LocARNA::TaintedInftyInt Class Reference

#include <infty_int.hh>

Inheritance diagram for LocARNA::TaintedInftyInt:

Public Types
typedef long int	base_type
	the base type

Public Member Functions
	TaintedInftyInt ()
	Construct empty.
	TaintedInftyInt (const base_type &x)
	Construct from base type. More...
bool	is_neg_infty () const
bool	is_pos_infty () const
bool	is_finite () const
bool	is_normal () const
base_type	finite_value () const
	Convert finite value to base type. More...
TaintedInftyInt &	operator= (const FiniteInt &x)
	Assignment. More...

Static Public Member Functions
static base_type	min_finite ()
	minimum finite value More...
static base_type	max_finite ()
	maximum finite value More...

Protected Attributes
base_type	val
	value

Static Protected Attributes
static const base_type	min_finity = std::numeric_limits<TaintedInftyInt::base_type>::min()/5
	minimum finite value
static const base_type	max_finity = -(std::numeric_limits<TaintedInftyInt::base_type>::min()/5)-1
	maximum finite value
static const base_type	min_normal_neg_infty = std::numeric_limits<TaintedInftyInt::base_type>::min()/5 * 3
	minimum normal infinite value
static const base_type	max_normal_pos_infty = -(std::numeric_limits<TaintedInftyInt::base_type>::min()/5 * 3) -1
	maximum normal infinite value

Friends
class	InftyInt
bool	operator== (const TaintedInftyInt &x, const TaintedInftyInt &y)
	Equality test. More...
TaintedInftyInt	operator+ (const TaintedInftyInt &x, const FiniteInt &y)
	Add. More...
TaintedInftyInt	operator- (const TaintedInftyInt &x, const FiniteInt &y)
	Subtract. More...
TaintedInftyInt	operator+ (const InftyInt &x, const InftyInt &y)
	Add. More...
TaintedInftyInt	operator- (const InftyInt &x, const InftyInt &y)
	Subtract. More...
TaintedInftyInt	min (const TaintedInftyInt &x, const TaintedInftyInt &y)
	Minimum. More...
TaintedInftyInt	max (const TaintedInftyInt &x, const TaintedInftyInt &y)
	Maximum. More...
bool	operator> (const TaintedInftyInt &x, const TaintedInftyInt &y)
bool	operator< (const TaintedInftyInt &x, const TaintedInftyInt &y)
bool	operator>= (const TaintedInftyInt &x, const TaintedInftyInt &y)
bool	operator<= (const TaintedInftyInt &x, const TaintedInftyInt &y)
std::ostream &	operator<< (std::ostream &out, const TaintedInftyInt &x)

Detailed Description

Potentially infinite value where finite values are integer. In contrast to class NormInfyInt, the representation of infinity can be denormalized, this means that it is not safe (and therefore not supported) to subtract or add a second potentially infinite value. In general, such non-normalized potentially infinite integers are produced as results of adding/subtracting normal potentially infinite integers.

The infinity integer classes TaintedInftyInt, InftyInt and FiniteInt support efficient addition and minimization/maximization of potentially infinite integer values. For this purpose, the range of the base type (long int) is restricted. With this encoding, two normal infinite values (InftyInt) of the same sign can be added without resulting in overflow. This yields a non-normal TaintedInftyInt, which still allows to add finite integers (FiniteInt) without overflow (at least as long as the added finite integers do not exceed the remaining range of [-m..m-1]), where m=2^(s-1) and s is the width of the base type, e.g. 64.

The range of the base type is split into subranges, where s is the number of bits in the base type:

negative infinity [ -m..-m/5 [ normal negative infinity [ -3m/5..-m/5 [ normalized negative infinity -2m/5 finite range [ -m/5 .. m/5 [ normal positive infinity [ m/5 .. 3m/5 [ normalized positive infinity 2m/5 positive infinity [ m/5 .. m [

Normalizing resets negative infinite values to -2m/5 and positive infinite values to 2m/5. In this way, adding two normalized infinite values of the same sign and some finite value using fast standard integer addition always works without overflow and results in a defined value in the infinite range.

Constructor & Destructor Documentation

LocARNA::TaintedInftyInt::TaintedInftyInt ( const base_type &  x )

inlineexplicit

Construct from base type.

Parameters

x	base type value

Member Function Documentation

base_type LocARNA::TaintedInftyInt::finite_value ( ) const

inline

Convert finite value to base type.

Returns

value

Precondition

is finite

bool LocARNA::TaintedInftyInt::is_finite ( ) const

inline

Test for finite

Returns

whether object has a finite value

bool LocARNA::TaintedInftyInt::is_neg_infty ( ) const

inline

Test for negative infinity

Returns

whether object represents negative infinity

bool LocARNA::TaintedInftyInt::is_normal ( ) const

inline

Test for finite or normal infinity

Returns

whether object is in the range of normal infinity (or finite)

bool LocARNA::TaintedInftyInt::is_pos_infty ( ) const

inline

Test for positive infinity

Returns

whether object represents positive infinity

static base_type LocARNA::TaintedInftyInt::max_finite ( )

inlinestatic

maximum finite value

Returns

maximum finite value

static base_type LocARNA::TaintedInftyInt::min_finite ( )

inlinestatic

minimum finite value

Returns

minimum finite value

TaintedInftyInt & LocARNA::TaintedInftyInt::operator= ( const FiniteInt &  x )

inline

Assignment.

Parameters

x	finite int to be assigned

Returns

*this

Friends And Related Function Documentation

TaintedInftyInt max ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Maximum.

Parameters

x	operand 1
y	operand 2

Returns

max of x and y

TaintedInftyInt min ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Minimum.

Parameters

x	operand 1
y	operand 2

Returns

min of x and y

TaintedInftyInt operator+ ( const TaintedInftyInt &  x, const FiniteInt &  y  )

friend

Add.

Parameters

x	operand 1
y	operand 2

Returns

x plus y

TaintedInftyInt operator+ ( const InftyInt &  x, const InftyInt &  y  )

friend

Add.

Parameters

x	operand 1
y	operand 2

Returns

x plus y

TaintedInftyInt operator- ( const TaintedInftyInt &  x, const FiniteInt &  y  )

friend

Subtract.

Parameters

x	operand 1
y	operand 2

Returns

x minus y

TaintedInftyInt operator- ( const InftyInt &  x, const InftyInt &  y  )

friend

Subtract.

Parameters

x	operand 1
y	operand 2

Returns

x minus y

bool operator< ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Less than operator

Parameters

x	operand 1
y	operand 2

Returns

whether x is less than y

Note

The result is undefined when comparing infinte values of the same sign.

std::ostream& operator<< ( std::ostream &  out, const TaintedInftyInt &  x  )

friend

Write TaintedInftyInt object to stream

Parameters

out	output stream
x	object

Returns

output stream after writing

Output operator for writing object of TaintedInftyInt to output stream

Parameters

out	the output stream
x	the object to be written

Returns

output stream after writing x

bool operator<= ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Less or equal than operator

Parameters

x	operand 1
y	operand 2

Returns

whether x is less or equal than y

Note

The result is undefined when comparing infinte values of the same sign.

bool operator== ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Equality test.

Parameters

x	operand 1 (tainted)
y	operand 2 (tainted)

Returns

whether x equals y

bool operator> ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Greater than operator

Parameters

x	operand 1
y	operand 2

Returns

whether x is greater than y

Note

The result is undefined when comparing infinte values of the same sign.

bool operator>= ( const TaintedInftyInt &  x, const TaintedInftyInt &  y  )

friend

Greater or equal than operator

Parameters

x	operand 1
y	operand 2

Returns

whether x is greater or equal than y

Note

The result is undefined when comparing infinte values of the same sign.

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

• src/LocARNA/infty_int.hh
• src/LocARNA/infty_int.cc