() const { // NOLINT(runtime/int)
// NOLINTNEXTLINE(runtime/int)
return static_cast<short>(static_cast<long long>(*this));
}
constexpr int128::operator unsigned short() const { // NOLINT(runtime/int)
return static_cast<unsigned short>(lo_); // NOLINT(runtime/int)
}
constexpr int128::operator int() const {
// NOLINTNEXTLINE(runtime/int)
return static_cast<int>(static_cast<long long>(*this));
}
constexpr int128::operator unsigned int() const {
return static_cast<unsigned int>(lo_);
}
constexpr int128::operator long() const { // NOLINT(runtime/int)
// NOLINTNEXTLINE(runtime/int)
return static_cast<long>(static_cast<long long>(*this));
}
constexpr int128::operator unsigned long() const { // NOLINT(runtime/int)
return static_cast<unsigned long>(lo_); // NOLINT(runtime/int)
}
constexpr int128::operator long long() const { // NOLINT(runtime/int)
// We don't bother checking the value of hi_. If *this < 0, lo_'s high bit
// must be set in order for the value to fit into a long long. Conversely, if
// lo_'s high bit is set, *this must be < 0 for the value to fit.
return int128_internal::BitCastToSigned(lo_);
}
constexpr int128::operator unsigned long long() const { // NOLINT(runtime/int)
return static_cast<unsigned long long>(lo_); // NOLINT(runtime/int)
}
// Forward declaration for conversion operators to floating point types.
int128 operator-(int128 v);
bool operator!=(int128 lhs, int128 rhs);
inline int128::operator float() const {
// We must convert the absolute value and then negate as needed, because
// floating point types are typically sign-magnitude. Otherwise, the
// difference between the high and low 64 bits when interpreted as two's
// complement overwhelms the precision of the mantissa.
//
// Also check to make sure we don't negate Int128Min()
return hi_ < 0 && *this != Int128Min()
? -static_cast<float>(-*this)
: static_cast<float>(lo_) +
std::ldexp(static_cast<float>(hi_), 64);
}
inline int128::operator double() const {
// See comment in int128::operator float() above.
return hi_ < 0 && *this != Int128Min()
? -static_cast<double>(-*this)
: static_cast<double>(lo_) +
std::ldexp(static_cast<double>(hi_), 64);
}
inline int128::operator long double() const {
// See comment in int128::operator float() above.
return hi_ < 0 && *this != Int128Min()
? -static_cast<long double>(-*this)
: static_cast<long double>(lo_) +
std::ldexp(static_cast<long double>(hi_), 64);
}
// Comparison operators.
inline bool operator==(int128 lhs, int128 rhs) {
return (Int128Low64(lhs) == Int128Low64(rhs) &&
Int128High64(lhs) == Int128High64(rhs));
}
inline bool operator!=(int128 lhs, int128 rhs) {
return !(lhs == rhs);
}
inline bool operator<(int128 lhs, int128 rhs) {
return (Int128High64(lhs) == Int128High64(rhs))
? (Int128Low64(lhs) < Int128Low64(rhs))
: (Int128High64(lhs) < Int128High64(rhs));
}
inline bool operator>(int128 lhs, int128 rhs) {
return (Int128High64(lhs) == Int128High64(rhs))
? (Int128Low64(lhs) > Int128Low64(rhs))
: (Int128High64(lhs) > Int128High64(rhs));
}
inline bool operator<=(int128 lhs, int128 rhs) {
return !(lhs > rhs);
}
inline bool operator>=(int128 lhs, int128 rhs) {
return !(lhs < rhs);
}
// Unary operators.
inline int128 operator-(int128 v) {
int64_t hi = ~Int128High64(v);
uint64_t lo = ~Int128Low64(v) + 1;
if (lo == 0) ++hi; // carry
return MakeInt128(hi, lo);
}
inline bool operator!(int128 v) {
return !Int128Low64(v) && !Int128High64(v);
}
inline int128 operator~(int128 val) {
return MakeInt128(~Int128High64(val), ~Int128Low64(val));
}
// Arithmetic operators.
inline int128 operator+(int128 lhs, int128 rhs) {
int128 result = MakeInt128(Int128High64(lhs) + Int128High64(rhs),
Int128Low64(lhs) + Int128Low64(rhs));
if (Int128Low64(result) < Int128Low64(lhs)) { // check for carry
return MakeInt128(Int128High64(result) + 1, Int128Low64(result));
}
return result;
}
inline int128 operator-(int128 lhs, int128 rhs) {
int128 result = MakeInt128(Int128High64(lhs) - Int128High64(rhs),
Int128Low64(lhs) - Int128Low64(rhs));
if (Int128Low64(lhs) < Int128Low64(rhs)) { // check for carry
return MakeInt128(Int128High64(result) - 1, Int128Low64(result));
}
return result;
}
inline int128 operator*(int128 lhs, int128 rhs) {
uint128 result = uint128(lhs) * rhs;
return MakeInt128(int128_internal::BitCastToSigned(Uint128High64(result)),
Uint128Low64(result));
}
inline int128 int128::operator++(int) {
int128 tmp(*this);
*this += 1;
return tmp;
}
inline int128 int128::operator--(int) {
int128 tmp(*this);
*this -= 1;
return tmp;
}
inline int128& int128::operator++() {
*this += 1;
return *this;
}
inline int128& int128::operator--() {
*this -= 1;
return *this;
}
inline int128 operator|(int128 lhs, int128 rhs) {
return MakeInt128(Int128High64(lhs) | Int128High64(rhs),
Int128Low64(lhs) | Int128Low64(rhs));
}
inline int128 operator&(int128 lhs, int128 rhs) {
return MakeInt128(Int128High64(lhs) & Int128High64(rhs),
Int128Low64(lhs) & Int128Low64(rhs));
}
inline int128 operator^(int128 lhs, int128 rhs) {
return MakeInt128(Int128High64(lhs) ^ Int128High64(rhs),
Int128Low64(lhs) ^ Int128Low64(rhs));
}
inline int128 operator<<(int128 lhs, int amount) {
// uint64_t shifts of >= 64 are undefined, so we need some special-casing.
if (amount < 64) {
if (amount != 0) {
return MakeInt128(
(Int128High64(lhs) << amount) |
static_cast<int64_t>(Int128Low64(lhs) >> (64 - amount)),
Int128Low64(lhs) << amount);
}
return lhs;
}
return MakeInt128(static_cast<int64_t>(Int128Low64(lhs) << (amount - 64)), 0);
}
inline int128 operator>>(int128 lhs, int amount) {
// uint64_t shifts of >= 64 are undefined, so we need some special-casing.
if (amount < 64) {
if (amount != 0) {
return MakeInt128(
Int128High64(lhs) >> amount,
(Int128Low64(lhs) >> amount) |
(static_cast<uint64_t>(Int128High64(lhs)) << (64 - amount)));
}
return lhs;
}
return MakeInt128(0,
static_cast<uint64_t>(Int128High64(lhs) >> (amount - 64)));
}