GEOS  3.13.0dev
Public Member Functions | Static Public Member Functions | List of all members
geos::precision::CommonBits Class Reference

Determines the maximum number of common most-significant bits in the mantissa of one or numbers. More...

#include <CommonBits.h>

Public Member Functions

void add (double num)
 
double getCommon ()
 

Static Public Member Functions

static int64_t signExpBits (int64_t num)
 Computes the bit pattern for the sign and exponent of a double-precision number. More...
 
static int numCommonMostSigMantissaBits (int64_t num1, int64_t num2)
 This computes the number of common most-significant bits in the mantissas of two double-precision numbers. More...
 
static int64_t zeroLowerBits (int64_t bits, int nBits)
 Zeroes the lower n bits of a bitstring. More...
 
static int getBit (int64_t bits, int i)
 Extracts the i'th bit of a bitstring. More...
 

Detailed Description

Determines the maximum number of common most-significant bits in the mantissa of one or numbers.

Can be used to compute the double-precision number which is represented by the common bits. If there are no common bits, the number computed is 0.0.

Member Function Documentation

◆ getBit()

static int geos::precision::CommonBits::getBit ( int64_t  bits,
int  i 
)
static

Extracts the i'th bit of a bitstring.

Parameters
bitsthe bitstring to extract from
ithe bit to extract
Returns
the value of the extracted bit

◆ numCommonMostSigMantissaBits()

static int geos::precision::CommonBits::numCommonMostSigMantissaBits ( int64_t  num1,
int64_t  num2 
)
static

This computes the number of common most-significant bits in the mantissas of two double-precision numbers.

It does not count the hidden bit, which is always 1. It does not determine whether the numbers have the same exponent - if they do not, the value computed by this function is meaningless.

Parameters
num1
num2
Returns
the number of common most-significant mantissa bits

◆ signExpBits()

static int64_t geos::precision::CommonBits::signExpBits ( int64_t  num)
static

Computes the bit pattern for the sign and exponent of a double-precision number.

Parameters
num
Returns
the bit pattern for the sign and exponent

◆ zeroLowerBits()

static int64_t geos::precision::CommonBits::zeroLowerBits ( int64_t  bits,
int  nBits 
)
static

Zeroes the lower n bits of a bitstring.

Parameters
bitsthe bitstring to alter
nBitsthe number of bits to zero
Returns
the zeroed bitstring

The documentation for this class was generated from the following file: