funcdata.hh File Reference

Utilities for processing data structures associated with a single function. More...

#include "architecture.hh"
#include "override.hh"
#include "heritage.hh"
#include "merge.hh"
#include "dynamic.hh"

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Classes
class	Funcdata
	Container for data structures associated with a single function. More...
class	PcodeEmitFd
	A p-code emitter for building PcodeOp objects. More...
class	AncestorRealistic
	Helper class for determining if Varnodes can trace their value from a legitimate source. More...

Functions
int4	opFlipInPlaceTest (PcodeOp *op, vector< PcodeOp * > &fliplist)
	Trace a boolean value to a set of PcodeOps that can be changed to flip the boolean value. More...
void	opFlipInPlaceExecute (Funcdata &data, vector< PcodeOp * > &fliplist)
	Perform op-code flips (in-place) to change a boolean value. More...
PcodeOp *	earliestUseInBlock (Varnode *vn, BlockBasic *bl)
	Get the earliest use/read of a Varnode in a specified basic block. More...
PcodeOp *	cseFindInBlock (PcodeOp *op, Varnode *vn, BlockBasic *bl, PcodeOp *earliest)
	Find a duplicate calculation of a given PcodeOp reading a specific Varnode. More...
PcodeOp *	cseElimination (Funcdata &data, PcodeOp *op1, PcodeOp *op2)
	Perform a Common Subexpression Elimination step. More...
void	cseEliminateList (Funcdata &data, vector< pair< uintm, PcodeOp * > > &list, vector< Varnode * > &outlist)
	Perform Common Subexpression Elimination on a list of Varnode descendants. More...

Detailed Description

Utilities for processing data structures associated with a single function.

Function Documentation

cseEliminateList()

void cseEliminateList	(	Funcdata &	data,
		vector< pair< uintm, PcodeOp * > > &	list,
		vector< Varnode * > &	outlist
	)

Perform Common Subexpression Elimination on a list of Varnode descendants.

The list consists of PcodeOp descendants of a single Varnode paired with a hash value. The hash serves as a primary test for duplicate calculations; if it doesn't match the PcodeOps aren't common subexpressions. This method searches for hash matches then does secondary testing and eliminates any redundancy it finds.

Parameters

data	is the function being modified
list	is the list of (hash, PcodeOp) pairs
outlist	will hold Varnodes produced by duplicate calculations

cseElimination()

PcodeOp* cseElimination	(	Funcdata &	data,
		PcodeOp *	op1,
		PcodeOp *	op2
	)

Perform a Common Subexpression Elimination step.

Assuming the two given PcodeOps perform the identical operation on identical operands (depth 1 functional equivalence) eliminate the redundancy. Return the remaining (dominating) PcodeOp. If neither op dominates the other, both are eliminated, and a new PcodeOp is built at a commonly accessible point.

Parameters

data	is the function being modified
op1	is the first of the given PcodeOps
op2	is the second given PcodeOp

Returns

the dominating PcodeOp

cseFindInBlock()

PcodeOp* cseFindInBlock	(	PcodeOp *	op,
		Varnode *	vn,
		BlockBasic *	bl,
		PcodeOp *	earliest
	)

Find a duplicate calculation of a given PcodeOp reading a specific Varnode.

We only match 1 level of calculation. Additionally the duplicate must occur in the indicated basic block, earlier than a specified op.

Parameters

op	is the given PcodeOp
vn	is the specific Varnode that must be involved in the calculation
bl	is the indicated basic block
earliest	is the specified op to be earlier than

Returns

the discovered duplicate PcodeOp or NULL

earliestUseInBlock()

PcodeOp* earliestUseInBlock	(	Varnode *	vn,
		BlockBasic *	bl
	)

Get the earliest use/read of a Varnode in a specified basic block.

Parameters

vn	is the Varnode to search for
bl	is the specified basic block in which to search

Returns

the earliest PcodeOp reading the Varnode or NULL

opFlipInPlaceExecute()

void opFlipInPlaceExecute	(	Funcdata &	data,
		vector< PcodeOp * > &	fliplist
	)

Perform op-code flips (in-place) to change a boolean value.

The precomputed list of PcodeOps have their op-codes modified to facilitate the flip.

Parameters

data	is the function being modified
fliplist	is the list of PcodeOps to modify

opFlipInPlaceTest()

int4 opFlipInPlaceTest	(	PcodeOp *	op,
		vector< PcodeOp * > &	fliplist
	)

Trace a boolean value to a set of PcodeOps that can be changed to flip the boolean value.

The boolean Varnode is either the output of the given PcodeOp or the first input if the PcodeOp is a CBRANCH. The list of ops that need flipping is returned in an array

Parameters

op	is the given PcodeOp
fliplist	is the array that will hold the ops to flip

Returns

0 if the change normalizes, 1 if the change is ambivalent, 2 if the change does not normalize