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

Inheritance diagram for ghidra::RulePopcountBoolXor:

Public Member Functions
	RulePopcountBoolXor (const string &g)
	Constructor.

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 ghidra::Rule
	Rule (const string &g, uint4 fl, const string &nm)
	Construct given group, properties name. More...

virtual	~Rule (void)
	Destructor.

const string &	getName (void) const
	Return the name of this Rule.

const string &	getGroup (void) const
	Return the group this Rule belongs to.

uint4	getNumTests (void)
	Get number of attempted applications.

uint4	getNumApply (void)
	Get number of successful applications.

void	setBreak (uint4 tp)
	Set a breakpoint on this Rule.

void	clearBreak (uint4 tp)
	Clear a breakpoint on this Rule.

void	clearBreakPoints (void)
	Clear all breakpoints on this Rule.

void	turnOnWarnings (void)
	Enable warnings for this Rule.

void	turnOffWarnings (void)
	Disable warnings for this Rule.

bool	isDisabled (void) const
	Return true if this Rule is disabled.

void	setDisable (void)
	Disable this Rule (within its pool)

void	clearDisable (void)
	Enable this Rule (within its pool)

bool	checkActionBreak (void)
	Check if an action breakpoint is turned on. More...

uint4	getBreakPoint (void) const
	Return breakpoint toggles.

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 ghidra::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 ghidra::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 ghidra::Rule.

References ghidra::Varnode::beginDescend(), ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INT_AND, ghidra::CPUI_INT_XOR, ghidra::Varnode::endDescend(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getNZMask(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::getOut(), ghidra::Varnode::getSize(), ghidra::Varnode::isConstant(), ghidra::Varnode::isWritten(), ghidra::Funcdata::newConstant(), ghidra::Funcdata::opRemoveInput(), ghidra::Funcdata::opSetInput(), and ghidra::Funcdata::opSetOpcode().

◆ clone()

virtual Rule* ghidra::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 ghidra::Rule.

References ghidra::ActionGroupList::contains(), and ghidra::AddTreeState::data.

◆ getBooleanResult()

Varnode * ghidra::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