blender/extern/fast_float/fast_float.h
Aras Pranckevicius 213cd39b6d OBJ: further optimize, cleanup and harden the new C++ importer
Continued improvements to the new C++ based OBJ importer.

Performance: about 2x faster.
- Rungholt.obj (several meshes, 263MB file): Windows 12.7s -> 5.9s, Mac 7.7s -> 3.1s.
- Blender 3.0 splash (24k meshes, 2.4GB file): Windows 97.3s -> 53.6s, Mac 137.3s -> 80.0s.
- "Windows" is VS2022, AMD Ryzen 5950X (32 threads), "Mac" is Xcode/clang 13, M1Max (10 threads).
- Slightly reduced memory usage during import as well.

The performance gains are a combination of several things:
- Replacing `std::stof` / `std::stoi` with C++17 `from_chars`.
- Stop reading input file char-by-char using `std::getline`, and instead read in 64kb chunks, and parse from there (taking care of possibly handling lines split mid-way due to chunk boundaries).
- Removing abstractions for splitting a line by some char,
- Avoid tiny memory allocations: instead of storing a vector of polygon corners in each face, store all the corners in one big array, and per-face only store indices "where do corners start, and how many". Likewise, don't store full string names of material/group names for each face; only store indices into overall material/group names arrays.
- Stop always doing mesh validation, which is slow. Do it just like the Alembic importer does: only do validation if found some invalid faces during import, or if requested by the user via an import setting checkbox (which defaults to off).
- Stop doing "collection sync" for each object being added; instead do the collection sync right after creating all the objects.

Cleanup / Robustness:

This reworking of parser (see "removing abstractions" point above) means that all the functions that were in `parser_string_utils` file are gone, and replaced with different set of functions. However they are not OBJ specific, so as pointed out during review of the previous differential, they are now in `source/blender/io/common` library.

Added gtest coverage for said functions as well; something that was only indirectly covered by obj tests previously.

Rework of some bits of parsing made the parser actually better able to deal with invalid syntax. E.g. previously, if a face corner were a `/123` string, it would have incorrectly treated that as a vertex index (since it would get "hey that's one number" after splitting a string by a slash), instead of properly marking it as invalid syntax.

Added gtest coverage for .mtl parsing; something that was not covered by any tests at all previously.

Reviewed By: Howard Trickey
Differential Revision: https://developer.blender.org/D14586
2022-04-17 22:07:43 +03:00

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// fast_float by Daniel Lemire
// fast_float by João Paulo Magalhaes
//
// with contributions from Eugene Golushkov
// with contributions from Maksim Kita
// with contributions from Marcin Wojdyr
// with contributions from Neal Richardson
// with contributions from Tim Paine
// with contributions from Fabio Pellacini
//
// Licensed under the Apache License, Version 2.0, or the
// MIT License at your option. This file may not be copied,
// modified, or distributed except according to those terms.
//
// MIT License Notice
//
// MIT License
//
// Copyright (c) 2021 The fast_float authors
//
// Permission is hereby granted, free of charge, to any
// person obtaining a copy of this software and associated
// documentation files (the "Software"), to deal in the
// Software without restriction, including without
// limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice
// shall be included in all copies or substantial portions
// of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
// SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
// IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Apache License (Version 2.0) Notice
//
// Copyright 2021 The fast_float authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
//
#ifndef FASTFLOAT_FAST_FLOAT_H
#define FASTFLOAT_FAST_FLOAT_H
#include <system_error>
namespace fast_float {
enum chars_format {
scientific = 1<<0,
fixed = 1<<2,
hex = 1<<3,
general = fixed | scientific
};
struct from_chars_result {
const char *ptr;
std::errc ec;
};
struct parse_options {
constexpr explicit parse_options(chars_format fmt = chars_format::general,
char dot = '.')
: format(fmt), decimal_point(dot) {}
/** Which number formats are accepted */
chars_format format;
/** The character used as decimal point */
char decimal_point;
};
/**
* This function parses the character sequence [first,last) for a number. It parses floating-point numbers expecting
* a locale-indepent format equivalent to what is used by std::strtod in the default ("C") locale.
* The resulting floating-point value is the closest floating-point values (using either float or double),
* using the "round to even" convention for values that would otherwise fall right in-between two values.
* That is, we provide exact parsing according to the IEEE standard.
*
* Given a successful parse, the pointer (`ptr`) in the returned value is set to point right after the
* parsed number, and the `value` referenced is set to the parsed value. In case of error, the returned
* `ec` contains a representative error, otherwise the default (`std::errc()`) value is stored.
*
* The implementation does not throw and does not allocate memory (e.g., with `new` or `malloc`).
*
* Like the C++17 standard, the `fast_float::from_chars` functions take an optional last argument of
* the type `fast_float::chars_format`. It is a bitset value: we check whether
* `fmt & fast_float::chars_format::fixed` and `fmt & fast_float::chars_format::scientific` are set
* to determine whether we allowe the fixed point and scientific notation respectively.
* The default is `fast_float::chars_format::general` which allows both `fixed` and `scientific`.
*/
template<typename T>
from_chars_result from_chars(const char *first, const char *last,
T &value, chars_format fmt = chars_format::general) noexcept;
/**
* Like from_chars, but accepts an `options` argument to govern number parsing.
*/
template<typename T>
from_chars_result from_chars_advanced(const char *first, const char *last,
T &value, parse_options options) noexcept;
}
#endif // FASTFLOAT_FAST_FLOAT_H
#ifndef FASTFLOAT_FLOAT_COMMON_H
#define FASTFLOAT_FLOAT_COMMON_H
#include <cfloat>
#include <cstdint>
#include <cassert>
#include <cstring>
#include <type_traits>
#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(__EMSCRIPTEN__))
#define FASTFLOAT_64BIT
#elif (defined(__i386) || defined(__i386__) || defined(_M_IX86) \
|| defined(__arm__) || defined(_M_ARM) \
|| defined(__MINGW32__))
#define FASTFLOAT_32BIT
#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
#elif SIZE_MAX == 0xffffffffffffffff
#define FASTFLOAT_64BIT
#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 FASTFLOAT_VISUAL_STUDIO 1
#endif
#ifdef _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>
#else
#include <endian.h>
#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
#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) { if (!(x)) abort(); }
#endif
#ifndef FASTFLOAT_DEBUG_ASSERT
#include <cassert>
#define FASTFLOAT_DEBUG_ASSERT(x) assert(x)
#endif
// rust style `try!()` macro, or `?` operator
#define FASTFLOAT_TRY(x) { if (!(x)) return false; }
namespace fast_float {
// Compares two ASCII strings in a case insensitive manner.
inline bool fastfloat_strncasecmp(const char *input1, const char *input2,
size_t length) {
char running_diff{0};
for (size_t i = 0; i < length; i++) {
running_diff |= (input1[i] ^ 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;
span(const T* _ptr, size_t _length) : ptr(_ptr), length(_length) {}
span() : ptr(nullptr), length(0) {}
constexpr size_t len() const noexcept {
return length;
}
const T& operator[](size_t index) const noexcept {
FASTFLOAT_DEBUG_ASSERT(index < length);
return ptr[index];
}
};
struct value128 {
uint64_t low;
uint64_t high;
value128(uint64_t _low, uint64_t _high) : low(_low), high(_high) {}
value128() : low(0), high(0) {}
};
/* result might be undefined when input_num is zero */
fastfloat_really_inline int leading_zeroes(uint64_t input_num) {
assert(input_num > 0);
#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 (int)(63 - leading_zero);
#else
int last_bit = 0;
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 - last_bit;
#endif
#else
return __builtin_clzll(input_num);
#endif
}
#ifdef FASTFLOAT_32BIT
// slow emulation routine for 32-bit
fastfloat_really_inline uint64_t emulu(uint32_t x, uint32_t y) {
return x * (uint64_t)y;
}
// slow emulation routine for 32-bit
#if !defined(__MINGW64__)
fastfloat_really_inline uint64_t _umul128(uint64_t ab, uint64_t cd,
uint64_t *hi) {
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 = !!(adbc < ad);
uint64_t lo = bd + (adbc << 32);
*hi = emulu((uint32_t)(ab >> 32), (uint32_t)(cd >> 32)) + (adbc >> 32) +
(adbc_carry << 32) + !!(lo < bd);
return lo;
}
#endif // !__MINGW64__
#endif // FASTFLOAT_32BIT
// compute 64-bit a*b
fastfloat_really_inline value128 full_multiplication(uint64_t a,
uint64_t b) {
value128 answer;
#ifdef _M_ARM64
// ARM64 has native support for 64-bit multiplications, no need to emulate
answer.high = __umulh(a, b);
answer.low = a * b;
#elif defined(FASTFLOAT_32BIT) || (defined(_WIN64) && !defined(__clang__))
answer.low = _umul128(a, b, &answer.high); // _umul128 not available on ARM64
#elif defined(FASTFLOAT_64BIT)
__uint128_t r = ((__uint128_t)a) * b;
answer.low = uint64_t(r);
answer.high = uint64_t(r >> 64);
#else
#error Not implemented
#endif
return answer;
}
struct adjusted_mantissa {
uint64_t mantissa{0};
int32_t power2{0}; // a negative value indicates an invalid result
adjusted_mantissa() = default;
bool operator==(const adjusted_mantissa &o) const {
return mantissa == o.mantissa && power2 == o.power2;
}
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;
constexpr static double powers_of_ten_double[] = {
1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11,
1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19, 1e20, 1e21, 1e22};
constexpr static float powers_of_ten_float[] = {1e0, 1e1, 1e2, 1e3, 1e4, 1e5,
1e6, 1e7, 1e8, 1e9, 1e10};
template <typename T> struct binary_format {
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();
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();
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 <> 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>::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>::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<float>::max_mantissa_fast_path() {
return uint64_t(2) << mantissa_explicit_bits();
}
template <>
inline constexpr double binary_format<double>::exact_power_of_ten(int64_t power) {
return powers_of_ten_double[power];
}
template <>
inline constexpr float binary_format<float>::exact_power_of_ten(int64_t power) {
return powers_of_ten_float[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>
fastfloat_really_inline void to_float(bool negative, adjusted_mantissa am, T &value) {
uint64_t word = am.mantissa;
word |= uint64_t(am.power2) << binary_format<T>::mantissa_explicit_bits();
word = negative
? word | (uint64_t(1) << binary_format<T>::sign_index()) : word;
#if FASTFLOAT_IS_BIG_ENDIAN == 1
if (std::is_same<T, float>::value) {
::memcpy(&value, (char *)&word + 4, sizeof(T)); // extract value at offset 4-7 if float on big-endian
} else {
::memcpy(&value, &word, sizeof(T));
}
#else
// For little-endian systems:
::memcpy(&value, &word, sizeof(T));
#endif
}
} // namespace fast_float
#endif
#ifndef FASTFLOAT_ASCII_NUMBER_H
#define FASTFLOAT_ASCII_NUMBER_H
#include <cctype>
#include <cstdint>
#include <cstring>
#include <iterator>
namespace fast_float {
// Next function can be micro-optimized, but compilers are entirely
// able to optimize it well.
fastfloat_really_inline bool is_integer(char c) noexcept { return c >= '0' && c <= '9'; }
fastfloat_really_inline uint64_t byteswap(uint64_t val) {
return (val & 0xFF00000000000000) >> 56
| (val & 0x00FF000000000000) >> 40
| (val & 0x0000FF0000000000) >> 24
| (val & 0x000000FF00000000) >> 8
| (val & 0x00000000FF000000) << 8
| (val & 0x0000000000FF0000) << 24
| (val & 0x000000000000FF00) << 40
| (val & 0x00000000000000FF) << 56;
}
fastfloat_really_inline uint64_t read_u64(const char *chars) {
uint64_t val;
::memcpy(&val, chars, sizeof(uint64_t));
#if FASTFLOAT_IS_BIG_ENDIAN == 1
// Need to read as-if the number was in little-endian order.
val = byteswap(val);
#endif
return val;
}
fastfloat_really_inline void write_u64(uint8_t *chars, uint64_t val) {
#if FASTFLOAT_IS_BIG_ENDIAN == 1
// Need to read as-if the number was in little-endian order.
val = byteswap(val);
#endif
::memcpy(chars, &val, sizeof(uint64_t));
}
// credit @aqrit
fastfloat_really_inline uint32_t parse_eight_digits_unrolled(uint64_t val) {
const uint64_t mask = 0x000000FF000000FF;
const uint64_t mul1 = 0x000F424000000064; // 100 + (1000000ULL << 32)
const uint64_t mul2 = 0x0000271000000001; // 1 + (10000ULL << 32)
val -= 0x3030303030303030;
val = (val * 10) + (val >> 8); // val = (val * 2561) >> 8;
val = (((val & mask) * mul1) + (((val >> 16) & mask) * mul2)) >> 32;
return uint32_t(val);
}
fastfloat_really_inline uint32_t parse_eight_digits_unrolled(const char *chars) noexcept {
return parse_eight_digits_unrolled(read_u64(chars));
}
// credit @aqrit
fastfloat_really_inline bool is_made_of_eight_digits_fast(uint64_t val) noexcept {
return !((((val + 0x4646464646464646) | (val - 0x3030303030303030)) &
0x8080808080808080));
}
fastfloat_really_inline bool is_made_of_eight_digits_fast(const char *chars) noexcept {
return is_made_of_eight_digits_fast(read_u64(chars));
}
typedef span<const char> byte_span;
struct parsed_number_string {
int64_t exponent{0};
uint64_t mantissa{0};
const char *lastmatch{nullptr};
bool negative{false};
bool valid{false};
bool too_many_digits{false};
// contains the range of the significant digits
byte_span integer{}; // non-nullable
byte_span fraction{}; // nullable
};
// Assuming that you use no more than 19 digits, this will
// parse an ASCII string.
fastfloat_really_inline
parsed_number_string parse_number_string(const char *p, const char *pend, parse_options options) noexcept {
const chars_format fmt = options.format;
const char decimal_point = options.decimal_point;
parsed_number_string answer;
answer.valid = false;
answer.too_many_digits = false;
answer.negative = (*p == '-');
if (*p == '-') { // C++17 20.19.3.(7.1) explicitly forbids '+' sign here
++p;
if (p == pend) {
return answer;
}
if (!is_integer(*p) && (*p != decimal_point)) { // a sign must be followed by an integer or the dot
return answer;
}
}
const char *const start_digits = p;
uint64_t i = 0; // an unsigned int avoids signed overflows (which are bad)
while ((std::distance(p, pend) >= 8) && is_made_of_eight_digits_fast(p)) {
i = i * 100000000 + parse_eight_digits_unrolled(p); // in rare cases, this will overflow, but that's ok
p += 8;
}
while ((p != pend) && is_integer(*p)) {
// a multiplication by 10 is cheaper than an arbitrary integer
// multiplication
i = 10 * i +
uint64_t(*p - '0'); // might overflow, we will handle the overflow later
++p;
}
const char *const end_of_integer_part = p;
int64_t digit_count = int64_t(end_of_integer_part - start_digits);
answer.integer = byte_span(start_digits, size_t(digit_count));
int64_t exponent = 0;
if ((p != pend) && (*p == decimal_point)) {
++p;
const char* before = p;
// can occur at most twice without overflowing, but let it occur more, since
// for integers with many digits, digit parsing is the primary bottleneck.
while ((std::distance(p, pend) >= 8) && is_made_of_eight_digits_fast(p)) {
i = i * 100000000 + parse_eight_digits_unrolled(p); // in rare cases, this will overflow, but that's ok
p += 8;
}
while ((p != pend) && is_integer(*p)) {
uint8_t digit = uint8_t(*p - '0');
++p;
i = i * 10 + digit; // in rare cases, this will overflow, but that's ok
}
exponent = before - p;
answer.fraction = byte_span(before, size_t(p - before));
digit_count -= exponent;
}
// we must have encountered at least one integer!
if (digit_count == 0) {
return answer;
}
int64_t exp_number = 0; // explicit exponential part
if ((fmt & chars_format::scientific) && (p != pend) && (('e' == *p) || ('E' == *p))) {
const char * location_of_e = p;
++p;
bool neg_exp = false;
if ((p != pend) && ('-' == *p)) {
neg_exp = true;
++p;
} else if ((p != pend) && ('+' == *p)) { // '+' on exponent is allowed by C++17 20.19.3.(7.1)
++p;
}
if ((p == pend) || !is_integer(*p)) {
if(!(fmt & chars_format::fixed)) {
// We are in error.
return answer;
}
// Otherwise, we will be ignoring the 'e'.
p = location_of_e;
} else {
while ((p != pend) && is_integer(*p)) {
uint8_t digit = uint8_t(*p - '0');
if (exp_number < 0x10000000) {
exp_number = 10 * exp_number + digit;
}
++p;
}
if(neg_exp) { exp_number = - exp_number; }
exponent += exp_number;
}
} else {
// If it scientific and not fixed, we have to bail out.
if((fmt & chars_format::scientific) && !(fmt & chars_format::fixed)) { return answer; }
}
answer.lastmatch = p;
answer.valid = true;
// If we frequently had to deal with long strings of digits,
// we could extend our code by using a 128-bit integer instead
// of a 64-bit integer. However, this is uncommon.
//
// We can deal with up to 19 digits.
if (digit_count > 19) { // this is uncommon
// It is possible that the integer had an overflow.
// We have to handle the case where we have 0.0000somenumber.
// We need to be mindful of the case where we only have zeroes...
// E.g., 0.000000000...000.
const char *start = start_digits;
while ((start != pend) && (*start == '0' || *start == decimal_point)) {
if(*start == '0') { digit_count --; }
start++;
}
if (digit_count > 19) {
answer.too_many_digits = true;
// Let us start again, this time, avoiding overflows.
// We don't need to check if is_integer, since we use the
// pre-tokenized spans from above.
i = 0;
p = answer.integer.ptr;
const char* int_end = p + answer.integer.len();
const uint64_t minimal_nineteen_digit_integer{1000000000000000000};
while((i < minimal_nineteen_digit_integer) && (p != int_end)) {
i = i * 10 + uint64_t(*p - '0');
++p;
}
if (i >= minimal_nineteen_digit_integer) { // We have a big integers
exponent = end_of_integer_part - p + exp_number;
} else { // We have a value with a fractional component.
p = answer.fraction.ptr;
const char* frac_end = p + answer.fraction.len();
while((i < minimal_nineteen_digit_integer) && (p != frac_end)) {
i = i * 10 + uint64_t(*p - '0');
++p;
}
exponent = answer.fraction.ptr - p + exp_number;
}
// We have now corrected both exponent and i, to a truncated value
}
}
answer.exponent = exponent;
answer.mantissa = i;
return answer;
}
} // namespace fast_float
#endif
#ifndef FASTFLOAT_FAST_TABLE_H
#define FASTFLOAT_FAST_TABLE_H
#include <cstdint>
namespace fast_float {
/**
* When mapping numbers from decimal to binary,
* we go from w * 10^q to m * 2^p but we have
* 10^q = 5^q * 2^q, so effectively
* we are trying to match
* w * 2^q * 5^q to m * 2^p. Thus the powers of two
* are not a concern since they can be represented
* exactly using the binary notation, only the powers of five
* affect the binary significand.
*/
/**
* The smallest non-zero float (binary64) is 2^1074.
* We take as input numbers of the form w x 10^q where w < 2^64.
* We have that w * 10^-343 < 2^(64-344) 5^-343 < 2^-1076.
* However, we have that
* (2^64-1) * 10^-342 = (2^64-1) * 2^-342 * 5^-342 > 2^1074.
* Thus it is possible for a number of the form w * 10^-342 where
* w is a 64-bit value to be a non-zero floating-point number.
*********
* Any number of form w * 10^309 where w>= 1 is going to be
* infinite in binary64 so we never need to worry about powers
* of 5 greater than 308.
*/
template <class unused = void>
struct powers_template {
constexpr static int smallest_power_of_five = binary_format<double>::smallest_power_of_ten();
constexpr static int largest_power_of_five = binary_format<double>::largest_power_of_ten();
constexpr static int number_of_entries = 2 * (largest_power_of_five - smallest_power_of_five + 1);
// Powers of five from 5^-342 all the way to 5^308 rounded toward one.
static const uint64_t power_of_five_128[number_of_entries];
};
template <class unused>
const uint64_t powers_template<unused>::power_of_five_128[number_of_entries] = {
0xeef453d6923bd65a,0x113faa2906a13b3f,
0x9558b4661b6565f8,0x4ac7ca59a424c507,
0xbaaee17fa23ebf76,0x5d79bcf00d2df649,
0xe95a99df8ace6f53,0xf4d82c2c107973dc,
0x91d8a02bb6c10594,0x79071b9b8a4be869,
0xb64ec836a47146f9,0x9748e2826cdee284,
0xe3e27a444d8d98b7,0xfd1b1b2308169b25,
0x8e6d8c6ab0787f72,0xfe30f0f5e50e20f7,
0xb208ef855c969f4f,0xbdbd2d335e51a935,
0xde8b2b66b3bc4723,0xad2c788035e61382,
0x8b16fb203055ac76,0x4c3bcb5021afcc31,
0xaddcb9e83c6b1793,0xdf4abe242a1bbf3d,
0xd953e8624b85dd78,0xd71d6dad34a2af0d,
0x87d4713d6f33aa6b,0x8672648c40e5ad68,
0xa9c98d8ccb009506,0x680efdaf511f18c2,
0xd43bf0effdc0ba48,0x212bd1b2566def2,
0x84a57695fe98746d,0x14bb630f7604b57,
0xa5ced43b7e3e9188,0x419ea3bd35385e2d,
0xcf42894a5dce35ea,0x52064cac828675b9,
0x818995ce7aa0e1b2,0x7343efebd1940993,
0xa1ebfb4219491a1f,0x1014ebe6c5f90bf8,
0xca66fa129f9b60a6,0xd41a26e077774ef6,
0xfd00b897478238d0,0x8920b098955522b4,
0x9e20735e8cb16382,0x55b46e5f5d5535b0,
0xc5a890362fddbc62,0xeb2189f734aa831d,
0xf712b443bbd52b7b,0xa5e9ec7501d523e4,
0x9a6bb0aa55653b2d,0x47b233c92125366e,
0xc1069cd4eabe89f8,0x999ec0bb696e840a,
0xf148440a256e2c76,0xc00670ea43ca250d,
0x96cd2a865764dbca,0x380406926a5e5728,
0xbc807527ed3e12bc,0xc605083704f5ecf2,
0xeba09271e88d976b,0xf7864a44c633682e,
0x93445b8731587ea3,0x7ab3ee6afbe0211d,
0xb8157268fdae9e4c,0x5960ea05bad82964,
0xe61acf033d1a45df,0x6fb92487298e33bd,
0x8fd0c16206306bab,0xa5d3b6d479f8e056,
0xb3c4f1ba87bc8696,0x8f48a4899877186c,
0xe0b62e2929aba83c,0x331acdabfe94de87,
0x8c71dcd9ba0b4925,0x9ff0c08b7f1d0b14,
0xaf8e5410288e1b6f,0x7ecf0ae5ee44dd9,
0xdb71e91432b1a24a,0xc9e82cd9f69d6150,
0x892731ac9faf056e,0xbe311c083a225cd2,
0xab70fe17c79ac6ca,0x6dbd630a48aaf406,
0xd64d3d9db981787d,0x92cbbccdad5b108,
0x85f0468293f0eb4e,0x25bbf56008c58ea5,
0xa76c582338ed2621,0xaf2af2b80af6f24e,
0xd1476e2c07286faa,0x1af5af660db4aee1,
0x82cca4db847945ca,0x50d98d9fc890ed4d,
0xa37fce126597973c,0xe50ff107bab528a0,
0xcc5fc196fefd7d0c,0x1e53ed49a96272c8,
0xff77b1fcbebcdc4f,0x25e8e89c13bb0f7a,
0x9faacf3df73609b1,0x77b191618c54e9ac,
0xc795830d75038c1d,0xd59df5b9ef6a2417,
0xf97ae3d0d2446f25,0x4b0573286b44ad1d,
0x9becce62836ac577,0x4ee367f9430aec32,
0xc2e801fb244576d5,0x229c41f793cda73f,
0xf3a20279ed56d48a,0x6b43527578c1110f,
0x9845418c345644d6,0x830a13896b78aaa9,
0xbe5691ef416bd60c,0x23cc986bc656d553,
0xedec366b11c6cb8f,0x2cbfbe86b7ec8aa8,
0x94b3a202eb1c3f39,0x7bf7d71432f3d6a9,
0xb9e08a83a5e34f07,0xdaf5ccd93fb0cc53,
0xe858ad248f5c22c9,0xd1b3400f8f9cff68,
0x91376c36d99995be,0x23100809b9c21fa1,
0xb58547448ffffb2d,0xabd40a0c2832a78a,
0xe2e69915b3fff9f9,0x16c90c8f323f516c,
0x8dd01fad907ffc3b,0xae3da7d97f6792e3,
0xb1442798f49ffb4a,0x99cd11cfdf41779c,
0xdd95317f31c7fa1d,0x40405643d711d583,
0x8a7d3eef7f1cfc52,0x482835ea666b2572,
0xad1c8eab5ee43b66,0xda3243650005eecf,
0xd863b256369d4a40,0x90bed43e40076a82,
0x873e4f75e2224e68,0x5a7744a6e804a291,
0xa90de3535aaae202,0x711515d0a205cb36,
0xd3515c2831559a83,0xd5a5b44ca873e03,
0x8412d9991ed58091,0xe858790afe9486c2,
0xa5178fff668ae0b6,0x626e974dbe39a872,
0xce5d73ff402d98e3,0xfb0a3d212dc8128f,
0x80fa687f881c7f8e,0x7ce66634bc9d0b99,
0xa139029f6a239f72,0x1c1fffc1ebc44e80,
0xc987434744ac874e,0xa327ffb266b56220,
0xfbe9141915d7a922,0x4bf1ff9f0062baa8,
0x9d71ac8fada6c9b5,0x6f773fc3603db4a9,
0xc4ce17b399107c22,0xcb550fb4384d21d3,
0xf6019da07f549b2b,0x7e2a53a146606a48,
0x99c102844f94e0fb,0x2eda7444cbfc426d,
0xc0314325637a1939,0xfa911155fefb5308,
0xf03d93eebc589f88,0x793555ab7eba27ca,
0x96267c7535b763b5,0x4bc1558b2f3458de,
0xbbb01b9283253ca2,0x9eb1aaedfb016f16,
0xea9c227723ee8bcb,0x465e15a979c1cadc,
0x92a1958a7675175f,0xbfacd89ec191ec9,
0xb749faed14125d36,0xcef980ec671f667b,
0xe51c79a85916f484,0x82b7e12780e7401a,
0x8f31cc0937ae58d2,0xd1b2ecb8b0908810,
0xb2fe3f0b8599ef07,0x861fa7e6dcb4aa15,
0xdfbdcece67006ac9,0x67a791e093e1d49a,
0x8bd6a141006042bd,0xe0c8bb2c5c6d24e0,
0xaecc49914078536d,0x58fae9f773886e18,
0xda7f5bf590966848,0xaf39a475506a899e,
0x888f99797a5e012d,0x6d8406c952429603,
0xaab37fd7d8f58178,0xc8e5087ba6d33b83,
0xd5605fcdcf32e1d6,0xfb1e4a9a90880a64,
0x855c3be0a17fcd26,0x5cf2eea09a55067f,
0xa6b34ad8c9dfc06f,0xf42faa48c0ea481e,
0xd0601d8efc57b08b,0xf13b94daf124da26,
0x823c12795db6ce57,0x76c53d08d6b70858,
0xa2cb1717b52481ed,0x54768c4b0c64ca6e,
0xcb7ddcdda26da268,0xa9942f5dcf7dfd09,
0xfe5d54150b090b02,0xd3f93b35435d7c4c,
0x9efa548d26e5a6e1,0xc47bc5014a1a6daf,
0xc6b8e9b0709f109a,0x359ab6419ca1091b,
0xf867241c8cc6d4c0,0xc30163d203c94b62,
0x9b407691d7fc44f8,0x79e0de63425dcf1d,
0xc21094364dfb5636,0x985915fc12f542e4,
0xf294b943e17a2bc4,0x3e6f5b7b17b2939d,
0x979cf3ca6cec5b5a,0xa705992ceecf9c42,
0xbd8430bd08277231,0x50c6ff782a838353,
0xece53cec4a314ebd,0xa4f8bf5635246428,
0x940f4613ae5ed136,0x871b7795e136be99,
0xb913179899f68584,0x28e2557b59846e3f,
0xe757dd7ec07426e5,0x331aeada2fe589cf,
0x9096ea6f3848984f,0x3ff0d2c85def7621,
0xb4bca50b065abe63,0xfed077a756b53a9,
0xe1ebce4dc7f16dfb,0xd3e8495912c62894,
0x8d3360f09cf6e4bd,0x64712dd7abbbd95c,
0xb080392cc4349dec,0xbd8d794d96aacfb3,
0xdca04777f541c567,0xecf0d7a0fc5583a0,
0x89e42caaf9491b60,0xf41686c49db57244,
0xac5d37d5b79b6239,0x311c2875c522ced5,
0xd77485cb25823ac7,0x7d633293366b828b,
0x86a8d39ef77164bc,0xae5dff9c02033197,
0xa8530886b54dbdeb,0xd9f57f830283fdfc,
0xd267caa862a12d66,0xd072df63c324fd7b,
0x8380dea93da4bc60,0x4247cb9e59f71e6d,
0xa46116538d0deb78,0x52d9be85f074e608,
0xcd795be870516656,0x67902e276c921f8b,
0x806bd9714632dff6,0xba1cd8a3db53b6,
0xa086cfcd97bf97f3,0x80e8a40eccd228a4,
0xc8a883c0fdaf7df0,0x6122cd128006b2cd,
0xfad2a4b13d1b5d6c,0x796b805720085f81,
0x9cc3a6eec6311a63,0xcbe3303674053bb0,
0xc3f490aa77bd60fc,0xbedbfc4411068a9c,
0xf4f1b4d515acb93b,0xee92fb5515482d44,
0x991711052d8bf3c5,0x751bdd152d4d1c4a,
0xbf5cd54678eef0b6,0xd262d45a78a0635d,
0xef340a98172aace4,0x86fb897116c87c34,
0x9580869f0e7aac0e,0xd45d35e6ae3d4da0,
0xbae0a846d2195712,0x8974836059cca109,
0xe998d258869facd7,0x2bd1a438703fc94b,
0x91ff83775423cc06,0x7b6306a34627ddcf,
0xb67f6455292cbf08,0x1a3bc84c17b1d542,
0xe41f3d6a7377eeca,0x20caba5f1d9e4a93,
0x8e938662882af53e,0x547eb47b7282ee9c,
0xb23867fb2a35b28d,0xe99e619a4f23aa43,
0xdec681f9f4c31f31,0x6405fa00e2ec94d4,
0x8b3c113c38f9f37e,0xde83bc408dd3dd04,
0xae0b158b4738705e,0x9624ab50b148d445,
0xd98ddaee19068c76,0x3badd624dd9b0957,
0x87f8a8d4cfa417c9,0xe54ca5d70a80e5d6,
0xa9f6d30a038d1dbc,0x5e9fcf4ccd211f4c,
0xd47487cc8470652b,0x7647c3200069671f,
0x84c8d4dfd2c63f3b,0x29ecd9f40041e073,
0xa5fb0a17c777cf09,0xf468107100525890,
0xcf79cc9db955c2cc,0x7182148d4066eeb4,
0x81ac1fe293d599bf,0xc6f14cd848405530,
0xa21727db38cb002f,0xb8ada00e5a506a7c,
0xca9cf1d206fdc03b,0xa6d90811f0e4851c,
0xfd442e4688bd304a,0x908f4a166d1da663,
0x9e4a9cec15763e2e,0x9a598e4e043287fe,
0xc5dd44271ad3cdba,0x40eff1e1853f29fd,
0xf7549530e188c128,0xd12bee59e68ef47c,
0x9a94dd3e8cf578b9,0x82bb74f8301958ce,
0xc13a148e3032d6e7,0xe36a52363c1faf01,
0xf18899b1bc3f8ca1,0xdc44e6c3cb279ac1,
0x96f5600f15a7b7e5,0x29ab103a5ef8c0b9,
0xbcb2b812db11a5de,0x7415d448f6b6f0e7,
0xebdf661791d60f56,0x111b495b3464ad21,
0x936b9fcebb25c995,0xcab10dd900beec34,
0xb84687c269ef3bfb,0x3d5d514f40eea742,
0xe65829b3046b0afa,0xcb4a5a3112a5112,
0x8ff71a0fe2c2e6dc,0x47f0e785eaba72ab,
0xb3f4e093db73a093,0x59ed216765690f56,
0xe0f218b8d25088b8,0x306869c13ec3532c,
0x8c974f7383725573,0x1e414218c73a13fb,
0xafbd2350644eeacf,0xe5d1929ef90898fa,
0xdbac6c247d62a583,0xdf45f746b74abf39,
0x894bc396ce5da772,0x6b8bba8c328eb783,
0xab9eb47c81f5114f,0x66ea92f3f326564,
0xd686619ba27255a2,0xc80a537b0efefebd,
0x8613fd0145877585,0xbd06742ce95f5f36,
0xa798fc4196e952e7,0x2c48113823b73704,
0xd17f3b51fca3a7a0,0xf75a15862ca504c5,
0x82ef85133de648c4,0x9a984d73dbe722fb,
0xa3ab66580d5fdaf5,0xc13e60d0d2e0ebba,
0xcc963fee10b7d1b3,0x318df905079926a8,
0xffbbcfe994e5c61f,0xfdf17746497f7052,
0x9fd561f1fd0f9bd3,0xfeb6ea8bedefa633,
0xc7caba6e7c5382c8,0xfe64a52ee96b8fc0,
0xf9bd690a1b68637b,0x3dfdce7aa3c673b0,
0x9c1661a651213e2d,0x6bea10ca65c084e,
0xc31bfa0fe5698db8,0x486e494fcff30a62,
0xf3e2f893dec3f126,0x5a89dba3c3efccfa,
0x986ddb5c6b3a76b7,0xf89629465a75e01c,
0xbe89523386091465,0xf6bbb397f1135823,
0xee2ba6c0678b597f,0x746aa07ded582e2c,
0x94db483840b717ef,0xa8c2a44eb4571cdc,
0xba121a4650e4ddeb,0x92f34d62616ce413,
0xe896a0d7e51e1566,0x77b020baf9c81d17,
0x915e2486ef32cd60,0xace1474dc1d122e,
0xb5b5ada8aaff80b8,0xd819992132456ba,
0xe3231912d5bf60e6,0x10e1fff697ed6c69,
0x8df5efabc5979c8f,0xca8d3ffa1ef463c1,
0xb1736b96b6fd83b3,0xbd308ff8a6b17cb2,
0xddd0467c64bce4a0,0xac7cb3f6d05ddbde,
0x8aa22c0dbef60ee4,0x6bcdf07a423aa96b,
0xad4ab7112eb3929d,0x86c16c98d2c953c6,
0xd89d64d57a607744,0xe871c7bf077ba8b7,
0x87625f056c7c4a8b,0x11471cd764ad4972,
0xa93af6c6c79b5d2d,0xd598e40d3dd89bcf,
0xd389b47879823479,0x4aff1d108d4ec2c3,
0x843610cb4bf160cb,0xcedf722a585139ba,
0xa54394fe1eedb8fe,0xc2974eb4ee658828,
0xce947a3da6a9273e,0x733d226229feea32,
0x811ccc668829b887,0x806357d5a3f525f,
0xa163ff802a3426a8,0xca07c2dcb0cf26f7,
0xc9bcff6034c13052,0xfc89b393dd02f0b5,
0xfc2c3f3841f17c67,0xbbac2078d443ace2,
0x9d9ba7832936edc0,0xd54b944b84aa4c0d,
0xc5029163f384a931,0xa9e795e65d4df11,
0xf64335bcf065d37d,0x4d4617b5ff4a16d5,
0x99ea0196163fa42e,0x504bced1bf8e4e45,
0xc06481fb9bcf8d39,0xe45ec2862f71e1d6,
0xf07da27a82c37088,0x5d767327bb4e5a4c,
0x964e858c91ba2655,0x3a6a07f8d510f86f,
0xbbe226efb628afea,0x890489f70a55368b,
0xeadab0aba3b2dbe5,0x2b45ac74ccea842e,
0x92c8ae6b464fc96f,0x3b0b8bc90012929d,
0xb77ada0617e3bbcb,0x9ce6ebb40173744,
0xe55990879ddcaabd,0xcc420a6a101d0515,
0x8f57fa54c2a9eab6,0x9fa946824a12232d,
0xb32df8e9f3546564,0x47939822dc96abf9,
0xdff9772470297ebd,0x59787e2b93bc56f7,
0x8bfbea76c619ef36,0x57eb4edb3c55b65a,
0xaefae51477a06b03,0xede622920b6b23f1,
0xdab99e59958885c4,0xe95fab368e45eced,
0x88b402f7fd75539b,0x11dbcb0218ebb414,
0xaae103b5fcd2a881,0xd652bdc29f26a119,
0xd59944a37c0752a2,0x4be76d3346f0495f,
0x857fcae62d8493a5,0x6f70a4400c562ddb,
0xa6dfbd9fb8e5b88e,0xcb4ccd500f6bb952,
0xd097ad07a71f26b2,0x7e2000a41346a7a7,
0x825ecc24c873782f,0x8ed400668c0c28c8,
0xa2f67f2dfa90563b,0x728900802f0f32fa,
0xcbb41ef979346bca,0x4f2b40a03ad2ffb9,
0xfea126b7d78186bc,0xe2f610c84987bfa8,
0x9f24b832e6b0f436,0xdd9ca7d2df4d7c9,
0xc6ede63fa05d3143,0x91503d1c79720dbb,
0xf8a95fcf88747d94,0x75a44c6397ce912a,
0x9b69dbe1b548ce7c,0xc986afbe3ee11aba,
0xc24452da229b021b,0xfbe85badce996168,
0xf2d56790ab41c2a2,0xfae27299423fb9c3,
0x97c560ba6b0919a5,0xdccd879fc967d41a,
0xbdb6b8e905cb600f,0x5400e987bbc1c920,
0xed246723473e3813,0x290123e9aab23b68,
0x9436c0760c86e30b,0xf9a0b6720aaf6521,
0xb94470938fa89bce,0xf808e40e8d5b3e69,
0xe7958cb87392c2c2,0xb60b1d1230b20e04,
0x90bd77f3483bb9b9,0xb1c6f22b5e6f48c2,
0xb4ecd5f01a4aa828,0x1e38aeb6360b1af3,
0xe2280b6c20dd5232,0x25c6da63c38de1b0,
0x8d590723948a535f,0x579c487e5a38ad0e,
0xb0af48ec79ace837,0x2d835a9df0c6d851,
0xdcdb1b2798182244,0xf8e431456cf88e65,
0x8a08f0f8bf0f156b,0x1b8e9ecb641b58ff,
0xac8b2d36eed2dac5,0xe272467e3d222f3f,
0xd7adf884aa879177,0x5b0ed81dcc6abb0f,
0x86ccbb52ea94baea,0x98e947129fc2b4e9,
0xa87fea27a539e9a5,0x3f2398d747b36224,
0xd29fe4b18e88640e,0x8eec7f0d19a03aad,
0x83a3eeeef9153e89,0x1953cf68300424ac,
0xa48ceaaab75a8e2b,0x5fa8c3423c052dd7,
0xcdb02555653131b6,0x3792f412cb06794d,
0x808e17555f3ebf11,0xe2bbd88bbee40bd0,
0xa0b19d2ab70e6ed6,0x5b6aceaeae9d0ec4,
0xc8de047564d20a8b,0xf245825a5a445275,
0xfb158592be068d2e,0xeed6e2f0f0d56712,
0x9ced737bb6c4183d,0x55464dd69685606b,
0xc428d05aa4751e4c,0xaa97e14c3c26b886,
0xf53304714d9265df,0xd53dd99f4b3066a8,
0x993fe2c6d07b7fab,0xe546a8038efe4029,
0xbf8fdb78849a5f96,0xde98520472bdd033,
0xef73d256a5c0f77c,0x963e66858f6d4440,
0x95a8637627989aad,0xdde7001379a44aa8,
0xbb127c53b17ec159,0x5560c018580d5d52,
0xe9d71b689dde71af,0xaab8f01e6e10b4a6,
0x9226712162ab070d,0xcab3961304ca70e8,
0xb6b00d69bb55c8d1,0x3d607b97c5fd0d22,
0xe45c10c42a2b3b05,0x8cb89a7db77c506a,
0x8eb98a7a9a5b04e3,0x77f3608e92adb242,
0xb267ed1940f1c61c,0x55f038b237591ed3,
0xdf01e85f912e37a3,0x6b6c46dec52f6688,
0x8b61313bbabce2c6,0x2323ac4b3b3da015,
0xae397d8aa96c1b77,0xabec975e0a0d081a,
0xd9c7dced53c72255,0x96e7bd358c904a21,
0x881cea14545c7575,0x7e50d64177da2e54,
0xaa242499697392d2,0xdde50bd1d5d0b9e9,
0xd4ad2dbfc3d07787,0x955e4ec64b44e864,
0x84ec3c97da624ab4,0xbd5af13bef0b113e,
0xa6274bbdd0fadd61,0xecb1ad8aeacdd58e,
0xcfb11ead453994ba,0x67de18eda5814af2,
0x81ceb32c4b43fcf4,0x80eacf948770ced7,
0xa2425ff75e14fc31,0xa1258379a94d028d,
0xcad2f7f5359a3b3e,0x96ee45813a04330,
0xfd87b5f28300ca0d,0x8bca9d6e188853fc,
0x9e74d1b791e07e48,0x775ea264cf55347e,
0xc612062576589dda,0x95364afe032a819e,
0xf79687aed3eec551,0x3a83ddbd83f52205,
0x9abe14cd44753b52,0xc4926a9672793543,
0xc16d9a0095928a27,0x75b7053c0f178294,
0xf1c90080baf72cb1,0x5324c68b12dd6339,
0x971da05074da7bee,0xd3f6fc16ebca5e04,
0xbce5086492111aea,0x88f4bb1ca6bcf585,
0xec1e4a7db69561a5,0x2b31e9e3d06c32e6,
0x9392ee8e921d5d07,0x3aff322e62439fd0,
0xb877aa3236a4b449,0x9befeb9fad487c3,
0xe69594bec44de15b,0x4c2ebe687989a9b4,
0x901d7cf73ab0acd9,0xf9d37014bf60a11,
0xb424dc35095cd80f,0x538484c19ef38c95,
0xe12e13424bb40e13,0x2865a5f206b06fba,
0x8cbccc096f5088cb,0xf93f87b7442e45d4,
0xafebff0bcb24aafe,0xf78f69a51539d749,
0xdbe6fecebdedd5be,0xb573440e5a884d1c,
0x89705f4136b4a597,0x31680a88f8953031,
0xabcc77118461cefc,0xfdc20d2b36ba7c3e,
0xd6bf94d5e57a42bc,0x3d32907604691b4d,
0x8637bd05af6c69b5,0xa63f9a49c2c1b110,
0xa7c5ac471b478423,0xfcf80dc33721d54,
0xd1b71758e219652b,0xd3c36113404ea4a9,
0x83126e978d4fdf3b,0x645a1cac083126ea,
0xa3d70a3d70a3d70a,0x3d70a3d70a3d70a4,
0xcccccccccccccccc,0xcccccccccccccccd,
0x8000000000000000,0x0,
0xa000000000000000,0x0,
0xc800000000000000,0x0,
0xfa00000000000000,0x0,
0x9c40000000000000,0x0,
0xc350000000000000,0x0,
0xf424000000000000,0x0,
0x9896800000000000,0x0,
0xbebc200000000000,0x0,
0xee6b280000000000,0x0,
0x9502f90000000000,0x0,
0xba43b74000000000,0x0,
0xe8d4a51000000000,0x0,
0x9184e72a00000000,0x0,
0xb5e620f480000000,0x0,
0xe35fa931a0000000,0x0,
0x8e1bc9bf04000000,0x0,
0xb1a2bc2ec5000000,0x0,
0xde0b6b3a76400000,0x0,
0x8ac7230489e80000,0x0,
0xad78ebc5ac620000,0x0,
0xd8d726b7177a8000,0x0,
0x878678326eac9000,0x0,
0xa968163f0a57b400,0x0,
0xd3c21bcecceda100,0x0,
0x84595161401484a0,0x0,
0xa56fa5b99019a5c8,0x0,
0xcecb8f27f4200f3a,0x0,
0x813f3978f8940984,0x4000000000000000,
0xa18f07d736b90be5,0x5000000000000000,
0xc9f2c9cd04674ede,0xa400000000000000,
0xfc6f7c4045812296,0x4d00000000000000,
0x9dc5ada82b70b59d,0xf020000000000000,
0xc5371912364ce305,0x6c28000000000000,
0xf684df56c3e01bc6,0xc732000000000000,
0x9a130b963a6c115c,0x3c7f400000000000,
0xc097ce7bc90715b3,0x4b9f100000000000,
0xf0bdc21abb48db20,0x1e86d40000000000,
0x96769950b50d88f4,0x1314448000000000,
0xbc143fa4e250eb31,0x17d955a000000000,
0xeb194f8e1ae525fd,0x5dcfab0800000000,
0x92efd1b8d0cf37be,0x5aa1cae500000000,
0xb7abc627050305ad,0xf14a3d9e40000000,
0xe596b7b0c643c719,0x6d9ccd05d0000000,
0x8f7e32ce7bea5c6f,0xe4820023a2000000,
0xb35dbf821ae4f38b,0xdda2802c8a800000,
0xe0352f62a19e306e,0xd50b2037ad200000,
0x8c213d9da502de45,0x4526f422cc340000,
0xaf298d050e4395d6,0x9670b12b7f410000,
0xdaf3f04651d47b4c,0x3c0cdd765f114000,
0x88d8762bf324cd0f,0xa5880a69fb6ac800,
0xab0e93b6efee0053,0x8eea0d047a457a00,
0xd5d238a4abe98068,0x72a4904598d6d880,
0x85a36366eb71f041,0x47a6da2b7f864750,
0xa70c3c40a64e6c51,0x999090b65f67d924,
0xd0cf4b50cfe20765,0xfff4b4e3f741cf6d,
0x82818f1281ed449f,0xbff8f10e7a8921a4,
0xa321f2d7226895c7,0xaff72d52192b6a0d,
0xcbea6f8ceb02bb39,0x9bf4f8a69f764490,
0xfee50b7025c36a08,0x2f236d04753d5b4,
0x9f4f2726179a2245,0x1d762422c946590,
0xc722f0ef9d80aad6,0x424d3ad2b7b97ef5,
0xf8ebad2b84e0d58b,0xd2e0898765a7deb2,
0x9b934c3b330c8577,0x63cc55f49f88eb2f,
0xc2781f49ffcfa6d5,0x3cbf6b71c76b25fb,
0xf316271c7fc3908a,0x8bef464e3945ef7a,
0x97edd871cfda3a56,0x97758bf0e3cbb5ac,
0xbde94e8e43d0c8ec,0x3d52eeed1cbea317,
0xed63a231d4c4fb27,0x4ca7aaa863ee4bdd,
0x945e455f24fb1cf8,0x8fe8caa93e74ef6a,
0xb975d6b6ee39e436,0xb3e2fd538e122b44,
0xe7d34c64a9c85d44,0x60dbbca87196b616,
0x90e40fbeea1d3a4a,0xbc8955e946fe31cd,
0xb51d13aea4a488dd,0x6babab6398bdbe41,
0xe264589a4dcdab14,0xc696963c7eed2dd1,
0x8d7eb76070a08aec,0xfc1e1de5cf543ca2,
0xb0de65388cc8ada8,0x3b25a55f43294bcb,
0xdd15fe86affad912,0x49ef0eb713f39ebe,
0x8a2dbf142dfcc7ab,0x6e3569326c784337,
0xacb92ed9397bf996,0x49c2c37f07965404,
0xd7e77a8f87daf7fb,0xdc33745ec97be906,
0x86f0ac99b4e8dafd,0x69a028bb3ded71a3,
0xa8acd7c0222311bc,0xc40832ea0d68ce0c,
0xd2d80db02aabd62b,0xf50a3fa490c30190,
0x83c7088e1aab65db,0x792667c6da79e0fa,
0xa4b8cab1a1563f52,0x577001b891185938,
0xcde6fd5e09abcf26,0xed4c0226b55e6f86,
0x80b05e5ac60b6178,0x544f8158315b05b4,
0xa0dc75f1778e39d6,0x696361ae3db1c721,
0xc913936dd571c84c,0x3bc3a19cd1e38e9,
0xfb5878494ace3a5f,0x4ab48a04065c723,
0x9d174b2dcec0e47b,0x62eb0d64283f9c76,
0xc45d1df942711d9a,0x3ba5d0bd324f8394,
0xf5746577930d6500,0xca8f44ec7ee36479,
0x9968bf6abbe85f20,0x7e998b13cf4e1ecb,
0xbfc2ef456ae276e8,0x9e3fedd8c321a67e,
0xefb3ab16c59b14a2,0xc5cfe94ef3ea101e,
0x95d04aee3b80ece5,0xbba1f1d158724a12,
0xbb445da9ca61281f,0x2a8a6e45ae8edc97,
0xea1575143cf97226,0xf52d09d71a3293bd,
0x924d692ca61be758,0x593c2626705f9c56,
0xb6e0c377cfa2e12e,0x6f8b2fb00c77836c,
0xe498f455c38b997a,0xb6dfb9c0f956447,
0x8edf98b59a373fec,0x4724bd4189bd5eac,
0xb2977ee300c50fe7,0x58edec91ec2cb657,
0xdf3d5e9bc0f653e1,0x2f2967b66737e3ed,
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0xae67f1e9aec07187,0xecd8590680a3aa11,
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0x884134fe908658b2,0x3109058d147fdcdd,
0xaa51823e34a7eede,0xbd4b46f0599fd415,
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0x850fadc09923329e,0x3e2cf6bc604ddb0,
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0x81f14fae158c5f6e,0x4fcb7e8f3f60c07e,
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0xc646d63501a1511d,0xb281e1fd541501b8,
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0x93ba47c980e98cdf,0xc66f336c36b10137,
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0xb01ae745b101e9e4,0x5ec05dcff72e7f8f,
0xdc21a1171d42645d,0x76707543f4fa1f73,
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0xabfa45da0edbde69,0x487db9d17636892,
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0x865b86925b9bc5c2,0xb8a2392ba45a9b2,
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0x8335616aed761f1f,0x7f44e6bd49e807b8,
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0x802221226be55a64,0xc2494954da2c9789,
0xa02aa96b06deb0fd,0xf2db9baa10b7bd6c,
0xc83553c5c8965d3d,0x6f92829494e5acc7,
0xfa42a8b73abbf48c,0xcb772339ba1f17f9,
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0xc38413cf25e2d70d,0xfef5138519684aba,
0xf46518c2ef5b8cd1,0x7eb258665fc25d69,
0x98bf2f79d5993802,0xef2f773ffbd97a61,
0xbeeefb584aff8603,0xaafb550ffacfd8fa,
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0x952ab45cfa97a0b2,0xdd945a747bf26183,
0xba756174393d88df,0x94f971119aeef9e4,
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0x91abb422ccb812ee,0xac62e055c10ab33a,
0xb616a12b7fe617aa,0x577b986b314d6009,
0xe39c49765fdf9d94,0xed5a7e85fda0b80b,
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0xb1d219647ae6b31c,0x596eb2d8ae258fc8,
0xde469fbd99a05fe3,0x6fca5f8ed9aef3bb,
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0xada72ccc20054ae9,0xaf561aa79a10ae6a,
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0xcf02b2c21207ef2e,0x94f967e45e03f4bb,
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0xca28a291859bbf93,0x7d7b8f7503cfdcfe,
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0x9defbf01b061adab,0x3a0888136afa64a7,
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0x9a3c2087a63f6399,0x36ac54e2f678864b,
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0x9316ff75dd87cbd8,0x9a7f12442d588f2,
0xb7dcbf5354e9bece,0xc11ed6d538aeb2f,
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0xb38d92d760ec4455,0x37c981dcc395a9ac,
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0x8c469ab843b89562,0x93956d7478ccec8e,
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0xdb2e51bfe9d0696a,0x6997b05fcc0319e,
0x88fcf317f22241e2,0x441fece3bdf81f03,
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0x85c7056562757456,0xf6872d5667844e49,
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0xd106f86e69d785c7,0xe13336d701beba52,
0x82a45b450226b39c,0xecc0024661173473,
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0xcc20ce9bd35c78a5,0x31ec038df7b441f4,
0xff290242c83396ce,0x7e67047175a15271,
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0xc75809c42c684dd1,0x52c07b78a3e60868,
0xf92e0c3537826145,0xa7709a56ccdf8a82,
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0xc2abf989935ddbfe,0x6acff893d00ea435,
0xf356f7ebf83552fe,0x583f6b8c4124d43,
0x98165af37b2153de,0xc3727a337a8b704a,
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0x9485d4d1c63e8be7,0x8addcb5645ac2ba8,
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0x910ab1d4db9914a0,0x1d9c9892400a22a2,
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0xe2a0b5dc971f303a,0x2e44ae64840fd61d,
0x8da471a9de737e24,0x5ceaecfed289e5d2,
0xb10d8e1456105dad,0x7425a83e872c5f47,
0xdd50f1996b947518,0xd12f124e28f77719,
0x8a5296ffe33cc92f,0x82bd6b70d99aaa6f,
0xace73cbfdc0bfb7b,0x636cc64d1001550b,
0xd8210befd30efa5a,0x3c47f7e05401aa4e,
0x8714a775e3e95c78,0x65acfaec34810a71,
0xa8d9d1535ce3b396,0x7f1839a741a14d0d,
0xd31045a8341ca07c,0x1ede48111209a050,
0x83ea2b892091e44d,0x934aed0aab460432,
0xa4e4b66b68b65d60,0xf81da84d5617853f,
0xce1de40642e3f4b9,0x36251260ab9d668e,
0x80d2ae83e9ce78f3,0xc1d72b7c6b426019,
0xa1075a24e4421730,0xb24cf65b8612f81f,
0xc94930ae1d529cfc,0xdee033f26797b627,
0xfb9b7cd9a4a7443c,0x169840ef017da3b1,
0x9d412e0806e88aa5,0x8e1f289560ee864e,
0xc491798a08a2ad4e,0xf1a6f2bab92a27e2,
0xf5b5d7ec8acb58a2,0xae10af696774b1db,
0x9991a6f3d6bf1765,0xacca6da1e0a8ef29,
0xbff610b0cc6edd3f,0x17fd090a58d32af3,
0xeff394dcff8a948e,0xddfc4b4cef07f5b0,
0x95f83d0a1fb69cd9,0x4abdaf101564f98e,
0xbb764c4ca7a4440f,0x9d6d1ad41abe37f1,
0xea53df5fd18d5513,0x84c86189216dc5ed,
0x92746b9be2f8552c,0x32fd3cf5b4e49bb4,
0xb7118682dbb66a77,0x3fbc8c33221dc2a1,
0xe4d5e82392a40515,0xfabaf3feaa5334a,
0x8f05b1163ba6832d,0x29cb4d87f2a7400e,
0xb2c71d5bca9023f8,0x743e20e9ef511012,
0xdf78e4b2bd342cf6,0x914da9246b255416,
0x8bab8eefb6409c1a,0x1ad089b6c2f7548e,
0xae9672aba3d0c320,0xa184ac2473b529b1,
0xda3c0f568cc4f3e8,0xc9e5d72d90a2741e,
0x8865899617fb1871,0x7e2fa67c7a658892,
0xaa7eebfb9df9de8d,0xddbb901b98feeab7,
0xd51ea6fa85785631,0x552a74227f3ea565,
0x8533285c936b35de,0xd53a88958f87275f,
0xa67ff273b8460356,0x8a892abaf368f137,
0xd01fef10a657842c,0x2d2b7569b0432d85,
0x8213f56a67f6b29b,0x9c3b29620e29fc73,
0xa298f2c501f45f42,0x8349f3ba91b47b8f,
0xcb3f2f7642717713,0x241c70a936219a73,
0xfe0efb53d30dd4d7,0xed238cd383aa0110,
0x9ec95d1463e8a506,0xf4363804324a40aa,
0xc67bb4597ce2ce48,0xb143c6053edcd0d5,
0xf81aa16fdc1b81da,0xdd94b7868e94050a,
0x9b10a4e5e9913128,0xca7cf2b4191c8326,
0xc1d4ce1f63f57d72,0xfd1c2f611f63a3f0,
0xf24a01a73cf2dccf,0xbc633b39673c8cec,
0x976e41088617ca01,0xd5be0503e085d813,
0xbd49d14aa79dbc82,0x4b2d8644d8a74e18,
0xec9c459d51852ba2,0xddf8e7d60ed1219e,
0x93e1ab8252f33b45,0xcabb90e5c942b503,
0xb8da1662e7b00a17,0x3d6a751f3b936243,
0xe7109bfba19c0c9d,0xcc512670a783ad4,
0x906a617d450187e2,0x27fb2b80668b24c5,
0xb484f9dc9641e9da,0xb1f9f660802dedf6,
0xe1a63853bbd26451,0x5e7873f8a0396973,
0x8d07e33455637eb2,0xdb0b487b6423e1e8,
0xb049dc016abc5e5f,0x91ce1a9a3d2cda62,
0xdc5c5301c56b75f7,0x7641a140cc7810fb,
0x89b9b3e11b6329ba,0xa9e904c87fcb0a9d,
0xac2820d9623bf429,0x546345fa9fbdcd44,
0xd732290fbacaf133,0xa97c177947ad4095,
0x867f59a9d4bed6c0,0x49ed8eabcccc485d,
0xa81f301449ee8c70,0x5c68f256bfff5a74,
0xd226fc195c6a2f8c,0x73832eec6fff3111,
0x83585d8fd9c25db7,0xc831fd53c5ff7eab,
0xa42e74f3d032f525,0xba3e7ca8b77f5e55,
0xcd3a1230c43fb26f,0x28ce1bd2e55f35eb,
0x80444b5e7aa7cf85,0x7980d163cf5b81b3,
0xa0555e361951c366,0xd7e105bcc332621f,
0xc86ab5c39fa63440,0x8dd9472bf3fefaa7,
0xfa856334878fc150,0xb14f98f6f0feb951,
0x9c935e00d4b9d8d2,0x6ed1bf9a569f33d3,
0xc3b8358109e84f07,0xa862f80ec4700c8,
0xf4a642e14c6262c8,0xcd27bb612758c0fa,
0x98e7e9cccfbd7dbd,0x8038d51cb897789c,
0xbf21e44003acdd2c,0xe0470a63e6bd56c3,
0xeeea5d5004981478,0x1858ccfce06cac74,
0x95527a5202df0ccb,0xf37801e0c43ebc8,
0xbaa718e68396cffd,0xd30560258f54e6ba,
0xe950df20247c83fd,0x47c6b82ef32a2069,
0x91d28b7416cdd27e,0x4cdc331d57fa5441,
0xb6472e511c81471d,0xe0133fe4adf8e952,
0xe3d8f9e563a198e5,0x58180fddd97723a6,
0x8e679c2f5e44ff8f,0x570f09eaa7ea7648,};
using powers = powers_template<>;
}
#endif
#ifndef FASTFLOAT_DECIMAL_TO_BINARY_H
#define FASTFLOAT_DECIMAL_TO_BINARY_H
#include <cfloat>
#include <cinttypes>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <cstring>
namespace fast_float {
// This will compute or rather approximate w * 5**q and return a pair of 64-bit words approximating
// the result, with the "high" part corresponding to the most significant bits and the
// low part corresponding to the least significant bits.
//
template <int bit_precision>
fastfloat_really_inline
value128 compute_product_approximation(int64_t q, uint64_t w) {
const int index = 2 * int(q - powers::smallest_power_of_five);
// For small values of q, e.g., q in [0,27], the answer is always exact because
// The line value128 firstproduct = full_multiplication(w, power_of_five_128[index]);
// gives the exact answer.
value128 firstproduct = full_multiplication(w, powers::power_of_five_128[index]);
static_assert((bit_precision >= 0) && (bit_precision <= 64), " precision should be in (0,64]");
constexpr uint64_t precision_mask = (bit_precision < 64) ?
(uint64_t(0xFFFFFFFFFFFFFFFF) >> bit_precision)
: uint64_t(0xFFFFFFFFFFFFFFFF);
if((firstproduct.high & precision_mask) == precision_mask) { // could further guard with (lower + w < lower)
// regarding the second product, we only need secondproduct.high, but our expectation is that the compiler will optimize this extra work away if needed.
value128 secondproduct = full_multiplication(w, powers::power_of_five_128[index + 1]);
firstproduct.low += secondproduct.high;
if(secondproduct.high > firstproduct.low) {
firstproduct.high++;
}
}
return firstproduct;
}
namespace detail {
/**
* For q in (0,350), we have that
* f = (((152170 + 65536) * q ) >> 16);
* is equal to
* floor(p) + q
* where
* p = log(5**q)/log(2) = q * log(5)/log(2)
*
* For negative values of q in (-400,0), we have that
* f = (((152170 + 65536) * q ) >> 16);
* is equal to
* -ceil(p) + q
* where
* p = log(5**-q)/log(2) = -q * log(5)/log(2)
*/
constexpr fastfloat_really_inline int32_t power(int32_t q) noexcept {
return (((152170 + 65536) * q) >> 16) + 63;
}
} // namespace detail
// create an adjusted mantissa, biased by the invalid power2
// for significant digits already multiplied by 10 ** q.
template <typename binary>
fastfloat_really_inline
adjusted_mantissa compute_error_scaled(int64_t q, uint64_t w, int lz) noexcept {
int hilz = int(w >> 63) ^ 1;
adjusted_mantissa answer;
answer.mantissa = w << hilz;
int bias = binary::mantissa_explicit_bits() - binary::minimum_exponent();
answer.power2 = int32_t(detail::power(int32_t(q)) + bias - hilz - lz - 62 + invalid_am_bias);
return answer;
}
// w * 10 ** q, without rounding the representation up.
// the power2 in the exponent will be adjusted by invalid_am_bias.
template <typename binary>
fastfloat_really_inline
adjusted_mantissa compute_error(int64_t q, uint64_t w) noexcept {
int lz = leading_zeroes(w);
w <<= lz;
value128 product = compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
return compute_error_scaled<binary>(q, product.high, lz);
}
// w * 10 ** q
// The returned value should be a valid ieee64 number that simply need to be packed.
// However, in some very rare cases, the computation will fail. In such cases, we
// return an adjusted_mantissa with a negative power of 2: the caller should recompute
// in such cases.
template <typename binary>
fastfloat_really_inline
adjusted_mantissa compute_float(int64_t q, uint64_t w) noexcept {
adjusted_mantissa answer;
if ((w == 0) || (q < binary::smallest_power_of_ten())) {
answer.power2 = 0;
answer.mantissa = 0;
// result should be zero
return answer;
}
if (q > binary::largest_power_of_ten()) {
// we want to get infinity:
answer.power2 = binary::infinite_power();
answer.mantissa = 0;
return answer;
}
// At this point in time q is in [powers::smallest_power_of_five, powers::largest_power_of_five].
// We want the most significant bit of i to be 1. Shift if needed.
int lz = leading_zeroes(w);
w <<= lz;
// The required precision is binary::mantissa_explicit_bits() + 3 because
// 1. We need the implicit bit
// 2. We need an extra bit for rounding purposes
// 3. We might lose a bit due to the "upperbit" routine (result too small, requiring a shift)
value128 product = compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
if(product.low == 0xFFFFFFFFFFFFFFFF) { // could guard it further
// In some very rare cases, this could happen, in which case we might need a more accurate
// computation that what we can provide cheaply. This is very, very unlikely.
//
const bool inside_safe_exponent = (q >= -27) && (q <= 55); // always good because 5**q <2**128 when q>=0,
// and otherwise, for q<0, we have 5**-q<2**64 and the 128-bit reciprocal allows for exact computation.
if(!inside_safe_exponent) {
return compute_error_scaled<binary>(q, product.high, lz);
}
}
// The "compute_product_approximation" function can be slightly slower than a branchless approach:
// value128 product = compute_product(q, w);
// but in practice, we can win big with the compute_product_approximation if its additional branch
// is easily predicted. Which is best is data specific.
int upperbit = int(product.high >> 63);
answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
answer.power2 = int32_t(detail::power(int32_t(q)) + upperbit - lz - binary::minimum_exponent());
if (answer.power2 <= 0) { // we have a subnormal?
// Here have that answer.power2 <= 0 so -answer.power2 >= 0
if(-answer.power2 + 1 >= 64) { // if we have more than 64 bits below the minimum exponent, you have a zero for sure.
answer.power2 = 0;
answer.mantissa = 0;
// result should be zero
return answer;
}
// next line is safe because -answer.power2 + 1 < 64
answer.mantissa >>= -answer.power2 + 1;
// Thankfully, we can't have both "round-to-even" and subnormals because
// "round-to-even" only occurs for powers close to 0.
answer.mantissa += (answer.mantissa & 1); // round up
answer.mantissa >>= 1;
// There is a weird scenario where we don't have a subnormal but just.
// Suppose we start with 2.2250738585072013e-308, we end up
// with 0x3fffffffffffff x 2^-1023-53 which is technically subnormal
// whereas 0x40000000000000 x 2^-1023-53 is normal. Now, we need to round
// up 0x3fffffffffffff x 2^-1023-53 and once we do, we are no longer
// subnormal, but we can only know this after rounding.
// So we only declare a subnormal if we are smaller than the threshold.
answer.power2 = (answer.mantissa < (uint64_t(1) << binary::mantissa_explicit_bits())) ? 0 : 1;
return answer;
}
// usually, we round *up*, but if we fall right in between and and we have an
// even basis, we need to round down
// We are only concerned with the cases where 5**q fits in single 64-bit word.
if ((product.low <= 1) && (q >= binary::min_exponent_round_to_even()) && (q <= binary::max_exponent_round_to_even()) &&
((answer.mantissa & 3) == 1) ) { // we may fall between two floats!
// To be in-between two floats we need that in doing
// answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
// ... we dropped out only zeroes. But if this happened, then we can go back!!!
if((answer.mantissa << (upperbit + 64 - binary::mantissa_explicit_bits() - 3)) == product.high) {
answer.mantissa &= ~uint64_t(1); // flip it so that we do not round up
}
}
answer.mantissa += (answer.mantissa & 1); // round up
answer.mantissa >>= 1;
if (answer.mantissa >= (uint64_t(2) << binary::mantissa_explicit_bits())) {
answer.mantissa = (uint64_t(1) << binary::mantissa_explicit_bits());
answer.power2++; // undo previous addition
}
answer.mantissa &= ~(uint64_t(1) << binary::mantissa_explicit_bits());
if (answer.power2 >= binary::infinite_power()) { // infinity
answer.power2 = binary::infinite_power();
answer.mantissa = 0;
}
return answer;
}
} // namespace fast_float
#endif
#ifndef FASTFLOAT_BIGINT_H
#define FASTFLOAT_BIGINT_H
#include <algorithm>
#include <cstdint>
#include <climits>
#include <cstring>
namespace fast_float {
// the limb width: we want efficient multiplication of double the bits in
// limb, or for 64-bit limbs, at least 64-bit multiplication where we can
// extract the high and low parts efficiently. this is every 64-bit
// architecture except for sparc, which emulates 128-bit multiplication.
// we might have platforms where `CHAR_BIT` is not 8, so let's avoid
// doing `8 * sizeof(limb)`.
#if defined(FASTFLOAT_64BIT) && !defined(__sparc)
#define FASTFLOAT_64BIT_LIMB
typedef uint64_t limb;
constexpr size_t limb_bits = 64;
#else
#define FASTFLOAT_32BIT_LIMB
typedef uint32_t limb;
constexpr size_t limb_bits = 32;
#endif
typedef span<limb> limb_span;
// number of bits in a bigint. this needs to be at least the number
// of bits required to store the largest bigint, which is
// `log2(10**(digits + max_exp))`, or `log2(10**(767 + 342))`, or
// ~3600 bits, so we round to 4000.
constexpr size_t bigint_bits = 4000;
constexpr size_t bigint_limbs = bigint_bits / limb_bits;
// vector-like type that is allocated on the stack. the entire
// buffer is pre-allocated, and only the length changes.
template <uint16_t size>
struct stackvec {
limb data[size];
// we never need more than 150 limbs
uint16_t length{0};
stackvec() = default;
stackvec(const stackvec &) = delete;
stackvec &operator=(const stackvec &) = delete;
stackvec(stackvec &&) = delete;
stackvec &operator=(stackvec &&other) = delete;
// create stack vector from existing limb span.
stackvec(limb_span s) {
FASTFLOAT_ASSERT(try_extend(s));
}
limb& operator[](size_t index) noexcept {
FASTFLOAT_DEBUG_ASSERT(index < length);
return data[index];
}
const limb& operator[](size_t index) const noexcept {
FASTFLOAT_DEBUG_ASSERT(index < length);
return data[index];
}
// index from the end of the container
const limb& rindex(size_t index) const noexcept {
FASTFLOAT_DEBUG_ASSERT(index < length);
size_t rindex = length - index - 1;
return data[rindex];
}
// set the length, without bounds checking.
void set_len(size_t len) noexcept {
length = uint16_t(len);
}
constexpr size_t len() const noexcept {
return length;
}
constexpr bool is_empty() const noexcept {
return length == 0;
}
constexpr size_t capacity() const noexcept {
return size;
}
// append item to vector, without bounds checking
void push_unchecked(limb value) noexcept {
data[length] = value;
length++;
}
// append item to vector, returning if item was added
bool try_push(limb value) noexcept {
if (len() < capacity()) {
push_unchecked(value);
return true;
} else {
return false;
}
}
// add items to the vector, from a span, without bounds checking
void extend_unchecked(limb_span s) noexcept {
limb* ptr = data + length;
::memcpy((void*)ptr, (const void*)s.ptr, sizeof(limb) * s.len());
set_len(len() + s.len());
}
// try to add items to the vector, returning if items were added
bool try_extend(limb_span s) noexcept {
if (len() + s.len() <= capacity()) {
extend_unchecked(s);
return true;
} else {
return false;
}
}
// resize the vector, without bounds checking
// if the new size is longer than the vector, assign value to each
// appended item.
void resize_unchecked(size_t new_len, limb value) noexcept {
if (new_len > len()) {
size_t count = new_len - len();
limb* first = data + len();
limb* last = first + count;
::std::fill(first, last, value);
set_len(new_len);
} else {
set_len(new_len);
}
}
// try to resize the vector, returning if the vector was resized.
bool try_resize(size_t new_len, limb value) noexcept {
if (new_len > capacity()) {
return false;
} else {
resize_unchecked(new_len, value);
return true;
}
}
// check if any limbs are non-zero after the given index.
// this needs to be done in reverse order, since the index
// is relative to the most significant limbs.
bool nonzero(size_t index) const noexcept {
while (index < len()) {
if (rindex(index) != 0) {
return true;
}
index++;
}
return false;
}
// normalize the big integer, so most-significant zero limbs are removed.
void normalize() noexcept {
while (len() > 0 && rindex(0) == 0) {
length--;
}
}
};
fastfloat_really_inline
uint64_t empty_hi64(bool& truncated) noexcept {
truncated = false;
return 0;
}
fastfloat_really_inline
uint64_t uint64_hi64(uint64_t r0, bool& truncated) noexcept {
truncated = false;
int shl = leading_zeroes(r0);
return r0 << shl;
}
fastfloat_really_inline
uint64_t uint64_hi64(uint64_t r0, uint64_t r1, bool& truncated) noexcept {
int shl = leading_zeroes(r0);
if (shl == 0) {
truncated = r1 != 0;
return r0;
} else {
int shr = 64 - shl;
truncated = (r1 << shl) != 0;
return (r0 << shl) | (r1 >> shr);
}
}
fastfloat_really_inline
uint64_t uint32_hi64(uint32_t r0, bool& truncated) noexcept {
return uint64_hi64(r0, truncated);
}
fastfloat_really_inline
uint64_t uint32_hi64(uint32_t r0, uint32_t r1, bool& truncated) noexcept {
uint64_t x0 = r0;
uint64_t x1 = r1;
return uint64_hi64((x0 << 32) | x1, truncated);
}
fastfloat_really_inline
uint64_t uint32_hi64(uint32_t r0, uint32_t r1, uint32_t r2, bool& truncated) noexcept {
uint64_t x0 = r0;
uint64_t x1 = r1;
uint64_t x2 = r2;
return uint64_hi64(x0, (x1 << 32) | x2, truncated);
}
// add two small integers, checking for overflow.
// we want an efficient operation. for msvc, where
// we don't have built-in intrinsics, this is still
// pretty fast.
fastfloat_really_inline
limb scalar_add(limb x, limb y, bool& overflow) noexcept {
limb z;
// gcc and clang
#if defined(__has_builtin)
#if __has_builtin(__builtin_add_overflow)
overflow = __builtin_add_overflow(x, y, &z);
return z;
#endif
#endif
// generic, this still optimizes correctly on MSVC.
z = x + y;
overflow = z < x;
return z;
}
// multiply two small integers, getting both the high and low bits.
fastfloat_really_inline
limb scalar_mul(limb x, limb y, limb& carry) noexcept {
#ifdef FASTFLOAT_64BIT_LIMB
#if defined(__SIZEOF_INT128__)
// GCC and clang both define it as an extension.
__uint128_t z = __uint128_t(x) * __uint128_t(y) + __uint128_t(carry);
carry = limb(z >> limb_bits);
return limb(z);
#else
// fallback, no native 128-bit integer multiplication with carry.
// on msvc, this optimizes identically, somehow.
value128 z = full_multiplication(x, y);
bool overflow;
z.low = scalar_add(z.low, carry, overflow);
z.high += uint64_t(overflow); // cannot overflow
carry = z.high;
return z.low;
#endif
#else
uint64_t z = uint64_t(x) * uint64_t(y) + uint64_t(carry);
carry = limb(z >> limb_bits);
return limb(z);
#endif
}
// add scalar value to bigint starting from offset.
// used in grade school multiplication
template <uint16_t size>
inline bool small_add_from(stackvec<size>& vec, limb y, size_t start) noexcept {
size_t index = start;
limb carry = y;
bool overflow;
while (carry != 0 && index < vec.len()) {
vec[index] = scalar_add(vec[index], carry, overflow);
carry = limb(overflow);
index += 1;
}
if (carry != 0) {
FASTFLOAT_TRY(vec.try_push(carry));
}
return true;
}
// add scalar value to bigint.
template <uint16_t size>
fastfloat_really_inline bool small_add(stackvec<size>& vec, limb y) noexcept {
return small_add_from(vec, y, 0);
}
// multiply bigint by scalar value.
template <uint16_t size>
inline bool small_mul(stackvec<size>& vec, limb y) noexcept {
limb carry = 0;
for (size_t index = 0; index < vec.len(); index++) {
vec[index] = scalar_mul(vec[index], y, carry);
}
if (carry != 0) {
FASTFLOAT_TRY(vec.try_push(carry));
}
return true;
}
// add bigint to bigint starting from index.
// used in grade school multiplication
template <uint16_t size>
bool large_add_from(stackvec<size>& x, limb_span y, size_t start) noexcept {
// the effective x buffer is from `xstart..x.len()`, so exit early
// if we can't get that current range.
if (x.len() < start || y.len() > x.len() - start) {
FASTFLOAT_TRY(x.try_resize(y.len() + start, 0));
}
bool carry = false;
for (size_t index = 0; index < y.len(); index++) {
limb xi = x[index + start];
limb yi = y[index];
bool c1 = false;
bool c2 = false;
xi = scalar_add(xi, yi, c1);
if (carry) {
xi = scalar_add(xi, 1, c2);
}
x[index + start] = xi;
carry = c1 | c2;
}
// handle overflow
if (carry) {
FASTFLOAT_TRY(small_add_from(x, 1, y.len() + start));
}
return true;
}
// add bigint to bigint.
template <uint16_t size>
fastfloat_really_inline bool large_add_from(stackvec<size>& x, limb_span y) noexcept {
return large_add_from(x, y, 0);
}
// grade-school multiplication algorithm
template <uint16_t size>
bool long_mul(stackvec<size>& x, limb_span y) noexcept {
limb_span xs = limb_span(x.data, x.len());
stackvec<size> z(xs);
limb_span zs = limb_span(z.data, z.len());
if (y.len() != 0) {
limb y0 = y[0];
FASTFLOAT_TRY(small_mul(x, y0));
for (size_t index = 1; index < y.len(); index++) {
limb yi = y[index];
stackvec<size> zi;
if (yi != 0) {
// re-use the same buffer throughout
zi.set_len(0);
FASTFLOAT_TRY(zi.try_extend(zs));
FASTFLOAT_TRY(small_mul(zi, yi));
limb_span zis = limb_span(zi.data, zi.len());
FASTFLOAT_TRY(large_add_from(x, zis, index));
}
}
}
x.normalize();
return true;
}
// grade-school multiplication algorithm
template <uint16_t size>
bool large_mul(stackvec<size>& x, limb_span y) noexcept {
if (y.len() == 1) {
FASTFLOAT_TRY(small_mul(x, y[0]));
} else {
FASTFLOAT_TRY(long_mul(x, y));
}
return true;
}
// big integer type. implements a small subset of big integer
// arithmetic, using simple algorithms since asymptotically
// faster algorithms are slower for a small number of limbs.
// all operations assume the big-integer is normalized.
struct bigint {
// storage of the limbs, in little-endian order.
stackvec<bigint_limbs> vec;
bigint(): vec() {}
bigint(const bigint &) = delete;
bigint &operator=(const bigint &) = delete;
bigint(bigint &&) = delete;
bigint &operator=(bigint &&other) = delete;
bigint(uint64_t value): vec() {
#ifdef FASTFLOAT_64BIT_LIMB
vec.push_unchecked(value);
#else
vec.push_unchecked(uint32_t(value));
vec.push_unchecked(uint32_t(value >> 32));
#endif
vec.normalize();
}
// get the high 64 bits from the vector, and if bits were truncated.
// this is to get the significant digits for the float.
uint64_t hi64(bool& truncated) const noexcept {
#ifdef FASTFLOAT_64BIT_LIMB
if (vec.len() == 0) {
return empty_hi64(truncated);
} else if (vec.len() == 1) {
return uint64_hi64(vec.rindex(0), truncated);
} else {
uint64_t result = uint64_hi64(vec.rindex(0), vec.rindex(1), truncated);
truncated |= vec.nonzero(2);
return result;
}
#else
if (vec.len() == 0) {
return empty_hi64(truncated);
} else if (vec.len() == 1) {
return uint32_hi64(vec.rindex(0), truncated);
} else if (vec.len() == 2) {
return uint32_hi64(vec.rindex(0), vec.rindex(1), truncated);
} else {
uint64_t result = uint32_hi64(vec.rindex(0), vec.rindex(1), vec.rindex(2), truncated);
truncated |= vec.nonzero(3);
return result;
}
#endif
}
// compare two big integers, returning the large value.
// assumes both are normalized. if the return value is
// negative, other is larger, if the return value is
// positive, this is larger, otherwise they are equal.
// the limbs are stored in little-endian order, so we
// must compare the limbs in ever order.
int compare(const bigint& other) const noexcept {
if (vec.len() > other.vec.len()) {
return 1;
} else if (vec.len() < other.vec.len()) {
return -1;
} else {
for (size_t index = vec.len(); index > 0; index--) {
limb xi = vec[index - 1];
limb yi = other.vec[index - 1];
if (xi > yi) {
return 1;
} else if (xi < yi) {
return -1;
}
}
return 0;
}
}
// shift left each limb n bits, carrying over to the new limb
// returns true if we were able to shift all the digits.
bool shl_bits(size_t n) noexcept {
// Internally, for each item, we shift left by n, and add the previous
// right shifted limb-bits.
// For example, we transform (for u8) shifted left 2, to:
// b10100100 b01000010
// b10 b10010001 b00001000
FASTFLOAT_DEBUG_ASSERT(n != 0);
FASTFLOAT_DEBUG_ASSERT(n < sizeof(limb) * 8);
size_t shl = n;
size_t shr = limb_bits - shl;
limb prev = 0;
for (size_t index = 0; index < vec.len(); index++) {
limb xi = vec[index];
vec[index] = (xi << shl) | (prev >> shr);
prev = xi;
}
limb carry = prev >> shr;
if (carry != 0) {
return vec.try_push(carry);
}
return true;
}
// move the limbs left by `n` limbs.
bool shl_limbs(size_t n) noexcept {
FASTFLOAT_DEBUG_ASSERT(n != 0);
if (n + vec.len() > vec.capacity()) {
return false;
} else if (!vec.is_empty()) {
// move limbs
limb* dst = vec.data + n;
const limb* src = vec.data;
::memmove(dst, src, sizeof(limb) * vec.len());
// fill in empty limbs
limb* first = vec.data;
limb* last = first + n;
::std::fill(first, last, 0);
vec.set_len(n + vec.len());
return true;
} else {
return true;
}
}
// move the limbs left by `n` bits.
bool shl(size_t n) noexcept {
size_t rem = n % limb_bits;
size_t div = n / limb_bits;
if (rem != 0) {
FASTFLOAT_TRY(shl_bits(rem));
}
if (div != 0) {
FASTFLOAT_TRY(shl_limbs(div));
}
return true;
}
// get the number of leading zeros in the bigint.
int ctlz() const noexcept {
if (vec.is_empty()) {
return 0;
} else {
#ifdef FASTFLOAT_64BIT_LIMB
return leading_zeroes(vec.rindex(0));
#else
// no use defining a specialized leading_zeroes for a 32-bit type.
uint64_t r0 = vec.rindex(0);
return leading_zeroes(r0 << 32);
#endif
}
}
// get the number of bits in the bigint.
int bit_length() const noexcept {
int lz = ctlz();
return int(limb_bits * vec.len()) - lz;
}
bool mul(limb y) noexcept {
return small_mul(vec, y);
}
bool add(limb y) noexcept {
return small_add(vec, y);
}
// multiply as if by 2 raised to a power.
bool pow2(uint32_t exp) noexcept {
return shl(exp);
}
// multiply as if by 5 raised to a power.
bool pow5(uint32_t exp) noexcept {
// multiply by a power of 5
static constexpr uint32_t large_step = 135;
static constexpr uint64_t small_power_of_5[] = {
1UL, 5UL, 25UL, 125UL, 625UL, 3125UL, 15625UL, 78125UL, 390625UL,
1953125UL, 9765625UL, 48828125UL, 244140625UL, 1220703125UL,
6103515625UL, 30517578125UL, 152587890625UL, 762939453125UL,
3814697265625UL, 19073486328125UL, 95367431640625UL, 476837158203125UL,
2384185791015625UL, 11920928955078125UL, 59604644775390625UL,
298023223876953125UL, 1490116119384765625UL, 7450580596923828125UL,
};
#ifdef FASTFLOAT_64BIT_LIMB
constexpr static limb large_power_of_5[] = {
1414648277510068013UL, 9180637584431281687UL, 4539964771860779200UL,
10482974169319127550UL, 198276706040285095UL};
#else
constexpr static limb large_power_of_5[] = {
4279965485U, 329373468U, 4020270615U, 2137533757U, 4287402176U,
1057042919U, 1071430142U, 2440757623U, 381945767U, 46164893U};
#endif
size_t large_length = sizeof(large_power_of_5) / sizeof(limb);
limb_span large = limb_span(large_power_of_5, large_length);
while (exp >= large_step) {
FASTFLOAT_TRY(large_mul(vec, large));
exp -= large_step;
}
#ifdef FASTFLOAT_64BIT_LIMB
uint32_t small_step = 27;
limb max_native = 7450580596923828125UL;
#else
uint32_t small_step = 13;
limb max_native = 1220703125U;
#endif
while (exp >= small_step) {
FASTFLOAT_TRY(small_mul(vec, max_native));
exp -= small_step;
}
if (exp != 0) {
FASTFLOAT_TRY(small_mul(vec, limb(small_power_of_5[exp])));
}
return true;
}
// multiply as if by 10 raised to a power.
bool pow10(uint32_t exp) noexcept {
FASTFLOAT_TRY(pow5(exp));
return pow2(exp);
}
};
} // namespace fast_float
#endif
#ifndef FASTFLOAT_ASCII_NUMBER_H
#define FASTFLOAT_ASCII_NUMBER_H
#include <cctype>
#include <cstdint>
#include <cstring>
#include <iterator>
namespace fast_float {
// Next function can be micro-optimized, but compilers are entirely
// able to optimize it well.
fastfloat_really_inline bool is_integer(char c) noexcept { return c >= '0' && c <= '9'; }
fastfloat_really_inline uint64_t byteswap(uint64_t val) {
return (val & 0xFF00000000000000) >> 56
| (val & 0x00FF000000000000) >> 40
| (val & 0x0000FF0000000000) >> 24
| (val & 0x000000FF00000000) >> 8
| (val & 0x00000000FF000000) << 8
| (val & 0x0000000000FF0000) << 24
| (val & 0x000000000000FF00) << 40
| (val & 0x00000000000000FF) << 56;
}
fastfloat_really_inline uint64_t read_u64(const char *chars) {
uint64_t val;
::memcpy(&val, chars, sizeof(uint64_t));
#if FASTFLOAT_IS_BIG_ENDIAN == 1
// Need to read as-if the number was in little-endian order.
val = byteswap(val);
#endif
return val;
}
fastfloat_really_inline void write_u64(uint8_t *chars, uint64_t val) {
#if FASTFLOAT_IS_BIG_ENDIAN == 1
// Need to read as-if the number was in little-endian order.
val = byteswap(val);
#endif
::memcpy(chars, &val, sizeof(uint64_t));
}
// credit @aqrit
fastfloat_really_inline uint32_t parse_eight_digits_unrolled(uint64_t val) {
const uint64_t mask = 0x000000FF000000FF;
const uint64_t mul1 = 0x000F424000000064; // 100 + (1000000ULL << 32)
const uint64_t mul2 = 0x0000271000000001; // 1 + (10000ULL << 32)
val -= 0x3030303030303030;
val = (val * 10) + (val >> 8); // val = (val * 2561) >> 8;
val = (((val & mask) * mul1) + (((val >> 16) & mask) * mul2)) >> 32;
return uint32_t(val);
}
fastfloat_really_inline uint32_t parse_eight_digits_unrolled(const char *chars) noexcept {
return parse_eight_digits_unrolled(read_u64(chars));
}
// credit @aqrit
fastfloat_really_inline bool is_made_of_eight_digits_fast(uint64_t val) noexcept {
return !((((val + 0x4646464646464646) | (val - 0x3030303030303030)) &
0x8080808080808080));
}
fastfloat_really_inline bool is_made_of_eight_digits_fast(const char *chars) noexcept {
return is_made_of_eight_digits_fast(read_u64(chars));
}
typedef span<const char> byte_span;
struct parsed_number_string {
int64_t exponent{0};
uint64_t mantissa{0};
const char *lastmatch{nullptr};
bool negative{false};
bool valid{false};
bool too_many_digits{false};
// contains the range of the significant digits
byte_span integer{}; // non-nullable
byte_span fraction{}; // nullable
};
// Assuming that you use no more than 19 digits, this will
// parse an ASCII string.
fastfloat_really_inline
parsed_number_string parse_number_string(const char *p, const char *pend, parse_options options) noexcept {
const chars_format fmt = options.format;
const char decimal_point = options.decimal_point;
parsed_number_string answer;
answer.valid = false;
answer.too_many_digits = false;
answer.negative = (*p == '-');
if (*p == '-') { // C++17 20.19.3.(7.1) explicitly forbids '+' sign here
++p;
if (p == pend) {
return answer;
}
if (!is_integer(*p) && (*p != decimal_point)) { // a sign must be followed by an integer or the dot
return answer;
}
}
const char *const start_digits = p;
uint64_t i = 0; // an unsigned int avoids signed overflows (which are bad)
while ((std::distance(p, pend) >= 8) && is_made_of_eight_digits_fast(p)) {
i = i * 100000000 + parse_eight_digits_unrolled(p); // in rare cases, this will overflow, but that's ok
p += 8;
}
while ((p != pend) && is_integer(*p)) {
// a multiplication by 10 is cheaper than an arbitrary integer
// multiplication
i = 10 * i +
uint64_t(*p - '0'); // might overflow, we will handle the overflow later
++p;
}
const char *const end_of_integer_part = p;
int64_t digit_count = int64_t(end_of_integer_part - start_digits);
answer.integer = byte_span(start_digits, size_t(digit_count));
int64_t exponent = 0;
if ((p != pend) && (*p == decimal_point)) {
++p;
const char* before = p;
// can occur at most twice without overflowing, but let it occur more, since
// for integers with many digits, digit parsing is the primary bottleneck.
while ((std::distance(p, pend) >= 8) && is_made_of_eight_digits_fast(p)) {
i = i * 100000000 + parse_eight_digits_unrolled(p); // in rare cases, this will overflow, but that's ok
p += 8;
}
while ((p != pend) && is_integer(*p)) {
uint8_t digit = uint8_t(*p - '0');
++p;
i = i * 10 + digit; // in rare cases, this will overflow, but that's ok
}
exponent = before - p;
answer.fraction = byte_span(before, size_t(p - before));
digit_count -= exponent;
}
// we must have encountered at least one integer!
if (digit_count == 0) {
return answer;
}
int64_t exp_number = 0; // explicit exponential part
if ((fmt & chars_format::scientific) && (p != pend) && (('e' == *p) || ('E' == *p))) {
const char * location_of_e = p;
++p;
bool neg_exp = false;
if ((p != pend) && ('-' == *p)) {
neg_exp = true;
++p;
} else if ((p != pend) && ('+' == *p)) { // '+' on exponent is allowed by C++17 20.19.3.(7.1)
++p;
}
if ((p == pend) || !is_integer(*p)) {
if(!(fmt & chars_format::fixed)) {
// We are in error.
return answer;
}
// Otherwise, we will be ignoring the 'e'.
p = location_of_e;
} else {
while ((p != pend) && is_integer(*p)) {
uint8_t digit = uint8_t(*p - '0');
if (exp_number < 0x10000000) {
exp_number = 10 * exp_number + digit;
}
++p;
}
if(neg_exp) { exp_number = - exp_number; }
exponent += exp_number;
}
} else {
// If it scientific and not fixed, we have to bail out.
if((fmt & chars_format::scientific) && !(fmt & chars_format::fixed)) { return answer; }
}
answer.lastmatch = p;
answer.valid = true;
// If we frequently had to deal with long strings of digits,
// we could extend our code by using a 128-bit integer instead
// of a 64-bit integer. However, this is uncommon.
//
// We can deal with up to 19 digits.
if (digit_count > 19) { // this is uncommon
// It is possible that the integer had an overflow.
// We have to handle the case where we have 0.0000somenumber.
// We need to be mindful of the case where we only have zeroes...
// E.g., 0.000000000...000.
const char *start = start_digits;
while ((start != pend) && (*start == '0' || *start == decimal_point)) {
if(*start == '0') { digit_count --; }
start++;
}
if (digit_count > 19) {
answer.too_many_digits = true;
// Let us start again, this time, avoiding overflows.
// We don't need to check if is_integer, since we use the
// pre-tokenized spans from above.
i = 0;
p = answer.integer.ptr;
const char* int_end = p + answer.integer.len();
const uint64_t minimal_nineteen_digit_integer{1000000000000000000};
while((i < minimal_nineteen_digit_integer) && (p != int_end)) {
i = i * 10 + uint64_t(*p - '0');
++p;
}
if (i >= minimal_nineteen_digit_integer) { // We have a big integers
exponent = end_of_integer_part - p + exp_number;
} else { // We have a value with a fractional component.
p = answer.fraction.ptr;
const char* frac_end = p + answer.fraction.len();
while((i < minimal_nineteen_digit_integer) && (p != frac_end)) {
i = i * 10 + uint64_t(*p - '0');
++p;
}
exponent = answer.fraction.ptr - p + exp_number;
}
// We have now corrected both exponent and i, to a truncated value
}
}
answer.exponent = exponent;
answer.mantissa = i;
return answer;
}
} // namespace fast_float
#endif
#ifndef FASTFLOAT_DIGIT_COMPARISON_H
#define FASTFLOAT_DIGIT_COMPARISON_H
#include <algorithm>
#include <cstdint>
#include <cstring>
#include <iterator>
namespace fast_float {
// 1e0 to 1e19
constexpr static uint64_t powers_of_ten_uint64[] = {
1UL, 10UL, 100UL, 1000UL, 10000UL, 100000UL, 1000000UL, 10000000UL, 100000000UL,
1000000000UL, 10000000000UL, 100000000000UL, 1000000000000UL, 10000000000000UL,
100000000000000UL, 1000000000000000UL, 10000000000000000UL, 100000000000000000UL,
1000000000000000000UL, 10000000000000000000UL};
// calculate the exponent, in scientific notation, of the number.
// this algorithm is not even close to optimized, but it has no practical
// effect on performance: in order to have a faster algorithm, we'd need
// to slow down performance for faster algorithms, and this is still fast.
fastfloat_really_inline int32_t scientific_exponent(parsed_number_string& num) noexcept {
uint64_t mantissa = num.mantissa;
int32_t exponent = int32_t(num.exponent);
while (mantissa >= 10000) {
mantissa /= 10000;
exponent += 4;
}
while (mantissa >= 100) {
mantissa /= 100;
exponent += 2;
}
while (mantissa >= 10) {
mantissa /= 10;
exponent += 1;
}
return exponent;
}
// this converts a native floating-point number to an extended-precision float.
template <typename T>
fastfloat_really_inline adjusted_mantissa to_extended(T value) noexcept {
using equiv_uint = typename binary_format<T>::equiv_uint;
constexpr equiv_uint exponent_mask = binary_format<T>::exponent_mask();
constexpr equiv_uint mantissa_mask = binary_format<T>::mantissa_mask();
constexpr equiv_uint hidden_bit_mask = binary_format<T>::hidden_bit_mask();
adjusted_mantissa am;
int32_t bias = binary_format<T>::mantissa_explicit_bits() - binary_format<T>::minimum_exponent();
equiv_uint bits;
::memcpy(&bits, &value, sizeof(T));
if ((bits & exponent_mask) == 0) {
// denormal
am.power2 = 1 - bias;
am.mantissa = bits & mantissa_mask;
} else {
// normal
am.power2 = int32_t((bits & exponent_mask) >> binary_format<T>::mantissa_explicit_bits());
am.power2 -= bias;
am.mantissa = (bits & mantissa_mask) | hidden_bit_mask;
}
return am;
}
// get the extended precision value of the halfway point between b and b+u.
// we are given a native float that represents b, so we need to adjust it
// halfway between b and b+u.
template <typename T>
fastfloat_really_inline adjusted_mantissa to_extended_halfway(T value) noexcept {
adjusted_mantissa am = to_extended(value);
am.mantissa <<= 1;
am.mantissa += 1;
am.power2 -= 1;
return am;
}
// round an extended-precision float to the nearest machine float.
template <typename T, typename callback>
fastfloat_really_inline void round(adjusted_mantissa& am, callback cb) noexcept {
int32_t mantissa_shift = 64 - binary_format<T>::mantissa_explicit_bits() - 1;
if (-am.power2 >= mantissa_shift) {
// have a denormal float
int32_t shift = -am.power2 + 1;
cb(am, std::min(shift, 64));
// check for round-up: if rounding-nearest carried us to the hidden bit.
am.power2 = (am.mantissa < (uint64_t(1) << binary_format<T>::mantissa_explicit_bits())) ? 0 : 1;
return;
}
// have a normal float, use the default shift.
cb(am, mantissa_shift);
// check for carry
if (am.mantissa >= (uint64_t(2) << binary_format<T>::mantissa_explicit_bits())) {
am.mantissa = (uint64_t(1) << binary_format<T>::mantissa_explicit_bits());
am.power2++;
}
// check for infinite: we could have carried to an infinite power
am.mantissa &= ~(uint64_t(1) << binary_format<T>::mantissa_explicit_bits());
if (am.power2 >= binary_format<T>::infinite_power()) {
am.power2 = binary_format<T>::infinite_power();
am.mantissa = 0;
}
}
template <typename callback>
fastfloat_really_inline
void round_nearest_tie_even(adjusted_mantissa& am, int32_t shift, callback cb) noexcept {
uint64_t mask;
uint64_t halfway;
if (shift == 64) {
mask = UINT64_MAX;
} else {
mask = (uint64_t(1) << shift) - 1;
}
if (shift == 0) {
halfway = 0;
} else {
halfway = uint64_t(1) << (shift - 1);
}
uint64_t truncated_bits = am.mantissa & mask;
uint64_t is_above = truncated_bits > halfway;
uint64_t is_halfway = truncated_bits == halfway;
// shift digits into position
if (shift == 64) {
am.mantissa = 0;
} else {
am.mantissa >>= shift;
}
am.power2 += shift;
bool is_odd = (am.mantissa & 1) == 1;
am.mantissa += uint64_t(cb(is_odd, is_halfway, is_above));
}
fastfloat_really_inline void round_down(adjusted_mantissa& am, int32_t shift) noexcept {
if (shift == 64) {
am.mantissa = 0;
} else {
am.mantissa >>= shift;
}
am.power2 += shift;
}
fastfloat_really_inline void skip_zeros(const char*& first, const char* last) noexcept {
uint64_t val;
while (std::distance(first, last) >= 8) {
::memcpy(&val, first, sizeof(uint64_t));
if (val != 0x3030303030303030) {
break;
}
first += 8;
}
while (first != last) {
if (*first != '0') {
break;
}
first++;
}
}
// determine if any non-zero digits were truncated.
// all characters must be valid digits.
fastfloat_really_inline bool is_truncated(const char* first, const char* last) noexcept {
// do 8-bit optimizations, can just compare to 8 literal 0s.
uint64_t val;
while (std::distance(first, last) >= 8) {
::memcpy(&val, first, sizeof(uint64_t));
if (val != 0x3030303030303030) {
return true;
}
first += 8;
}
while (first != last) {
if (*first != '0') {
return true;
}
first++;
}
return false;
}
fastfloat_really_inline bool is_truncated(byte_span s) noexcept {
return is_truncated(s.ptr, s.ptr + s.len());
}
fastfloat_really_inline
void parse_eight_digits(const char*& p, limb& value, size_t& counter, size_t& count) noexcept {
value = value * 100000000 + parse_eight_digits_unrolled(p);
p += 8;
counter += 8;
count += 8;
}
fastfloat_really_inline
void parse_one_digit(const char*& p, limb& value, size_t& counter, size_t& count) noexcept {
value = value * 10 + limb(*p - '0');
p++;
counter++;
count++;
}
fastfloat_really_inline
void add_native(bigint& big, limb power, limb value) noexcept {
big.mul(power);
big.add(value);
}
fastfloat_really_inline void round_up_bigint(bigint& big, size_t& count) noexcept {
// need to round-up the digits, but need to avoid rounding
// ....9999 to ...10000, which could cause a false halfway point.
add_native(big, 10, 1);
count++;
}
// parse the significant digits into a big integer
inline void parse_mantissa(bigint& result, parsed_number_string& num, size_t max_digits, size_t& digits) noexcept {
// try to minimize the number of big integer and scalar multiplication.
// therefore, try to parse 8 digits at a time, and multiply by the largest
// scalar value (9 or 19 digits) for each step.
size_t counter = 0;
digits = 0;
limb value = 0;
#ifdef FASTFLOAT_64BIT_LIMB
size_t step = 19;
#else
size_t step = 9;
#endif
// process all integer digits.
const char* p = num.integer.ptr;
const char* pend = p + num.integer.len();
skip_zeros(p, pend);
// process all digits, in increments of step per loop
while (p != pend) {
while ((std::distance(p, pend) >= 8) && (step - counter >= 8) && (max_digits - digits >= 8)) {
parse_eight_digits(p, value, counter, digits);
}
while (counter < step && p != pend && digits < max_digits) {
parse_one_digit(p, value, counter, digits);
}
if (digits == max_digits) {
// add the temporary value, then check if we've truncated any digits
add_native(result, limb(powers_of_ten_uint64[counter]), value);
bool truncated = is_truncated(p, pend);
if (num.fraction.ptr != nullptr) {
truncated |= is_truncated(num.fraction);
}
if (truncated) {
round_up_bigint(result, digits);
}
return;
} else {
add_native(result, limb(powers_of_ten_uint64[counter]), value);
counter = 0;
value = 0;
}
}
// add our fraction digits, if they're available.
if (num.fraction.ptr != nullptr) {
p = num.fraction.ptr;
pend = p + num.fraction.len();
if (digits == 0) {
skip_zeros(p, pend);
}
// process all digits, in increments of step per loop
while (p != pend) {
while ((std::distance(p, pend) >= 8) && (step - counter >= 8) && (max_digits - digits >= 8)) {
parse_eight_digits(p, value, counter, digits);
}
while (counter < step && p != pend && digits < max_digits) {
parse_one_digit(p, value, counter, digits);
}
if (digits == max_digits) {
// add the temporary value, then check if we've truncated any digits
add_native(result, limb(powers_of_ten_uint64[counter]), value);
bool truncated = is_truncated(p, pend);
if (truncated) {
round_up_bigint(result, digits);
}
return;
} else {
add_native(result, limb(powers_of_ten_uint64[counter]), value);
counter = 0;
value = 0;
}
}
}
if (counter != 0) {
add_native(result, limb(powers_of_ten_uint64[counter]), value);
}
}
template <typename T>
inline adjusted_mantissa positive_digit_comp(bigint& bigmant, int32_t exponent) noexcept {
FASTFLOAT_ASSERT(bigmant.pow10(uint32_t(exponent)));
adjusted_mantissa answer;
bool truncated;
answer.mantissa = bigmant.hi64(truncated);
int bias = binary_format<T>::mantissa_explicit_bits() - binary_format<T>::minimum_exponent();
answer.power2 = bigmant.bit_length() - 64 + bias;
round<T>(answer, [truncated](adjusted_mantissa& a, int32_t shift) {
round_nearest_tie_even(a, shift, [truncated](bool is_odd, bool is_halfway, bool is_above) -> bool {
return is_above || (is_halfway && truncated) || (is_odd && is_halfway);
});
});
return answer;
}
// the scaling here is quite simple: we have, for the real digits `m * 10^e`,
// and for the theoretical digits `n * 2^f`. Since `e` is always negative,
// to scale them identically, we do `n * 2^f * 5^-f`, so we now have `m * 2^e`.
// we then need to scale by `2^(f- e)`, and then the two significant digits
// are of the same magnitude.
template <typename T>
inline adjusted_mantissa negative_digit_comp(bigint& bigmant, adjusted_mantissa am, int32_t exponent) noexcept {
bigint& real_digits = bigmant;
int32_t real_exp = exponent;
// get the value of `b`, rounded down, and get a bigint representation of b+h
adjusted_mantissa am_b = am;
// gcc7 buf: use a lambda to remove the noexcept qualifier bug with -Wnoexcept-type.
round<T>(am_b, [](adjusted_mantissa&a, int32_t shift) { round_down(a, shift); });
T b;
to_float(false, am_b, b);
adjusted_mantissa theor = to_extended_halfway(b);
bigint theor_digits(theor.mantissa);
int32_t theor_exp = theor.power2;
// scale real digits and theor digits to be same power.
int32_t pow2_exp = theor_exp - real_exp;
uint32_t pow5_exp = uint32_t(-real_exp);
if (pow5_exp != 0) {
FASTFLOAT_ASSERT(theor_digits.pow5(pow5_exp));
}
if (pow2_exp > 0) {
FASTFLOAT_ASSERT(theor_digits.pow2(uint32_t(pow2_exp)));
} else if (pow2_exp < 0) {
FASTFLOAT_ASSERT(real_digits.pow2(uint32_t(-pow2_exp)));
}
// compare digits, and use it to director rounding
int ord = real_digits.compare(theor_digits);
adjusted_mantissa answer = am;
round<T>(answer, [ord](adjusted_mantissa& a, int32_t shift) {
round_nearest_tie_even(a, shift, [ord](bool is_odd, bool _, bool __) -> bool {
(void)_; // not needed, since we've done our comparison
(void)__; // not needed, since we've done our comparison
if (ord > 0) {
return true;
} else if (ord < 0) {
return false;
} else {
return is_odd;
}
});
});
return answer;
}
// parse the significant digits as a big integer to unambiguously round the
// the significant digits. here, we are trying to determine how to round
// an extended float representation close to `b+h`, halfway between `b`
// (the float rounded-down) and `b+u`, the next positive float. this
// algorithm is always correct, and uses one of two approaches. when
// the exponent is positive relative to the significant digits (such as
// 1234), we create a big-integer representation, get the high 64-bits,
// determine if any lower bits are truncated, and use that to direct
// rounding. in case of a negative exponent relative to the significant
// digits (such as 1.2345), we create a theoretical representation of
// `b` as a big-integer type, scaled to the same binary exponent as
// the actual digits. we then compare the big integer representations
// of both, and use that to direct rounding.
template <typename T>
inline adjusted_mantissa digit_comp(parsed_number_string& num, adjusted_mantissa am) noexcept {
// remove the invalid exponent bias
am.power2 -= invalid_am_bias;
int32_t sci_exp = scientific_exponent(num);
size_t max_digits = binary_format<T>::max_digits();
size_t digits = 0;
bigint bigmant;
parse_mantissa(bigmant, num, max_digits, digits);
// can't underflow, since digits is at most max_digits.
int32_t exponent = sci_exp + 1 - int32_t(digits);
if (exponent >= 0) {
return positive_digit_comp<T>(bigmant, exponent);
} else {
return negative_digit_comp<T>(bigmant, am, exponent);
}
}
} // namespace fast_float
#endif
#ifndef FASTFLOAT_PARSE_NUMBER_H
#define FASTFLOAT_PARSE_NUMBER_H
#include <cmath>
#include <cstring>
#include <limits>
#include <system_error>
namespace fast_float {
namespace detail {
/**
* Special case +inf, -inf, nan, infinity, -infinity.
* The case comparisons could be made much faster given that we know that the
* strings a null-free and fixed.
**/
template <typename T>
from_chars_result parse_infnan(const char *first, const char *last, T &value) noexcept {
from_chars_result answer;
answer.ptr = first;
answer.ec = std::errc(); // be optimistic
bool minusSign = false;
if (*first == '-') { // assume first < last, so dereference without checks; C++17 20.19.3.(7.1) explicitly forbids '+' here
minusSign = true;
++first;
}
if (last - first >= 3) {
if (fastfloat_strncasecmp(first, "nan", 3)) {
answer.ptr = (first += 3);
value = minusSign ? -std::numeric_limits<T>::quiet_NaN() : std::numeric_limits<T>::quiet_NaN();
// Check for possible nan(n-char-seq-opt), C++17 20.19.3.7, C11 7.20.1.3.3. At least MSVC produces nan(ind) and nan(snan).
if(first != last && *first == '(') {
for(const char* ptr = first + 1; ptr != last; ++ptr) {
if (*ptr == ')') {
answer.ptr = ptr + 1; // valid nan(n-char-seq-opt)
break;
}
else if(!(('a' <= *ptr && *ptr <= 'z') || ('A' <= *ptr && *ptr <= 'Z') || ('0' <= *ptr && *ptr <= '9') || *ptr == '_'))
break; // forbidden char, not nan(n-char-seq-opt)
}
}
return answer;
}
if (fastfloat_strncasecmp(first, "inf", 3)) {
if ((last - first >= 8) && fastfloat_strncasecmp(first + 3, "inity", 5)) {
answer.ptr = first + 8;
} else {
answer.ptr = first + 3;
}
value = minusSign ? -std::numeric_limits<T>::infinity() : std::numeric_limits<T>::infinity();
return answer;
}
}
answer.ec = std::errc::invalid_argument;
return answer;
}
} // namespace detail
template<typename T>
from_chars_result from_chars(const char *first, const char *last,
T &value, chars_format fmt /*= chars_format::general*/) noexcept {
return from_chars_advanced(first, last, value, parse_options{fmt});
}
template<typename T>
from_chars_result from_chars_advanced(const char *first, const char *last,
T &value, parse_options options) noexcept {
static_assert (std::is_same<T, double>::value || std::is_same<T, float>::value, "only float and double are supported");
from_chars_result answer;
if (first == last) {
answer.ec = std::errc::invalid_argument;
answer.ptr = first;
return answer;
}
parsed_number_string pns = parse_number_string(first, last, options);
if (!pns.valid) {
return detail::parse_infnan(first, last, value);
}
answer.ec = std::errc(); // be optimistic
answer.ptr = pns.lastmatch;
// Next is Clinger's fast path.
if (binary_format<T>::min_exponent_fast_path() <= pns.exponent && pns.exponent <= binary_format<T>::max_exponent_fast_path() && pns.mantissa <=binary_format<T>::max_mantissa_fast_path() && !pns.too_many_digits) {
value = T(pns.mantissa);
if (pns.exponent < 0) { value = value / binary_format<T>::exact_power_of_ten(-pns.exponent); }
else { value = value * binary_format<T>::exact_power_of_ten(pns.exponent); }
if (pns.negative) { value = -value; }
return answer;
}
adjusted_mantissa am = compute_float<binary_format<T>>(pns.exponent, pns.mantissa);
if(pns.too_many_digits && am.power2 >= 0) {
if(am != compute_float<binary_format<T>>(pns.exponent, pns.mantissa + 1)) {
am = compute_error<binary_format<T>>(pns.exponent, pns.mantissa);
}
}
// If we called compute_float<binary_format<T>>(pns.exponent, pns.mantissa) and we have an invalid power (am.power2 < 0),
// then we need to go the long way around again. This is very uncommon.
if(am.power2 < 0) { am = digit_comp<T>(pns, am); }
to_float(pns.negative, am, value);
return answer;
}
} // namespace fast_float
#endif