Package org.apache.sysds.utils

Interface DoubleParser

public interface DoubleParser

A fast double parser inspired from https://github.com/wrandelshofer/FastDoubleParser

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	DoubleParser.UInt128

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DOUBLE_EXPONENT_BIAS
static final int	DOUBLE_MAX_EXPONENT_POWER_OF_TEN
static final int	DOUBLE_MAX_EXPONENT_POWER_OF_TWO
static final int	DOUBLE_MIN_EXPONENT_POWER_OF_TEN
static final double[]	DOUBLE_POWERS_OF_TEN
static final int	DOUBLE_SIGNIFICAND_WIDTH
static final String	ILLEGAL_OFFSET_OR_ILLEGAL_LENGTH
static final long[]	MANTISSA_64	When mapping numbers from decimal to binary, we go from w * 10^q to m * 2^p, but we have 10^q = 5^q * 2^q, so effectively we are trying to match w * 2^q * 5^q to m * 2^p.
static final int	MAX_EXPONENT_NUMBER
static final long	MINIMAL_NINETEEN_DIGIT_INTEGER
static final String	SYNTAX_ERROR

Method Summary

Static Methods

Modifier and Type	Method	Description
static double	parseFloatingPointLiteral(String str, int offset, int endIndex)
static long	unsignedMultiplyHigh(long x, long y)

Field Details

MAX_EXPONENT_NUMBER

static final int MAX_EXPONENT_NUMBER

See Also:

• Constant Field Values

ILLEGAL_OFFSET_OR_ILLEGAL_LENGTH

static final String ILLEGAL_OFFSET_OR_ILLEGAL_LENGTH

See Also:

• Constant Field Values

SYNTAX_ERROR

static final String SYNTAX_ERROR

See Also:

• Constant Field Values

MINIMAL_NINETEEN_DIGIT_INTEGER

static final long MINIMAL_NINETEEN_DIGIT_INTEGER

See Also:

• Constant Field Values

DOUBLE_MIN_EXPONENT_POWER_OF_TEN

static final int DOUBLE_MIN_EXPONENT_POWER_OF_TEN

See Also:

• Constant Field Values

DOUBLE_MAX_EXPONENT_POWER_OF_TEN

static final int DOUBLE_MAX_EXPONENT_POWER_OF_TEN

See Also:

• Constant Field Values

DOUBLE_SIGNIFICAND_WIDTH

static final int DOUBLE_SIGNIFICAND_WIDTH

See Also:

• Constant Field Values

DOUBLE_POWERS_OF_TEN

static final double[] DOUBLE_POWERS_OF_TEN

DOUBLE_MAX_EXPONENT_POWER_OF_TWO

static final int DOUBLE_MAX_EXPONENT_POWER_OF_TWO

See Also:

• Constant Field Values

DOUBLE_EXPONENT_BIAS

static final int DOUBLE_EXPONENT_BIAS

See Also:

• Constant Field Values

MANTISSA_64

static final long[] MANTISSA_64

When mapping numbers from decimal to binary, we go from w * 10^q to m * 2^p, but we have 10^q = 5^q * 2^q, so effectively we are trying to match w * 2^q * 5^q to m * 2^p.

Thus, the powers of two are not a concern since they can be represented exactly using the binary notation, only the powers of five affect the binary significand.

The mantissas of powers of ten from -308 to 308, extended out to sixty-four bits. The array contains the powers of ten approximated as a 64-bit mantissa. It goes from 10^-325 to 10^308 (inclusively). The mantissa is truncated, and never rounded up. Uses about 5 KB.

 long getMantissaHigh(int q) {
  MANTISSA_64[q - SMALLEST_POWER_OF_TEN];
 }
 

Method Details

parseFloatingPointLiteral

static double parseFloatingPointLiteral(String str,
 int offset,
 int endIndex)

unsignedMultiplyHigh

static long unsignedMultiplyHigh(long x,
 long y)