RulePopcountBoolXor Class Reference

Simplify boolean expressions that are combined through POPCOUNT. More...

Inheritance diagram for RulePopcountBoolXor:

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 Varnode *	getBooleanResult (Varnode *vn, int4 bitPos, int4 &constRes)
	Extract boolean Varnode producing bit at given Varnode and position. 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 boolean expressions that are combined through POPCOUNT.

Expressions involving boolean values (b1 and b2) are converted, such as:

• popcount((b1 << 6) | (b2 << 2)) & 1 => b1 ^ b2

Member Function Documentation

applyOp()

int4 RulePopcountBoolXor::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_COPY, CPUI_INT_AND, CPUI_INT_XOR, leastsigbit_set(), mostsigbit_set(), Funcdata::newConstant(), Funcdata::opRemoveInput(), Funcdata::opSetInput(), Funcdata::opSetOpcode(), and popcount().

clone()

virtual Rule* RulePopcountBoolXor::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().

getBooleanResult()

Varnode * RulePopcountBoolXor::getBooleanResult ( Varnode *  vn, int4  bitPos, int4 &  constRes  )

static

Extract boolean Varnode producing bit at given Varnode and position.

The boolean value may be shifted, extended and combined with other booleans through a series of operations. We return the Varnode that is the actual result of the boolean operation. If the given Varnode is constant, return null but pass back whether the given bit position is 0 or 1. If no boolean value can be found, return null and pass back -1.

Parameters

vn	is the given Varnode containing the extended/shifted boolean
bitPos	is the bit position of the desired boolean value
constRes	is used to pass back a constant boolean result

Returns

the boolean Varnode producing the desired value or null

References CPUI_INT_AND, CPUI_INT_LEFT, CPUI_INT_OR, CPUI_INT_RIGHT, CPUI_INT_SEXT, CPUI_INT_SRIGHT, CPUI_INT_XOR, CPUI_INT_ZEXT, CPUI_PIECE, and CPUI_SUBPIECE.

getOpList()

void RulePopcountBoolXor::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_POPCOUNT.

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

• ruleaction.hh
• ruleaction.cc