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fast_float/include/fast_float/float_common.h

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#ifndef FASTFLOAT_FLOAT_COMMON_H
#define FASTFLOAT_FLOAT_COMMON_H
#include <cfloat>
#include <cstdint>
#include <cassert>
#include <cstring>
#include <limits>
#include <type_traits>
#include <system_error>
#ifdef __has_include
#if __has_include(<stdfloat>) && (__cplusplus > 202002L || (defined(_MSVC_LANG) && (_MSVC_LANG > 202002L)))
#include <stdfloat>
#endif
#endif
#include "constexpr_feature_detect.h"
#define FASTFLOAT_VERSION_MAJOR 8
#define FASTFLOAT_VERSION_MINOR 1
#define FASTFLOAT_VERSION_PATCH 0
#define FASTFLOAT_STRINGIZE_IMPL(x) #x
#define FASTFLOAT_STRINGIZE(x) FASTFLOAT_STRINGIZE_IMPL(x)
#define FASTFLOAT_VERSION_STR \
FASTFLOAT_STRINGIZE(FASTFLOAT_VERSION_MAJOR) \
"." FASTFLOAT_STRINGIZE(FASTFLOAT_VERSION_MINOR) "." FASTFLOAT_STRINGIZE( \
FASTFLOAT_VERSION_PATCH)
#define FASTFLOAT_VERSION \
(FASTFLOAT_VERSION_MAJOR * 10000 + FASTFLOAT_VERSION_MINOR * 100 + \
FASTFLOAT_VERSION_PATCH)
namespace fast_float {
// The number of digits in the mantissa.
typedef uint_fast16_t am_digits;
// The number of bits in the limb.
typedef uint_fast8_t limb_t;
typedef uint_fast8_t chars_format_t;
enum class chars_format : chars_format_t;
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
namespace detail {
constexpr chars_format basic_json_fmt = chars_format(1 << 4);
constexpr chars_format basic_fortran_fmt = chars_format(1 << 5);
} // namespace detail
#endif
enum class chars_format : chars_format_t {
scientific = 1 << 0,
fixed = 1 << 1,
general = fixed | scientific,
hex = 1 << 2,
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
no_infnan = 1 << 3,
// RFC 8259: https://datatracker.ietf.org/doc/html/rfc8259#section-6
json = chars_format_t(detail::basic_json_fmt) | general | no_infnan,
// Extension of RFC 8259 where, e.g., "inf" and "nan" are allowed.
json_or_infnan = chars_format_t(detail::basic_json_fmt) | general,
fortran = chars_format_t(detail::basic_fortran_fmt) | general,
allow_leading_plus = 1 << 6,
skip_white_space = 1 << 7,
#endif
};
template <typename UC> struct from_chars_result_t {
UC const *ptr;
std::errc ec;
// https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2497r0.html
constexpr explicit operator bool() const noexcept {
return ec == std::errc();
}
};
using from_chars_result = from_chars_result_t<char>;
template <typename UC> struct parse_options_t {
constexpr explicit parse_options_t(
chars_format const fmt = chars_format::general, UC const dot = UC('.'),
uint_fast8_t const b = 10) noexcept
: format(fmt), decimal_point(dot), base(b) {
FASTFLOAT_ASSUME(base >= 2 && base <= 36);
}
/** Which number formats are accepted */
chars_format format;
/** The character used as decimal point */
UC decimal_point;
/** The base used for integers */
uint_fast8_t base; /* only allowed from 2 to 36 */
};
using parse_options = parse_options_t<char>;
} // namespace fast_float
#if FASTFLOAT_HAS_BIT_CAST
#include <bit>
#endif
#if (defined(__x86_64) || defined(__x86_64__) || defined(_M_X64) || \
defined(__amd64) || defined(__aarch64__) || defined(_M_ARM64) || \
defined(__MINGW64__) || defined(__s390x__) || \
(defined(__ppc64__) || defined(__PPC64__) || defined(__ppc64le__) || \
defined(__PPC64LE__)) || \
defined(__loongarch64) || (defined(__riscv) && __riscv_xlen == 64))
#define FASTFLOAT_64BIT 1
#elif (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
defined(__arm__) || defined(_M_ARM) || defined(__ppc__) || \
defined(__MINGW32__) || defined(__EMSCRIPTEN__) || \
(defined(__riscv) && __riscv_xlen == 32))
#define FASTFLOAT_32BIT 1
#else
// Need to check incrementally, since SIZE_MAX is a size_t, avoid overflow.
// We can never tell the register width, but the SIZE_MAX is a good
// approximation. UINTPTR_MAX and INTPTR_MAX are optional, so avoid them for max
// portability.
#if SIZE_MAX == 0xffff
#error Unknown platform (16-bit, unsupported)
#elif SIZE_MAX == 0xffffffff
#define FASTFLOAT_32BIT 1
#elif SIZE_MAX == 0xffffffffffffffff
#define FASTFLOAT_64BIT 1
#else
#error Unknown platform (not 32-bit, not 64-bit?)
#endif
#endif
#if ((defined(_WIN32) || defined(_WIN64)) && !defined(__clang__)) || \
(defined(_M_ARM64) && !defined(__MINGW32__))
#include <intrin.h>
#endif
#if defined(_MSC_VER) && !defined(__clang__)
#define FASTFLOAT_VISUAL_STUDIO 1
#endif
#if defined __BYTE_ORDER__ && defined __ORDER_BIG_ENDIAN__
#define FASTFLOAT_IS_BIG_ENDIAN (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
#elif defined _WIN32
#define FASTFLOAT_IS_BIG_ENDIAN 0
#else
#if defined(__APPLE__) || defined(__FreeBSD__)
#include <machine/endian.h>
#elif defined(sun) || defined(__sun)
#include <sys/byteorder.h>
#elif defined(__MVS__)
#include <sys/endian.h>
#else
#ifdef __has_include
#if __has_include(<endian.h>)
#include <endian.h>
#endif //__has_include(<endian.h>)
#endif //__has_include
#endif
#
#ifndef __BYTE_ORDER__
// safe choice
#define FASTFLOAT_IS_BIG_ENDIAN 0
#endif
#
#ifndef __ORDER_LITTLE_ENDIAN__
// safe choice
#define FASTFLOAT_IS_BIG_ENDIAN 0
#endif
#
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define FASTFLOAT_IS_BIG_ENDIAN 0
#else
#define FASTFLOAT_IS_BIG_ENDIAN 1
#endif
#endif
#if defined(__SSE2__) || (defined(FASTFLOAT_VISUAL_STUDIO) && \
(defined(_M_AMD64) || defined(_M_X64) || \
(defined(_M_IX86_FP) && _M_IX86_FP == 2)))
#define FASTFLOAT_SSE2 1
#endif
#if defined(__aarch64__) || defined(_M_ARM64)
#define FASTFLOAT_NEON 1
#endif
#if defined(FASTFLOAT_SSE2) || defined(FASTFLOAT_NEON)
#define FASTFLOAT_HAS_SIMD 1
#endif
#if defined(__GNUC__)
// disable -Wcast-align=strict (GCC only)
#define FASTFLOAT_SIMD_DISABLE_WARNINGS \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wcast-align\"")
#else
#define FASTFLOAT_SIMD_DISABLE_WARNINGS
#endif
#if defined(__GNUC__)
#define FASTFLOAT_SIMD_RESTORE_WARNINGS _Pragma("GCC diagnostic pop")
#else
#define FASTFLOAT_SIMD_RESTORE_WARNINGS
#endif
#ifdef FASTFLOAT_VISUAL_STUDIO
#define fastfloat_really_inline __forceinline
#else
#define fastfloat_really_inline inline __attribute__((always_inline))
#endif
#ifndef FASTFLOAT_ASSERT
#define FASTFLOAT_ASSERT(x) \
{ ((void)(x)); }
#endif
#ifndef FASTFLOAT_DEBUG_ASSERT
#define FASTFLOAT_DEBUG_ASSERT(x) \
{ ((void)(x)); }
#endif
// rust style `try!()` macro, or `?` operator
#define FASTFLOAT_TRY(x) \
{ \
if (!(x)) \
return false; \
}
#define FASTFLOAT_ENABLE_IF(...) \
typename std::enable_if<(__VA_ARGS__), int>::type
namespace fast_float {
fastfloat_really_inline constexpr bool cpp20_and_in_constexpr() noexcept {
#if FASTFLOAT_HAS_IS_CONSTANT_EVALUATED
return std::is_constant_evaluated();
#else
return false;
#endif
}
template <typename T>
struct is_supported_float_type
: std::integral_constant<
bool, std::is_same<T, double>::value || std::is_same<T, float>::value
#ifdef __STDCPP_FLOAT64_T__
|| std::is_same<T, std::float64_t>::value
#endif
#ifdef __STDCPP_FLOAT32_T__
|| std::is_same<T, std::float32_t>::value
#endif
#ifdef __STDCPP_FLOAT16_T__
|| std::is_same<T, std::float16_t>::value
#endif
#ifdef __STDCPP_BFLOAT16_T__
|| std::is_same<T, std::bfloat16_t>::value
#endif
> {
};
template <typename T>
using equiv_uint_t = typename std::conditional<
sizeof(T) == 1, uint8_t,
typename std::conditional<
sizeof(T) == 2, uint16_t,
typename std::conditional<sizeof(T) == 4, uint32_t,
uint64_t>::type>::type>::type;
template <typename T> struct is_supported_integer_type : std::is_integral<T> {};
template <typename UC>
struct is_supported_char_type
: std::integral_constant<bool, std::is_same<UC, char>::value ||
std::is_same<UC, wchar_t>::value ||
std::is_same<UC, char16_t>::value ||
std::is_same<UC, char32_t>::value
#ifdef __cpp_char8_t
|| std::is_same<UC, char8_t>::value
#endif
> {
};
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
// Compares two ASCII strings in a case insensitive manner.
template <typename UC>
inline FASTFLOAT_CONSTEXPR14 bool
fastfloat_strncasecmp(UC const *actual_mixedcase, UC const *expected_lowercase,
uint8_t const length) noexcept {
for (uint8_t i = 0; i != length; ++i) {
UC const actual = actual_mixedcase[i];
if ((actual < 256 ? actual | 32 : actual) != expected_lowercase[i]) {
return false;
}
}
return true;
}
#endif
#ifndef FLT_EVAL_METHOD
#error "FLT_EVAL_METHOD should be defined, please include cfloat."
#endif
// a pointer and a length to a contiguous block of memory
template <typename T> struct span {
T const *ptr;
am_digits length;
constexpr span(T const *_ptr, am_digits _length) noexcept
: ptr(_ptr), length(_length) {}
constexpr span() noexcept : ptr(nullptr), length(0) {}
constexpr am_digits len() const noexcept { return length; }
FASTFLOAT_CONSTEXPR14 const T &operator[](am_digits index) const noexcept {
FASTFLOAT_DEBUG_ASSERT(index < length);
return ptr[index];
}
};
struct value128 {
uint64_t low;
uint64_t high;
constexpr value128(uint64_t _low, uint64_t _high) noexcept
: low(_low), high(_high) {}
constexpr value128() noexcept : low(0), high(0) {}
};
/* Helper C++14 constexpr generic implementation of leading_zeroes */
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 limb_t
leading_zeroes_generic(uint64_t input_num, uint32_t last_bit = 0) noexcept {
if (input_num & uint64_t(0xffffffff00000000)) {
input_num >>= 32;
last_bit |= 32;
}
if (input_num & uint64_t(0xffff0000)) {
input_num >>= 16;
last_bit |= 16;
}
if (input_num & uint64_t(0xff00)) {
input_num >>= 8;
last_bit |= 8;
}
if (input_num & uint64_t(0xf0)) {
input_num >>= 4;
last_bit |= 4;
}
if (input_num & uint64_t(0xc)) {
input_num >>= 2;
last_bit |= 2;
}
if (input_num & uint64_t(0x2)) { /* input_num >>= 1; */
last_bit |= 1;
}
return 63 - (limb_t)last_bit;
}
/* result might be undefined when input_num is zero */
fastfloat_really_inline FASTFLOAT_CONSTEXPR20 limb_t
leading_zeroes(uint64_t input_num) noexcept {
assert(input_num > 0);
FASTFLOAT_ASSUME(input_num > 0);
if (cpp20_and_in_constexpr()) {
return leading_zeroes_generic(input_num);
}
#ifdef FASTFLOAT_VISUAL_STUDIO
#if defined(_M_X64) || defined(_M_ARM64)
unsigned long leading_zero = 0;
// Search the mask data from most significant bit (MSB)
// to least significant bit (LSB) for a set bit (1).
_BitScanReverse64(&leading_zero, input_num);
return (limb_t)(63 - leading_zero);
#else
return (limb_t)leading_zeroes_generic(input_num);
#endif
#else
return (limb_t)__builtin_clzll(input_num);
#endif
}
// slow emulation routine for 32-bit
fastfloat_really_inline constexpr uint64_t emulu(uint32_t x,
uint32_t y) noexcept {
return x * (uint64_t)y;
}
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 uint64_t
umul128_generic(uint64_t ab, uint64_t cd, uint64_t *hi) noexcept {
uint64_t ad = emulu((uint32_t)(ab >> 32), (uint32_t)cd);
uint64_t bd = emulu((uint32_t)ab, (uint32_t)cd);
uint64_t adbc = ad + emulu((uint32_t)ab, (uint32_t)(cd >> 32));
uint64_t adbc_carry = (uint64_t)(adbc < ad);
uint64_t lo = bd + (adbc << 32);
*hi = emulu((uint32_t)(ab >> 32), (uint32_t)(cd >> 32)) + (adbc >> 32) +
(adbc_carry << 32) + (uint64_t)(lo < bd);
return lo;
}
#ifdef FASTFLOAT_32BIT
// slow emulation routine for 32-bit
#if !defined(__MINGW64__)
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 uint64_t
_umul128(uint64_t ab, uint64_t cd, uint64_t *hi) noexcept {
return umul128_generic(ab, cd, hi);
}
#endif // !__MINGW64__
#endif // FASTFLOAT_32BIT
// compute 64-bit a*b
fastfloat_really_inline FASTFLOAT_CONSTEXPR20 value128
full_multiplication(uint64_t a, uint64_t b) noexcept {
if (cpp20_and_in_constexpr()) {
value128 answer;
answer.low = umul128_generic(a, b, &answer.high);
return answer;
}
value128 answer;
#if defined(_M_ARM64) && !defined(__MINGW32__)
// ARM64 has native support for 64-bit multiplications, no need to emulate
// But MinGW on ARM64 doesn't have native support for 64-bit multiplications
answer.high = __umulh(a, b);
answer.low = a * b;
#elif defined(FASTFLOAT_32BIT) || \
(defined(_WIN64) && !defined(__clang__) && !defined(_M_ARM64))
answer.low = _umul128(a, b, &answer.high); // _umul128 not available on ARM64
#elif defined(FASTFLOAT_64BIT) && defined(__SIZEOF_INT128__)
__uint128_t r = ((__uint128_t)a) * b;
answer.low = uint64_t(r);
answer.high = uint64_t(r >> 64);
#else
answer.low = umul128_generic(a, b, &answer.high);
#endif
return answer;
}
// Value of the mantissa.
typedef uint_fast64_t am_mant_t;
// Size of bits in the mantissa and path and rounding shifts
typedef int_fast8_t am_bits_t;
// Power bias is signed for handling a denormal float
// or an invalid mantissa.
typedef int16_t am_pow_t; // can't be int_fast16_t because invalid_am_bias
// hacks. Needs rewriting this.
// Bias so we can get the real exponent with an invalid adjusted_mantissa.
constexpr static am_pow_t invalid_am_bias = -0x8000;
struct adjusted_mantissa {
am_mant_t mantissa;
am_pow_t power2;
adjusted_mantissa() noexcept = default;
constexpr bool operator==(adjusted_mantissa const &o) const noexcept {
return mantissa == o.mantissa && power2 == o.power2;
}
constexpr bool operator!=(adjusted_mantissa const &o) const noexcept {
return mantissa != o.mantissa || power2 != o.power2;
}
};
// used for binary_format_lookup_tables<T>::max_mantissa
constexpr am_mant_t constant_55555 = 5 * 5 * 5 * 5 * 5;
template <typename T, typename U = void> struct binary_format_lookup_tables;
template <typename T> struct binary_format : binary_format_lookup_tables<T> {
using equiv_uint = equiv_uint_t<T>;
static constexpr limb_t mantissa_explicit_bits();
static constexpr am_pow_t minimum_exponent();
static constexpr am_pow_t infinite_power();
static constexpr am_bits_t sign_index();
static constexpr am_bits_t
min_exponent_fast_path(); // used when fegetround() == FE_TONEAREST
static constexpr am_bits_t max_exponent_fast_path();
static constexpr am_bits_t max_exponent_round_to_even();
static constexpr am_bits_t min_exponent_round_to_even();
static constexpr equiv_uint max_mantissa_fast_path(am_pow_t power);
static constexpr equiv_uint
max_mantissa_fast_path(); // used when fegetround() == FE_TONEAREST
static constexpr am_pow_t largest_power_of_ten();
static constexpr am_pow_t smallest_power_of_ten();
static constexpr T exact_power_of_ten(am_pow_t power);
static constexpr am_digits max_digits();
static constexpr equiv_uint exponent_mask();
static constexpr equiv_uint mantissa_mask();
static constexpr equiv_uint hidden_bit_mask();
};
template <typename U> struct binary_format_lookup_tables<double, U> {
static constexpr double powers_of_ten[] = {
1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11,
1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19, 1e20, 1e21, 1e22};
// Largest integer value v so that (5**index * v) <= 1<<53.
// 0x20000000000000 == 1 << 53
static constexpr uint64_t max_mantissa[] = {
0x20000000000000,
0x20000000000000 / 5,
0x20000000000000 / (5 * 5),
0x20000000000000 / (5 * 5 * 5),
0x20000000000000 / (5 * 5 * 5 * 5),
0x20000000000000 / (constant_55555),
0x20000000000000 / (constant_55555 * 5),
0x20000000000000 / (constant_55555 * 5 * 5),
0x20000000000000 / (constant_55555 * 5 * 5 * 5),
0x20000000000000 / (constant_55555 * 5 * 5 * 5 * 5),
0x20000000000000 / (constant_55555 * constant_55555),
0x20000000000000 / (constant_55555 * constant_55555 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * 5 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * 5 * 5 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555 * 5),
0x20000000000000 /
(constant_55555 * constant_55555 * constant_55555 * 5 * 5),
0x20000000000000 /
(constant_55555 * constant_55555 * constant_55555 * 5 * 5 * 5),
0x20000000000000 /
(constant_55555 * constant_55555 * constant_55555 * 5 * 5 * 5 * 5),
0x20000000000000 /
(constant_55555 * constant_55555 * constant_55555 * constant_55555),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555 *
constant_55555 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555 *
constant_55555 * 5 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555 *
constant_55555 * 5 * 5 * 5),
0x20000000000000 / (constant_55555 * constant_55555 * constant_55555 *
constant_55555 * 5 * 5 * 5 * 5)};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename U>
constexpr double binary_format_lookup_tables<double, U>::powers_of_ten[];
template <typename U>
constexpr uint64_t binary_format_lookup_tables<double, U>::max_mantissa[];
#endif
template <typename U> struct binary_format_lookup_tables<float, U> {
static constexpr float powers_of_ten[] = {1e0f, 1e1f, 1e2f, 1e3f, 1e4f, 1e5f,
1e6f, 1e7f, 1e8f, 1e9f, 1e10f};
// Largest integer value v so that (5**index * v) <= 1<<24.
// 0x1000000 == 1<<24
static constexpr uint32_t max_mantissa[] = {
0x1000000,
0x1000000 / 5,
0x1000000 / (5 * 5),
0x1000000 / (5 * 5 * 5),
0x1000000 / (5 * 5 * 5 * 5),
0x1000000 / (constant_55555),
0x1000000 / (constant_55555 * 5),
0x1000000 / (constant_55555 * 5 * 5),
0x1000000 / (constant_55555 * 5 * 5 * 5),
0x1000000 / (constant_55555 * 5 * 5 * 5 * 5),
0x1000000 / (constant_55555 * constant_55555),
0x1000000 / (constant_55555 * constant_55555 * 5)};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename U>
constexpr float binary_format_lookup_tables<float, U>::powers_of_ten[];
template <typename U>
constexpr uint32_t binary_format_lookup_tables<float, U>::max_mantissa[];
#endif
template <>
inline constexpr am_bits_t binary_format<double>::min_exponent_fast_path() {
#if (FLT_EVAL_METHOD != 1) && (FLT_EVAL_METHOD != 0)
return 0;
#else
return -22;
#endif
}
template <>
inline constexpr am_bits_t binary_format<float>::min_exponent_fast_path() {
#if (FLT_EVAL_METHOD != 1) && (FLT_EVAL_METHOD != 0)
return 0;
#else
return -10;
#endif
}
template <>
inline constexpr limb_t binary_format<double>::mantissa_explicit_bits() {
return 52;
}
template <>
inline constexpr limb_t binary_format<float>::mantissa_explicit_bits() {
return 23;
}
template <>
inline constexpr am_bits_t binary_format<double>::max_exponent_round_to_even() {
return 23;
}
template <>
inline constexpr am_bits_t binary_format<float>::max_exponent_round_to_even() {
return 10;
}
template <>
inline constexpr am_bits_t binary_format<double>::min_exponent_round_to_even() {
return -4;
}
template <>
inline constexpr am_bits_t binary_format<float>::min_exponent_round_to_even() {
return -17;
}
template <>
inline constexpr am_pow_t binary_format<double>::minimum_exponent() {
return -1023;
}
template <> inline constexpr am_pow_t binary_format<float>::minimum_exponent() {
return -127;
}
template <> inline constexpr am_pow_t binary_format<double>::infinite_power() {
return 0x7FF;
}
template <> inline constexpr am_pow_t binary_format<float>::infinite_power() {
return 0xFF;
}
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
template <> inline constexpr am_bits_t binary_format<double>::sign_index() {
return 63;
}
template <> inline constexpr am_bits_t binary_format<float>::sign_index() {
return 31;
}
#endif
template <>
inline constexpr am_bits_t binary_format<double>::max_exponent_fast_path() {
return 22;
}
template <>
inline constexpr am_bits_t binary_format<float>::max_exponent_fast_path() {
return 10;
}
template <typename T>
inline constexpr typename binary_format<T>::equiv_uint
binary_format<T>::max_mantissa_fast_path() {
return binary_format<T>::equiv_uint(2) << mantissa_explicit_bits();
}
// credit: Jakub Jelínek
#ifdef __STDCPP_FLOAT16_T__
template <typename U> struct binary_format_lookup_tables<std::float16_t, U> {
static constexpr std::float16_t powers_of_ten[] = {1e0f16, 1e1f16, 1e2f16,
1e3f16, 1e4f16};
// Largest integer value v so that (5**index * v) <= 1<<11.
// 0x800 == 1<<11
static constexpr uint16_t max_mantissa[] = {0x800,
0x800 / 5,
0x800 / (5 * 5),
0x800 / (5 * 5 * 5),
0x800 / (5 * 5 * 5 * 5),
0x800 / (constant_55555)};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename U>
constexpr std::float16_t
binary_format_lookup_tables<std::float16_t, U>::powers_of_ten[];
template <typename U>
constexpr uint16_t
binary_format_lookup_tables<std::float16_t, U>::max_mantissa[];
#endif
template <>
inline constexpr std::float16_t
binary_format<std::float16_t>::exact_power_of_ten(am_pow_t power) {
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)powers_of_ten[0], powers_of_ten[power];
}
template <>
inline constexpr binary_format<std::float16_t>::equiv_uint
binary_format<std::float16_t>::exponent_mask() {
return 0x7C00;
}
template <>
inline constexpr binary_format<std::float16_t>::equiv_uint
binary_format<std::float16_t>::mantissa_mask() {
return 0x03FF;
}
template <>
inline constexpr binary_format<std::float16_t>::equiv_uint
binary_format<std::float16_t>::hidden_bit_mask() {
return 0x0400;
}
template <>
inline constexpr am_bits_t
binary_format<std::float16_t>::max_exponent_fast_path() {
return 4;
}
template <>
inline constexpr limb_t
binary_format<std::float16_t>::mantissa_explicit_bits() {
return 10;
}
template <>
inline constexpr binary_format<std::float16_t>::equiv_uint
binary_format<std::float16_t>::max_mantissa_fast_path(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 4);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)max_mantissa[0], max_mantissa[power];
}
template <>
inline constexpr am_bits_t
binary_format<std::float16_t>::min_exponent_fast_path() {
return 0;
}
template <>
inline constexpr am_bits_t
binary_format<std::float16_t>::max_exponent_round_to_even() {
return 5;
}
template <>
inline constexpr am_bits_t
binary_format<std::float16_t>::min_exponent_round_to_even() {
return -22;
}
template <>
inline constexpr am_pow_t binary_format<std::float16_t>::minimum_exponent() {
return -15;
}
template <>
inline constexpr am_pow_t binary_format<std::float16_t>::infinite_power() {
return 0x1F;
}
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
template <>
inline constexpr am_bits_t binary_format<std::float16_t>::sign_index() {
return 15;
}
#endif
template <>
inline constexpr am_pow_t
binary_format<std::float16_t>::largest_power_of_ten() {
return 4;
}
template <>
inline constexpr am_pow_t
binary_format<std::float16_t>::smallest_power_of_ten() {
return -27;
}
template <>
inline constexpr am_digits binary_format<std::float16_t>::max_digits() {
return 22;
}
#endif // __STDCPP_FLOAT16_T__
// credit: Jakub Jelínek
#ifdef __STDCPP_BFLOAT16_T__
template <typename U> struct binary_format_lookup_tables<std::bfloat16_t, U> {
static constexpr std::bfloat16_t powers_of_ten[] = {1e0bf16, 1e1bf16, 1e2bf16,
1e3bf16};
// Largest integer value v so that (5**index * v) <= 1<<8.
// 0x100 == 1<<8
static constexpr uint16_t max_mantissa[] = {0x100, 0x100 / 5, 0x100 / (5 * 5),
0x100 / (5 * 5 * 5),
0x100 / (5 * 5 * 5 * 5)};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename U>
constexpr std::bfloat16_t
binary_format_lookup_tables<std::bfloat16_t, U>::powers_of_ten[];
template <typename U>
constexpr uint64_t
binary_format_lookup_tables<std::bfloat16_t, U>::max_mantissa[];
#endif
template <>
inline constexpr std::bfloat16_t
binary_format<std::bfloat16_t>::exact_power_of_ten(am_pow_t power) {
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)powers_of_ten[0], powers_of_ten[power];
}
template <>
inline constexpr am_bits_t
binary_format<std::bfloat16_t>::max_exponent_fast_path() {
return 3;
}
template <>
inline constexpr binary_format<std::bfloat16_t>::equiv_uint
binary_format<std::bfloat16_t>::exponent_mask() {
return 0x7F80;
}
template <>
inline constexpr binary_format<std::bfloat16_t>::equiv_uint
binary_format<std::bfloat16_t>::mantissa_mask() {
return 0x007F;
}
template <>
inline constexpr binary_format<std::bfloat16_t>::equiv_uint
binary_format<std::bfloat16_t>::hidden_bit_mask() {
return 0x0080;
}
template <>
inline constexpr limb_t
binary_format<std::bfloat16_t>::mantissa_explicit_bits() {
return 7;
}
template <>
inline constexpr binary_format<std::bfloat16_t>::equiv_uint
binary_format<std::bfloat16_t>::max_mantissa_fast_path(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 3);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)max_mantissa[0], max_mantissa[power];
}
template <>
inline constexpr am_bits_t
binary_format<std::bfloat16_t>::min_exponent_fast_path() {
return 0;
}
template <>
inline constexpr am_bits_t
binary_format<std::bfloat16_t>::max_exponent_round_to_even() {
return 3;
}
template <>
inline constexpr am_bits_t
binary_format<std::bfloat16_t>::min_exponent_round_to_even() {
return -24;
}
template <>
inline constexpr am_pow_t binary_format<std::bfloat16_t>::minimum_exponent() {
return -127;
}
template <>
inline constexpr am_pow_t binary_format<std::bfloat16_t>::infinite_power() {
return 0xFF;
}
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
template <>
inline constexpr am_bits_t binary_format<std::bfloat16_t>::sign_index() {
return 15;
}
#endif
template <>
inline constexpr am_pow_t
binary_format<std::bfloat16_t>::largest_power_of_ten() {
return 38;
}
template <>
inline constexpr am_pow_t
binary_format<std::bfloat16_t>::smallest_power_of_ten() {
return -60;
}
template <>
inline constexpr am_digits binary_format<std::bfloat16_t>::max_digits() {
return 98;
}
#endif // __STDCPP_BFLOAT16_T__
template <>
inline constexpr binary_format<double>::equiv_uint
binary_format<double>::max_mantissa_fast_path(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 22);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)max_mantissa[0], max_mantissa[power];
}
template <>
inline constexpr binary_format<float>::equiv_uint
binary_format<float>::max_mantissa_fast_path(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 10);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)max_mantissa[0], max_mantissa[power];
}
template <>
inline constexpr double
binary_format<double>::exact_power_of_ten(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 22);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)powers_of_ten[0], powers_of_ten[power];
}
template <>
inline constexpr float
binary_format<float>::exact_power_of_ten(am_pow_t power) {
// caller is responsible to ensure that
FASTFLOAT_ASSUME(power >= 0 && power <= 10);
//
// Work around clang bug https://godbolt.org/z/zedh7rrhc
return (void)powers_of_ten[0], powers_of_ten[power];
}
template <>
inline constexpr am_pow_t binary_format<double>::largest_power_of_ten() {
return 308;
}
template <>
inline constexpr am_pow_t binary_format<float>::largest_power_of_ten() {
return 38;
}
template <>
inline constexpr am_pow_t binary_format<double>::smallest_power_of_ten() {
return -342;
}
template <>
inline constexpr am_pow_t binary_format<float>::smallest_power_of_ten() {
return -64;
}
template <> inline constexpr am_digits binary_format<double>::max_digits() {
return 769;
}
template <> inline constexpr am_digits binary_format<float>::max_digits() {
return 114;
}
template <>
inline constexpr binary_format<float>::equiv_uint
binary_format<float>::exponent_mask() {
return 0x7F800000;
}
template <>
inline constexpr binary_format<double>::equiv_uint
binary_format<double>::exponent_mask() {
return 0x7FF0000000000000;
}
template <>
inline constexpr binary_format<float>::equiv_uint
binary_format<float>::mantissa_mask() {
return 0x007FFFFF;
}
template <>
inline constexpr binary_format<double>::equiv_uint
binary_format<double>::mantissa_mask() {
return 0x000FFFFFFFFFFFFF;
}
template <>
inline constexpr binary_format<float>::equiv_uint
binary_format<float>::hidden_bit_mask() {
return 0x00800000;
}
template <>
inline constexpr binary_format<double>::equiv_uint
binary_format<double>::hidden_bit_mask() {
return 0x0010000000000000;
}
template <typename T>
fastfloat_really_inline FASTFLOAT_CONSTEXPR20 void to_float(
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
bool const negative,
#endif
adjusted_mantissa const &am, T &value) noexcept {
using equiv_uint = equiv_uint_t<T>;
equiv_uint word = equiv_uint(am.mantissa);
word = equiv_uint(word | equiv_uint(am.power2)
<< binary_format<T>::mantissa_explicit_bits());
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
word =
equiv_uint(word | equiv_uint(negative) << binary_format<T>::sign_index());
#endif
#if FASTFLOAT_HAS_BIT_CAST
value =
#if FASTFLOAT_HAS_BIT_CAST == 1
std::
#endif
bit_cast<T>(word);
#else
::memcpy(&value, &word, sizeof(T));
#endif
}
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
template <typename = void> struct space_lut {
static constexpr uint8_t value[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename T> constexpr uint8_t space_lut<T>::value[];
#endif
template <typename UC> constexpr bool is_space(UC c) {
return c < 256 && space_lut<>::value[uint8_t(c)];
}
#endif
template <typename UC> static constexpr uint64_t int_cmp_zeros() {
static_assert((sizeof(UC) == 1) || (sizeof(UC) == 2) || (sizeof(UC) == 4),
"Unsupported character size");
return (sizeof(UC) == 1) ? 0x3030303030303030
: (sizeof(UC) == 2)
? (uint64_t(UC('0')) << 48 | uint64_t(UC('0')) << 32 |
uint64_t(UC('0')) << 16 | UC('0'))
: (uint64_t(UC('0')) << 32 | UC('0'));
}
template <typename UC> static constexpr int int_cmp_len() {
return sizeof(uint64_t) / sizeof(UC);
}
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
template <typename UC> constexpr UC const *str_const_nan();
template <> constexpr char const *str_const_nan<char>() { return "nan"; }
template <> constexpr wchar_t const *str_const_nan<wchar_t>() { return L"nan"; }
template <> constexpr char16_t const *str_const_nan<char16_t>() {
return u"nan";
}
template <> constexpr char32_t const *str_const_nan<char32_t>() {
return U"nan";
}
#ifdef __cpp_char8_t
template <> constexpr char8_t const *str_const_nan<char8_t>() {
return u8"nan";
}
#endif
template <typename UC> constexpr UC const *str_const_inf();
template <> constexpr char const *str_const_inf<char>() { return "infinity"; }
template <> constexpr wchar_t const *str_const_inf<wchar_t>() {
return L"infinity";
}
template <> constexpr char16_t const *str_const_inf<char16_t>() {
return u"infinity";
}
template <> constexpr char32_t const *str_const_inf<char32_t>() {
return U"infinity";
}
#ifdef __cpp_char8_t
template <> constexpr char8_t const *str_const_inf<char8_t>() {
return u8"infinity";
}
#endif
#endif
template <typename = void> struct int_luts {
static constexpr uint8_t chdigit[] = {
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 255, 255,
255, 255, 255, 255, 255, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
35, 255, 255, 255, 255, 255, 255, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255};
static constexpr uint8_t maxdigits_u64[] = {
64, 41, 32, 28, 25, 23, 22, 21, 20, 19, 18, 18, 17, 17, 16, 16, 16, 16,
15, 15, 15, 15, 14, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 13, 13};
static constexpr uint64_t min_safe_u64[] = {
9223372036854775808ull, 12157665459056928801ull, 4611686018427387904,
7450580596923828125, 4738381338321616896, 3909821048582988049,
9223372036854775808ull, 12157665459056928801ull, 10000000000000000000ull,
5559917313492231481, 2218611106740436992, 8650415919381337933,
2177953337809371136, 6568408355712890625, 1152921504606846976,
2862423051509815793, 6746640616477458432, 15181127029874798299ull,
1638400000000000000, 3243919932521508681, 6221821273427820544,
11592836324538749809ull, 876488338465357824, 1490116119384765625,
2481152873203736576, 4052555153018976267, 6502111422497947648,
10260628712958602189ull, 15943230000000000000ull, 787662783788549761,
1152921504606846976, 1667889514952984961, 2386420683693101056,
3379220508056640625, 4738381338321616896};
};
#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
template <typename T> constexpr uint8_t int_luts<T>::chdigit[];
template <typename T> constexpr uint8_t int_luts<T>::maxdigits_u64[];
template <typename T> constexpr uint64_t int_luts<T>::min_safe_u64[];
#endif
template <typename UC>
fastfloat_really_inline constexpr uint_fast8_t ch_to_digit(UC c) noexcept {
// wchar_t and char can be signed, so we need to be careful.
using UnsignedUC = typename std::make_unsigned<UC>::type;
return int_luts<>::chdigit[static_cast<unsigned char>(
static_cast<UnsignedUC>(c) &
static_cast<UnsignedUC>(
-((static_cast<UnsignedUC>(c) & ~0xFFull) == 0)))];
}
fastfloat_really_inline constexpr uint_fast8_t
max_digits_u64(uint_fast8_t base) noexcept {
return int_luts<>::maxdigits_u64[base - 2];
}
// If a u64 is exactly max_digits_u64() in length, this is
// the value below which it has definitely overflowed.
fastfloat_really_inline constexpr uint64_t
min_safe_u64(uint_fast8_t base) noexcept {
return int_luts<>::min_safe_u64[base - 2];
}
static_assert(std::is_same<equiv_uint_t<double>, uint64_t>::value,
"equiv_uint should be uint64_t for double");
static_assert(std::numeric_limits<double>::is_iec559,
"double must fulfill the requirements of IEC 559 (IEEE 754)");
static_assert(std::is_same<equiv_uint_t<float>, uint32_t>::value,
"equiv_uint should be uint32_t for float");
static_assert(std::numeric_limits<float>::is_iec559,
"float must fulfill the requirements of IEC 559 (IEEE 754)");
#ifdef __STDCPP_FLOAT64_T__
static_assert(std::is_same<equiv_uint_t<std::float64_t>, uint64_t>::value,
"equiv_uint should be uint64_t for std::float64_t");
static_assert(
std::numeric_limits<std::float64_t>::is_iec559,
"std::float64_t must fulfill the requirements of IEC 559 (IEEE 754)");
template <>
struct binary_format<std::float64_t> : public binary_format<double> {};
#endif // __STDCPP_FLOAT64_T__
#ifdef __STDCPP_FLOAT32_T__
static_assert(std::is_same<equiv_uint_t<std::float32_t>, uint32_t>::value,
"equiv_uint should be uint32_t for std::float32_t");
static_assert(
std::numeric_limits<std::float32_t>::is_iec559,
"std::float32_t must fulfill the requirements of IEC 559 (IEEE 754)");
template <>
struct binary_format<std::float32_t> : public binary_format<float> {};
#endif // __STDCPP_FLOAT32_T__
#ifdef __STDCPP_FLOAT16_T__
static_assert(
std::is_same<binary_format<std::float16_t>::equiv_uint, uint16_t>::value,
"equiv_uint should be uint16_t for std::float16_t");
static_assert(
std::numeric_limits<std::float16_t>::is_iec559,
"std::float16_t must fulfill the requirements of IEC 559 (IEEE 754)");
#endif // __STDCPP_FLOAT16_T__
#ifdef __STDCPP_BFLOAT16_T__
static_assert(
std::is_same<binary_format<std::bfloat16_t>::equiv_uint, uint16_t>::value,
"equiv_uint should be uint16_t for std::bfloat16_t");
static_assert(
std::numeric_limits<std::bfloat16_t>::is_iec559,
"std::bfloat16_t must fulfill the requirements of IEC 559 (IEEE 754)");
#endif // __STDCPP_BFLOAT16_T__
constexpr chars_format operator~(chars_format rhs) noexcept {
using int_type = std::underlying_type<chars_format>::type;
return static_cast<chars_format>(~static_cast<int_type>(rhs));
}
constexpr chars_format operator&(chars_format lhs, chars_format rhs) noexcept {
using int_type = std::underlying_type<chars_format>::type;
return static_cast<chars_format>(static_cast<int_type>(lhs) &
static_cast<int_type>(rhs));
}
constexpr chars_format operator|(chars_format lhs, chars_format rhs) noexcept {
using int_type = std::underlying_type<chars_format>::type;
return static_cast<chars_format>(static_cast<int_type>(lhs) |
static_cast<int_type>(rhs));
}
constexpr chars_format operator^(chars_format lhs, chars_format rhs) noexcept {
using int_type = std::underlying_type<chars_format>::type;
return static_cast<chars_format>(static_cast<int_type>(lhs) ^
static_cast<int_type>(rhs));
}
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 chars_format &
operator&=(chars_format &lhs, chars_format rhs) noexcept {
return lhs = (lhs & rhs);
}
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 chars_format &
operator|=(chars_format &lhs, chars_format rhs) noexcept {
return lhs = (lhs | rhs);
}
fastfloat_really_inline FASTFLOAT_CONSTEXPR14 chars_format &
operator^=(chars_format &lhs, chars_format rhs) noexcept {
return lhs = (lhs ^ rhs);
}
} // namespace fast_float
#endif
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