diff options
| -rw-r--r-- | absl/base/internal/cycleclock.cc | 18 | ||||
| -rw-r--r-- | absl/container/internal/compressed_tuple.h | 6 | ||||
| -rw-r--r-- | absl/strings/BUILD.bazel | 1 | ||||
| -rw-r--r-- | absl/strings/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | absl/strings/internal/str_format/convert_test.cc | 74 | ||||
| -rw-r--r-- | absl/strings/internal/str_format/float_conversion.cc | 497 | ||||
| -rw-r--r-- | absl/types/internal/optional.h | 36 | ||||
| -rw-r--r-- | absl/types/optional.h | 29 |
8 files changed, 78 insertions, 584 deletions
diff --git a/absl/base/internal/cycleclock.cc b/absl/base/internal/cycleclock.cc index 4b553c29a2c3..e9844b7177a1 100644 --- a/absl/base/internal/cycleclock.cc +++ b/absl/base/internal/cycleclock.cc @@ -55,10 +55,23 @@ static constexpr int32_t kShift = 2; static constexpr double kFrequencyScale = 1.0 / (1 << kShift); static std::atomic<CycleClockSourceFunc> cycle_clock_source; +CycleClockSourceFunc LoadCycleClockSource() { + // Optimize for the common case (no callback) by first doing a relaxed load; + // this is significantly faster on non-x86 platforms. + if (cycle_clock_source.load(std::memory_order_relaxed) == nullptr) { + return nullptr; + } + // This corresponds to the store(std::memory_order_release) in + // CycleClockSource::Register, and makes sure that any updates made prior to + // registering the callback are visible to this thread before the callback is + // invoked. + return cycle_clock_source.load(std::memory_order_acquire); +} + } // namespace int64_t CycleClock::Now() { - auto fn = cycle_clock_source.load(std::memory_order_relaxed); + auto fn = LoadCycleClockSource(); if (fn == nullptr) { return base_internal::UnscaledCycleClock::Now() >> kShift; } @@ -70,7 +83,8 @@ double CycleClock::Frequency() { } void CycleClockSource::Register(CycleClockSourceFunc source) { - cycle_clock_source.store(source, std::memory_order_relaxed); + // Corresponds to the load(std::memory_order_acquire) in LoadCycleClockSource. + cycle_clock_source.store(source, std::memory_order_release); } #else diff --git a/absl/container/internal/compressed_tuple.h b/absl/container/internal/compressed_tuple.h index b9bd91afda60..bb3471f5d747 100644 --- a/absl/container/internal/compressed_tuple.h +++ b/absl/container/internal/compressed_tuple.h @@ -38,13 +38,13 @@ #include "absl/utility/utility.h" -#ifdef _MSC_VER +#if defined(_MSC_VER) && !defined(__NVCC__) // We need to mark these classes with this declspec to ensure that // CompressedTuple happens. #define ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC __declspec(empty_bases) -#else // _MSC_VER +#else #define ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC -#endif // _MSC_VER +#endif namespace absl { namespace container_internal { diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel index acf91e574cf8..9640ff4627cb 100644 --- a/absl/strings/BUILD.bazel +++ b/absl/strings/BUILD.bazel @@ -557,7 +557,6 @@ cc_library( visibility = ["//visibility:private"], deps = [ ":strings", - "//absl/base:bits", "//absl/base:core_headers", "//absl/container:inlined_vector", "//absl/meta:type_traits", diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt index 461b279d5c6e..d3393a39eb46 100644 --- a/absl/strings/CMakeLists.txt +++ b/absl/strings/CMakeLists.txt @@ -384,7 +384,6 @@ absl_cc_library( COPTS ${ABSL_DEFAULT_COPTS} DEPS - absl::bits absl::strings absl::core_headers absl::inlined_vector diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc index b272dd7b5cfa..99cc0afe4eb3 100644 --- a/absl/strings/internal/str_format/convert_test.cc +++ b/absl/strings/internal/str_format/convert_test.cc @@ -2,7 +2,6 @@ #include <stdarg.h> #include <stdio.h> #include <cmath> -#include <limits> #include <string> #include "gtest/gtest.h" @@ -398,8 +397,8 @@ TEST_F(FormatConvertTest, Float) { #endif // _MSC_VER const char *const kFormats[] = { - "%", "%.3", "%8.5", "%9", "%.5000", "%.60", "%.30", "%03", - "%+", "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"}; + "%", "%.3", "%8.5", "%9", "%.60", "%.30", "%03", "%+", + "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"}; std::vector<double> doubles = {0.0, -0.0, @@ -439,36 +438,12 @@ TEST_F(FormatConvertTest, Float) { } } - // Workaround libc bug. - // https://sourceware.org/bugzilla/show_bug.cgi?id=22142 - if (StrPrint("%f", std::numeric_limits<double>::max()) != - "1797693134862315708145274237317043567980705675258449965989174768031" - "5726078002853876058955863276687817154045895351438246423432132688946" - "4182768467546703537516986049910576551282076245490090389328944075868" - "5084551339423045832369032229481658085593321233482747978262041447231" - "68738177180919299881250404026184124858368.000000") { - for (auto &d : doubles) { - using L = std::numeric_limits<double>; - double d2 = std::abs(d); - if (d2 == L::max() || d2 == L::min() || d2 == L::denorm_min()) { - d = 0; - } - } - } - for (const char *fmt : kFormats) { for (char f : {'f', 'F', // 'g', 'G', // 'a', 'A', // 'e', 'E'}) { std::string fmt_str = std::string(fmt) + f; - - if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') { - // This particular test takes way too long with snprintf. - // Disable for the case we are not implementing natively. - continue; - } - for (double d : doubles) { int i = -10; FormatArgImpl args[2] = {FormatArgImpl(d), FormatArgImpl(i)}; @@ -479,24 +454,27 @@ TEST_F(FormatConvertTest, Float) { ASSERT_EQ(StrPrint(fmt_str.c_str(), d, i), FormatPack(format, absl::MakeSpan(args))) << fmt_str << " " << StrPrint("%.18g", d) << " " - << StrPrint("%a", d) << " " << StrPrint("%.1080f", d); + << StrPrint("%.999f", d); } } } } TEST_F(FormatConvertTest, LongDouble) { -#if _MSC_VER - // MSVC has a different rounding policy than us so we can't test our - // implementation against the native one there. - return; -#endif // _MSC_VER - const char *const kFormats[] = {"%", "%.3", "%8.5", "%9", "%.5000", + const char *const kFormats[] = {"%", "%.3", "%8.5", "%9", "%.60", "%+", "% ", "%-10"}; + // This value is not representable in double, but it is in long double that + // uses the extended format. + // This is to verify that we are not truncating the value mistakenly through a + // double. + long double very_precise = 10000000000000000.25L; + std::vector<long double> doubles = { 0.0, -0.0, + very_precise, + 1 / very_precise, std::numeric_limits<long double>::max(), -std::numeric_limits<long double>::max(), std::numeric_limits<long double>::min(), @@ -504,44 +482,22 @@ TEST_F(FormatConvertTest, LongDouble) { std::numeric_limits<long double>::infinity(), -std::numeric_limits<long double>::infinity()}; - for (long double base : {1.L, 12.L, 123.L, 1234.L, 12345.L, 123456.L, - 1234567.L, 12345678.L, 123456789.L, 1234567890.L, - 12345678901.L, 123456789012.L, 1234567890123.L, - // This value is not representable in double, but it - // is in long double that uses the extended format. - // This is to verify that we are not truncating the - // value mistakenly through a double. - 10000000000000000.25L}) { - for (int exp : {-1000, -500, 0, 500, 1000}) { - for (int sign : {1, -1}) { - doubles.push_back(sign * std::ldexp(base, exp)); - doubles.push_back(sign / std::ldexp(base, exp)); - } - } - } - for (const char *fmt : kFormats) { for (char f : {'f', 'F', // 'g', 'G', // 'a', 'A', // 'e', 'E'}) { std::string fmt_str = std::string(fmt) + 'L' + f; - - if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') { - // This particular test takes way too long with snprintf. - // Disable for the case we are not implementing natively. - continue; - } - for (auto d : doubles) { FormatArgImpl arg(d); UntypedFormatSpecImpl format(fmt_str); // We use ASSERT_EQ here because failures are usually correlated and a // bug would print way too many failed expectations causing the test to // time out. - ASSERT_EQ(StrPrint(fmt_str.c_str(), d), FormatPack(format, {&arg, 1})) + ASSERT_EQ(StrPrint(fmt_str.c_str(), d), + FormatPack(format, {&arg, 1})) << fmt_str << " " << StrPrint("%.18Lg", d) << " " - << StrPrint("%La", d) << " " << StrPrint("%.1080Lf", d); + << StrPrint("%.999Lf", d); } } } diff --git a/absl/strings/internal/str_format/float_conversion.cc b/absl/strings/internal/str_format/float_conversion.cc index 20012b5876cc..6176db9cb5a2 100644 --- a/absl/strings/internal/str_format/float_conversion.cc +++ b/absl/strings/internal/str_format/float_conversion.cc @@ -2,476 +2,15 @@ #include <string.h> #include <algorithm> -#include <array> #include <cassert> #include <cmath> -#include <limits> #include <string> -#include "absl/base/attributes.h" -#include "absl/base/internal/bits.h" -#include "absl/base/optimization.h" -#include "absl/meta/type_traits.h" -#include "absl/numeric/int128.h" -#include "absl/types/span.h" - namespace absl { namespace str_format_internal { namespace { -// Calculates `10 * (*v) + carry` and stores the result in `*v` and returns -// the carry. -template <typename Int> -inline Int MultiplyBy10WithCarry(Int *v, Int carry) { - using NextInt = absl::conditional_t<sizeof(Int) == 4, uint64_t, uint128>; - static_assert(sizeof(void *) >= sizeof(Int), - "Don't want to use uint128 in 32-bit mode. It is too slow."); - NextInt tmp = 10 * static_cast<NextInt>(*v) + carry; - *v = static_cast<Int>(tmp); - return static_cast<Int>(tmp >> (sizeof(Int) * 8)); -} - -// Calculates `(2^64 * carry + *v) / 10`. -// Stores the quotient in `*v` and returns the remainder. -// Requires: `0 <= carry <= 9` -inline uint64_t DivideBy10WithCarry(uint64_t *v, uint64_t carry) { - constexpr uint64_t divisor = 10; - // 2^64 / divisor = word_quotient + word_remainder / divisor - constexpr uint64_t word_quotient = (uint64_t{1} << 63) / (divisor / 2); - constexpr uint64_t word_remainder = uint64_t{} - word_quotient * divisor; - - const uint64_t mod = *v % divisor; - const uint64_t next_carry = word_remainder * carry + mod; - *v = *v / divisor + carry * word_quotient + next_carry / divisor; - return next_carry % divisor; -} - -int LeadingZeros(uint64_t v) { return base_internal::CountLeadingZeros64(v); } -int LeadingZeros(uint128 v) { - auto high = static_cast<uint64_t>(v >> 64); - auto low = static_cast<uint64_t>(v); - return high != 0 ? base_internal::CountLeadingZeros64(high) - : 64 + base_internal::CountLeadingZeros64(low); -} - -int TrailingZeros(uint64_t v) { - return base_internal::CountTrailingZerosNonZero64(v); -} -int TrailingZeros(uint128 v) { - auto high = static_cast<uint64_t>(v >> 64); - auto low = static_cast<uint64_t>(v); - return low == 0 ? 64 + base_internal::CountTrailingZerosNonZero64(high) - : base_internal::CountTrailingZerosNonZero64(low); -} - -// The buffer must have an extra digit that is known to not need rounding. -// This is done below by having an extra '0' digit on the left. -void RoundUp(char *last_digit) { - char *p = last_digit; - while (*p == '9' || *p == '.') { - if (*p == '9') *p = '0'; - --p; - } - ++*p; -} - -void RoundToEven(char *last_digit) { - char *p = last_digit; - if (*p == '.') --p; - if (*p % 2 == 1) RoundUp(p); -} - -char *PrintIntegralDigitsFromRightDynamic(uint128 v, Span<uint32_t> array, - int exp, char *p) { - if (v == 0) { - *--p = '0'; - return p; - } - - int w = exp / 32; - const int offset = exp % 32; - // Left shift v by exp bits. - array[w] = static_cast<uint32_t>(v << offset); - for (v >>= (32 - offset); v; v >>= 32) array[++w] = static_cast<uint32_t>(v); - - // While we have more than one word available, go in chunks of 1e9. - // We are guaranteed to have at least those many digits. - // `w` holds the largest populated word, so keep it updated. - while (w > 0) { - uint32_t carry = 0; - for (int i = w; i >= 0; --i) { - uint64_t tmp = uint64_t{array[i]} + (uint64_t{carry} << 32); - array[i] = tmp / uint64_t{1000000000}; - carry = tmp % uint64_t{1000000000}; - } - // If the highest word is now empty, remove it from view. - if (array[w] == 0) --w; - - for (int i = 0; i < 9; ++i, carry /= 10) { - *--p = carry % 10 + '0'; - } - } - - // Print the leftover of the last word. - for (auto last = array[0]; last != 0; last /= 10) { - *--p = last % 10 + '0'; - } - - return p; -} - -struct FractionalResult { - const char *end; - int precision; -}; - -FractionalResult PrintFractionalDigitsDynamic(uint128 v, Span<uint32_t> array, - char *p, int exp, int precision) { - int w = exp / 32; - const int offset = exp % 32; - - // Right shift `v` by `exp` bits. - array[w] = static_cast<uint32_t>(v << (32 - offset)); - v >>= offset; - // Make sure we don't overflow the array. We already calculated that non-zero - // bits fit, so we might not have space for leading zero bits. - for (int pos = w; v; v >>= 32) array[--pos] = static_cast<uint32_t>(v); - - // Multiply the whole sequence by 10. - // On each iteration, the leftover carry word is the next digit. - // `w` holds the largest populated word, so keep it updated. - for (; w >= 0 && precision > 0; --precision) { - uint32_t carry = 0; - for (int i = w; i >= 0; --i) { - carry = MultiplyBy10WithCarry(&array[i], carry); - } - // If the lowest word is now empty, remove it from view. - if (array[w] == 0) --w; - *p++ = carry + '0'; - } - - constexpr uint32_t threshold = 0x80000000; - if (array[0] < threshold) { - // We round down, so nothing to do. - } else if (array[0] > threshold || - std::any_of(&array[1], &array[w + 1], - [](uint32_t word) { return word != 0; })) { - RoundUp(p - 1); - } else { - RoundToEven(p - 1); - } - return {p, precision}; -} - -// Generic digit printer. -// `bits` determines how many bits of termporary space it needs for the -// calcualtions. -template <int bits, typename = void> -class DigitPrinter { - static constexpr int kInts = (bits + 31) / 32; - - public: - // Quick upper bound for the number of decimal digits we need. - // This would be std::ceil(std::log10(std::pow(2, bits))), but that is not - // constexpr. - static constexpr int kDigits10 = 1 + (bits + 9) / 10 * 3 + bits / 900; - using InputType = uint128; - - static char *PrintIntegralDigitsFromRight(InputType v, int exp, char *end) { - std::array<uint32_t, kInts> array{}; - return PrintIntegralDigitsFromRightDynamic(v, absl::MakeSpan(array), exp, - end); - } - - static FractionalResult PrintFractionalDigits(InputType v, char *p, int exp, - int precision) { - std::array<uint32_t, kInts> array{}; - return PrintFractionalDigitsDynamic(v, absl::MakeSpan(array), p, exp, - precision); - } -}; - -// Specialiation for 64-bit working space. -// This is a performance optimization over the generic primary template. -// Only enabled in 64-bit platforms. The generic one is faster in 32-bit -// platforms. -template <int bits> -class DigitPrinter<bits, absl::enable_if_t<bits == 64 && (sizeof(void *) >= - sizeof(uint64_t))>> { - public: - static constexpr size_t kDigits10 = 20; - using InputType = uint64_t; - - static char *PrintIntegralDigitsFromRight(uint64_t v, int exp, char *p) { - v <<= exp; - do { - *--p = DivideBy10WithCarry(&v, 0) + '0'; - } while (v != 0); - return p; - } - - static FractionalResult PrintFractionalDigits(uint64_t v, char *p, int exp, - int precision) { - v <<= (64 - exp); - while (precision > 0) { - if (!v) return {p, precision}; - *p++ = MultiplyBy10WithCarry(&v, uint64_t{}) + '0'; - --precision; - } - - // We need to round. - if (v < 0x8000000000000000) { - // We round down, so nothing to do. - } else if (v > 0x8000000000000000) { - // We round up. - RoundUp(p - 1); - } else { - RoundToEven(p - 1); - } - - assert(precision == 0); - // Precision can only be zero here. Return a constant instead. - return {p, 0}; - } -}; - -// Specialiation for 128-bit working space. -// This is a performance optimization over the generic primary template. -template <int bits> -class DigitPrinter<bits, absl::enable_if_t<bits == 128 && (sizeof(void *) >= - sizeof(uint64_t))>> { - public: - static constexpr size_t kDigits10 = 40; - using InputType = uint128; - - static char *PrintIntegralDigitsFromRight(uint128 v, int exp, char *p) { - v <<= exp; - auto high = static_cast<uint64_t>(v >> 64); - auto low = static_cast<uint64_t>(v); - - do { - uint64_t carry = DivideBy10WithCarry(&high, 0); - carry = DivideBy10WithCarry(&low, carry); - *--p = carry + '0'; - } while (high != 0u); - - while (low != 0u) { - *--p = DivideBy10WithCarry(&low, 0) + '0'; - } - return p; - } - - static FractionalResult PrintFractionalDigits(uint128 v, char *p, int exp, - int precision) { - v <<= (128 - exp); - auto high = static_cast<uint64_t>(v >> 64); - auto low = static_cast<uint64_t>(v); - - // While we have digits to print and `low` is not empty, do the long - // multiplication. - while (precision > 0 && low != 0) { - uint64_t carry = MultiplyBy10WithCarry(&low, uint64_t{}); - carry = MultiplyBy10WithCarry(&high, carry); - - *p++ = carry + '0'; - --precision; - } - - // Now `low` is empty, so use a faster approach for the rest of the digits. - // This block is pretty much the same as the main loop for the 64-bit case - // above. - while (precision > 0) { - if (!high) return {p, precision}; - *p++ = MultiplyBy10WithCarry(&high, uint64_t{}) + '0'; - --precision; - } - - // We need to round. - if (high < 0x8000000000000000) { - // We round down, so nothing to do. - } else if (high > 0x8000000000000000 || low != 0) { - // We round up. - RoundUp(p - 1); - } else { - RoundToEven(p - 1); - } - - assert(precision == 0); - // Precision can only be zero here. Return a constant instead. - return {p, 0}; - } -}; - -struct FormatState { - char sign_char; - int precision; - const ConversionSpec &conv; - FormatSinkImpl *sink; -}; - -void FinalPrint(string_view data, int trailing_zeros, - const FormatState &state) { - if (state.conv.width() < 0) { - // No width specified. Fast-path. - if (state.sign_char != '\0') state.sink->Append(1, state.sign_char); - state.sink->Append(data); - state.sink->Append(trailing_zeros, '0'); - return; - } - - int left_spaces = 0, zeros = 0, right_spaces = 0; - int total_size = (state.sign_char != 0 ? 1 : 0) + - static_cast<int>(data.size()) + trailing_zeros; - int missing_chars = std::max(state.conv.width() - total_size, 0); - if (state.conv.flags().left) { - right_spaces = missing_chars; - } else if (state.conv.flags().zero) { - zeros = missing_chars; - } else { - left_spaces = missing_chars; - } - - state.sink->Append(left_spaces, ' '); - if (state.sign_char != '\0') state.sink->Append(1, state.sign_char); - state.sink->Append(zeros, '0'); - state.sink->Append(data); - state.sink->Append(trailing_zeros, '0'); - state.sink->Append(right_spaces, ' '); -} - -template <int num_bits, typename Int> -void FormatFPositiveExp(Int v, int exp, const FormatState &state) { - using IntegralPrinter = DigitPrinter<num_bits>; - char buffer[IntegralPrinter::kDigits10 + /* . */ 1]; - buffer[IntegralPrinter::kDigits10] = '.'; - - const char *digits = IntegralPrinter::PrintIntegralDigitsFromRight( - static_cast<typename IntegralPrinter::InputType>(v), exp, - buffer + sizeof(buffer) - 1); - size_t size = buffer + sizeof(buffer) - digits; - - // In `alt` mode (flag #) we keep the `.` even if there are no fractional - // digits. In non-alt mode, we strip it. - if (ABSL_PREDICT_FALSE(state.precision == 0 && !state.conv.flags().alt)) { - --size; - } - - FinalPrint(string_view(digits, size), state.precision, state); -} - -template <int num_bits, typename Int> -void FormatFNegativeExp(Int v, int exp, const FormatState &state) { - constexpr int input_bits = sizeof(Int) * 8; - - using IntegralPrinter = DigitPrinter<input_bits>; - using FractionalPrinter = DigitPrinter<num_bits>; - - static constexpr size_t integral_size = - 1 + /* in case we need to round up an extra digit */ - IntegralPrinter::kDigits10 + 1; - char buffer[integral_size + /* . */ 1 + num_bits]; - buffer[integral_size] = '.'; - char *const integral_digits_end = buffer + integral_size; - char *integral_digits_start; - char *const fractional_digits_start = buffer + integral_size + 1; - - if (exp < input_bits) { - integral_digits_start = IntegralPrinter::PrintIntegralDigitsFromRight( - v >> exp, 0, integral_digits_end); - } else { - integral_digits_start = integral_digits_end - 1; - *integral_digits_start = '0'; - } - - // PrintFractionalDigits may pull a carried 1 all the way up through the - // integral portion. - integral_digits_start[-1] = '0'; - auto fractional_result = FractionalPrinter::PrintFractionalDigits( - static_cast<typename FractionalPrinter::InputType>(v), - fractional_digits_start, exp, state.precision); - if (integral_digits_start[-1] != '0') --integral_digits_start; - - size_t size = fractional_result.end - integral_digits_start; - - // In `alt` mode (flag #) we keep the `.` even if there are no fractional - // digits. In non-alt mode, we strip it. - if (ABSL_PREDICT_FALSE(state.precision == 0 && !state.conv.flags().alt)) { - --size; - } - FinalPrint(string_view(integral_digits_start, size), - fractional_result.precision, state); -} - -template <typename Int> -void FormatF(Int mantissa, int exp, const FormatState &state) { - // Remove trailing zeros as they are not useful. - // This helps use faster implementations/less stack space in some cases. - if (mantissa != 0) { - int trailing = TrailingZeros(mantissa); - mantissa >>= trailing; - exp += trailing; - } - - // The table driven dispatch gives us two benefits: fast distpatch and - // prevent inlining. - // We must not inline any of the functions below (other than the ones for - // 64-bit) to avoid blowing up this stack frame. - - if (exp >= 0) { - // We will left shift the mantissa. Calculate how many bits we need. - // Special case 64-bit as we will use a uint64_t for it. Use a table for the - // rest and unconditionally use uint128. - const int total_bits = sizeof(Int) * 8 - LeadingZeros(mantissa) + exp; - - if (total_bits <= 64) { - return FormatFPositiveExp<64>(mantissa, exp, state); - } else { - using Formatter = void (*)(uint128, int, const FormatState &); - static constexpr Formatter kFormatters[] = { - FormatFPositiveExp<1 << 7>, FormatFPositiveExp<1 << 8>, - FormatFPositiveExp<1 << 9>, FormatFPositiveExp<1 << 10>, - FormatFPositiveExp<1 << 11>, FormatFPositiveExp<1 << 12>, - FormatFPositiveExp<1 << 13>, FormatFPositiveExp<1 << 14>, - FormatFPositiveExp<1 << 15>, - }; - static constexpr int max_total_bits = - sizeof(Int) * 8 + std::numeric_limits<long double>::max_exponent; - assert(total_bits <= max_total_bits); - static_assert(max_total_bits <= (1 << 15), ""); - const int log2 = - 64 - LeadingZeros((static_cast<uint64_t>(total_bits) - 1) / 128); - assert(log2 < std::end(kFormatters) - std::begin(kFormatters)); - kFormatters[log2](mantissa, exp, state); - } - } else { - exp = -exp; - - // We know we don't need more than Int itself for the integral part. - // We need `precision` fractional digits, but there are at most `exp` - // non-zero digits after the decimal point. The rest will be zeros. - // Special case 64-bit as we will use a uint64_t for it. Use a table for the - // rest and unconditionally use uint128. - - if (exp <= 64) { - return FormatFNegativeExp<64>(mantissa, exp, state); - } else { - using Formatter = void (*)(uint128, int, const FormatState &); - static constexpr Formatter kFormatters[] = { - FormatFNegativeExp<1 << 7>, FormatFNegativeExp<1 << 8>, - FormatFNegativeExp<1 << 9>, FormatFNegativeExp<1 << 10>, - FormatFNegativeExp<1 << 11>, FormatFNegativeExp<1 << 12>, - FormatFNegativeExp<1 << 13>, FormatFNegativeExp<1 << 14>}; - static_assert( - -std::numeric_limits<long double>::min_exponent <= (1 << 14), ""); - const int log2 = - 64 - LeadingZeros((static_cast<uint64_t>(exp) - 1) / 128); - assert(log2 < std::end(kFormatters) - std::begin(kFormatters)); - kFormatters[log2](mantissa, exp, state); - } - } -} - char *CopyStringTo(string_view v, char *out) { std::memcpy(out, v.data(), v.size()); return out + v.size(); @@ -556,7 +95,7 @@ template <typename Float> bool ConvertNonNumericFloats(char sign_char, Float v, const ConversionSpec &conv, FormatSinkImpl *sink) { char text[4], *ptr = text; - if (sign_char != '\0') *ptr++ = sign_char; + if (sign_char) *ptr++ = sign_char; if (std::isnan(v)) { ptr = std::copy_n(conv.conv().upper() ? "NAN" : "nan", 3, ptr); } else if (std::isinf(v)) { @@ -626,12 +165,7 @@ constexpr bool CanFitMantissa() { template <typename Float> struct Decomposed { - using MantissaType = - absl::conditional_t<std::is_same<long double, Float>::value, uint128, - uint64_t>; - static_assert(std::numeric_limits<Float>::digits <= sizeof(MantissaType) * 8, - ""); - MantissaType mantissa; + Float mantissa; int exponent; }; @@ -642,8 +176,7 @@ Decomposed<Float> Decompose(Float v) { Float m = std::frexp(v, &exp); m = std::ldexp(m, std::numeric_limits<Float>::digits); exp -= std::numeric_limits<Float>::digits; - - return {static_cast<typename Decomposed<Float>::MantissaType>(m), exp}; + return {m, exp}; } // Print 'digits' as decimal. @@ -801,7 +334,7 @@ bool FloatToBuffer(Decomposed<Float> decomposed, int precision, Buffer *out, static_cast<std::uint64_t>(decomposed.exponent), precision, out, exp)) return true; -#if defined(ABSL_HAVE_INTRINSIC_INT128) +#if defined(__SIZEOF_INT128__) // If that is not enough, try with __uint128_t. return CanFitMantissa<Float, __uint128_t>() && FloatToBufferImpl<__uint128_t, Float, mode>( @@ -829,7 +362,7 @@ void WriteBufferToSink(char sign_char, string_view str, } sink->Append(left_spaces, ' '); - if (sign_char != '\0') sink->Append(1, sign_char); + if (sign_char) sink->Append(1, sign_char); sink->Append(zeros, '0'); sink->Append(str); sink->Append(right_spaces, ' '); @@ -866,9 +399,12 @@ bool FloatToSink(const Float v, const ConversionSpec &conv, switch (conv.conv().id()) { case ConversionChar::f: case ConversionChar::F: - FormatF(decomposed.mantissa, decomposed.exponent, - {sign_char, precision, conv, sink}); - return true; + if (!FloatToBuffer<FormatStyle::Fixed>(decomposed, precision, &buffer, + nullptr)) { + return FallbackToSnprintf(v, conv, sink); + } + if (!conv.flags().alt && buffer.back() == '.') buffer.pop_back(); + break; case ConversionChar::e: case ConversionChar::E: @@ -930,22 +466,11 @@ bool FloatToSink(const Float v, const ConversionSpec &conv, bool ConvertFloatImpl(long double v, const ConversionSpec &conv, FormatSinkImpl *sink) { - if (std::numeric_limits<long double>::digits == - 2 * std::numeric_limits<double>::digits) { - // This is the `double-double` representation of `long double`. - // We do not handle it natively. Fallback to snprintf. - return FallbackToSnprintf(v, conv, sink); - } - return FloatToSink(v, conv, sink); } bool ConvertFloatImpl(float v, const ConversionSpec &conv, FormatSinkImpl *sink) { - // DivideBy10WithCarry is not actually used in some builds. This here silences - // the "unused" warning. We just need to put it in any function that is really - // used. - (void)&DivideBy10WithCarry; return FloatToSink(v, conv, sink); } diff --git a/absl/types/internal/optional.h b/absl/types/internal/optional.h index 562c84ef5af7..8acbda20d559 100644 --- a/absl/types/internal/optional.h +++ b/absl/types/internal/optional.h @@ -25,6 +25,34 @@ #include "absl/meta/type_traits.h" #include "absl/utility/utility.h" +// ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +// +// Inheriting constructors is supported in GCC 4.8+, Clang 3.3+ and MSVC 2015. +// __cpp_inheriting_constructors is a predefined macro and a recommended way to +// check for this language feature, but GCC doesn't support it until 5.0 and +// Clang doesn't support it until 3.6. +// Also, MSVC 2015 has a bug: it doesn't inherit the constexpr template +// constructor. For example, the following code won't work on MSVC 2015 Update3: +// struct Base { +// int t; +// template <typename T> +// constexpr Base(T t_) : t(t_) {} +// }; +// struct Foo : Base { +// using Base::Base; +// } +// constexpr Foo foo(0); // doesn't work on MSVC 2015 +#if defined(__clang__) +#if __has_feature(cxx_inheriting_constructors) +#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 +#endif +#elif (defined(__GNUC__) && \ + (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 8)) || \ + (__cpp_inheriting_constructors >= 200802) || \ + (defined(_MSC_VER) && _MSC_VER >= 1910) +#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 +#endif + namespace absl { // Forward declaration @@ -108,7 +136,7 @@ template <typename T> class optional_data_base : public optional_data_dtor_base<T> { protected: using base = optional_data_dtor_base<T>; -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using base::base; #else optional_data_base() = default; @@ -151,7 +179,7 @@ class optional_data; template <typename T> class optional_data<T, true> : public optional_data_base<T> { protected: -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using optional_data_base<T>::optional_data_base; #else optional_data() = default; @@ -165,7 +193,7 @@ class optional_data<T, true> : public optional_data_base<T> { template <typename T> class optional_data<T, false> : public optional_data_base<T> { protected: -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using optional_data_base<T>::optional_data_base; #else template <typename... Args> @@ -361,4 +389,6 @@ struct optional_hash_base<T, decltype(std::hash<absl::remove_const_t<T> >()( } // namespace optional_internal } // namespace absl +#undef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS + #endif // ABSL_TYPES_INTERNAL_OPTIONAL_H_ diff --git a/absl/types/optional.h b/absl/types/optional.h index 17f789847386..579833196424 100644 --- a/absl/types/optional.h +++ b/absl/types/optional.h @@ -64,34 +64,6 @@ using std::nullopt; #include "absl/types/bad_optional_access.h" #include "absl/types/internal/optional.h" -// ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS -// -// Inheriting constructors is supported in GCC 4.8+, Clang 3.3+ and MSVC 2015. -// __cpp_inheriting_constructors is a predefined macro and a recommended way to -// check for this language feature, but GCC doesn't support it until 5.0 and -// Clang doesn't support it until 3.6. -// Also, MSVC 2015 has a bug: it doesn't inherit the constexpr template -// constructor. For example, the following code won't work on MSVC 2015 Update3: -// struct Base { -// int t; -// template <typename T> -// constexpr Base(T t_) : t(t_) {} -// }; -// struct Foo : Base { -// using Base::Base; -// } -// constexpr Foo foo(0); // doesn't work on MSVC 2015 -#if defined(__clang__) -#if __has_feature(cxx_inheriting_constructors) -#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 -#endif -#elif (defined(__GNUC__) && \ - (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 8)) || \ - (__cpp_inheriting_constructors >= 200802) || \ - (defined(_MSC_VER) && _MSC_VER >= 1910) -#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 -#endif - namespace absl { // nullopt_t @@ -791,7 +763,6 @@ struct hash<absl::optional<T> > } // namespace std -#undef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS #undef ABSL_MSVC_CONSTEXPR_BUG_IN_UNION_LIKE_CLASS #endif // ABSL_HAVE_STD_OPTIONAL |