double_conversion Namespace Reference

Namespaces
namespace	PowersOfTenCache

Classes
class	Bignum
class	DiyFp
class	Double
class	DoubleToStringConverter
class	Single
class	StringBuilder
class	StringToDoubleConverter
class	UInt128
class	Vector

Enumerations
enum	BignumDtoaMode { BIGNUM_DTOA_SHORTEST , BIGNUM_DTOA_SHORTEST_SINGLE , BIGNUM_DTOA_FIXED , BIGNUM_DTOA_PRECISION }
enum	FastDtoaMode { FAST_DTOA_SHORTEST , FAST_DTOA_SHORTEST_SINGLE , FAST_DTOA_PRECISION }

Functions
static int	NormalizedExponent (uint64_t significand, int exponent)
static int	EstimatePower (int exponent)
static void	InitialScaledStartValues (uint64_t significand, int exponent, bool lower_boundary_is_closer, int estimated_power, bool need_boundary_deltas, Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus)
static void	FixupMultiply10 (int estimated_power, bool is_even, int *decimal_point, Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus)
static void	GenerateShortestDigits (Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus, bool is_even, Vector< char > buffer, int *length)
static void	BignumToFixed (int requested_digits, int *decimal_point, Bignum *numerator, Bignum *denominator, Vector< char > buffer, int *length)
static void	GenerateCountedDigits (int count, int *decimal_point, Bignum *numerator, Bignum *denominator, Vector< char > buffer, int *length)
void	BignumDtoa (double v, BignumDtoaMode mode, int requested_digits, Vector< char > buffer, int *length, int *decimal_point)
static void	InitialScaledStartValuesPositiveExponent (uint64_t significand, int exponent, int estimated_power, bool need_boundary_deltas, Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus)
static void	InitialScaledStartValuesNegativeExponentPositivePower (uint64_t significand, int exponent, int estimated_power, bool need_boundary_deltas, Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus)
static void	InitialScaledStartValuesNegativeExponentNegativePower (uint64_t significand, int exponent, int estimated_power, bool need_boundary_deltas, Bignum *numerator, Bignum *denominator, Bignum *delta_minus, Bignum *delta_plus)
template<typename S >
static int	BitSize (const S value)
static uint64_t	ReadUInt64 (const Vector< const char > buffer, const int from, const int digits_to_read)
static uint64_t	HexCharValue (const int c)
template<typename S >
static int	SizeInHexChars (S number)
static char	HexCharOfValue (const int value)
static BignumDtoaMode	DtoaToBignumDtoaMode (DoubleToStringConverter::DtoaMode dtoa_mode)
static bool	RoundWeed (Vector< char > buffer, int length, uint64_t distance_too_high_w, uint64_t unsafe_interval, uint64_t rest, uint64_t ten_kappa, uint64_t unit)
static bool	RoundWeedCounted (Vector< char > buffer, int length, uint64_t rest, uint64_t ten_kappa, uint64_t unit, int *kappa)
static void	BiggestPowerTen (uint32_t number, int number_bits, uint32_t *power, int *exponent_plus_one)
static bool	DigitGen (DiyFp low, DiyFp w, DiyFp high, Vector< char > buffer, int *length, int *kappa)
static bool	DigitGenCounted (DiyFp w, int requested_digits, Vector< char > buffer, int *length, int *kappa)
static bool	Grisu3 (double v, FastDtoaMode mode, Vector< char > buffer, int *length, int *decimal_exponent)
static bool	Grisu3Counted (double v, int requested_digits, Vector< char > buffer, int *length, int *decimal_exponent)
bool	FastDtoa (double v, FastDtoaMode mode, int requested_digits, Vector< char > buffer, int *length, int *decimal_point)
static void	FillDigits32FixedLength (uint32_t number, int requested_length, Vector< char > buffer, int *length)
static void	FillDigits32 (uint32_t number, Vector< char > buffer, int *length)
static void	FillDigits64FixedLength (uint64_t number, Vector< char > buffer, int *length)
static void	FillDigits64 (uint64_t number, Vector< char > buffer, int *length)
static void	RoundUp (Vector< char > buffer, int *length, int *decimal_point)
static void	FillFractionals (uint64_t fractionals, int exponent, int fractional_count, Vector< char > buffer, int *length, int *decimal_point)
static void	TrimZeros (Vector< char > buffer, int *length, int *decimal_point)
bool	FastFixedDtoa (double v, int fractional_count, Vector< char > buffer, int *length, int *decimal_point)
static uint64_t	double_to_uint64 (double d)
static double	uint64_to_double (uint64_t d64)
static uint32_t	float_to_uint32 (float f)
static float	uint32_to_float (uint32_t d32)
static bool	isWhitespace (int x)
template<class Iterator >
static bool	AdvanceToNonspace (Iterator *current, Iterator end)
static bool	isDigit (int x, int radix)
static double	SignedZero (bool sign)
static bool	IsDecimalDigitForRadix (int c, int radix)
static bool	IsCharacterDigitForRadix (int c, int radix, char a_character)
template<class Iterator >
static bool	Advance (Iterator *it, uc16 separator, int base, Iterator &end)
template<class Iterator >
static bool	IsHexFloatString (Iterator start, Iterator end, uc16 separator, bool allow_trailing_junk)
template<int radix_log_2, class Iterator >
static double	RadixStringToIeee (Iterator *current, Iterator end, bool sign, uc16 separator, bool parse_as_hex_float, bool allow_trailing_junk, double junk_string_value, bool read_as_double, bool *result_is_junk)
static Vector< const char >	TrimLeadingZeros (Vector< const char > buffer)
static void	CutToMaxSignificantDigits (Vector< const char > buffer, int exponent, char *significant_buffer, int *significant_exponent)
static void	TrimAndCut (Vector< const char > buffer, int exponent, char *buffer_copy_space, int space_size, Vector< const char > *trimmed, int *updated_exponent)
static uint64_t	ReadUint64 (Vector< const char > buffer, int *number_of_read_digits)
static void	ReadDiyFp (Vector< const char > buffer, DiyFp *result, int *remaining_decimals)
static bool	DoubleStrtod (Vector< const char > trimmed, int exponent, double *result)
static DiyFp	AdjustmentPowerOfTen (int exponent)
static bool	DiyFpStrtod (Vector< const char > buffer, int exponent, double *result)
static int	CompareBufferWithDiyFp (Vector< const char > buffer, int exponent, DiyFp diy_fp)
static bool	ComputeGuess (Vector< const char > trimmed, int exponent, double *guess)
static bool	IsDigit (const char d)
static bool	IsNonZeroDigit (const char d)
static bool	AssertTrimmedDigits (const Vector< const char > &buffer)
double	StrtodTrimmed (Vector< const char > trimmed, int exponent)
double	Strtod (Vector< const char > buffer, int exponent)
static float	SanitizedDoubletof (double d)
float	Strtof (Vector< const char > buffer, int exponent)
float	StrtofTrimmed (Vector< const char > trimmed, int exponent)
Vector< const char >	TrimTrailingZeros (Vector< const char > buffer)
int	StrLength (const char *string)
template<class Dest , class Source >
Dest	BitCast (const Source &source)
template<class Dest , class Source >
Dest	BitCast (Source *source)

Variables
static const int	kMinimalTargetExponent = -60
static const int	kMaximalTargetExponent = -32
static unsigned int const	kSmallPowersOfTen []
static const int	kFastDtoaMaximalLength = 17
static const int	kFastDtoaMaximalSingleLength = 9
static const int	kDoubleSignificandSize = 53
const int	kMaxSignificantDigits = 772
static const char	kWhitespaceTable7 [] = { 32, 13, 10, 9, 11, 12 }
static const int	kWhitespaceTable7Length = DOUBLE_CONVERSION_ARRAY_SIZE(kWhitespaceTable7)
static const uc16	kWhitespaceTable16 []
static const int	kWhitespaceTable16Length = DOUBLE_CONVERSION_ARRAY_SIZE(kWhitespaceTable16)
static const int	kMaxUint64DecimalDigits = 19
static const int	kMaxDecimalPower = 309
static const int	kMinDecimalPower = -324
static const uint64_t	kMaxUint64 = DOUBLE_CONVERSION_UINT64_2PART_C(0xFFFFFFFF, FFFFFFFF)
static const int	kMaxSignificantDecimalDigits = 780

Enumeration Type Documentation

BignumDtoaMode

enum double_conversion::BignumDtoaMode

Enumerator
BIGNUM_DTOA_SHORTEST
BIGNUM_DTOA_SHORTEST_SINGLE
BIGNUM_DTOA_FIXED
BIGNUM_DTOA_PRECISION

Definition at line 35 of file bignum-dtoa.h.

                    {
  // Return the shortest correct representation.
  // For example the output of 0.299999999999999988897 is (the less accurate but
  // correct) 0.3.
  BIGNUM_DTOA_SHORTEST,
  // Same as BIGNUM_DTOA_SHORTEST but for single-precision floats.
  BIGNUM_DTOA_SHORTEST_SINGLE,
  // Return a fixed number of digits after the decimal point.
  // For instance fixed(0.1, 4) becomes 0.1000
  // If the input number is big, the output will be big.
  BIGNUM_DTOA_FIXED,
  // Return a fixed number of digits, no matter what the exponent is.
  BIGNUM_DTOA_PRECISION
};

FastDtoaMode

enum double_conversion::FastDtoaMode

Enumerator
FAST_DTOA_SHORTEST
FAST_DTOA_SHORTEST_SINGLE
FAST_DTOA_PRECISION

Definition at line 35 of file fast-dtoa.h.

                  {
  // Computes the shortest representation of the given input. The returned
  // result will be the most accurate number of this length. Longer
  // representations might be more accurate.
  FAST_DTOA_SHORTEST,
  // Same as FAST_DTOA_SHORTEST but for single-precision floats.
  FAST_DTOA_SHORTEST_SINGLE,
  // Computes a representation where the precision (number of digits) is
  // given as input. The precision is independent of the decimal point.
  FAST_DTOA_PRECISION
};

Function Documentation

AdjustmentPowerOfTen()

static DiyFp double_conversion::AdjustmentPowerOfTen ( int  exponent )

static

Definition at line 247 of file strtod.cc.

                                                {
  DOUBLE_CONVERSION_ASSERT(0 < exponent);
  DOUBLE_CONVERSION_ASSERT(exponent < PowersOfTenCache::kDecimalExponentDistance);
  // Simply hardcode the remaining powers for the given decimal exponent
  // distance.
  DOUBLE_CONVERSION_ASSERT(PowersOfTenCache::kDecimalExponentDistance == 8);
  switch (exponent) {
    case 1: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0xa0000000, 00000000), -60);
    case 2: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0xc8000000, 00000000), -57);
    case 3: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0xfa000000, 00000000), -54);
    case 4: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0x9c400000, 00000000), -50);
    case 5: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0xc3500000, 00000000), -47);
    case 6: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0xf4240000, 00000000), -44);
    case 7: return DiyFp(DOUBLE_CONVERSION_UINT64_2PART_C(0x98968000, 00000000), -40);
    default:
      DOUBLE_CONVERSION_UNREACHABLE();
  }
}

Advance()

template<class Iterator >

static bool double_conversion::Advance ( Iterator *  it, uc16  separator, int  base, Iterator &  end  )

static

Definition at line 190 of file string-to-double.cc.

                                                                            {
  if (separator == StringToDoubleConverter::kNoSeparator) {
    ++(*it);
    return *it == end;
  }
  if (!isDigit(**it, base)) {
    ++(*it);
    return *it == end;
  }
  ++(*it);
  if (*it == end) return true;
  if (*it + 1 == end) return false;
  if (**it == separator && isDigit(*(*it + 1), base)) {
    ++(*it);
  }
  return *it == end;
}

AdvanceToNonspace()

template<class Iterator >

static bool double_conversion::AdvanceToNonspace ( Iterator *  current, Iterator  end  )

inlinestatic

Definition at line 139 of file string-to-double.cc.

                                                                      {
  while (*current != end) {
    if (!isWhitespace(**current)) return true;
    ++*current;
  }
  return false;
}

AssertTrimmedDigits()

static bool double_conversion::AssertTrimmedDigits ( const Vector< const char > &  buffer )

static

Definition at line 457 of file strtod.cc.

                                                                  {
  for(int i = 0; i < buffer.length(); ++i) {
    if(!IsDigit(buffer[i])) {
      return false;
    }
  }
  return (buffer.length() == 0) || (IsNonZeroDigit(buffer[0]) && IsNonZeroDigit(buffer[buffer.length()-1]));
}

BiggestPowerTen()

static void double_conversion::BiggestPowerTen ( uint32_t  number, int  number_bits, uint32_t *  power, int *  exponent_plus_one  )

static

Definition at line 240 of file fast-dtoa.cc.

                                                    {
  DOUBLE_CONVERSION_ASSERT(number < (1u << (number_bits + 1)));
  // 1233/4096 is approximately 1/lg(10).
  int exponent_plus_one_guess = ((number_bits + 1) * 1233 >> 12);
  // We increment to skip over the first entry in the kPowersOf10 table.
  // Note: kPowersOf10[i] == 10^(i-1).
  exponent_plus_one_guess++;
  // We don't have any guarantees that 2^number_bits <= number.
  if (number < kSmallPowersOfTen[exponent_plus_one_guess]) {
    exponent_plus_one_guess--;
  }
  *power = kSmallPowersOfTen[exponent_plus_one_guess];
  *exponent_plus_one = exponent_plus_one_guess;
}

BignumDtoa()

void double_conversion::BignumDtoa	(	double	v,
		BignumDtoaMode	mode,
		int	requested_digits,
		Vector< char >	buffer,
		int *	length,
		int *	decimal_point
	)

Definition at line 89 of file bignum-dtoa.cc.

                                                                      {
  DOUBLE_CONVERSION_ASSERT(v > 0);
  DOUBLE_CONVERSION_ASSERT(!Double(v).IsSpecial());
  uint64_t significand;
  int exponent;
  bool lower_boundary_is_closer;
  if (mode == BIGNUM_DTOA_SHORTEST_SINGLE) {
    float f = static_cast<float>(v);
    DOUBLE_CONVERSION_ASSERT(f == v);
    significand = Single(f).Significand();
    exponent = Single(f).Exponent();
    lower_boundary_is_closer = Single(f).LowerBoundaryIsCloser();
  } else {
    significand = Double(v).Significand();
    exponent = Double(v).Exponent();
    lower_boundary_is_closer = Double(v).LowerBoundaryIsCloser();
  }
  bool need_boundary_deltas =
      (mode == BIGNUM_DTOA_SHORTEST || mode == BIGNUM_DTOA_SHORTEST_SINGLE);
 
  bool is_even = (significand & 1) == 0;
  int normalized_exponent = NormalizedExponent(significand, exponent);
  // estimated_power might be too low by 1.
  int estimated_power = EstimatePower(normalized_exponent);
 
  // Shortcut for Fixed.
  // The requested digits correspond to the digits after the point. If the
  // number is much too small, then there is no need in trying to get any
  // digits.
  if (mode == BIGNUM_DTOA_FIXED && -estimated_power - 1 > requested_digits) {
    buffer[0] = '\0';
    *length = 0;
    // Set decimal-point to -requested_digits. This is what Gay does.
    // Note that it should not have any effect anyways since the string is
    // empty.
    *decimal_point = -requested_digits;
    return;
  }
 
  Bignum numerator;
  Bignum denominator;
  Bignum delta_minus;
  Bignum delta_plus;
  // Make sure the bignum can grow large enough. The smallest double equals
  // 4e-324. In this case the denominator needs fewer than 324*4 binary digits.
  // The maximum double is 1.7976931348623157e308 which needs fewer than
  // 308*4 binary digits.
  DOUBLE_CONVERSION_ASSERT(Bignum::kMaxSignificantBits >= 324*4);
  InitialScaledStartValues(significand, exponent, lower_boundary_is_closer,
                           estimated_power, need_boundary_deltas,
                           &numerator, &denominator,
                           &delta_minus, &delta_plus);
  // We now have v = (numerator / denominator) * 10^estimated_power.
  FixupMultiply10(estimated_power, is_even, decimal_point,
                  &numerator, &denominator,
                  &delta_minus, &delta_plus);
  // We now have v = (numerator / denominator) * 10^(decimal_point-1), and
  //  1 <= (numerator + delta_plus) / denominator < 10
  switch (mode) {
    case BIGNUM_DTOA_SHORTEST:
    case BIGNUM_DTOA_SHORTEST_SINGLE:
      GenerateShortestDigits(&numerator, &denominator,
                             &delta_minus, &delta_plus,
                             is_even, buffer, length);
      break;
    case BIGNUM_DTOA_FIXED:
      BignumToFixed(requested_digits, decimal_point,
                    &numerator, &denominator,
                    buffer, length);
      break;
    case BIGNUM_DTOA_PRECISION:
      GenerateCountedDigits(requested_digits, decimal_point,
                            &numerator, &denominator,
                            buffer, length);
      break;
    default:
      DOUBLE_CONVERSION_UNREACHABLE();
  }
  buffer[*length] = '\0';
}

BignumToFixed()

static void double_conversion::BignumToFixed ( int  requested_digits, int *  decimal_point, Bignum *  numerator, Bignum *  denominator, Vector< char >  buffer, int *  length  )

static

Definition at line 326 of file bignum-dtoa.cc.

                                                            {
  // Note that we have to look at more than just the requested_digits, since
  // a number could be rounded up. Example: v=0.5 with requested_digits=0.
  // Even though the power of v equals 0 we can't just stop here.
  if (-(*decimal_point) > requested_digits) {
    // The number is definitively too small.
    // Ex: 0.001 with requested_digits == 1.
    // Set decimal-point to -requested_digits. This is what Gay does.
    // Note that it should not have any effect anyways since the string is
    // empty.
    *decimal_point = -requested_digits;
    *length = 0;
    return;
  } else if (-(*decimal_point) == requested_digits) {
    // We only need to verify if the number rounds down or up.
    // Ex: 0.04 and 0.06 with requested_digits == 1.
    DOUBLE_CONVERSION_ASSERT(*decimal_point == -requested_digits);
    // Initially the fraction lies in range (1, 10]. Multiply the denominator
    // by 10 so that we can compare more easily.
    denominator->Times10();
    if (Bignum::PlusCompare(*numerator, *numerator, *denominator) >= 0) {
      // If the fraction is >= 0.5 then we have to include the rounded
      // digit.
      buffer[0] = '1';
      *length = 1;
      (*decimal_point)++;
    } else {
      // Note that we caught most of similar cases earlier.
      *length = 0;
    }
    return;
  } else {
    // The requested digits correspond to the digits after the point.
    // The variable 'needed_digits' includes the digits before the point.
    int needed_digits = (*decimal_point) + requested_digits;
    GenerateCountedDigits(needed_digits, decimal_point,
                          numerator, denominator,
                          buffer, length);
  }
}

BitCast() [1/2]

template<class Dest , class Source >

Dest double_conversion::BitCast

(

const Source &

source

)

Definition at line 395 of file utils.h.

                                   {
  // Compile time assertion: sizeof(Dest) == sizeof(Source)
  // A compile error here means your Dest and Source have different sizes.
#if __cplusplus >= 201103L
  static_assert(sizeof(Dest) == sizeof(Source),
                "source and destination size mismatch");
#else
  DOUBLE_CONVERSION_UNUSED
  typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
#endif
 
  Dest dest;
  memmove(&dest, &source, sizeof(dest));
  return dest;
}

BitCast() [2/2]

template<class Dest , class Source >

Dest double_conversion::BitCast

(

Source *

source

)

Definition at line 412 of file utils.h.

                             {
  return BitCast<Dest>(reinterpret_cast<uintptr_t>(source));
}

BitSize()

template<typename S >

static int double_conversion::BitSize ( const S  value )

static

Definition at line 49 of file bignum.cc.

                                  {
  (void) value;  // Mark variable as used.
  return 8 * sizeof(value);
}

CompareBufferWithDiyFp()

static int double_conversion::CompareBufferWithDiyFp ( Vector< const char >  buffer, int  exponent, DiyFp  diy_fp  )

static

Definition at line 388 of file strtod.cc.

                                                {
  DOUBLE_CONVERSION_ASSERT(buffer.length() + exponent <= kMaxDecimalPower + 1);
  DOUBLE_CONVERSION_ASSERT(buffer.length() + exponent > kMinDecimalPower);
  DOUBLE_CONVERSION_ASSERT(buffer.length() <= kMaxSignificantDecimalDigits);
  // Make sure that the Bignum will be able to hold all our numbers.
  // Our Bignum implementation has a separate field for exponents. Shifts will
  // consume at most one bigit (< 64 bits).
  // ln(10) == 3.3219...
  DOUBLE_CONVERSION_ASSERT(((kMaxDecimalPower + 1) * 333 / 100) < Bignum::kMaxSignificantBits);
  Bignum buffer_bignum;
  Bignum diy_fp_bignum;
  buffer_bignum.AssignDecimalString(buffer);
  diy_fp_bignum.AssignUInt64(diy_fp.f());
  if (exponent >= 0) {
    buffer_bignum.MultiplyByPowerOfTen(exponent);
  } else {
    diy_fp_bignum.MultiplyByPowerOfTen(-exponent);
  }
  if (diy_fp.e() > 0) {
    diy_fp_bignum.ShiftLeft(diy_fp.e());
  } else {
    buffer_bignum.ShiftLeft(-diy_fp.e());
  }
  return Bignum::Compare(buffer_bignum, diy_fp_bignum);
}

ComputeGuess()

static bool double_conversion::ComputeGuess ( Vector< const char >  trimmed, int  exponent, double *  guess  )

static

Definition at line 419 of file strtod.cc.

                                        {
  if (trimmed.length() == 0) {
    *guess = 0.0;
    return true;
  }
  if (exponent + trimmed.length() - 1 >= kMaxDecimalPower) {
    *guess = Double::Infinity();
    return true;
  }
  if (exponent + trimmed.length() <= kMinDecimalPower) {
    *guess = 0.0;
    return true;
  }
 
  if (DoubleStrtod(trimmed, exponent, guess) ||
      DiyFpStrtod(trimmed, exponent, guess)) {
    return true;
  }
  if (*guess == Double::Infinity()) {
    return true;
  }
  return false;
}

CutToMaxSignificantDigits()

static void double_conversion::CutToMaxSignificantDigits ( Vector< const char >  buffer, int  exponent, char *  significant_buffer, int *  significant_exponent  )

static

Definition at line 104 of file strtod.cc.

                                                                  {
  for (int i = 0; i < kMaxSignificantDecimalDigits - 1; ++i) {
    significant_buffer[i] = buffer[i];
  }
  // The input buffer has been trimmed. Therefore the last digit must be
  // different from '0'.
  DOUBLE_CONVERSION_ASSERT(buffer[buffer.length() - 1] != '0');
  // Set the last digit to be non-zero. This is sufficient to guarantee
  // correct rounding.
  significant_buffer[kMaxSignificantDecimalDigits - 1] = '1';
  *significant_exponent =
      exponent + (buffer.length() - kMaxSignificantDecimalDigits);
}

DigitGen()

static bool double_conversion::DigitGen ( DiyFp  low, DiyFp  w, DiyFp  high, Vector< char >  buffer, int *  length, int *  kappa  )

static

Definition at line 300 of file fast-dtoa.cc.

                                 {
  DOUBLE_CONVERSION_ASSERT(low.e() == w.e() && w.e() == high.e());
  DOUBLE_CONVERSION_ASSERT(low.f() + 1 <= high.f() - 1);
  DOUBLE_CONVERSION_ASSERT(kMinimalTargetExponent <= w.e() && w.e() <= kMaximalTargetExponent);
  // low, w and high are imprecise, but by less than one ulp (unit in the last
  // place).
  // If we remove (resp. add) 1 ulp from low (resp. high) we are certain that
  // the new numbers are outside of the interval we want the final
  // representation to lie in.
  // Inversely adding (resp. removing) 1 ulp from low (resp. high) would yield
  // numbers that are certain to lie in the interval. We will use this fact
  // later on.
  // We will now start by generating the digits within the uncertain
  // interval. Later we will weed out representations that lie outside the safe
  // interval and thus _might_ lie outside the correct interval.
  uint64_t unit = 1;
  DiyFp too_low = DiyFp(low.f() - unit, low.e());
  DiyFp too_high = DiyFp(high.f() + unit, high.e());
  // too_low and too_high are guaranteed to lie outside the interval we want the
  // generated number in.
  DiyFp unsafe_interval = DiyFp::Minus(too_high, too_low);
  // We now cut the input number into two parts: the integral digits and the
  // fractionals. We will not write any decimal separator though, but adapt
  // kappa instead.
  // Reminder: we are currently computing the digits (stored inside the buffer)
  // such that:   too_low < buffer * 10^kappa < too_high
  // We use too_high for the digit_generation and stop as soon as possible.
  // If we stop early we effectively round down.
  DiyFp one = DiyFp(static_cast<uint64_t>(1) << -w.e(), w.e());
  // Division by one is a shift.
  uint32_t integrals = static_cast<uint32_t>(too_high.f() >> -one.e());
  // Modulo by one is an and.
  uint64_t fractionals = too_high.f() & (one.f() - 1);
  uint32_t divisor;
  int divisor_exponent_plus_one;
  BiggestPowerTen(integrals, DiyFp::kSignificandSize - (-one.e()),
                  &divisor, &divisor_exponent_plus_one);
  *kappa = divisor_exponent_plus_one;
  *length = 0;
  // Loop invariant: buffer = too_high / 10^kappa  (integer division)
  // The invariant holds for the first iteration: kappa has been initialized
  // with the divisor exponent + 1. And the divisor is the biggest power of ten
  // that is smaller than integrals.
  while (*kappa > 0) {
    int digit = integrals / divisor;
    DOUBLE_CONVERSION_ASSERT(digit <= 9);
    buffer[*length] = static_cast<char>('0' + digit);
    (*length)++;
    integrals %= divisor;
    (*kappa)--;
    // Note that kappa now equals the exponent of the divisor and that the
    // invariant thus holds again.
    uint64_t rest =
        (static_cast<uint64_t>(integrals) << -one.e()) + fractionals;
    // Invariant: too_high = buffer * 10^kappa + DiyFp(rest, one.e())
    // Reminder: unsafe_interval.e() == one.e()
    if (rest < unsafe_interval.f()) {
      // Rounding down (by not emitting the remaining digits) yields a number
      // that lies within the unsafe interval.
      return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f(),
                       unsafe_interval.f(), rest,
                       static_cast<uint64_t>(divisor) << -one.e(), unit);
    }
    divisor /= 10;
  }
 
  // The integrals have been generated. We are at the point of the decimal
  // separator. In the following loop we simply multiply the remaining digits by
  // 10 and divide by one. We just need to pay attention to multiply associated
  // data (like the interval or 'unit'), too.
  // Note that the multiplication by 10 does not overflow, because w.e >= -60
  // and thus one.e >= -60.
  DOUBLE_CONVERSION_ASSERT(one.e() >= -60);
  DOUBLE_CONVERSION_ASSERT(fractionals < one.f());
  DOUBLE_CONVERSION_ASSERT(DOUBLE_CONVERSION_UINT64_2PART_C(0xFFFFFFFF, FFFFFFFF) / 10 >= one.f());
  for (;;) {
    fractionals *= 10;
    unit *= 10;
    unsafe_interval.set_f(unsafe_interval.f() * 10);
    // Integer division by one.
    int digit = static_cast<int>(fractionals >> -one.e());
    DOUBLE_CONVERSION_ASSERT(digit <= 9);
    buffer[*length] = static_cast<char>('0' + digit);
    (*length)++;
    fractionals &= one.f() - 1;  // Modulo by one.
    (*kappa)--;
    if (fractionals < unsafe_interval.f()) {
      return RoundWeed(buffer, *length, DiyFp::Minus(too_high, w).f() * unit,
                       unsafe_interval.f(), fractionals, one.f(), unit);
    }
  }
}

DigitGenCounted()

static bool double_conversion::DigitGenCounted ( DiyFp  w, int  requested_digits, Vector< char >  buffer, int *  length, int *  kappa  )

static

Definition at line 428 of file fast-dtoa.cc.

                                        {
  DOUBLE_CONVERSION_ASSERT(kMinimalTargetExponent <= w.e() && w.e() <= kMaximalTargetExponent);
  DOUBLE_CONVERSION_ASSERT(kMinimalTargetExponent >= -60);
  DOUBLE_CONVERSION_ASSERT(kMaximalTargetExponent <= -32);
  // w is assumed to have an error less than 1 unit. Whenever w is scaled we
  // also scale its error.
  uint64_t w_error = 1;
  // We cut the input number into two parts: the integral digits and the
  // fractional digits. We don't emit any decimal separator, but adapt kappa
  // instead. Example: instead of writing "1.2" we put "12" into the buffer and
  // increase kappa by 1.
  DiyFp one = DiyFp(static_cast<uint64_t>(1) << -w.e(), w.e());
  // Division by one is a shift.
  uint32_t integrals = static_cast<uint32_t>(w.f() >> -one.e());
  // Modulo by one is an and.
  uint64_t fractionals = w.f() & (one.f() - 1);
  uint32_t divisor;
  int divisor_exponent_plus_one;
  BiggestPowerTen(integrals, DiyFp::kSignificandSize - (-one.e()),
                  &divisor, &divisor_exponent_plus_one);
  *kappa = divisor_exponent_plus_one;
  *length = 0;
 
  // Loop invariant: buffer = w / 10^kappa  (integer division)
  // The invariant holds for the first iteration: kappa has been initialized
  // with the divisor exponent + 1. And the divisor is the biggest power of ten
  // that is smaller than 'integrals'.
  while (*kappa > 0) {
    int digit = integrals / divisor;
    DOUBLE_CONVERSION_ASSERT(digit <= 9);
    buffer[*length] = static_cast<char>('0' + digit);
    (*length)++;
    requested_digits--;
    integrals %= divisor;
    (*kappa)--;
    // Note that kappa now equals the exponent of the divisor and that the
    // invariant thus holds again.
    if (requested_digits == 0) break;
    divisor /= 10;
  }
 
  if (requested_digits == 0) {
    uint64_t rest =
        (static_cast<uint64_t>(integrals) << -one.e()) + fractionals;
    return RoundWeedCounted(buffer, *length, rest,
                            static_cast<uint64_t>(divisor) << -one.e(), w_error,
                            kappa);
  }
 
  // The integrals have been generated. We are at the point of the decimal
  // separator. In the following loop we simply multiply the remaining digits by
  // 10 and divide by one. We just need to pay attention to multiply associated
  // data (the 'unit'), too.
  // Note that the multiplication by 10 does not overflow, because w.e >= -60
  // and thus one.e >= -60.
  DOUBLE_CONVERSION_ASSERT(one.e() >= -60);
  DOUBLE_CONVERSION_ASSERT(fractionals < one.f());
  DOUBLE_CONVERSION_ASSERT(DOUBLE_CONVERSION_UINT64_2PART_C(0xFFFFFFFF, FFFFFFFF) / 10 >= one.f());
  while (requested_digits > 0 && fractionals > w_error) {
    fractionals *= 10;
    w_error *= 10;
    // Integer division by one.
    int digit = static_cast<int>(fractionals >> -one.e());
    DOUBLE_CONVERSION_ASSERT(digit <= 9);
    buffer[*length] = static_cast<char>('0' + digit);
    (*length)++;
    requested_digits--;
    fractionals &= one.f() - 1;  // Modulo by one.
    (*kappa)--;
  }
  if (requested_digits != 0) return false;
  return RoundWeedCounted(buffer, *length, fractionals, one.f(), w_error,
                          kappa);
}

DiyFpStrtod()

static bool double_conversion::DiyFpStrtod ( Vector< const char >  buffer, int  exponent, double *  result  )

static

Definition at line 270 of file strtod.cc.

                                        {
  DiyFp input;
  int remaining_decimals;
  ReadDiyFp(buffer, &input, &remaining_decimals);
  // Since we may have dropped some digits the input is not accurate.
  // If remaining_decimals is different than 0 than the error is at most
  // .5 ulp (unit in the last place).
  // We don't want to deal with fractions and therefore keep a common
  // denominator.
  const int kDenominatorLog = 3;
  const int kDenominator = 1 << kDenominatorLog;
  // Move the remaining decimals into the exponent.
  exponent += remaining_decimals;
  uint64_t error = (remaining_decimals == 0 ? 0 : kDenominator / 2);
 
  int old_e = input.e();
  input.Normalize();
  error <<= old_e - input.e();
 
  DOUBLE_CONVERSION_ASSERT(exponent <= PowersOfTenCache::kMaxDecimalExponent);
  if (exponent < PowersOfTenCache::kMinDecimalExponent) {
    *result = 0.0;
    return true;
  }
  DiyFp cached_power;
  int cached_decimal_exponent;
  PowersOfTenCache::GetCachedPowerForDecimalExponent(exponent,
                                                     &cached_power,
                                                     &cached_decimal_exponent);
 
  if (cached_decimal_exponent != exponent) {
    int adjustment_exponent = exponent - cached_decimal_exponent;
    DiyFp adjustment_power = AdjustmentPowerOfTen(adjustment_exponent);
    input.Multiply(adjustment_power);
    if (kMaxUint64DecimalDigits - buffer.length() >= adjustment_exponent) {
      // The product of input with the adjustment power fits into a 64 bit
      // integer.
      DOUBLE_CONVERSION_ASSERT(DiyFp::kSignificandSize == 64);
    } else {
      // The adjustment power is exact. There is hence only an error of 0.5.
      error += kDenominator / 2;
    }
  }
 
  input.Multiply(cached_power);
  // The error introduced by a multiplication of a*b equals
  //   error_a + error_b + error_a*error_b/2^64 + 0.5
  // Substituting a with 'input' and b with 'cached_power' we have
  //   error_b = 0.5  (all cached powers have an error of less than 0.5 ulp),
  //   error_ab = 0 or 1 / kDenominator > error_a*error_b/ 2^64
  int error_b = kDenominator / 2;
  int error_ab = (error == 0 ? 0 : 1);  // We round up to 1.
  int fixed_error = kDenominator / 2;
  error += error_b + error_ab + fixed_error;
 
  old_e = input.e();
  input.Normalize();
  error <<= old_e - input.e();
 
  // See if the double's significand changes if we add/subtract the error.
  int order_of_magnitude = DiyFp::kSignificandSize + input.e();
  int effective_significand_size =
      Double::SignificandSizeForOrderOfMagnitude(order_of_magnitude);
  int precision_digits_count =
      DiyFp::kSignificandSize - effective_significand_size;
  if (precision_digits_count + kDenominatorLog >= DiyFp::kSignificandSize) {
    // This can only happen for very small denormals. In this case the
    // half-way multiplied by the denominator exceeds the range of an uint64.
    // Simply shift everything to the right.
    int shift_amount = (precision_digits_count + kDenominatorLog) -
        DiyFp::kSignificandSize + 1;
    input.set_f(input.f() >> shift_amount);
    input.set_e(input.e() + shift_amount);
    // We add 1 for the lost precision of error, and kDenominator for
    // the lost precision of input.f().
    error = (error >> shift_amount) + 1 + kDenominator;
    precision_digits_count -= shift_amount;
  }
  // We use uint64_ts now. This only works if the DiyFp uses uint64_ts too.
  DOUBLE_CONVERSION_ASSERT(DiyFp::kSignificandSize == 64);
  DOUBLE_CONVERSION_ASSERT(precision_digits_count < 64);
  uint64_t one64 = 1;
  uint64_t precision_bits_mask = (one64 << precision_digits_count) - 1;
  uint64_t precision_bits = input.f() & precision_bits_mask;
  uint64_t half_way = one64 << (precision_digits_count - 1);
  precision_bits *= kDenominator;
  half_way *= kDenominator;
  DiyFp rounded_input(input.f() >> precision_digits_count,
                      input.e() + precision_digits_count);
  if (precision_bits >= half_way + error) {
    rounded_input.set_f(rounded_input.f() + 1);
  }
  // If the last_bits are too close to the half-way case than we are too
  // inaccurate and round down. In this case we return false so that we can
  // fall back to a more precise algorithm.
 
  *result = Double(rounded_input).value();
  if (half_way - error < precision_bits && precision_bits < half_way + error) {
    // Too imprecise. The caller will have to fall back to a slower version.
    // However the returned number is guaranteed to be either the correct
    // double, or the next-lower double.
    return false;
  } else {
    return true;
  }
}

double_to_uint64()

static uint64_t double_conversion::double_to_uint64 ( double  d )

static

Definition at line 36 of file ieee.h.

{ return BitCast<uint64_t>(d); }

DoubleStrtod()

static bool double_conversion::DoubleStrtod ( Vector< const char >  trimmed, int  exponent, double *  result  )

static

Definition at line 190 of file strtod.cc.

                                         {
#if !defined(DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS)
  // Avoid "unused parameter" warnings
  (void) trimmed;
  (void) exponent;
  (void) result;
  // On x86 the floating-point stack can be 64 or 80 bits wide. If it is
  // 80 bits wide (as is the case on Linux) then double-rounding occurs and the
  // result is not accurate.
  // We know that Windows32 uses 64 bits and is therefore accurate.
  return false;
#else
  if (trimmed.length() <= kMaxExactDoubleIntegerDecimalDigits) {
    int read_digits;
    // The trimmed input fits into a double.
    // If the 10^exponent (resp. 10^-exponent) fits into a double too then we
    // can compute the result-double simply by multiplying (resp. dividing) the
    // two numbers.
    // This is possible because IEEE guarantees that floating-point operations
    // return the best possible approximation.
    if (exponent < 0 && -exponent < kExactPowersOfTenSize) {
      // 10^-exponent fits into a double.
      *result = static_cast<double>(ReadUint64(trimmed, &read_digits));
      DOUBLE_CONVERSION_ASSERT(read_digits == trimmed.length());
      *result /= exact_powers_of_ten[-exponent];
      return true;
    }
    if (0 <= exponent && exponent < kExactPowersOfTenSize) {
      // 10^exponent fits into a double.
      *result = static_cast<double>(ReadUint64(trimmed, &read_digits));
      DOUBLE_CONVERSION_ASSERT(read_digits == trimmed.length());
      *result *= exact_powers_of_ten[exponent];
      return true;
    }
    int remaining_digits =
        kMaxExactDoubleIntegerDecimalDigits - trimmed.length();
    if ((0 <= exponent) &&
        (exponent - remaining_digits < kExactPowersOfTenSize)) {
      // The trimmed string was short and we can multiply it with
      // 10^remaining_digits. As a result the remaining exponent now fits
      // into a double too.
      *result = static_cast<double>(ReadUint64(trimmed, &read_digits));
      DOUBLE_CONVERSION_ASSERT(read_digits == trimmed.length());
      *result *= exact_powers_of_ten[remaining_digits];
      *result *= exact_powers_of_ten[exponent - remaining_digits];
      return true;
    }
  }
  return false;
#endif
}

DtoaToBignumDtoaMode()

static BignumDtoaMode double_conversion::DtoaToBignumDtoaMode ( DoubleToStringConverter::DtoaMode  dtoa_mode )

static

Definition at line 372 of file double-to-string.cc.

                                               {
  switch (dtoa_mode) {
    case DoubleToStringConverter::SHORTEST:  return BIGNUM_DTOA_SHORTEST;
    case DoubleToStringConverter::SHORTEST_SINGLE:
        return BIGNUM_DTOA_SHORTEST_SINGLE;
    case DoubleToStringConverter::FIXED:     return BIGNUM_DTOA_FIXED;
    case DoubleToStringConverter::PRECISION: return BIGNUM_DTOA_PRECISION;
    default:
      DOUBLE_CONVERSION_UNREACHABLE();
  }
}

EstimatePower()

static int double_conversion::EstimatePower ( int  exponent )

static

Definition at line 385 of file bignum-dtoa.cc.

                                       {
  // This function estimates log10 of v where v = f*2^e (with e == exponent).
  // Note that 10^floor(log10(v)) <= v, but v <= 10^ceil(log10(v)).
  // Note that f is bounded by its container size. Let p = 53 (the double's
  // significand size). Then 2^(p-1) <= f < 2^p.
  //
  // Given that log10(v) == log2(v)/log2(10) and e+(len(f)-1) is quite close
  // to log2(v) the function is simplified to (e+(len(f)-1)/log2(10)).
  // The computed number undershoots by less than 0.631 (when we compute log3
  // and not log10).
  //
  // Optimization: since we only need an approximated result this computation
  // can be performed on 64 bit integers. On x86/x64 architecture the speedup is
  // not really measurable, though.
  //
  // Since we want to avoid overshooting we decrement by 1e10 so that
  // floating-point imprecisions don't affect us.
  //
  // Explanation for v's boundary m+: the computation takes advantage of
  // the fact that 2^(p-1) <= f < 2^p. Boundaries still satisfy this requirement
  // (even for denormals where the delta can be much more important).
 
  const double k1Log10 = 0.30102999566398114;  // 1/lg(10)
 
  // For doubles len(f) == 53 (don't forget the hidden bit).
  const int kSignificandSize = Double::kSignificandSize;
  double estimate = ceil((exponent + kSignificandSize - 1) * k1Log10 - 1e-10);
  return static_cast<int>(estimate);
}

FastDtoa()

bool double_conversion::FastDtoa	(	double	v,
		FastDtoaMode	mode,
		int	requested_digits,
		Vector< char >	buffer,
		int *	length,
		int *	decimal_point
	)

Definition at line 635 of file fast-dtoa.cc.

                                  {
  DOUBLE_CONVERSION_ASSERT(v > 0);
  DOUBLE_CONVERSION_ASSERT(!Double(v).IsSpecial());
 
  bool result = false;
  int decimal_exponent = 0;
  switch (mode) {
    case FAST_DTOA_SHORTEST:
    case FAST_DTOA_SHORTEST_SINGLE:
      result = Grisu3(v, mode, buffer, length, &decimal_exponent);
      break;
    case FAST_DTOA_PRECISION:
      result = Grisu3Counted(v, requested_digits,
                             buffer, length, &decimal_exponent);
      break;
    default:
      DOUBLE_CONVERSION_UNREACHABLE();
  }
  if (result) {
    *decimal_point = *length + decimal_exponent;
    buffer[*length] = '\0';
  }
  return result;
}

FastFixedDtoa()

bool double_conversion::FastFixedDtoa	(	double	v,
		int	fractional_count,
		Vector< char >	buffer,
		int *	length,
		int *	decimal_point
	)

Definition at line 310 of file fixed-dtoa.cc.

                                       {
  const uint32_t kMaxUInt32 = 0xFFFFFFFF;
  uint64_t significand = Double(v).Significand();
  int exponent = Double(v).Exponent();
  // v = significand * 2^exponent (with significand a 53bit integer).
  // If the exponent is larger than 20 (i.e. we may have a 73bit number) then we
  // don't know how to compute the representation. 2^73 ~= 9.5*10^21.
  // If necessary this limit could probably be increased, but we don't need
  // more.
  if (exponent > 20) return false;
  if (fractional_count > 20) return false;
  *length = 0;
  // At most kDoubleSignificandSize bits of the significand are non-zero.
  // Given a 64 bit integer we have 11 0s followed by 53 potentially non-zero
  // bits:  0..11*..0xxx..53*..xx
  if (exponent + kDoubleSignificandSize > 64) {
    // The exponent must be > 11.
    //
    // We know that v = significand * 2^exponent.
    // And the exponent > 11.
    // We simplify the task by dividing v by 10^17.
    // The quotient delivers the first digits, and the remainder fits into a 64
    // bit number.
    // Dividing by 10^17 is equivalent to dividing by 5^17*2^17.
    const uint64_t kFive17 = DOUBLE_CONVERSION_UINT64_2PART_C(0xB1, A2BC2EC5);  // 5^17
    uint64_t divisor = kFive17;
    int divisor_power = 17;
    uint64_t dividend = significand;
    uint32_t quotient;
    uint64_t remainder;
    // Let v = f * 2^e with f == significand and e == exponent.
    // Then need q (quotient) and r (remainder) as follows:
    //   v            = q * 10^17       + r
    //   f * 2^e      = q * 10^17       + r
    //   f * 2^e      = q * 5^17 * 2^17 + r
    // If e > 17 then
    //   f * 2^(e-17) = q * 5^17        + r/2^17
    // else
    //   f  = q * 5^17 * 2^(17-e) + r/2^e
    if (exponent > divisor_power) {
      // We only allow exponents of up to 20 and therefore (17 - e) <= 3
      dividend <<= exponent - divisor_power;
      quotient = static_cast<uint32_t>(dividend / divisor);
      remainder = (dividend % divisor) << divisor_power;
    } else {
      divisor <<= divisor_power - exponent;
      quotient = static_cast<uint32_t>(dividend / divisor);
      remainder = (dividend % divisor) << exponent;
    }
    FillDigits32(quotient, buffer, length);
    FillDigits64FixedLength(remainder, buffer, length);
    *decimal_point = *length;
  } else if (exponent >= 0) {
    // 0 <= exponent <= 11
    significand <<= exponent;
    FillDigits64(significand, buffer, length);
    *decimal_point = *length;
  } else if (exponent > -kDoubleSignificandSize) {
    // We have to cut the number.
    uint64_t integrals = significand >> -exponent;
    uint64_t fractionals = significand - (integrals << -exponent);
    if (integrals > kMaxUInt32) {
      FillDigits64(integrals, buffer, length);
    } else {
      FillDigits32(static_cast<uint32_t>(integrals), buffer, length);
    }
    *decimal_point = *length;
    FillFractionals(fractionals, exponent, fractional_count,
                    buffer, length, decimal_point);
  } else if (exponent < -128) {
    // This configuration (with at most 20 digits) means that all digits must be
    // 0.
    DOUBLE_CONVERSION_ASSERT(fractional_count <= 20);
    buffer[0] = '\0';
    *length = 0;
    *decimal_point = -fractional_count;
  } else {
    *decimal_point = 0;
    FillFractionals(significand, exponent, fractional_count,
                    buffer, length, decimal_point);
  }
  TrimZeros(buffer, length, decimal_point);
  buffer[*length] = '\0';
  if ((*length) == 0) {
    // The string is empty and the decimal_point thus has no importance. Mimic
    // Gay's dtoa and set it to -fractional_count.
    *decimal_point = -fractional_count;
  }
  return true;
}

FillDigits32()

static void double_conversion::FillDigits32 ( uint32_t  number, Vector< char >  buffer, int *  length  )

static

Definition at line 130 of file fixed-dtoa.cc.

                                                                            {
  int number_length = 0;
  // We fill the digits in reverse order and exchange them afterwards.
  while (number != 0) {
    int digit = number % 10;
    number /= 10;
    buffer[(*length) + number_length] = static_cast<char>('0' + digit);
    number_length++;
  }
  // Exchange the digits.
  int i = *length;
  int j = *length + number_length - 1;
  while (i < j) {
    char tmp = buffer[i];
    buffer[i] = buffer[j];
    buffer[j] = tmp;
    i++;
    j--;
  }
  *length += number_length;
}

FillDigits32FixedLength()

static void double_conversion::FillDigits32FixedLength ( uint32_t  number, int  requested_length, Vector< char >  buffer, int *  length  )

static

Definition at line 120 of file fixed-dtoa.cc.

                                                                      {
  for (int i = requested_length - 1; i >= 0; --i) {
    buffer[(*length) + i] = '0' + number % 10;
    number /= 10;
  }
  *length += requested_length;
}

FillDigits64()

static void double_conversion::FillDigits64 ( uint64_t  number, Vector< char >  buffer, int *  length  )

static

Definition at line 168 of file fixed-dtoa.cc.

                                                                            {
  const uint32_t kTen7 = 10000000;
  // For efficiency cut the number into 3 uint32_t parts, and print those.
  uint32_t part2 = static_cast<uint32_t>(number % kTen7);
  number /= kTen7;
  uint32_t part1 = static_cast<uint32_t>(number % kTen7);
  uint32_t part0 = static_cast<uint32_t>(number / kTen7);
 
  if (part0 != 0) {
    FillDigits32(part0, buffer, length);
    FillDigits32FixedLength(part1, 7, buffer, length);
    FillDigits32FixedLength(part2, 7, buffer, length);
  } else if (part1 != 0) {
    FillDigits32(part1, buffer, length);
    FillDigits32FixedLength(part2, 7, buffer, length);
  } else {
    FillDigits32(part2, buffer, length);
  }
}

FillDigits64FixedLength()

static void double_conversion::FillDigits64FixedLength ( uint64_t  number, Vector< char >  buffer, int *  length  )

static

Definition at line 153 of file fixed-dtoa.cc.

                                                                      {
  const uint32_t kTen7 = 10000000;
  // For efficiency cut the number into 3 uint32_t parts, and print those.
  uint32_t part2 = static_cast<uint32_t>(number % kTen7);
  number /= kTen7;
  uint32_t part1 = static_cast<uint32_t>(number % kTen7);
  uint32_t part0 = static_cast<uint32_t>(number / kTen7);
 
  FillDigits32FixedLength(part0, 3, buffer, length);
  FillDigits32FixedLength(part1, 7, buffer, length);
  FillDigits32FixedLength(part2, 7, buffer, length);
}

FillFractionals()

static void double_conversion::FillFractionals ( uint64_t  fractionals, int  exponent, int  fractional_count, Vector< char >  buffer, int *  length, int *  decimal_point  )

static

Definition at line 230 of file fixed-dtoa.cc.

                                                             {
  DOUBLE_CONVERSION_ASSERT(-128 <= exponent && exponent <= 0);
  // 'fractionals' is a fixed-point number, with binary point at bit
  // (-exponent). Inside the function the non-converted remainder of fractionals
  // is a fixed-point number, with binary point at bit 'point'.
  if (-exponent <= 64) {
    // One 64 bit number is sufficient.
    DOUBLE_CONVERSION_ASSERT(fractionals >> 56 == 0);
    int point = -exponent;
    for (int i = 0; i < fractional_count; ++i) {
      if (fractionals == 0) break;
      // Instead of multiplying by 10 we multiply by 5 and adjust the point
      // location. This way the fractionals variable will not overflow.
      // Invariant at the beginning of the loop: fractionals < 2^point.
      // Initially we have: point <= 64 and fractionals < 2^56
      // After each iteration the point is decremented by one.
      // Note that 5^3 = 125 < 128 = 2^7.
      // Therefore three iterations of this loop will not overflow fractionals
      // (even without the subtraction at the end of the loop body). At this
      // time point will satisfy point <= 61 and therefore fractionals < 2^point
      // and any further multiplication of fractionals by 5 will not overflow.
      fractionals *= 5;
      point--;
      int digit = static_cast<int>(fractionals >> point);
      DOUBLE_CONVERSION_ASSERT(digit <= 9);
      buffer[*length] = static_cast<char>('0' + digit);
      (*length)++;
      fractionals -= static_cast<uint64_t>(digit) << point;
    }
    // If the first bit after the point is set we have to round up.
    DOUBLE_CONVERSION_ASSERT(fractionals == 0 || point - 1 >= 0);
    if ((fractionals != 0) && ((fractionals >> (point - 1)) & 1) == 1) {
      RoundUp(buffer, length, decimal_point);
    }
  } else {  // We need 128 bits.
    DOUBLE_CONVERSION_ASSERT(64 < -exponent && -exponent <= 128);
    UInt128 fractionals128 = UInt128(fractionals, 0);
    fractionals128.Shift(-exponent - 64);
    int point = 128;
    for (int i = 0; i < fractional_count; ++i) {
      if (fractionals128.IsZero()) break;
      // As before: instead of multiplying by 10 we multiply by 5 and adjust the
      // point location.
      // This multiplication will not overflow for the same reasons as before.
      fractionals128.Multiply(5);
      point--;
      int digit = fractionals128.DivModPowerOf2(point);
      DOUBLE_CONVERSION_ASSERT(digit <= 9);
      buffer[*length] = static_cast<char>('0' + digit);
      (*length)++;
    }
    if (fractionals128.BitAt(point - 1) == 1) {
      RoundUp(buffer, length, decimal_point);
    }
  }
}

FixupMultiply10()

static void double_conversion::FixupMultiply10 ( int  estimated_power, bool  is_even, int *  decimal_point, Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus  )

static

Definition at line 612 of file bignum-dtoa.cc.

                                                                     {
  bool in_range;
  if (is_even) {
    // For IEEE doubles half-way cases (in decimal system numbers ending with 5)
    // are rounded to the closest floating-point number with even significand.
    in_range = Bignum::PlusCompare(*numerator, *delta_plus, *denominator) >= 0;
  } else {
    in_range = Bignum::PlusCompare(*numerator, *delta_plus, *denominator) > 0;
  }
  if (in_range) {
    // Since numerator + delta_plus >= denominator we already have
    // 1 <= numerator/denominator < 10. Simply update the estimated_power.
    *decimal_point = estimated_power + 1;
  } else {
    *decimal_point = estimated_power;
    numerator->Times10();
    if (Bignum::Equal(*delta_minus, *delta_plus)) {
      delta_minus->Times10();
      delta_plus->AssignBignum(*delta_minus);
    } else {
      delta_minus->Times10();
      delta_plus->Times10();
    }
  }
}

float_to_uint32()

static uint32_t double_conversion::float_to_uint32 ( float  f )

static

Definition at line 38 of file ieee.h.

{ return BitCast<uint32_t>(f); }

GenerateCountedDigits()

static void double_conversion::GenerateCountedDigits ( int  count, int *  decimal_point, Bignum *  numerator, Bignum *  denominator, Vector< char >  buffer, int *  length  )

static

Definition at line 283 of file bignum-dtoa.cc.

                                                                    {
  DOUBLE_CONVERSION_ASSERT(count >= 0);
  for (int i = 0; i < count - 1; ++i) {
    uint16_t digit;
    digit = numerator->DivideModuloIntBignum(*denominator);
    DOUBLE_CONVERSION_ASSERT(digit <= 9);  // digit is a uint16_t and therefore always positive.
    // digit = numerator / denominator (integer division).
    // numerator = numerator % denominator.
    buffer[i] = static_cast<char>(digit + '0');
    // Prepare for next iteration.
    numerator->Times10();
  }
  // Generate the last digit.
  uint16_t digit;
  digit = numerator->DivideModuloIntBignum(*denominator);
  if (Bignum::PlusCompare(*numerator, *numerator, *denominator) >= 0) {
    digit++;
  }
  DOUBLE_CONVERSION_ASSERT(digit <= 10);
  buffer[count - 1] = static_cast<char>(digit + '0');
  // Correct bad digits (in case we had a sequence of '9's). Propagate the
  // carry until we hat a non-'9' or til we reach the first digit.
  for (int i = count - 1; i > 0; --i) {
    if (buffer[i] != '0' + 10) break;
    buffer[i] = '0';
    buffer[i - 1]++;
  }
  if (buffer[0] == '0' + 10) {
    // Propagate a carry past the top place.
    buffer[0] = '1';
    (*decimal_point)++;
  }
  *length = count;
}

GenerateShortestDigits()

static void double_conversion::GenerateShortestDigits ( Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus, bool  is_even, Vector< char >  buffer, int *  length  )

static

Definition at line 185 of file bignum-dtoa.cc.

                                                                     {
  // Small optimization: if delta_minus and delta_plus are the same just reuse
  // one of the two bignums.
  if (Bignum::Equal(*delta_minus, *delta_plus)) {
    delta_plus = delta_minus;
  }
  *length = 0;
  for (;;) {
    uint16_t digit;
    digit = numerator->DivideModuloIntBignum(*denominator);
    DOUBLE_CONVERSION_ASSERT(digit <= 9);  // digit is a uint16_t and therefore always positive.
    // digit = numerator / denominator (integer division).
    // numerator = numerator % denominator.
    buffer[(*length)++] = static_cast<char>(digit + '0');
 
    // Can we stop already?
    // If the remainder of the division is less than the distance to the lower
    // boundary we can stop. In this case we simply round down (discarding the
    // remainder).
    // Similarly we test if we can round up (using the upper boundary).
    bool in_delta_room_minus;
    bool in_delta_room_plus;
    if (is_even) {
      in_delta_room_minus = Bignum::LessEqual(*numerator, *delta_minus);
    } else {
      in_delta_room_minus = Bignum::Less(*numerator, *delta_minus);
    }
    if (is_even) {
      in_delta_room_plus =
          Bignum::PlusCompare(*numerator, *delta_plus, *denominator) >= 0;
    } else {
      in_delta_room_plus =
          Bignum::PlusCompare(*numerator, *delta_plus, *denominator) > 0;
    }
    if (!in_delta_room_minus && !in_delta_room_plus) {
      // Prepare for next iteration.
      numerator->Times10();
      delta_minus->Times10();
      // We optimized delta_plus to be equal to delta_minus (if they share the
      // same value). So don't multiply delta_plus if they point to the same
      // object.
      if (delta_minus != delta_plus) {
        delta_plus->Times10();
      }
    } else if (in_delta_room_minus && in_delta_room_plus) {
      // Let's see if 2*numerator < denominator.
      // If yes, then the next digit would be < 5 and we can round down.
      int compare = Bignum::PlusCompare(*numerator, *numerator, *denominator);
      if (compare < 0) {
        // Remaining digits are less than .5. -> Round down (== do nothing).
      } else if (compare > 0) {
        // Remaining digits are more than .5 of denominator. -> Round up.
        // Note that the last digit could not be a '9' as otherwise the whole
        // loop would have stopped earlier.
        // We still have an assert here in case the preconditions were not
        // satisfied.
        DOUBLE_CONVERSION_ASSERT(buffer[(*length) - 1] != '9');
        buffer[(*length) - 1]++;
      } else {
        // Halfway case.
        // TODO(floitsch): need a way to solve half-way cases.
        //   For now let's round towards even (since this is what Gay seems to
        //   do).
 
        if ((buffer[(*length) - 1] - '0') % 2 == 0) {
          // Round down => Do nothing.
        } else {
          DOUBLE_CONVERSION_ASSERT(buffer[(*length) - 1] != '9');
          buffer[(*length) - 1]++;
        }
      }
      return;
    } else if (in_delta_room_minus) {
      // Round down (== do nothing).
      return;
    } else {  // in_delta_room_plus
      // Round up.
      // Note again that the last digit could not be '9' since this would have
      // stopped the loop earlier.
      // We still have an DOUBLE_CONVERSION_ASSERT here, in case the preconditions were not
      // satisfied.
      DOUBLE_CONVERSION_ASSERT(buffer[(*length) -1] != '9');
      buffer[(*length) - 1]++;
      return;
    }
  }
}

Grisu3()

static bool double_conversion::Grisu3 ( double  v, FastDtoaMode  mode, Vector< char >  buffer, int *  length, int *  decimal_exponent  )

static

Definition at line 519 of file fast-dtoa.cc.

                                          {
  DiyFp w = Double(v).AsNormalizedDiyFp();
  // boundary_minus and boundary_plus are the boundaries between v and its
  // closest floating-point neighbors. Any number strictly between
  // boundary_minus and boundary_plus will round to v when convert to a double.
  // Grisu3 will never output representations that lie exactly on a boundary.
  DiyFp boundary_minus, boundary_plus;
  if (mode == FAST_DTOA_SHORTEST) {
    Double(v).NormalizedBoundaries(&boundary_minus, &boundary_plus);
  } else {
    DOUBLE_CONVERSION_ASSERT(mode == FAST_DTOA_SHORTEST_SINGLE);
    float single_v = static_cast<float>(v);
    Single(single_v).NormalizedBoundaries(&boundary_minus, &boundary_plus);
  }
  DOUBLE_CONVERSION_ASSERT(boundary_plus.e() == w.e());
  DiyFp ten_mk;  // Cached power of ten: 10^-k
  int mk;        // -k
  int ten_mk_minimal_binary_exponent =
     kMinimalTargetExponent - (w.e() + DiyFp::kSignificandSize);
  int ten_mk_maximal_binary_exponent =
     kMaximalTargetExponent - (w.e() + DiyFp::kSignificandSize);
  PowersOfTenCache::GetCachedPowerForBinaryExponentRange(
      ten_mk_minimal_binary_exponent,
      ten_mk_maximal_binary_exponent,
      &ten_mk, &mk);
  DOUBLE_CONVERSION_ASSERT((kMinimalTargetExponent <= w.e() + ten_mk.e() +
          DiyFp::kSignificandSize) &&
         (kMaximalTargetExponent >= w.e() + ten_mk.e() +
          DiyFp::kSignificandSize));
  // Note that ten_mk is only an approximation of 10^-k. A DiyFp only contains a
  // 64 bit significand and ten_mk is thus only precise up to 64 bits.
 
  // The DiyFp::Times procedure rounds its result, and ten_mk is approximated
  // too. The variable scaled_w (as well as scaled_boundary_minus/plus) are now
  // off by a small amount.
  // In fact: scaled_w - w*10^k < 1ulp (unit in the last place) of scaled_w.
  // In other words: let f = scaled_w.f() and e = scaled_w.e(), then
  //           (f-1) * 2^e < w*10^k < (f+1) * 2^e
  DiyFp scaled_w = DiyFp::Times(w, ten_mk);
  DOUBLE_CONVERSION_ASSERT(scaled_w.e() ==
         boundary_plus.e() + ten_mk.e() + DiyFp::kSignificandSize);
  // In theory it would be possible to avoid some recomputations by computing
  // the difference between w and boundary_minus/plus (a power of 2) and to
  // compute scaled_boundary_minus/plus by subtracting/adding from
  // scaled_w. However the code becomes much less readable and the speed
  // enhancements are not terrific.
  DiyFp scaled_boundary_minus = DiyFp::Times(boundary_minus, ten_mk);
  DiyFp scaled_boundary_plus  = DiyFp::Times(boundary_plus,  ten_mk);
 
  // DigitGen will generate the digits of scaled_w. Therefore we have
  // v == (double) (scaled_w * 10^-mk).
  // Set decimal_exponent == -mk and pass it to DigitGen. If scaled_w is not an
  // integer than it will be updated. For instance if scaled_w == 1.23 then
  // the buffer will be filled with "123" and the decimal_exponent will be
  // decreased by 2.
  int kappa;
  bool result = DigitGen(scaled_boundary_minus, scaled_w, scaled_boundary_plus,
                         buffer, length, &kappa);
  *decimal_exponent = -mk + kappa;
  return result;
}

Grisu3Counted()

static bool double_conversion::Grisu3Counted ( double  v, int  requested_digits, Vector< char >  buffer, int *  length, int *  decimal_exponent  )

static

Definition at line 591 of file fast-dtoa.cc.

                                                 {
  DiyFp w = Double(v).AsNormalizedDiyFp();
  DiyFp ten_mk;  // Cached power of ten: 10^-k
  int mk;        // -k
  int ten_mk_minimal_binary_exponent =
     kMinimalTargetExponent - (w.e() + DiyFp::kSignificandSize);
  int ten_mk_maximal_binary_exponent =
     kMaximalTargetExponent - (w.e() + DiyFp::kSignificandSize);
  PowersOfTenCache::GetCachedPowerForBinaryExponentRange(
      ten_mk_minimal_binary_exponent,
      ten_mk_maximal_binary_exponent,
      &ten_mk, &mk);
  DOUBLE_CONVERSION_ASSERT((kMinimalTargetExponent <= w.e() + ten_mk.e() +
          DiyFp::kSignificandSize) &&
         (kMaximalTargetExponent >= w.e() + ten_mk.e() +
          DiyFp::kSignificandSize));
  // Note that ten_mk is only an approximation of 10^-k. A DiyFp only contains a
  // 64 bit significand and ten_mk is thus only precise up to 64 bits.
 
  // The DiyFp::Times procedure rounds its result, and ten_mk is approximated
  // too. The variable scaled_w (as well as scaled_boundary_minus/plus) are now
  // off by a small amount.
  // In fact: scaled_w - w*10^k < 1ulp (unit in the last place) of scaled_w.
  // In other words: let f = scaled_w.f() and e = scaled_w.e(), then
  //           (f-1) * 2^e < w*10^k < (f+1) * 2^e
  DiyFp scaled_w = DiyFp::Times(w, ten_mk);
 
  // We now have (double) (scaled_w * 10^-mk).
  // DigitGen will generate the first requested_digits digits of scaled_w and
  // return together with a kappa such that scaled_w ~= buffer * 10^kappa. (It
  // will not always be exactly the same since DigitGenCounted only produces a
  // limited number of digits.)
  int kappa;
  bool result = DigitGenCounted(scaled_w, requested_digits,
                                buffer, length, &kappa);
  *decimal_exponent = -mk + kappa;
  return result;
}

HexCharOfValue()

static char double_conversion::HexCharOfValue ( const int  value )

static

Definition at line 580 of file bignum.cc.

                                            {
  DOUBLE_CONVERSION_ASSERT(0 <= value && value <= 16);
  if (value < 10) {
    return static_cast<char>(value + '0');
  }
  return static_cast<char>(value - 10 + 'A');
}

HexCharValue()

static uint64_t double_conversion::HexCharValue ( const int  c )

static

Definition at line 118 of file bignum.cc.

                                          {
  if ('0' <= c && c <= '9') {
    return c - '0';
  }
  if ('a' <= c && c <= 'f') {
    return 10 + c - 'a';
  }
  DOUBLE_CONVERSION_ASSERT('A' <= c && c <= 'F');
  return 10 + c - 'A';
}

InitialScaledStartValues()

static void double_conversion::InitialScaledStartValues ( uint64_t  significand, int  exponent, bool  lower_boundary_is_closer, int  estimated_power, bool  need_boundary_deltas, Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus  )

static

Definition at line 568 of file bignum-dtoa.cc.

                                                         {
  if (exponent >= 0) {
    InitialScaledStartValuesPositiveExponent(
        significand, exponent, estimated_power, need_boundary_deltas,
        numerator, denominator, delta_minus, delta_plus);
  } else if (estimated_power >= 0) {
    InitialScaledStartValuesNegativeExponentPositivePower(
        significand, exponent, estimated_power, need_boundary_deltas,
        numerator, denominator, delta_minus, delta_plus);
  } else {
    InitialScaledStartValuesNegativeExponentNegativePower(
        significand, exponent, estimated_power, need_boundary_deltas,
        numerator, denominator, delta_minus, delta_plus);
  }
 
  if (need_boundary_deltas && lower_boundary_is_closer) {
    // The lower boundary is closer at half the distance of "normal" numbers.
    // Increase the common denominator and adapt all but the delta_minus.
    denominator->ShiftLeft(1);  // *2
    numerator->ShiftLeft(1);    // *2
    delta_plus->ShiftLeft(1);   // *2
  }
}

InitialScaledStartValuesNegativeExponentNegativePower()

static void double_conversion::InitialScaledStartValuesNegativeExponentNegativePower ( uint64_t  significand, int  exponent, int  estimated_power, bool  need_boundary_deltas, Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus  )

static

Definition at line 484 of file bignum-dtoa.cc.

                                             {
  // Instead of multiplying the denominator with 10^estimated_power we
  // multiply all values (numerator and deltas) by 10^-estimated_power.
 
  // Use numerator as temporary container for power_ten.
  Bignum* power_ten = numerator;
  power_ten->AssignPowerUInt16(10, -estimated_power);
 
  if (need_boundary_deltas) {
    // Since power_ten == numerator we must make a copy of 10^estimated_power
    // before we complete the computation of the numerator.
    // delta_plus = delta_minus = 10^estimated_power
    delta_plus->AssignBignum(*power_ten);
    delta_minus->AssignBignum(*power_ten);
  }
 
  // numerator = significand * 2 * 10^-estimated_power
  //  since v = significand * 2^exponent this is equivalent to
  // numerator = v * 10^-estimated_power * 2 * 2^-exponent.
  // Remember: numerator has been abused as power_ten. So no need to assign it
  //  to itself.
  DOUBLE_CONVERSION_ASSERT(numerator == power_ten);
  numerator->MultiplyByUInt64(significand);
 
  // denominator = 2 * 2^-exponent with exponent < 0.
  denominator->AssignUInt16(1);
  denominator->ShiftLeft(-exponent);
 
  if (need_boundary_deltas) {
    // Introduce a common denominator so that the deltas to the boundaries are
    // integers.
    numerator->ShiftLeft(1);
    denominator->ShiftLeft(1);
    // With this shift the boundaries have their correct value, since
    // delta_plus = 10^-estimated_power, and
    // delta_minus = 10^-estimated_power.
    // These assignments have been done earlier.
    // The adjustments if f == 2^p-1 (lower boundary is closer) are done later.
  }
}

InitialScaledStartValuesNegativeExponentPositivePower()

static void double_conversion::InitialScaledStartValuesNegativeExponentPositivePower ( uint64_t  significand, int  exponent, int  estimated_power, bool  need_boundary_deltas, Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus  )

static

Definition at line 450 of file bignum-dtoa.cc.

                                             {
  // v = f * 2^e with e < 0, and with estimated_power >= 0.
  // This means that e is close to 0 (have a look at how estimated_power is
  // computed).
 
  // numerator = significand
  //  since v = significand * 2^exponent this is equivalent to
  //  numerator = v * / 2^-exponent
  numerator->AssignUInt64(significand);
  // denominator = 10^estimated_power * 2^-exponent (with exponent < 0)
  denominator->AssignPowerUInt16(10, estimated_power);
  denominator->ShiftLeft(-exponent);
 
  if (need_boundary_deltas) {
    // Introduce a common denominator so that the deltas to the boundaries are
    // integers.
    denominator->ShiftLeft(1);
    numerator->ShiftLeft(1);
    // Let v = f * 2^e, then m+ - v = 1/2 * 2^e; With the common
    // denominator (of 2) delta_plus equals 2^e.
    // Given that the denominator already includes v's exponent the distance
    // to the boundaries is simply 1.
    delta_plus->AssignUInt16(1);
    // Same for delta_minus. The adjustments if f == 2^p-1 are done later.
    delta_minus->AssignUInt16(1);
  }
}

InitialScaledStartValuesPositiveExponent()

static void double_conversion::InitialScaledStartValuesPositiveExponent ( uint64_t  significand, int  exponent, int  estimated_power, bool  need_boundary_deltas, Bignum *  numerator, Bignum *  denominator, Bignum *  delta_minus, Bignum *  delta_plus  )

static

Definition at line 417 of file bignum-dtoa.cc.

                                             {
  // A positive exponent implies a positive power.
  DOUBLE_CONVERSION_ASSERT(estimated_power >= 0);
  // Since the estimated_power is positive we simply multiply the denominator
  // by 10^estimated_power.
 
  // numerator = v.
  numerator->AssignUInt64(significand);
  numerator->ShiftLeft(exponent);
  // denominator = 10^estimated_power.
  denominator->AssignPowerUInt16(10, estimated_power);
 
  if (need_boundary_deltas) {
    // Introduce a common denominator so that the deltas to the boundaries are
    // integers.
    denominator->ShiftLeft(1);
    numerator->ShiftLeft(1);
    // Let v = f * 2^e, then m+ - v = 1/2 * 2^e; With the common
    // denominator (of 2) delta_plus equals 2^e.
    delta_plus->AssignUInt16(1);
    delta_plus->ShiftLeft(exponent);
    // Same for delta_minus. The adjustments if f == 2^p-1 are done later.
    delta_minus->AssignUInt16(1);
    delta_minus->ShiftLeft(exponent);
  }
}

IsCharacterDigitForRadix()

static bool double_conversion::IsCharacterDigitForRadix ( int  c, int  radix, char  a_character  )

static

Definition at line 184 of file string-to-double.cc.

                                                                         {
  return radix > 10 && c >= a_character && c < a_character + radix - 10;
}

IsDecimalDigitForRadix()

static bool double_conversion::IsDecimalDigitForRadix ( int  c, int  radix  )

inlinestatic

Definition at line 173 of file string-to-double.cc.

                                                            {
  return '0' <= c && c <= '9' && (c - '0') < radix;
}

IsDigit()

static bool double_conversion::IsDigit ( const char  d )

static

Definition at line 444 of file strtod.cc.

                                  {
  return ('0' <= d) && (d <= '9');
}

isDigit()

static bool double_conversion::isDigit ( int  x, int  radix  )

static

Definition at line 148 of file string-to-double.cc.

                                      {
  return (x >= '0' && x <= '9' && x < '0' + radix)
      || (radix > 10 && x >= 'a' && x < 'a' + radix - 10)
      || (radix > 10 && x >= 'A' && x < 'A' + radix - 10);
}

IsHexFloatString()

template<class Iterator >

static bool double_conversion::IsHexFloatString ( Iterator  start, Iterator  end, uc16  separator, bool  allow_trailing_junk  )

static

Definition at line 216 of file string-to-double.cc.

                                                       {
  DOUBLE_CONVERSION_ASSERT(start != end);
 
  Iterator current = start;
 
  bool saw_digit = false;
  while (isDigit(*current, 16)) {
    saw_digit = true;
    if (Advance(&current, separator, 16, end)) return false;
  }
  if (*current == '.') {
    if (Advance(&current, separator, 16, end)) return false;
    while (isDigit(*current, 16)) {
      saw_digit = true;
      if (Advance(&current, separator, 16, end)) return false;
    }
  }
  if (!saw_digit) return false;
  if (*current != 'p' && *current != 'P') return false;
  if (Advance(&current, separator, 16, end)) return false;
  if (*current == '+' || *current == '-') {
    if (Advance(&current, separator, 16, end)) return false;
  }
  if (!isDigit(*current, 10)) return false;
  if (Advance(&current, separator, 16, end)) return true;
  while (isDigit(*current, 10)) {
    if (Advance(&current, separator, 16, end)) return true;
  }
  return allow_trailing_junk || !AdvanceToNonspace(&current, end);
}

IsNonZeroDigit()

static bool double_conversion::IsNonZeroDigit ( const char  d )

static

Definition at line 448 of file strtod.cc.

                                         {
  return ('1' <= d) && (d <= '9');
}

isWhitespace()

static bool double_conversion::isWhitespace ( int  x )

static

Definition at line 123 of file string-to-double.cc.

                                {
  if (x < 128) {
    for (int i = 0; i < kWhitespaceTable7Length; i++) {
      if (kWhitespaceTable7[i] == x) return true;
    }
  } else {
    for (int i = 0; i < kWhitespaceTable16Length; i++) {
      if (kWhitespaceTable16[i] == x) return true;
    }
  }
  return false;
}

NormalizedExponent()

static int double_conversion::NormalizedExponent ( uint64_t  significand, int  exponent  )

static

Definition at line 37 of file bignum-dtoa.cc.

                                                                  {
  DOUBLE_CONVERSION_ASSERT(significand != 0);
  while ((significand & Double::kHiddenBit) == 0) {
    significand = significand << 1;
    exponent = exponent - 1;
  }
  return exponent;
}

RadixStringToIeee()

template<int radix_log_2, class Iterator >

static double double_conversion::RadixStringToIeee ( Iterator *  current, Iterator  end, bool  sign, uc16  separator, bool  parse_as_hex_float, bool  allow_trailing_junk, double  junk_string_value, bool  read_as_double, bool *  result_is_junk  )

static

Definition at line 256 of file string-to-double.cc.

                                                      {
  DOUBLE_CONVERSION_ASSERT(*current != end);
  DOUBLE_CONVERSION_ASSERT(!parse_as_hex_float ||
      IsHexFloatString(*current, end, separator, allow_trailing_junk));
 
  const int kDoubleSize = Double::kSignificandSize;
  const int kSingleSize = Single::kSignificandSize;
  const int kSignificandSize = read_as_double? kDoubleSize: kSingleSize;
 
  *result_is_junk = true;
 
  int64_t number = 0;
  int exponent = 0;
  const int radix = (1 << radix_log_2);
  // Whether we have encountered a '.' and are parsing the decimal digits.
  // Only relevant if parse_as_hex_float is true.
  bool post_decimal = false;
 
  // Skip leading 0s.
  while (**current == '0') {
    if (Advance(current, separator, radix, end)) {
      *result_is_junk = false;
      return SignedZero(sign);
    }
  }
 
  while (true) {
    int digit;
    if (IsDecimalDigitForRadix(**current, radix)) {
      digit = static_cast<char>(**current) - '0';
      if (post_decimal) exponent -= radix_log_2;
    } else if (IsCharacterDigitForRadix(**current, radix, 'a')) {
      digit = static_cast<char>(**current) - 'a' + 10;
      if (post_decimal) exponent -= radix_log_2;
    } else if (IsCharacterDigitForRadix(**current, radix, 'A')) {
      digit = static_cast<char>(**current) - 'A' + 10;
      if (post_decimal) exponent -= radix_log_2;
    } else if (parse_as_hex_float && **current == '.') {
      post_decimal = true;
      Advance(current, separator, radix, end);
      DOUBLE_CONVERSION_ASSERT(*current != end);
      continue;
    } else if (parse_as_hex_float && (**current == 'p' || **current == 'P')) {
      break;
    } else {
      if (allow_trailing_junk || !AdvanceToNonspace(current, end)) {
        break;
      } else {
        return junk_string_value;
      }
    }
 
    number = number * radix + digit;
    int overflow = static_cast<int>(number >> kSignificandSize);
    if (overflow != 0) {
      // Overflow occurred. Need to determine which direction to round the
      // result.
      int overflow_bits_count = 1;
      while (overflow > 1) {
        overflow_bits_count++;
        overflow >>= 1;
      }
 
      int dropped_bits_mask = ((1 << overflow_bits_count) - 1);
      int dropped_bits = static_cast<int>(number) & dropped_bits_mask;
      number >>= overflow_bits_count;
      exponent += overflow_bits_count;
 
      bool zero_tail = true;
      for (;;) {
        if (Advance(current, separator, radix, end)) break;
        if (parse_as_hex_float && **current == '.') {
          // Just run over the '.'. We are just trying to see whether there is
          // a non-zero digit somewhere.
          Advance(current, separator, radix, end);
          DOUBLE_CONVERSION_ASSERT(*current != end);
          post_decimal = true;
        }
        if (!isDigit(**current, radix)) break;
        zero_tail = zero_tail && **current == '0';
        if (!post_decimal) exponent += radix_log_2;
      }
 
      if (!parse_as_hex_float &&
          !allow_trailing_junk &&
          AdvanceToNonspace(current, end)) {
        return junk_string_value;
      }
 
      int middle_value = (1 << (overflow_bits_count - 1));
      if (dropped_bits > middle_value) {
        number++;  // Rounding up.
      } else if (dropped_bits == middle_value) {
        // Rounding to even to consistency with decimals: half-way case rounds
        // up if significant part is odd and down otherwise.
        if ((number & 1) != 0 || !zero_tail) {
          number++;  // Rounding up.
        }
      }
 
      // Rounding up may cause overflow.
      if ((number & ((int64_t)1 << kSignificandSize)) != 0) {
        exponent++;
        number >>= 1;
      }
      break;
    }
    if (Advance(current, separator, radix, end)) break;
  }
 
  DOUBLE_CONVERSION_ASSERT(number < ((int64_t)1 << kSignificandSize));
  DOUBLE_CONVERSION_ASSERT(static_cast<int64_t>(static_cast<double>(number)) == number);
 
  *result_is_junk = false;
 
  if (parse_as_hex_float) {
    DOUBLE_CONVERSION_ASSERT(**current == 'p' || **current == 'P');
    Advance(current, separator, radix, end);
    DOUBLE_CONVERSION_ASSERT(*current != end);
    bool is_negative = false;
    if (**current == '+') {
      Advance(current, separator, radix, end);
      DOUBLE_CONVERSION_ASSERT(*current != end);
    } else if (**current == '-') {
      is_negative = true;
      Advance(current, separator, radix, end);
      DOUBLE_CONVERSION_ASSERT(*current != end);
    }
    int written_exponent = 0;
    while (IsDecimalDigitForRadix(**current, 10)) {
      // No need to read exponents if they are too big. That could potentially overflow
      // the `written_exponent` variable.
      if (abs(written_exponent) <= 100 * Double::kMaxExponent) {
        written_exponent = 10 * written_exponent + **current - '0';
      }
      if (Advance(current, separator, radix, end)) break;
    }
    if (is_negative) written_exponent = -written_exponent;
    exponent += written_exponent;
  }
 
  if (exponent == 0 || number == 0) {
    if (sign) {
      if (number == 0) return -0.0;
      number = -number;
    }
    return static_cast<double>(number);
  }
 
  DOUBLE_CONVERSION_ASSERT(number != 0);
  double result = Double(DiyFp(number, exponent)).value();
  return sign ? -result : result;
}

ReadDiyFp()

static void double_conversion::ReadDiyFp ( Vector< const char >  buffer, DiyFp *  result, int *  remaining_decimals  )

static

Definition at line 169 of file strtod.cc.

                                               {
  int read_digits;
  uint64_t significand = ReadUint64(buffer, &read_digits);
  if (buffer.length() == read_digits) {
    *result = DiyFp(significand, 0);
    *remaining_decimals = 0;
  } else {
    // Round the significand.
    if (buffer[read_digits] >= '5') {
      significand++;
    }
    // Compute the binary exponent.
    int exponent = 0;
    *result = DiyFp(significand, exponent);
    *remaining_decimals = buffer.length() - read_digits;
  }
}

ReadUInt64()

static uint64_t double_conversion::ReadUInt64 ( const Vector< const char >  buffer, const int  from, const int  digits_to_read  )

static

Definition at line 84 of file bignum.cc.

                                                     {
  uint64_t result = 0;
  for (int i = from; i < from + digits_to_read; ++i) {
    const int digit = buffer[i] - '0';
    DOUBLE_CONVERSION_ASSERT(0 <= digit && digit <= 9);
    result = result * 10 + digit;
  }
  return result;
}

ReadUint64()

static uint64_t double_conversion::ReadUint64 ( Vector< const char >  buffer, int *  number_of_read_digits  )

static

Definition at line 151 of file strtod.cc.

                                                       {
  uint64_t result = 0;
  int i = 0;
  while (i < buffer.length() && result <= (kMaxUint64 / 10 - 1)) {
    int digit = buffer[i++] - '0';
    DOUBLE_CONVERSION_ASSERT(0 <= digit && digit <= 9);
    result = 10 * result + digit;
  }
  *number_of_read_digits = i;
  return result;
}

RoundUp()

static void double_conversion::RoundUp ( Vector< char >  buffer, int *  length, int *  decimal_point  )

static

Definition at line 189 of file fixed-dtoa.cc.

                                                                          {
  // An empty buffer represents 0.
  if (*length == 0) {
    buffer[0] = '1';
    *decimal_point = 1;
    *length = 1;
    return;
  }
  // Round the last digit until we either have a digit that was not '9' or until
  // we reached the first digit.
  buffer[(*length) - 1]++;
  for (int i = (*length) - 1; i > 0; --i) {
    if (buffer[i] != '0' + 10) {
      return;
    }
    buffer[i] = '0';
    buffer[i - 1]++;
  }
  // If the first digit is now '0' + 10, we would need to set it to '0' and add
  // a '1' in front. However we reach the first digit only if all following
  // digits had been '9' before rounding up. Now all trailing digits are '0' and
  // we simply switch the first digit to '1' and update the decimal-point
  // (indicating that the point is now one digit to the right).
  if (buffer[0] == '0' + 10) {
    buffer[0] = '1';
    (*decimal_point)++;
  }
}

RoundWeed()

static bool double_conversion::RoundWeed ( Vector< char >  buffer, int  length, uint64_t  distance_too_high_w, uint64_t  unsafe_interval, uint64_t  rest, uint64_t  ten_kappa, uint64_t  unit  )

static

Definition at line 61 of file fast-dtoa.cc.

                                     {
  uint64_t small_distance = distance_too_high_w - unit;
  uint64_t big_distance = distance_too_high_w + unit;
  // Let w_low  = too_high - big_distance, and
  //     w_high = too_high - small_distance.
  // Note: w_low < w < w_high
  //
  // The real w (* unit) must lie somewhere inside the interval
  // ]w_low; w_high[ (often written as "(w_low; w_high)")
 
  // Basically the buffer currently contains a number in the unsafe interval
  // ]too_low; too_high[ with too_low < w < too_high
  //
  //  too_high - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  //                     ^v 1 unit            ^      ^                 ^      ^
  //  boundary_high ---------------------     .      .                 .      .
  //                     ^v 1 unit            .      .                 .      .
  //   - - - - - - - - - - - - - - - - - - -  +  - - + - - - - - -     .      .
  //                                          .      .         ^       .      .
  //                                          .  big_distance  .       .      .
  //                                          .      .         .       .    rest
  //                              small_distance     .         .       .      .
  //                                          v      .         .       .      .
  //  w_high - - - - - - - - - - - - - - - - - -     .         .       .      .
  //                     ^v 1 unit                   .         .       .      .
  //  w ----------------------------------------     .         .       .      .
  //                     ^v 1 unit                   v         .       .      .
  //  w_low  - - - - - - - - - - - - - - - - - - - - -         .       .      .
  //                                                           .       .      v
  //  buffer --------------------------------------------------+-------+--------
  //                                                           .       .
  //                                                  safe_interval    .
  //                                                           v       .
  //   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -     .
  //                     ^v 1 unit                                     .
  //  boundary_low -------------------------                     unsafe_interval
  //                     ^v 1 unit                                     v
  //  too_low  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  //
  //
  // Note that the value of buffer could lie anywhere inside the range too_low
  // to too_high.
  //
  // boundary_low, boundary_high and w are approximations of the real boundaries
  // and v (the input number). They are guaranteed to be precise up to one unit.
  // In fact the error is guaranteed to be strictly less than one unit.
  //
  // Anything that lies outside the unsafe interval is guaranteed not to round
  // to v when read again.
  // Anything that lies inside the safe interval is guaranteed to round to v
  // when read again.
  // If the number inside the buffer lies inside the unsafe interval but not
  // inside the safe interval then we simply do not know and bail out (returning
  // false).
  //
  // Similarly we have to take into account the imprecision of 'w' when finding
  // the closest representation of 'w'. If we have two potential
  // representations, and one is closer to both w_low and w_high, then we know
  // it is closer to the actual value v.
  //
  // By generating the digits of too_high we got the largest (closest to
  // too_high) buffer that is still in the unsafe interval. In the case where
  // w_high < buffer < too_high we try to decrement the buffer.
  // This way the buffer approaches (rounds towards) w.
  // There are 3 conditions that stop the decrementation process:
  //   1) the buffer is already below w_high
  //   2) decrementing the buffer would make it leave the unsafe interval
  //   3) decrementing the buffer would yield a number below w_high and farther
  //      away than the current number. In other words:
  //              (buffer{-1} < w_high) && w_high - buffer{-1} > buffer - w_high
  // Instead of using the buffer directly we use its distance to too_high.
  // Conceptually rest ~= too_high - buffer
  // We need to do the following tests in this order to avoid over- and
  // underflows.
  DOUBLE_CONVERSION_ASSERT(rest <= unsafe_interval);
  while (rest < small_distance &&  // Negated condition 1
         unsafe_interval - rest >= ten_kappa &&  // Negated condition 2
         (rest + ten_kappa < small_distance ||  // buffer{-1} > w_high
          small_distance - rest >= rest + ten_kappa - small_distance)) {
    buffer[length - 1]--;
    rest += ten_kappa;
  }
 
  // We have approached w+ as much as possible. We now test if approaching w-
  // would require changing the buffer. If yes, then we have two possible
  // representations close to w, but we cannot decide which one is closer.
  if (rest < big_distance &&
      unsafe_interval - rest >= ten_kappa &&
      (rest + ten_kappa < big_distance ||
       big_distance - rest > rest + ten_kappa - big_distance)) {
    return false;
  }
 
  // Weeding test.
  //   The safe interval is [too_low + 2 ulp; too_high - 2 ulp]
  //   Since too_low = too_high - unsafe_interval this is equivalent to
  //      [too_high - unsafe_interval + 4 ulp; too_high - 2 ulp]
  //   Conceptually we have: rest ~= too_high - buffer
  return (2 * unit <= rest) && (rest <= unsafe_interval - 4 * unit);
}

RoundWeedCounted()

static bool double_conversion::RoundWeedCounted ( Vector< char >  buffer, int  length, uint64_t  rest, uint64_t  ten_kappa, uint64_t  unit, int *  kappa  )

static

Definition at line 181 of file fast-dtoa.cc.

                                         {
  DOUBLE_CONVERSION_ASSERT(rest < ten_kappa);
  // The following tests are done in a specific order to avoid overflows. They
  // will work correctly with any uint64 values of rest < ten_kappa and unit.
  //
  // If the unit is too big, then we don't know which way to round. For example
  // a unit of 50 means that the real number lies within rest +/- 50. If
  // 10^kappa == 40 then there is no way to tell which way to round.
  if (unit >= ten_kappa) return false;
  // Even if unit is just half the size of 10^kappa we are already completely
  // lost. (And after the previous test we know that the expression will not
  // over/underflow.)
  if (ten_kappa - unit <= unit) return false;
  // If 2 * (rest + unit) <= 10^kappa we can safely round down.
  if ((ten_kappa - rest > rest) && (ten_kappa - 2 * rest >= 2 * unit)) {
    return true;
  }
  // If 2 * (rest - unit) >= 10^kappa, then we can safely round up.
  if ((rest > unit) && (ten_kappa - (rest - unit) <= (rest - unit))) {
    // Increment the last digit recursively until we find a non '9' digit.
    buffer[length - 1]++;
    for (int i = length - 1; i > 0; --i) {
      if (buffer[i] != '0' + 10) break;
      buffer[i] = '0';
      buffer[i - 1]++;
    }
    // If the first digit is now '0'+ 10 we had a buffer with all '9's. With the
    // exception of the first digit all digits are now '0'. Simply switch the
    // first digit to '1' and adjust the kappa. Example: "99" becomes "10" and
    // the power (the kappa) is increased.
    if (buffer[0] == '0' + 10) {
      buffer[0] = '1';
      (*kappa) += 1;
    }
    return true;
  }
  return false;
}

SanitizedDoubletof()

static float double_conversion::SanitizedDoubletof ( double  d )

static

Definition at line 497 of file strtod.cc.

                                          {
  DOUBLE_CONVERSION_ASSERT(d >= 0.0);
  // ASAN has a sanitize check that disallows casting doubles to floats if
  // they are too big.
  // https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks
  // The behavior should be covered by IEEE 754, but some projects use this
  // flag, so work around it.
  float max_finite = 3.4028234663852885981170418348451692544e+38;
  // The half-way point between the max-finite and infinity value.
  // Since infinity has an even significand everything equal or greater than
  // this value should become infinity.
  double half_max_finite_infinity =
      3.40282356779733661637539395458142568448e+38;
  if (d >= max_finite) {
    if (d >= half_max_finite_infinity) {
      return Single::Infinity();
    } else {
      return max_finite;
    }
  } else {
    return static_cast<float>(d);
  }
}

SignedZero()

static double double_conversion::SignedZero ( bool  sign )

static

Definition at line 155 of file string-to-double.cc.

                                    {
  return sign ? -0.0 : 0.0;
}

SizeInHexChars()

template<typename S >

static int double_conversion::SizeInHexChars ( S  number )

static

Definition at line 569 of file bignum.cc.

                                    {
  DOUBLE_CONVERSION_ASSERT(number > 0);
  int result = 0;
  while (number != 0) {
    number >>= 4;
    result++;
  }
  return result;
}

StrLength()

int double_conversion::StrLength ( const char *  string )

inline

Definition at line 241 of file utils.h.

                                         {
  size_t length = strlen(string);
  DOUBLE_CONVERSION_ASSERT(length == static_cast<size_t>(static_cast<int>(length)));
  return static_cast<int>(length);
}

Strtod()

double double_conversion::Strtod	(	Vector< const char >	buffer,
		int	exponent
	)

Definition at line 488 of file strtod.cc.

                                                       {
  char copy_buffer[kMaxSignificantDecimalDigits];
  Vector<const char> trimmed;
  int updated_exponent;
  TrimAndCut(buffer, exponent, copy_buffer, kMaxSignificantDecimalDigits,
             &trimmed, &updated_exponent);
  return StrtodTrimmed(trimmed, updated_exponent);
}

StrtodTrimmed()

double double_conversion::StrtodTrimmed	(	Vector< const char >	trimmed,
		int	exponent
	)

Definition at line 466 of file strtod.cc.

                                                               {
  DOUBLE_CONVERSION_ASSERT(trimmed.length() <= kMaxSignificantDecimalDigits);
  DOUBLE_CONVERSION_ASSERT(AssertTrimmedDigits(trimmed));
  double guess;
  const bool is_correct = ComputeGuess(trimmed, exponent, &guess);
  if (is_correct) {
    return guess;
  }
  DiyFp upper_boundary = Double(guess).UpperBoundary();
  int comparison = CompareBufferWithDiyFp(trimmed, exponent, upper_boundary);
  if (comparison < 0) {
    return guess;
  } else if (comparison > 0) {
    return Double(guess).NextDouble();
  } else if ((Double(guess).Significand() & 1) == 0) {
    // Round towards even.
    return guess;
  } else {
    return Double(guess).NextDouble();
  }
}

Strtof()

float double_conversion::Strtof	(	Vector< const char >	buffer,
		int	exponent
	)

Definition at line 521 of file strtod.cc.

                                                      {
  char copy_buffer[kMaxSignificantDecimalDigits];
  Vector<const char> trimmed;
  int updated_exponent;
  TrimAndCut(buffer, exponent, copy_buffer, kMaxSignificantDecimalDigits,
             &trimmed, &updated_exponent);
  exponent = updated_exponent;
  return StrtofTrimmed(trimmed, exponent);
}

StrtofTrimmed()

float double_conversion::StrtofTrimmed	(	Vector< const char >	trimmed,
		int	exponent
	)

Definition at line 531 of file strtod.cc.

                                                              {
  DOUBLE_CONVERSION_ASSERT(trimmed.length() <= kMaxSignificantDecimalDigits);
  DOUBLE_CONVERSION_ASSERT(AssertTrimmedDigits(trimmed));
 
  double double_guess;
  bool is_correct = ComputeGuess(trimmed, exponent, &double_guess);
 
  float float_guess = SanitizedDoubletof(double_guess);
  if (float_guess == double_guess) {
    // This shortcut triggers for integer values.
    return float_guess;
  }
 
  // We must catch double-rounding. Say the double has been rounded up, and is
  // now a boundary of a float, and rounds up again. This is why we have to
  // look at previous too.
  // Example (in decimal numbers):
  //    input: 12349
  //    high-precision (4 digits): 1235
  //    low-precision (3 digits):
  //       when read from input: 123
  //       when rounded from high precision: 124.
  // To do this we simply look at the neighbors of the correct result and see
  // if they would round to the same float. If the guess is not correct we have
  // to look at four values (since two different doubles could be the correct
  // double).
 
  double double_next = Double(double_guess).NextDouble();
  double double_previous = Double(double_guess).PreviousDouble();
 
  float f1 = SanitizedDoubletof(double_previous);
  float f2 = float_guess;
  float f3 = SanitizedDoubletof(double_next);
  float f4;
  if (is_correct) {
    f4 = f3;
  } else {
    double double_next2 = Double(double_next).NextDouble();
    f4 = SanitizedDoubletof(double_next2);
  }
  (void) f2;  // Mark variable as used.
  DOUBLE_CONVERSION_ASSERT(f1 <= f2 && f2 <= f3 && f3 <= f4);
 
  // If the guess doesn't lie near a single-precision boundary we can simply
  // return its float-value.
  if (f1 == f4) {
    return float_guess;
  }
 
  DOUBLE_CONVERSION_ASSERT((f1 != f2 && f2 == f3 && f3 == f4) ||
         (f1 == f2 && f2 != f3 && f3 == f4) ||
         (f1 == f2 && f2 == f3 && f3 != f4));
 
  // guess and next are the two possible candidates (in the same way that
  // double_guess was the lower candidate for a double-precision guess).
  float guess = f1;
  float next = f4;
  DiyFp upper_boundary;
  if (guess == 0.0f) {
    float min_float = 1e-45f;
    upper_boundary = Double(static_cast<double>(min_float) / 2).AsDiyFp();
  } else {
    upper_boundary = Single(guess).UpperBoundary();
  }
  int comparison = CompareBufferWithDiyFp(trimmed, exponent, upper_boundary);
  if (comparison < 0) {
    return guess;
  } else if (comparison > 0) {
    return next;
  } else if ((Single(guess).Significand() & 1) == 0) {
    // Round towards even.
    return guess;
  } else {
    return next;
  }
}

TrimAndCut()

static void double_conversion::TrimAndCut ( Vector< const char >  buffer, int  exponent, char *  buffer_copy_space, int  space_size, Vector< const char > *  trimmed, int *  updated_exponent  )

static

Definition at line 126 of file strtod.cc.

                                                                           {
  Vector<const char> left_trimmed = TrimLeadingZeros(buffer);
  Vector<const char> right_trimmed = TrimTrailingZeros(left_trimmed);
  exponent += left_trimmed.length() - right_trimmed.length();
  if (right_trimmed.length() > kMaxSignificantDecimalDigits) {
    (void) space_size;  // Mark variable as used.
    DOUBLE_CONVERSION_ASSERT(space_size >= kMaxSignificantDecimalDigits);
    CutToMaxSignificantDigits(right_trimmed, exponent,
                              buffer_copy_space, updated_exponent);
    *trimmed = Vector<const char>(buffer_copy_space,
                                 kMaxSignificantDecimalDigits);
  } else {
    *trimmed = right_trimmed;
    *updated_exponent = exponent;
  }
}

TrimLeadingZeros()

static Vector< const char > double_conversion::TrimLeadingZeros ( Vector< const char >  buffer )

static

Definition at line 95 of file strtod.cc.

                                                                      {
  for (int i = 0; i < buffer.length(); i++) {
    if (buffer[i] != '0') {
      return buffer.SubVector(i, buffer.length());
    }
  }
  return Vector<const char>(buffer.start(), 0);
}

TrimTrailingZeros()

Vector< const char > double_conversion::TrimTrailingZeros ( Vector< const char >  buffer )

inline

Definition at line 53 of file strtod.h.

                                                                       {
  for (int i = buffer.length() - 1; i >= 0; --i) {
    if (buffer[i] != '0') {
      return buffer.SubVector(0, i + 1);
    }
  }
  return Vector<const char>(buffer.start(), 0);
}

TrimZeros()

static void double_conversion::TrimZeros ( Vector< char >  buffer, int *  length, int *  decimal_point  )

static

Definition at line 292 of file fixed-dtoa.cc.

                                                                            {
  while (*length > 0 && buffer[(*length) - 1] == '0') {
    (*length)--;
  }
  int first_non_zero = 0;
  while (first_non_zero < *length && buffer[first_non_zero] == '0') {
    first_non_zero++;
  }
  if (first_non_zero != 0) {
    for (int i = first_non_zero; i < *length; ++i) {
      buffer[i - first_non_zero] = buffer[i];
    }
    *length -= first_non_zero;
    *decimal_point -= first_non_zero;
  }
}

uint32_to_float()

static float double_conversion::uint32_to_float ( uint32_t  d32 )

static

Definition at line 39 of file ieee.h.

{ return BitCast<float>(d32); }

uint64_to_double()

static double double_conversion::uint64_to_double ( uint64_t  d64 )

static

Definition at line 37 of file ieee.h.

{ return BitCast<double>(d64); }

Variable Documentation

kDoubleSignificandSize

const int double_conversion::kDoubleSignificandSize = 53

static

Definition at line 117 of file fixed-dtoa.cc.

kFastDtoaMaximalLength

const int double_conversion::kFastDtoaMaximalLength = 17

static

Definition at line 49 of file fast-dtoa.h.

kFastDtoaMaximalSingleLength

const int double_conversion::kFastDtoaMaximalSingleLength = 9

static

Definition at line 51 of file fast-dtoa.h.

kMaxDecimalPower

const int double_conversion::kMaxDecimalPower = 309

static

Definition at line 53 of file strtod.cc.

kMaximalTargetExponent

const int double_conversion::kMaximalTargetExponent = -32

static

Definition at line 43 of file fast-dtoa.cc.

kMaxSignificantDecimalDigits

const int double_conversion::kMaxSignificantDecimalDigits = 780

static

Definition at line 93 of file strtod.cc.

kMaxSignificantDigits

const int double_conversion::kMaxSignificantDigits = 772

Definition at line 109 of file string-to-double.cc.

kMaxUint64

const uint64_t double_conversion::kMaxUint64 = DOUBLE_CONVERSION_UINT64_2PART_C(0xFFFFFFFF, FFFFFFFF)

static

Definition at line 57 of file strtod.cc.

kMaxUint64DecimalDigits

const int double_conversion::kMaxUint64DecimalDigits = 19

static

Definition at line 45 of file strtod.cc.

kMinDecimalPower

const int double_conversion::kMinDecimalPower = -324

static

Definition at line 54 of file strtod.cc.

kMinimalTargetExponent

const int double_conversion::kMinimalTargetExponent = -60

static

Definition at line 42 of file fast-dtoa.cc.

kSmallPowersOfTen

unsigned int const double_conversion::kSmallPowersOfTen[]

static

Initial value:

=
    {0, 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
     1000000000}

Definition at line 236 of file fast-dtoa.cc.

kWhitespaceTable16

const uc16 double_conversion::kWhitespaceTable16[]

static

Initial value:

= {
  160, 8232, 8233, 5760, 6158, 8192, 8193, 8194, 8195,
  8196, 8197, 8198, 8199, 8200, 8201, 8202, 8239, 8287, 12288, 65279
}

Definition at line 116 of file string-to-double.cc.

kWhitespaceTable16Length

const int double_conversion::kWhitespaceTable16Length = DOUBLE_CONVERSION_ARRAY_SIZE(kWhitespaceTable16)

static

Definition at line 120 of file string-to-double.cc.

kWhitespaceTable7

const char double_conversion::kWhitespaceTable7[] = { 32, 13, 10, 9, 11, 12 }

static

Definition at line 112 of file string-to-double.cc.

kWhitespaceTable7Length

const int double_conversion::kWhitespaceTable7Length = DOUBLE_CONVERSION_ARRAY_SIZE(kWhitespaceTable7)

static

Definition at line 113 of file string-to-double.cc.