retdec
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Optimizes the structure of if statements. More...
#include <if_structure_optimizer.h>
Public Member Functions | |
IfStructureOptimizer (ShPtr< Module > module) | |
Constructs a new optimizer. More... | |
virtual std::string | getId () const override |
Returns the ID of the optimizer. More... | |
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Optimizer (ShPtr< Module > module) | |
Constructs a new optimizer. More... | |
ShPtr< Module > | optimize () |
Performs all the optimizations of the specific optimizer. More... | |
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virtual void | visit (ShPtr< GlobalVarDef > varDef) override |
virtual void | visit (ShPtr< Function > func) override |
virtual void | visit (ShPtr< AssignStmt > stmt) override |
virtual void | visit (ShPtr< BreakStmt > stmt) override |
virtual void | visit (ShPtr< CallStmt > stmt) override |
virtual void | visit (ShPtr< ContinueStmt > stmt) override |
virtual void | visit (ShPtr< EmptyStmt > stmt) override |
virtual void | visit (ShPtr< ForLoopStmt > stmt) override |
virtual void | visit (ShPtr< UForLoopStmt > stmt) override |
virtual void | visit (ShPtr< GotoStmt > stmt) override |
virtual void | visit (ShPtr< ReturnStmt > stmt) override |
virtual void | visit (ShPtr< SwitchStmt > stmt) override |
virtual void | visit (ShPtr< UnreachableStmt > stmt) override |
virtual void | visit (ShPtr< VarDefStmt > stmt) override |
virtual void | visit (ShPtr< WhileLoopStmt > stmt) override |
virtual void | visit (ShPtr< AddOpExpr > expr) override |
virtual void | visit (ShPtr< AddressOpExpr > expr) override |
virtual void | visit (ShPtr< AndOpExpr > expr) override |
virtual void | visit (ShPtr< ArrayIndexOpExpr > expr) override |
virtual void | visit (ShPtr< AssignOpExpr > expr) override |
virtual void | visit (ShPtr< BitAndOpExpr > expr) override |
virtual void | visit (ShPtr< BitOrOpExpr > expr) override |
virtual void | visit (ShPtr< BitShlOpExpr > expr) override |
virtual void | visit (ShPtr< BitShrOpExpr > expr) override |
virtual void | visit (ShPtr< BitXorOpExpr > expr) override |
virtual void | visit (ShPtr< CallExpr > expr) override |
virtual void | visit (ShPtr< CommaOpExpr > expr) override |
virtual void | visit (ShPtr< DerefOpExpr > expr) override |
virtual void | visit (ShPtr< DivOpExpr > expr) override |
virtual void | visit (ShPtr< EqOpExpr > expr) override |
virtual void | visit (ShPtr< GtEqOpExpr > expr) override |
virtual void | visit (ShPtr< GtOpExpr > expr) override |
virtual void | visit (ShPtr< LtEqOpExpr > expr) override |
virtual void | visit (ShPtr< LtOpExpr > expr) override |
virtual void | visit (ShPtr< ModOpExpr > expr) override |
virtual void | visit (ShPtr< MulOpExpr > expr) override |
virtual void | visit (ShPtr< NegOpExpr > expr) override |
virtual void | visit (ShPtr< NeqOpExpr > expr) override |
virtual void | visit (ShPtr< NotOpExpr > expr) override |
virtual void | visit (ShPtr< OrOpExpr > expr) override |
virtual void | visit (ShPtr< StructIndexOpExpr > expr) override |
virtual void | visit (ShPtr< SubOpExpr > expr) override |
virtual void | visit (ShPtr< TernaryOpExpr > expr) override |
virtual void | visit (ShPtr< Variable > var) override |
virtual void | visit (ShPtr< BitCastExpr > expr) override |
virtual void | visit (ShPtr< ExtCastExpr > expr) override |
virtual void | visit (ShPtr< FPToIntCastExpr > expr) override |
virtual void | visit (ShPtr< IntToFPCastExpr > expr) override |
virtual void | visit (ShPtr< IntToPtrCastExpr > expr) override |
virtual void | visit (ShPtr< PtrToIntCastExpr > expr) override |
virtual void | visit (ShPtr< TruncCastExpr > expr) override |
virtual void | visit (ShPtr< ConstArray > constant) override |
virtual void | visit (ShPtr< ConstBool > constant) override |
virtual void | visit (ShPtr< ConstFloat > constant) override |
virtual void | visit (ShPtr< ConstInt > constant) override |
virtual void | visit (ShPtr< ConstNullPointer > constant) override |
virtual void | visit (ShPtr< ConstString > constant) override |
virtual void | visit (ShPtr< ConstStruct > constant) override |
virtual void | visit (ShPtr< ConstSymbol > constant) override |
virtual void | visit (ShPtr< ArrayType > type) override |
virtual void | visit (ShPtr< FloatType > type) override |
virtual void | visit (ShPtr< IntType > type) override |
virtual void | visit (ShPtr< PointerType > type) override |
virtual void | visit (ShPtr< StringType > type) override |
virtual void | visit (ShPtr< StructType > type) override |
virtual void | visit (ShPtr< FunctionType > type) override |
virtual void | visit (ShPtr< VoidType > type) override |
virtual void | visit (ShPtr< UnknownType > type) override |
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virtual | ~Visitor ()=default |
Private Member Functions | |
bool | tryOptimization1 (ShPtr< IfStmt > stmt) |
Tries the optimization (1) from the class description on stmt. More... | |
bool | tryOptimization2 (ShPtr< IfStmt > stmt) |
Tries the optimization (2) from the class description on stmt. More... | |
bool | tryOptimization3 (ShPtr< IfStmt > stmt) |
Tries the optimization (3) from the class description on stmt. More... | |
bool | tryOptimization4 (ShPtr< IfStmt > stmt) |
Tries the optimization (4) from the class description on stmt. More... | |
bool | tryOptimization5 (ShPtr< IfStmt > stmt) |
Tries the optimization (5) from the class description on stmt. More... | |
Visitor Interface | |
virtual void | visit (ShPtr< IfStmt > stmt) override |
virtual void | visit (ShPtr< GlobalVarDef > varDef) override |
virtual void | visit (ShPtr< Function > func) override |
virtual void | visit (ShPtr< AssignStmt > stmt) override |
virtual void | visit (ShPtr< BreakStmt > stmt) override |
virtual void | visit (ShPtr< CallStmt > stmt) override |
virtual void | visit (ShPtr< ContinueStmt > stmt) override |
virtual void | visit (ShPtr< EmptyStmt > stmt) override |
virtual void | visit (ShPtr< ForLoopStmt > stmt) override |
virtual void | visit (ShPtr< UForLoopStmt > stmt) override |
virtual void | visit (ShPtr< GotoStmt > stmt) override |
virtual void | visit (ShPtr< IfStmt > stmt) override |
virtual void | visit (ShPtr< ReturnStmt > stmt) override |
virtual void | visit (ShPtr< SwitchStmt > stmt) override |
virtual void | visit (ShPtr< UnreachableStmt > stmt) override |
virtual void | visit (ShPtr< VarDefStmt > stmt) override |
virtual void | visit (ShPtr< WhileLoopStmt > stmt) override |
virtual void | visit (ShPtr< AddOpExpr > expr) override |
virtual void | visit (ShPtr< AddressOpExpr > expr) override |
virtual void | visit (ShPtr< AndOpExpr > expr) override |
virtual void | visit (ShPtr< ArrayIndexOpExpr > expr) override |
virtual void | visit (ShPtr< AssignOpExpr > expr) override |
virtual void | visit (ShPtr< BitAndOpExpr > expr) override |
virtual void | visit (ShPtr< BitOrOpExpr > expr) override |
virtual void | visit (ShPtr< BitShlOpExpr > expr) override |
virtual void | visit (ShPtr< BitShrOpExpr > expr) override |
virtual void | visit (ShPtr< BitXorOpExpr > expr) override |
virtual void | visit (ShPtr< CallExpr > expr) override |
virtual void | visit (ShPtr< CommaOpExpr > expr) override |
virtual void | visit (ShPtr< DerefOpExpr > expr) override |
virtual void | visit (ShPtr< DivOpExpr > expr) override |
virtual void | visit (ShPtr< EqOpExpr > expr) override |
virtual void | visit (ShPtr< GtEqOpExpr > expr) override |
virtual void | visit (ShPtr< GtOpExpr > expr) override |
virtual void | visit (ShPtr< LtEqOpExpr > expr) override |
virtual void | visit (ShPtr< LtOpExpr > expr) override |
virtual void | visit (ShPtr< ModOpExpr > expr) override |
virtual void | visit (ShPtr< MulOpExpr > expr) override |
virtual void | visit (ShPtr< NegOpExpr > expr) override |
virtual void | visit (ShPtr< NeqOpExpr > expr) override |
virtual void | visit (ShPtr< NotOpExpr > expr) override |
virtual void | visit (ShPtr< OrOpExpr > expr) override |
virtual void | visit (ShPtr< StructIndexOpExpr > expr) override |
virtual void | visit (ShPtr< SubOpExpr > expr) override |
virtual void | visit (ShPtr< TernaryOpExpr > expr) override |
virtual void | visit (ShPtr< Variable > var) override |
virtual void | visit (ShPtr< BitCastExpr > expr) override |
virtual void | visit (ShPtr< ExtCastExpr > expr) override |
virtual void | visit (ShPtr< FPToIntCastExpr > expr) override |
virtual void | visit (ShPtr< IntToFPCastExpr > expr) override |
virtual void | visit (ShPtr< IntToPtrCastExpr > expr) override |
virtual void | visit (ShPtr< PtrToIntCastExpr > expr) override |
virtual void | visit (ShPtr< TruncCastExpr > expr) override |
virtual void | visit (ShPtr< ConstArray > constant) override |
virtual void | visit (ShPtr< ConstBool > constant) override |
virtual void | visit (ShPtr< ConstFloat > constant) override |
virtual void | visit (ShPtr< ConstInt > constant) override |
virtual void | visit (ShPtr< ConstNullPointer > constant) override |
virtual void | visit (ShPtr< ConstString > constant) override |
virtual void | visit (ShPtr< ConstStruct > constant) override |
virtual void | visit (ShPtr< ConstSymbol > constant) override |
virtual void | visit (ShPtr< ArrayType > type) override |
virtual void | visit (ShPtr< FloatType > type) override |
virtual void | visit (ShPtr< IntType > type) override |
virtual void | visit (ShPtr< PointerType > type) override |
virtual void | visit (ShPtr< StringType > type) override |
virtual void | visit (ShPtr< StructType > type) override |
virtual void | visit (ShPtr< FunctionType > type) override |
virtual void | visit (ShPtr< VoidType > type) override |
virtual void | visit (ShPtr< UnknownType > type) override |
Additional Inherited Members | |
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template<class OptimizerType , typename... Args> | |
static ShPtr< Module > | optimize (ShPtr< Module > module, Args &&... args) |
Creates an instance of OptimizerType with the given arguments and optimizes the given module by it. More... | |
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FuncOptimizer (ShPtr< Module > module) | |
Constructs a new function optimizer. More... | |
virtual void | doOptimization () override |
Performs the optimization on all functions in the module. More... | |
virtual void | runOnFunction (ShPtr< Function > func) |
Performs all optimizations on the given function. More... | |
template<typename T > | |
void | visitNestedAndSuccessorStatements (ShPtr< T > stmt) |
Visits the given statement, its nested statements, and successor statements (depending on the settings of the visitor). More... | |
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virtual void | doInitialization () |
Performs pre-optimization matters. More... | |
virtual void | doFinalization () |
Performs post-optimization matters. More... | |
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OrderedAllVisitor (bool visitSuccessors=true, bool visitNestedStmts=true) | |
Constructs a new visitor. More... | |
virtual void | visitStmt (ShPtr< Statement > stmt, bool visitSuccessors=true, bool visitNestedStmts=true) |
Visits the given statement, and possibly its successors or nested statements. More... | |
void | restart (bool visitSuccessors=true, bool visitNestedStmts=true) |
"Restarts" the visitor so it is in the state like it was when it was created. More... | |
bool | makeAccessedAndCheckIfAccessed (ShPtr< Type > type) |
Makes the given type accessed. More... | |
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Visitor ()=default | |
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ShPtr< Function > | currFunc |
Function that is currently being optimized. More... | |
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ShPtr< Module > | module |
The module that is being optimized. More... | |
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ShPtr< Statement > | lastStmt |
Statement that has been accessed as the last one. More... | |
StmtUSet | accessedStmts |
A set of all accessed statements. More... | |
TypeUSet | accessedTypes |
A set of all accessed types. More... | |
bool | visitSuccessors |
Should statements' successor be accessed? More... | |
bool | visitNestedStmts |
Should nested statements be accessed? More... | |
Optimizes the structure of if statements.
This optimization optimizes the structure of if statements. More specifically, it transforms if/else-if/else clauses so the resulting code become more readable.
The following transformations are performed:
(1) If there is an if-else statement, where the body of the if clause ends with a return or unreachable statement, then the body of the else clause can be put after the if statement and the else clause can be removed. For example, the following code
can be optimized into
(2) Similar to (1), but the return/unreachable statement is in the if clause. For example, the following code
can be optimized into
(3) To decrease the level of nesting, we transform every piece of code of the form
to
However, this is done only if (A) contains more statements than (B). In this way, a hierarchy of if statements like this
gets squeezed into a more readable form
(4) If there are two successive if statements with no else-if/else clauses and with identical bodies (both ending with a return/unreachable statement), the conditions may be joined by the or
operator, so only one if statement will remain (of course, their bodies are merged). For example, the following code
may be transformed into
(5) If there is an else clause with no statements, we can remove it. For example, the following code
may be transformed into
Instances of this class have reference object semantics.
This is a concrete optimizer which should not be subclassed.
Constructs a new optimizer.
[in] | module | Module to be optimized. |
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inlineoverridevirtual |
Returns the ID of the optimizer.
Implements retdec::llvmir2hll::Optimizer.
Tries the optimization (1) from the class description on stmt.
true
if stmt has been optimized, false
otherwise. Tries the optimization (2) from the class description on stmt.
true
if stmt has been optimized, false
otherwise. Tries the optimization (3) from the class description on stmt.
true
if stmt has been optimized, false
otherwise. Tries the optimization (4) from the class description on stmt.
true
if stmt has been optimized, false
otherwise. Tries the optimization (5) from the class description on stmt.
true
if stmt has been optimized, false
otherwise.
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Reimplemented from retdec::llvmir2hll::OrderedAllVisitor.
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