628 lines
22 KiB
C++
628 lines
22 KiB
C++
// Copyright 2020-2023 Daniel Lemire
|
|
// Copyright 2023 Matt Borland
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// https://www.boost.org/LICENSE_1_0.txt
|
|
//
|
|
// Derivative of: https://github.com/fastfloat/fast_float
|
|
|
|
#ifndef BOOST_CHARCONV_DETAIL_FASTFLOAT_FLOAT_COMMON_HPP
|
|
#define BOOST_CHARCONV_DETAIL_FASTFLOAT_FLOAT_COMMON_HPP
|
|
|
|
#include <boost/charconv/detail/fast_float/constexpr_feature_detect.hpp>
|
|
#include <boost/charconv/detail/from_chars_result.hpp>
|
|
#include <boost/charconv/detail/config.hpp>
|
|
#include <boost/charconv/chars_format.hpp>
|
|
#include <cfloat>
|
|
#include <cstdint>
|
|
#include <cassert>
|
|
#include <cstring>
|
|
#include <type_traits>
|
|
#include <system_error>
|
|
|
|
namespace boost { namespace charconv { namespace detail { namespace fast_float {
|
|
|
|
|
|
template <typename UC>
|
|
struct parse_options_t {
|
|
constexpr explicit parse_options_t(chars_format fmt = chars_format::general,
|
|
UC dot = UC('.'))
|
|
: format(fmt), decimal_point(dot) {}
|
|
|
|
/** Which number formats are accepted */
|
|
chars_format format;
|
|
/** The character used as decimal point */
|
|
UC decimal_point;
|
|
};
|
|
using parse_options = parse_options_t<char>;
|
|
|
|
}}}}
|
|
|
|
#if BOOST_CHARCONV_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__)) )
|
|
#define BOOST_CHARCONV_FASTFLOAT_64BIT 1
|
|
#elif (defined(__i386) || defined(__i386__) || defined(_M_IX86) \
|
|
|| defined(__arm__) || defined(_M_ARM) || defined(__ppc__) \
|
|
|| defined(__MINGW32__) || defined(__EMSCRIPTEN__))
|
|
#define BOOST_CHARCONV_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 BOOST_CHARCONV_FASTFLOAT_32BIT 1
|
|
#elif SIZE_MAX == 0xffffffffffffffff
|
|
#define BOOST_CHARCONV_FASTFLOAT_64BIT 1
|
|
#else
|
|
#error Unknown platform (not 32-bit, not 64-bit?)
|
|
#endif
|
|
#endif
|
|
|
|
#if ((defined(_WIN32) || defined(_WIN64)) && !defined(__clang__))
|
|
#include <intrin.h>
|
|
#endif
|
|
|
|
#if defined(_MSC_VER) && !defined(__clang__)
|
|
#define BOOST_CHARCONV_FASTFLOAT_VISUAL_STUDIO 1
|
|
#endif
|
|
|
|
#if defined __BYTE_ORDER__ && defined __ORDER_BIG_ENDIAN__
|
|
#define BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
|
|
#elif defined _WIN32
|
|
#define BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN 0
|
|
#else
|
|
#if defined(__APPLE__) || defined(__FreeBSD__)
|
|
#include <machine/endian.h>
|
|
#elif defined(sun) || defined(__sun)
|
|
#include <sys/byteorder.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 BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN 0
|
|
#endif
|
|
#
|
|
#ifndef __ORDER_LITTLE_ENDIAN__
|
|
// safe choice
|
|
#define BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN 0
|
|
#endif
|
|
#
|
|
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
|
|
#define BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN 0
|
|
#else
|
|
#define BOOST_CHARCONV_FASTFLOAT_IS_BIG_ENDIAN 1
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef BOOST_CHARCONV_FASTFLOAT_ASSERT
|
|
#define BOOST_CHARCONV_FASTFLOAT_ASSERT(x) { ((void)(x)); }
|
|
#endif
|
|
|
|
#ifndef BOOST_CHARCONV_FASTFLOAT_DEBUG_ASSERT
|
|
#define BOOST_CHARCONV_FASTFLOAT_DEBUG_ASSERT(x) { ((void)(x)); }
|
|
#endif
|
|
|
|
// rust style `try!()` macro, or `?` operator
|
|
#define BOOST_CHARCONV_FASTFLOAT_TRY(x) { if (!(x)) return false; }
|
|
|
|
namespace boost { namespace charconv { namespace detail { namespace fast_float {
|
|
|
|
BOOST_FORCEINLINE constexpr bool cpp20_and_in_constexpr() {
|
|
#if BOOST_CHARCONV_FASTFLOAT_HAS_IS_CONSTANT_EVALUATED
|
|
return std::is_constant_evaluated();
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
// Compares two ASCII strings in a case insensitive manner.
|
|
template <typename UC>
|
|
inline BOOST_CHARCONV_FASTFLOAT_CONSTEXPR14 bool
|
|
fastfloat_strncasecmp(UC const * input1, UC const * input2, size_t length) {
|
|
char running_diff{0};
|
|
for (size_t i = 0; i < length; ++i) {
|
|
running_diff |= (char(input1[i]) ^ char(input2[i]));
|
|
}
|
|
return (running_diff == 0) || (running_diff == 32);
|
|
}
|
|
|
|
#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 {
|
|
const T* ptr;
|
|
size_t length;
|
|
constexpr span(const T* _ptr, size_t _length) : ptr(_ptr), length(_length) {}
|
|
constexpr span() : ptr(nullptr), length(0) {}
|
|
|
|
constexpr size_t len() const noexcept {
|
|
return length;
|
|
}
|
|
|
|
BOOST_CHARCONV_FASTFLOAT_CONSTEXPR14 const T& operator[](size_t index) const noexcept {
|
|
BOOST_CHARCONV_FASTFLOAT_DEBUG_ASSERT(index < length);
|
|
return ptr[index];
|
|
}
|
|
};
|
|
|
|
struct value128 {
|
|
uint64_t low;
|
|
uint64_t high;
|
|
constexpr value128(uint64_t _low, uint64_t _high) : low(_low), high(_high) {}
|
|
constexpr value128() : low(0), high(0) {}
|
|
};
|
|
|
|
/* Helper C++11 constexpr generic implementation of leading_zeroes */
|
|
BOOST_FORCEINLINE constexpr
|
|
int leading_zeroes_generic(uint64_t input_num, int last_bit = 0) {
|
|
return (
|
|
((input_num & uint64_t(0xffffffff00000000)) && (input_num >>= 32, last_bit |= 32)),
|
|
((input_num & uint64_t( 0xffff0000)) && (input_num >>= 16, last_bit |= 16)),
|
|
((input_num & uint64_t( 0xff00)) && (input_num >>= 8, last_bit |= 8)),
|
|
((input_num & uint64_t( 0xf0)) && (input_num >>= 4, last_bit |= 4)),
|
|
((input_num & uint64_t( 0xc)) && (input_num >>= 2, last_bit |= 2)),
|
|
((input_num & uint64_t( 0x2)) && (input_num >>= 1, last_bit |= 1)),
|
|
63 - last_bit
|
|
);
|
|
}
|
|
|
|
/* result might be undefined when input_num is zero */
|
|
BOOST_FORCEINLINE BOOST_CHARCONV_FASTFLOAT_CONSTEXPR20
|
|
int leading_zeroes(uint64_t input_num) {
|
|
assert(input_num > 0);
|
|
if (cpp20_and_in_constexpr()) {
|
|
return leading_zeroes_generic(input_num);
|
|
}
|
|
#ifdef BOOST_CHARCONV_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 (int)(63 - leading_zero);
|
|
#else
|
|
return leading_zeroes_generic(input_num);
|
|
#endif
|
|
#else
|
|
return __builtin_clzll(input_num);
|
|
#endif
|
|
}
|
|
|
|
// slow emulation routine for 32-bit
|
|
BOOST_FORCEINLINE constexpr uint64_t emulu(uint32_t x, uint32_t y) {
|
|
return x * static_cast<uint64_t>(y);
|
|
}
|
|
|
|
BOOST_FORCEINLINE BOOST_CHARCONV_FASTFLOAT_CONSTEXPR14
|
|
uint64_t umul128_generic(uint64_t ab, uint64_t cd, uint64_t *hi) {
|
|
uint64_t ad = emulu(static_cast<uint32_t>(ab >> 32), static_cast<uint32_t>(cd));
|
|
uint64_t bd = emulu(static_cast<uint32_t>(ab), static_cast<uint32_t>(cd));
|
|
uint64_t adbc = ad + emulu(static_cast<uint32_t>(ab), static_cast<uint32_t>(cd >> 32));
|
|
uint64_t adbc_carry = !!(adbc < ad);
|
|
uint64_t lo = bd + (adbc << 32);
|
|
*hi = emulu(static_cast<uint32_t>(ab >> 32), static_cast<uint32_t>(cd >> 32)) + (adbc >> 32) +
|
|
(adbc_carry << 32) + !!(lo < bd);
|
|
return lo;
|
|
}
|
|
|
|
#ifdef BOOST_CHARCONV_FASTFLOAT_32BIT
|
|
|
|
// slow emulation routine for 32-bit
|
|
#if !defined(__MINGW64__)
|
|
BOOST_FORCEINLINE BOOST_CHARCONV_FASTFLOAT_CONSTEXPR14
|
|
uint64_t _umul128(uint64_t ab, uint64_t cd, uint64_t *hi) {
|
|
return umul128_generic(ab, cd, hi);
|
|
}
|
|
#endif // !__MINGW64__
|
|
|
|
#endif // BOOST_CHARCONV_FASTFLOAT_32BIT
|
|
|
|
|
|
// compute 64-bit a*b
|
|
BOOST_FORCEINLINE BOOST_CHARCONV_FASTFLOAT_CONSTEXPR20
|
|
value128 full_multiplication(uint64_t a, uint64_t b) {
|
|
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(BOOST_CHARCONV_FASTFLOAT_32BIT) || (defined(_WIN64) && !defined(__clang__))
|
|
unsigned long long high;
|
|
answer.low = _umul128(a, b, &high); // _umul128 not available on ARM64
|
|
answer.high = static_cast<uint64_t>(high);
|
|
#elif defined(BOOST_CHARCONV_FASTFLOAT_64BIT)
|
|
__uint128_t r = (static_cast<__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;
|
|
}
|
|
|
|
struct adjusted_mantissa {
|
|
uint64_t mantissa{0};
|
|
int32_t power2{0}; // a negative value indicates an invalid result
|
|
adjusted_mantissa() = default;
|
|
constexpr bool operator==(const adjusted_mantissa &o) const {
|
|
return mantissa == o.mantissa && power2 == o.power2;
|
|
}
|
|
constexpr bool operator!=(const adjusted_mantissa &o) const {
|
|
return mantissa != o.mantissa || power2 != o.power2;
|
|
}
|
|
};
|
|
|
|
// Bias so we can get the real exponent with an invalid adjusted_mantissa.
|
|
constexpr static int32_t invalid_am_bias = -0x8000;
|
|
|
|
// used for binary_format_lookup_tables<T>::max_mantissa
|
|
constexpr uint64_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 = typename std::conditional<sizeof(T) == 4, uint32_t, uint64_t>::type;
|
|
|
|
static inline constexpr int mantissa_explicit_bits();
|
|
static inline constexpr int minimum_exponent();
|
|
static inline constexpr int infinite_power();
|
|
static inline constexpr int sign_index();
|
|
static inline constexpr int min_exponent_fast_path(); // used when fegetround() == FE_TONEAREST
|
|
static inline constexpr int max_exponent_fast_path();
|
|
static inline constexpr int max_exponent_round_to_even();
|
|
static inline constexpr int min_exponent_round_to_even();
|
|
static inline constexpr uint64_t max_mantissa_fast_path(int64_t power);
|
|
static inline constexpr uint64_t max_mantissa_fast_path(); // used when fegetround() == FE_TONEAREST
|
|
static inline constexpr int largest_power_of_ten();
|
|
static inline constexpr int smallest_power_of_ten();
|
|
static inline constexpr T exact_power_of_ten(int64_t power);
|
|
static inline constexpr size_t max_digits();
|
|
static inline constexpr equiv_uint exponent_mask();
|
|
static inline constexpr equiv_uint mantissa_mask();
|
|
static inline 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.
|
|
// 0x10000000000000 == 1 << 53
|
|
static constexpr std::uint64_t max_mantissa[] = {
|
|
UINT64_C(0x10000000000000),
|
|
UINT64_C(0x10000000000000) / UINT64_C(5),
|
|
UINT64_C(0x10000000000000) / (UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * constant_55555),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * constant_55555 * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x10000000000000) / (constant_55555 * constant_55555 * constant_55555 * constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5))};
|
|
};
|
|
|
|
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[];
|
|
|
|
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 uint64_t max_mantissa[] = {
|
|
UINT64_C(0x1000000),
|
|
UINT64_C(0x1000000) / UINT64_C(5),
|
|
UINT64_C(0x1000000) / (UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (constant_55555),
|
|
UINT64_C(0x1000000) / (constant_55555 * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (constant_55555 * UINT64_C(5) * UINT64_C(5) * UINT64_C(5) * UINT64_C(5)),
|
|
UINT64_C(0x1000000) / (constant_55555 * constant_55555),
|
|
UINT64_C(0x1000000) / (constant_55555 * constant_55555 * UINT64_C(5))};
|
|
};
|
|
|
|
template <typename U>
|
|
constexpr float binary_format_lookup_tables<float, U>::powers_of_ten[];
|
|
|
|
template <typename U>
|
|
constexpr uint64_t binary_format_lookup_tables<float, U>::max_mantissa[];
|
|
|
|
template <> inline constexpr int 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 int 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 int binary_format<double>::mantissa_explicit_bits() {
|
|
return 52;
|
|
}
|
|
template <> inline constexpr int binary_format<float>::mantissa_explicit_bits() {
|
|
return 23;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<double>::max_exponent_round_to_even() {
|
|
return 23;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<float>::max_exponent_round_to_even() {
|
|
return 10;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<double>::min_exponent_round_to_even() {
|
|
return -4;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<float>::min_exponent_round_to_even() {
|
|
return -17;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<double>::minimum_exponent() {
|
|
return -1023;
|
|
}
|
|
template <> inline constexpr int binary_format<float>::minimum_exponent() {
|
|
return -127;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<double>::infinite_power() {
|
|
return 0x7FF;
|
|
}
|
|
template <> inline constexpr int binary_format<float>::infinite_power() {
|
|
return 0xFF;
|
|
}
|
|
|
|
template <> inline constexpr int binary_format<double>::sign_index() { return 63; }
|
|
template <> inline constexpr int binary_format<float>::sign_index() { return 31; }
|
|
|
|
template <> inline constexpr int binary_format<double>::max_exponent_fast_path() {
|
|
return 22;
|
|
}
|
|
template <> inline constexpr int binary_format<float>::max_exponent_fast_path() {
|
|
return 10;
|
|
}
|
|
|
|
template <> inline constexpr uint64_t binary_format<double>::max_mantissa_fast_path() {
|
|
return uint64_t(2) << mantissa_explicit_bits();
|
|
}
|
|
template <> inline constexpr uint64_t binary_format<double>::max_mantissa_fast_path(int64_t power) {
|
|
// caller is responsible to ensure that
|
|
// power >= 0 && power <= 22
|
|
//
|
|
// Work around clang bug https://godbolt.org/z/zedh7rrhc
|
|
return (void)max_mantissa[0], max_mantissa[power];
|
|
}
|
|
template <> inline constexpr uint64_t binary_format<float>::max_mantissa_fast_path() {
|
|
return uint64_t(2) << mantissa_explicit_bits();
|
|
}
|
|
template <> inline constexpr uint64_t binary_format<float>::max_mantissa_fast_path(int64_t power) {
|
|
// caller is responsible to ensure that
|
|
// 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(int64_t power) {
|
|
// 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(int64_t power) {
|
|
// Work around clang bug https://godbolt.org/z/zedh7rrhc
|
|
return (void)powers_of_ten[0], powers_of_ten[power];
|
|
}
|
|
|
|
|
|
template <>
|
|
inline constexpr int binary_format<double>::largest_power_of_ten() {
|
|
return 308;
|
|
}
|
|
template <>
|
|
inline constexpr int binary_format<float>::largest_power_of_ten() {
|
|
return 38;
|
|
}
|
|
|
|
template <>
|
|
inline constexpr int binary_format<double>::smallest_power_of_ten() {
|
|
return -342;
|
|
}
|
|
template <>
|
|
inline constexpr int binary_format<float>::smallest_power_of_ten() {
|
|
return -65;
|
|
}
|
|
|
|
template <> inline constexpr size_t binary_format<double>::max_digits() {
|
|
return 769;
|
|
}
|
|
template <> inline constexpr size_t 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>
|
|
BOOST_FORCEINLINE BOOST_CHARCONV_FASTFLOAT_CONSTEXPR20
|
|
void to_float(bool negative, adjusted_mantissa am, T &value) {
|
|
using uint = typename binary_format<T>::equiv_uint;
|
|
uint word = static_cast<uint>(am.mantissa);
|
|
word |= uint(am.power2) << binary_format<T>::mantissa_explicit_bits();
|
|
word |= uint(negative) << binary_format<T>::sign_index();
|
|
#if BOOST_CHARCONV_FASTFLOAT_HAS_BIT_CAST
|
|
value = std::bit_cast<T>(word);
|
|
#else
|
|
::memcpy(&value, &word, sizeof(T));
|
|
#endif
|
|
}
|
|
|
|
#ifdef BOOST_CHARCONV_FASTFLOAT_SKIP_WHITE_SPACE // disabled by default
|
|
template <typename = void>
|
|
struct space_lut {
|
|
static constexpr bool 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};
|
|
};
|
|
|
|
template <typename T>
|
|
constexpr bool space_lut<T>::value[];
|
|
|
|
inline constexpr bool is_space(uint8_t c) { return space_lut<>::value[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);
|
|
}
|
|
template<typename UC>
|
|
static constexpr UC const * str_const_nan()
|
|
{
|
|
return nullptr;
|
|
}
|
|
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";
|
|
}
|
|
template<typename UC>
|
|
static constexpr UC const * str_const_inf()
|
|
{
|
|
return nullptr;
|
|
}
|
|
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";
|
|
}
|
|
|
|
}}}} // namespaces
|
|
|
|
#endif
|