This class observes instruction insertions/removals. More...

Inheritance diagram for llvm::InstructionSelect::MIIteratorMaintainer:

Public Member Functions
void	MF_HandleInsertion (MachineInstr &MI) override
	Callback after an insertion. This should not modify the MI directly.

void	MF_HandleRemoval (MachineInstr &MI) override
	Callback before a removal. This should not modify the MI directly.

void	reportFullyCreatedInstrs ()

Public Member Functions inherited from llvm::MachineFunction::Delegate
virtual	~Delegate ()=default

virtual void	MF_HandleInsertion (MachineInstr &MI)=0
	Callback after an insertion. This should not modify the MI directly.

virtual void	MF_HandleRemoval (MachineInstr &MI)=0
	Callback before a removal. This should not modify the MI directly.

virtual void	MF_HandleChangeDesc (MachineInstr &MI, const MCInstrDesc &TID)
	Callback before changing MCInstrDesc.

Public Attributes
MachineBasicBlock::reverse_iterator	MII

Detailed Description

This class observes instruction insertions/removals.

InstructionSelect stores an iterator of the instruction prior to the one that is currently being selected to determine which instruction to select next. Previously this meant that selecting multiple instructions at once was illegal behavior due to potential invalidation of this iterator. This is a non-obvious limitation for selector implementers. Therefore, to allow deletion of arbitrary instructions, we detect this case and continue selection with the predecessor of the deleted instruction.

Definition at line 78 of file InstructionSelect.cpp.