DoubleBits manipulates Double numbers by using bit manipulation and bit-field extraction. More...
#include <DoubleBits.h>
Public Member Functions | |
DoubleBits (double nx) | |
double | getDouble () const |
int64 | biasedExponent () const |
Determines the exponent for the number. | |
int | getExponent () const |
Determines the exponent for the number. | |
void | zeroLowerBits (int nBits) |
int | getBit (int i) const |
int | numCommonMantissaBits (const DoubleBits &db) const |
This computes the number of common most-significant bits in the mantissa. | |
std::string | toString () const |
A representation of the Double bits formatted for easy readability. | |
Static Public Member Functions | |
static double | powerOf2 (int exp) |
static int | exponent (double d) |
static double | truncateToPowerOfTwo (double d) |
static std::string | toBinaryString (double d) |
static double | maximumCommonMantissa (double d1, double d2) |
Static Public Attributes | |
static const int | EXPONENT_BIAS = 1023 |
DoubleBits manipulates Double numbers by using bit manipulation and bit-field extraction.
For some operations (such as determining the exponent) this is more accurate than using mathematical operations (which suffer from round-off error).
The algorithms and constants in this class apply only to IEEE-754 double-precision floating point format.
int geos::index::quadtree::DoubleBits::numCommonMantissaBits | ( | const DoubleBits & | db | ) | const |
This computes the number of common most-significant bits in the mantissa.
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.
db |