DIExpressionOptimizer.cpp File Reference

#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/IR/DebugInfoMetadata.h"

Go to the source code of this file.

Functions
static std::optional< uint64_t >	isConstantVal (DIExpression::ExprOperand Op)
	Returns true if the Op is a DW_OP_constu.
static bool	isNeutralElement (uint64_t Op, uint64_t Val)
	Returns true if an operation and operand result in a No Op.
static std::optional< uint64_t >	foldOperationIfPossible (uint64_t Const1, uint64_t Const2, dwarf::LocationAtom Operator)
	Try to fold Const1 and Const2 by applying Operator and returning the result, if there is an overflow, return a std::nullopt.
static bool	operationsAreFoldableAndCommutative (dwarf::LocationAtom Operator1, dwarf::LocationAtom Operator2)
	Returns true if the two operations Operator1 and Operator2 are commutative and can be folded.
static void	consumeOneOperator (DIExpressionCursor &Cursor, uint64_t &Loc, const DIExpression::ExprOperand &Op)
	Consume one operator and its operand(s).
void	startFromBeginning (uint64_t &Loc, DIExpressionCursor &Cursor, ArrayRef< uint64_t > WorkingOps)
	Reset the Cursor to the beginning of the WorkingOps.
static SmallVector< uint64_t >	canonicalizeDwarfOperations (ArrayRef< uint64_t > WorkingOps)
	This function will canonicalize:
static SmallVector< uint64_t >	optimizeDwarfOperations (ArrayRef< uint64_t > WorkingOps)
	This function will convert:
static bool	tryFoldNoOpMath (uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t &Loc, DIExpressionCursor &Cursor, SmallVectorImpl< uint64_t > &WorkingOps)
	{DW_OP_constu, 0, DW_OP_[plus, minus, shl, shr]} -> {} {DW_OP_constu, 1, DW_OP_[mul, div]} -> {}
static bool	tryFoldConstants (uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t &Loc, DIExpressionCursor &Cursor, SmallVectorImpl< uint64_t > &WorkingOps)
	{DW_OP_constu, Const1, DW_OP_constu, Const2, DW_OP_[plus, minus, mul, div, shl, shr] -> {DW_OP_constu, Const1 [+, -, *, /, <<, >>] Const2}
static bool	tryFoldCommutativeMath (uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t &Loc, DIExpressionCursor &Cursor, SmallVectorImpl< uint64_t > &WorkingOps)
	{DW_OP_constu, Const1, DW_OP_[plus, mul], DW_OP_constu, Const2, DW_OP_[plus, mul]} -> {DW_OP_constu, Const1 [+, *] Const2, DW_OP_[plus, mul]}
static bool	tryFoldCommutativeMathWithArgInBetween (uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t &Loc, DIExpressionCursor &Cursor, SmallVectorImpl< uint64_t > &WorkingOps)
	{DW_OP_constu, Const1, DW_OP_[plus, mul], DW_OP_LLVM_arg, Arg1, DW_OP_[plus, mul], DW_OP_constu, Const2, DW_OP_[plus, mul]} -> {DW_OP_constu, Const1 [+, *] Const2, DW_OP_[plus, mul], DW_OP_LLVM_arg, Arg1, DW_OP_[plus, mul]}

Function Documentation

canonicalizeDwarfOperations()

SmallVector< uint64_t > canonicalizeDwarfOperations ( ArrayRef< uint64_t > WorkingOps )

static

This function will canonicalize:

1. DW_OP_plus_uconst to DW_OP_constu <const-val> DW_OP_plus
2. DW_OP_lit<n> to DW_OP_constu <n>

Expression has no operations, break.

Definition at line 115 of file DIExpressionOptimizer.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::ArrayRef< T >::begin(), consumeOneOperator(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::ArrayRef< T >::size().

Referenced by llvm::DIExpression::foldConstantMath().

consumeOneOperator()

void consumeOneOperator ( DIExpressionCursor & Cursor, uint64_t & Loc, const DIExpression::ExprOperand & Op )

static

Consume one operator and its operand(s).

Definition at line 98 of file DIExpressionOptimizer.cpp.

Referenced by canonicalizeDwarfOperations(), llvm::DIExpression::foldConstantMath(), optimizeDwarfOperations(), tryFoldCommutativeMath(), tryFoldCommutativeMathWithArgInBetween(), and tryFoldConstants().

foldOperationIfPossible()

std::optional< uint64_t > foldOperationIfPossible ( uint64_t Const1, uint64_t Const2, dwarf::LocationAtom Operator )

static

Try to fold Const1 and Const2 by applying Operator and returning the result, if there is an overflow, return a std::nullopt.

Definition at line 45 of file DIExpressionOptimizer.cpp.

References llvm::countl_zero(), llvm::countr_zero(), llvm::SaturatingAdd(), and llvm::SaturatingMultiply().

Referenced by tryFoldCommutativeMath(), tryFoldCommutativeMathWithArgInBetween(), and tryFoldConstants().

isConstantVal()

std::optional< uint64_t > isConstantVal ( DIExpression::ExprOperand Op )

static

Returns true if the Op is a DW_OP_constu.

Definition at line 20 of file DIExpressionOptimizer.cpp.

Referenced by llvm::DIExpression::foldConstantMath(), tryFoldCommutativeMath(), tryFoldCommutativeMathWithArgInBetween(), and tryFoldConstants().

isNeutralElement()

bool isNeutralElement ( uint64_t Op, uint64_t Val )

static

Returns true if an operation and operand result in a No Op.

Definition at line 27 of file DIExpressionOptimizer.cpp.

Referenced by tryFoldNoOpMath().

operationsAreFoldableAndCommutative()

bool operationsAreFoldableAndCommutative ( dwarf::LocationAtom Operator1, dwarf::LocationAtom Operator2 )

static

Returns true if the two operations Operator1 and Operator2 are commutative and can be folded.

Definition at line 91 of file DIExpressionOptimizer.cpp.

Referenced by tryFoldCommutativeMath(), and tryFoldCommutativeMathWithArgInBetween().

optimizeDwarfOperations()

SmallVector< uint64_t > optimizeDwarfOperations ( ArrayRef< uint64_t > WorkingOps )

static

This function will convert:

1. DW_OP_constu <const-val> DW_OP_plus to DW_OP_plus_uconst
2. DW_OP_constu, 0 to DW_OP_lit0

Expression has no operations, exit.

Expression has no more operations, copy into ResultOps and exit.

Definition at line 150 of file DIExpressionOptimizer.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::ArrayRef< T >::begin(), consumeOneOperator(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::ArrayRef< T >::size().

Referenced by llvm::DIExpression::foldConstantMath().

startFromBeginning()

void startFromBeginning	(	uint64_t &	Loc,
		DIExpressionCursor &	Cursor,
		ArrayRef< uint64_t >	WorkingOps )

Reset the Cursor to the beginning of the WorkingOps.

Definition at line 105 of file DIExpressionOptimizer.cpp.

Referenced by tryFoldCommutativeMath(), tryFoldCommutativeMathWithArgInBetween(), tryFoldConstants(), and tryFoldNoOpMath().

tryFoldCommutativeMath()

bool tryFoldCommutativeMath ( uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t & Loc, DIExpressionCursor & Cursor, SmallVectorImpl< uint64_t > & WorkingOps )

static

{DW_OP_constu, Const1, DW_OP_[plus, mul], DW_OP_constu, Const2, DW_OP_[plus, mul]} -> {DW_OP_constu, Const1 [+, *] Const2, DW_OP_[plus, mul]}

Definition at line 234 of file DIExpressionOptimizer.cpp.

References AbstractManglingParser< Derived, Alloc >::Ops, llvm::SmallVectorTemplateCommon< T, typename >::begin(), consumeOneOperator(), llvm::SmallVectorImpl< T >::erase(), foldOperationIfPossible(), isConstantVal(), operationsAreFoldableAndCommutative(), and startFromBeginning().

Referenced by llvm::DIExpression::foldConstantMath().

tryFoldCommutativeMathWithArgInBetween()

bool tryFoldCommutativeMathWithArgInBetween ( uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t & Loc, DIExpressionCursor & Cursor, SmallVectorImpl< uint64_t > & WorkingOps )

static

{DW_OP_constu, Const1, DW_OP_[plus, mul], DW_OP_LLVM_arg, Arg1, DW_OP_[plus, mul], DW_OP_constu, Const2, DW_OP_[plus, mul]} -> {DW_OP_constu, Const1 [+, *] Const2, DW_OP_[plus, mul], DW_OP_LLVM_arg, Arg1, DW_OP_[plus, mul]}

Definition at line 262 of file DIExpressionOptimizer.cpp.

References AbstractManglingParser< Derived, Alloc >::Ops, llvm::SmallVectorTemplateCommon< T, typename >::begin(), consumeOneOperator(), llvm::dwarf::DW_OP_LLVM_arg, llvm::SmallVectorImpl< T >::erase(), foldOperationIfPossible(), isConstantVal(), operationsAreFoldableAndCommutative(), and startFromBeginning().

Referenced by llvm::DIExpression::foldConstantMath().

tryFoldConstants()

bool tryFoldConstants ( uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t & Loc, DIExpressionCursor & Cursor, SmallVectorImpl< uint64_t > & WorkingOps )

static

{DW_OP_constu, Const1, DW_OP_constu, Const2, DW_OP_[plus, minus, mul, div, shl, shr] -> {DW_OP_constu, Const1 [+, -, *, /, <<, >>] Const2}

Definition at line 209 of file DIExpressionOptimizer.cpp.

References AbstractManglingParser< Derived, Alloc >::Ops, llvm::SmallVectorTemplateCommon< T, typename >::begin(), consumeOneOperator(), llvm::SmallVectorImpl< T >::erase(), foldOperationIfPossible(), isConstantVal(), and startFromBeginning().

Referenced by llvm::DIExpression::foldConstantMath().

tryFoldNoOpMath()

bool tryFoldNoOpMath ( uint64_t Const1, ArrayRef< DIExpression::ExprOperand > Ops, uint64_t & Loc, DIExpressionCursor & Cursor, SmallVectorImpl< uint64_t > & WorkingOps )

static

{DW_OP_constu, 0, DW_OP_[plus, minus, shl, shr]} -> {} {DW_OP_constu, 1, DW_OP_[mul, div]} -> {}

Definition at line 193 of file DIExpressionOptimizer.cpp.

References AbstractManglingParser< Derived, Alloc >::Ops, llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::SmallVectorImpl< T >::erase(), isNeutralElement(), and startFromBeginning().

Referenced by llvm::DIExpression::foldConstantMath().