cetus.hir

Class RangeExpression

java.lang.Object

cetus.hir.Expression

cetus.hir.RangeExpression

All Implemented Interfaces:

Printable, Traversable, java.lang.Cloneable, java.lang.Comparable<Expression>

public class RangeExpression
extends Expression

RangeExpression represents a symbolic range with a lower bound expression and an upper bound expression. RangeAnalysis uses RangeExpression to compute a valid value ranges of variables at program points.

Constructor Summary

Constructors

Constructor and Description
RangeExpression(Expression lb, Expression ub) Constructs a range expression with the given lower and upper bounds.

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(Expression e) Compares the range expression with the specified expression for order.
static void	defaultPrint(RangeExpression e, java.io.PrintWriter o) Prints the range expression on the specified print writer.
Expression	getLB() Returns the lower bound of this range expression.
static Expression	getOmega() Returns a new instanceof omega expression which is [-inf:inf].
Expression	getSize() Returns the size of the span bounded by this range expression.
Expression	getUB() Returns the upper bound of this range expression.
boolean	isBounded() Returns true if neither lb nor ub is infinity.
boolean	isEmpty() Checks if this range expression has a lower bound greater than the upper bound.
boolean	isOmega() Checks if this range expression does not have any closed bounds.
void	setLB(Expression lb) Sets the lower bound with the specified expression.
void	setUB(Expression ub) Sets the upper bound with the specified expression.
Expression	toExpression() Converts this range expression to a non-range expression if the lower bound is equal to the upper bound.
static RangeExpression	toRange(Expression e) Converts an arbitrary expression to a range expression by setting the same lower bound and upper bound.
java.lang.String	toString() Returns a string representation of the range expression.

Methods inherited from class cetus.hir.Expression

clone, equals, findExpression, getChildren, getParent, getStatement, hashCode, needsParens, print, printSelf, removeChild, setChild, setParens, setParent, setPrintMethod, swapWith, verify

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

RangeExpression

public RangeExpression(Expression lb,
               Expression ub)

Constructs a range expression with the given lower and upper bounds.

Parameters:

lb - the lower bound expression.

ub - the upper bound expression.

Throws:

java.lang.IllegalArgumentException - if lb or ub is invalid.

NotAnOrphanException - if lb or ub has a parent.

Method Detail

defaultPrint

public static void defaultPrint(RangeExpression e,
                java.io.PrintWriter o)

Prints the range expression on the specified print writer.

toString

public java.lang.String toString()

Returns a string representation of the range expression. The returned string is equivalent to the printed stream through defaultPrint(cetus.hir.RangeExpression, java.io.PrintWriter).

Overrides:

toString in class Expression

Returns:

the string representation.

compareTo

public int compareTo(Expression e)

Compares the range expression with the specified expression for order.

Specified by:

compareTo in interface java.lang.Comparable<Expression>

Overrides:

compareTo in class Expression

Returns:

0 if they are equal, -1 otherwise.

setLB

public void setLB(Expression lb)

Sets the lower bound with the specified expression.

Parameters:

lb - the new lower bound.

Throws:

NotAnOrphanException - if lb has a parent.

setUB

public void setUB(Expression ub)

Sets the upper bound with the specified expression.

Parameters:

ub - the new upper bound

Throws:

NotAnOrphanException - if ub has a parent.

getLB

public Expression getLB()

Returns the lower bound of this range expression.

getUB

public Expression getUB()

Returns the upper bound of this range expression.

isEmpty

public boolean isEmpty()

Checks if this range expression has a lower bound greater than the upper bound. The comparison is possible only for literals and infinity expression.

isOmega

public boolean isOmega()

Checks if this range expression does not have any closed bounds.

isBounded

public boolean isBounded()

Returns true if neither lb nor ub is infinity.

toRange

public static RangeExpression toRange(Expression e)

Converts an arbitrary expression to a range expression by setting the same lower bound and upper bound.

toExpression

public Expression toExpression()

Converts this range expression to a non-range expression if the lower bound is equal to the upper bound.

getOmega

public static Expression getOmega()

Returns a new instanceof omega expression which is [-inf:inf].

Returns:

a new omega expression.

getSize

public Expression getSize()

Returns the size of the span bounded by this range expression.

Returns:

the resulting expression or null if not bounded.