RuleDivTermAdd Class Reference

Simplify expressions associated with optimized division expressions. More...

Inheritance diagram for RuleDivTermAdd:

Public Member Functions
virtual Rule *	clone (const ActionGroupList &grouplist) const
	Clone the Rule. More...
virtual void	getOpList (vector< uint4 > &oplist) const
	List of op codes this rule operates on. More...
virtual int4	applyOp (PcodeOp *op, Funcdata &data)
	Attempt to apply this Rule. More...
Public Member Functions inherited from Rule
	Rule (const string &g, uint4 fl, const string &nm)
	Construct given group, properties name. More...
bool	checkActionBreak (void)
	Check if an action breakpoint is turned on. More...
virtual void	reset (Funcdata &data)
	Reset this Rule. More...
virtual void	resetStats (void)
	Reset Rule statistics. More...
virtual void	printStatistics (ostream &s) const
	Print statistics for this Rule. More...

Static Public Member Functions
static PcodeOp *	findSubshift (PcodeOp *op, int4 &n, OpCode &shiftopc)
	Check for shift form of expression. More...

Additional Inherited Members
Public Types inherited from Rule
enum	typeflags { type_disable = 1, rule_debug = 2, warnings_on = 4, warnings_given = 8 }
	Properties associated with a Rule. More...

Detailed Description

Simplify expressions associated with optimized division expressions.

The form looks like:

• sub(ext(V)*c,b)>>d + V -> sub( (ext(V)*(c+2^n))>>n,0)

where n = d + b*8, and the left-shift signedness (if it exists) matches the extension signedness.

Member Function Documentation

applyOp()

int4 RuleDivTermAdd::applyOp ( PcodeOp *  op, Funcdata &  data  )

virtual

Attempt to apply this Rule.

This method contains the main logic for applying the Rule. It must use a given PcodeOp as the point at which the Rule applies. If it does apply, changes are made directly to the function and 1 (non-zero) is returned, otherwise 0 is returned.

Parameters

op	is the given PcodeOp where the Rule may apply
data	is the function to which to apply

Reimplemented from Rule.

References CPUI_INT_ADD, CPUI_INT_MULT, CPUI_INT_RIGHT, CPUI_INT_SEXT, CPUI_INT_SRIGHT, CPUI_INT_ZEXT, CPUI_MAX, CPUI_SUBPIECE, findSubshift(), Funcdata::newConstant(), Funcdata::newOp(), Funcdata::newUniqueOut(), Funcdata::opInsertBefore(), Funcdata::opSetInput(), Funcdata::opSetOpcode(), and signbit_negative().

clone()

virtual Rule* RuleDivTermAdd::clone ( const ActionGroupList &  grouplist ) const

inlinevirtual

Clone the Rule.

If this Rule is a member of one of the groups in the grouplist, this returns a clone of the Rule, otherwise NULL is returned.

Parameters

grouplist

is the list of groups being cloned

Returns

the cloned Rule or NULL

Implements Rule.

References ActionGroupList::contains().

findSubshift()

PcodeOp * RuleDivTermAdd::findSubshift ( PcodeOp *  op, int4 &  n, OpCode &  shiftopc  )

static

Check for shift form of expression.

Look for the two forms:

• sub(V,c) or
• sub(V,c) >> n

Pass back whether a shift was involved and the total truncation in bits: n+c*8

Parameters

op	is the root of the expression
n	is the reference that will hold the total truncation
shiftopc	will hold the shift OpCode if used, CPUI_MAX otherwise

Returns

the SUBPIECE op if present or NULL otherwise

References CPUI_MAX, and CPUI_SUBPIECE.

Referenced by applyOp().

getOpList()

void RuleDivTermAdd::getOpList ( vector< uint4 > &  oplist ) const

virtual

List of op codes this rule operates on.

Populate the given array with all possible OpCodes this Rule might apply to. By default, this method returns all possible OpCodes

Parameters

oplist

is the array to populate

Reimplemented from Rule.

References CPUI_INT_RIGHT, CPUI_INT_SRIGHT, and CPUI_SUBPIECE.

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

• ruleaction.hh
• ruleaction.cc