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-rw-r--r--absl/strings/BUILD.bazel1
-rw-r--r--absl/strings/CMakeLists.txt1
-rw-r--r--absl/strings/internal/str_format/convert_test.cc74
-rw-r--r--absl/strings/internal/str_format/float_conversion.cc497
4 files changed, 26 insertions, 547 deletions
diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index acf91e57..9640ff46 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 461b279d..d3393a39 100644
--- a/absl/strings/CMakeLists.txt
+++ b/absl/strings/CMakeLists.txt
@@ -384,7 +384,6 @@ absl_cc_library(
COPTS
${ABSL_DEFAULT_COPTS}
DEPS
- absl::bits
absl::strings
absl::core_headers
absl::inlined_vector
diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc
index b272dd7b..99cc0afe 100644
--- a/absl/strings/internal/str_format/convert_test.cc
+++ b/absl/strings/internal/str_format/convert_test.cc
@@ -2,7 +2,6 @@
#include <stdarg.h>
#include <stdio.h>
#include <cmath>
-#include <limits>
#include <string>
#include "gtest/gtest.h"
@@ -398,8 +397,8 @@ TEST_F(FormatConvertTest, Float) {
#endif // _MSC_VER
const char *const kFormats[] = {
- "%", "%.3", "%8.5", "%9", "%.5000", "%.60", "%.30", "%03",
- "%+", "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*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 20012b58..6176db9c 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);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 03:49:04 +0000