Utilities for manipulating generated AVR machine code. More...

#include "Target/AVR/MCTargetDesc/AVRAsmBackend.h"

Inheritance diagram for llvm::AVRAsmBackend:

Public Member Functions
	AVRAsmBackend (Triple::OSType OSType)

void	adjustFixupValue (const MCFixup &Fixup, const MCValue &Target, uint64_t &Value, MCContext *Ctx=nullptr) const

std::unique_ptr< MCObjectTargetWriter >	createObjectTargetWriter () const override

void	applyFixup (const MCAssembler &Asm, const MCFixup &Fixup, const MCValue &Target, MutableArrayRef< char > Data, uint64_t Value, bool IsResolved, const MCSubtargetInfo *STI) const override
	Apply the `Value` for given `Fixup` into the provided data fragment, at the offset specified by the fixup and following the fixup kind as appropriate.

std::optional< MCFixupKind >	getFixupKind (StringRef Name) const override
	Map a relocation name used in .reloc to a fixup kind.

const MCFixupKindInfo &	getFixupKindInfo (MCFixupKind Kind) const override
	Get information on a fixup kind.

unsigned	getNumFixupKinds () const override
	Get the number of target specific fixup kinds.

bool	fixupNeedsRelaxation (const MCFixup &Fixup, uint64_t Value, const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const override
	Simple predicate for targets where !Resolved implies requiring relaxation.

bool	writeNopData (raw_ostream &OS, uint64_t Count, const MCSubtargetInfo *STI) const override
	Write an (optimal) nop sequence of Count bytes to the given output.

bool	shouldForceRelocation (const MCAssembler &Asm, const MCFixup &Fixup, const MCValue &Target, const MCSubtargetInfo *STI) override
	Hook to check if a relocation is needed for some target specific reason.

Public Member Functions inherited from llvm::MCAsmBackend
	MCAsmBackend (const MCAsmBackend &)=delete

MCAsmBackend &	operator= (const MCAsmBackend &)=delete

virtual	~MCAsmBackend ()

virtual bool	allowAutoPadding () const
	Return true if this target might automatically pad instructions and thus need to emit padding enable/disable directives around sensative code.

virtual bool	allowEnhancedRelaxation () const
	Return true if this target allows an unrelaxable instruction to be emitted into RelaxableFragment and then we can increase its size in a tricky way for optimization.

virtual void	emitInstructionBegin (MCObjectStreamer &OS, const MCInst &Inst, const MCSubtargetInfo &STI)
	Give the target a chance to manipulate state related to instruction alignment (e.g.

virtual void	emitInstructionEnd (MCObjectStreamer &OS, const MCInst &Inst)

virtual void	reset ()
	lifetime management

std::unique_ptr< MCObjectWriter >	createObjectWriter (raw_pwrite_stream &OS) const
	Create a new MCObjectWriter instance for use by the assembler backend to emit the final object file.

std::unique_ptr< MCObjectWriter >	createDwoObjectWriter (raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS) const
	Create an MCObjectWriter that writes two object files: a .o file which is linked into the final program and a .dwo file which is used by debuggers.

virtual std::unique_ptr< MCObjectTargetWriter >	createObjectTargetWriter () const =0

virtual unsigned	getMinimumNopSize () const
	Returns the minimum size of a nop in bytes on this target.

virtual unsigned	getMaximumNopSize (const MCSubtargetInfo &STI) const
	Returns the maximum size of a nop in bytes on this target.

virtual bool	writeNopData (raw_ostream &OS, uint64_t Count, const MCSubtargetInfo *STI) const =0
	Write an (optimal) nop sequence of Count bytes to the given output.

virtual void	finishLayout (MCAssembler const &Asm, MCAsmLayout &Layout) const
	Give backend an opportunity to finish layout after relaxation.

virtual void	handleAssemblerFlag (MCAssemblerFlag Flag)
	Handle any target-specific assembler flags. By default, do nothing.

virtual uint32_t	generateCompactUnwindEncoding (const MCDwarfFrameInfo FI, const MCContext Ctxt) const
	Generate the compact unwind encoding for the CFI instructions.

virtual bool	isMicroMips (const MCSymbol *Sym) const
	Check whether a given symbol has been flagged with MICROMIPS flag.

bool	isDarwinCanonicalPersonality (const MCSymbol *Sym) const

virtual bool	shouldInsertExtraNopBytesForCodeAlign (const MCAlignFragment &AF, unsigned &Size)
	Hook to check if extra nop bytes must be inserted for alignment directive.

virtual bool	shouldInsertFixupForCodeAlign (MCAssembler &Asm, const MCAsmLayout &Layout, MCAlignFragment &AF)
	Hook which indicates if the target requires a fixup to be generated when handling an align directive in an executable section.

virtual bool	evaluateTargetFixup (const MCAssembler &Asm, const MCAsmLayout &Layout, const MCFixup &Fixup, const MCFragment DF, const MCValue &Target, const MCSubtargetInfo STI, uint64_t &Value, bool &WasForced)

virtual bool	handleAddSubRelocations (const MCAsmLayout &Layout, const MCFragment &F, const MCFixup &Fixup, const MCValue &Target, uint64_t &FixedValue) const

virtual bool	mayNeedRelaxation (const MCInst &Inst, const MCSubtargetInfo &STI) const
	Check whether the given instruction may need relaxation.

virtual bool	fixupNeedsRelaxationAdvanced (const MCFixup &Fixup, bool Resolved, uint64_t Value, const MCRelaxableFragment *DF, const MCAsmLayout &Layout, const bool WasForced) const
	Target specific predicate for whether a given fixup requires the associated instruction to be relaxed.

virtual void	relaxInstruction (MCInst &Inst, const MCSubtargetInfo &STI) const
	Relax the instruction in the given fragment to the next wider instruction.

virtual bool	relaxDwarfLineAddr (MCDwarfLineAddrFragment &DF, MCAsmLayout &Layout, bool &WasRelaxed) const

virtual bool	relaxDwarfCFA (MCDwarfCallFrameFragment &DF, MCAsmLayout &Layout, bool &WasRelaxed) const

virtual std::pair< bool, bool >	relaxLEB128 (MCLEBFragment &LF, MCAsmLayout &Layout, int64_t &Value) const

Additional Inherited Members
Public Attributes inherited from llvm::MCAsmBackend
const llvm::endianness	Endian

const unsigned	RelaxFixupKind
	Fixup kind used for linker relaxation. Currently only used by RISC-V.

Protected Member Functions inherited from llvm::MCAsmBackend
	MCAsmBackend (llvm::endianness Endian, unsigned RelaxFixupKind=MaxFixupKind)

Detailed Description

Utilities for manipulating generated AVR machine code.

Definition at line 29 of file AVRAsmBackend.h.

Constructor & Destructor Documentation

◆ AVRAsmBackend()

llvm::AVRAsmBackend::AVRAsmBackend ( Triple::OSType OSType )

inline

Definition at line 31 of file AVRAsmBackend.h.

Member Function Documentation

◆ adjustFixupValue()

void llvm::AVRAsmBackend::adjustFixupValue	(	const MCFixup &	Fixup,
		const MCValue &	Target,
		uint64_t &	Value,
		MCContext *	Ctx = `nullptr`
	)		const

Definition at line 252 of file AVRAsmBackend.cpp.

References adjust::ldi::fixup(), Fixup, adjust::fixup_13_pcrel(), llvm::AVR::fixup_13_pcrel, llvm::AVR::fixup_16, llvm::AVR::fixup_16_pm, adjust::fixup_6(), llvm::AVR::fixup_6, adjust::fixup_6_adiw(), llvm::AVR::fixup_6_adiw, adjust::fixup_7_pcrel(), llvm::AVR::fixup_7_pcrel, adjust::fixup_call(), llvm::AVR::fixup_call, llvm::AVR::fixup_hh8_ldi, llvm::AVR::fixup_hh8_ldi_neg, llvm::AVR::fixup_hh8_ldi_pm, llvm::AVR::fixup_hh8_ldi_pm_neg, llvm::AVR::fixup_hi8_ldi, llvm::AVR::fixup_hi8_ldi_gs, llvm::AVR::fixup_hi8_ldi_neg, llvm::AVR::fixup_hi8_ldi_pm, llvm::AVR::fixup_hi8_ldi_pm_neg, llvm::AVR::fixup_ldi, adjust::fixup_lds_sts_16(), llvm::AVR::fixup_lds_sts_16, llvm::AVR::fixup_lo8_ldi, llvm::AVR::fixup_lo8_ldi_gs, llvm::AVR::fixup_lo8_ldi_neg, llvm::AVR::fixup_lo8_ldi_pm, llvm::AVR::fixup_lo8_ldi_pm_neg, llvm::AVR::fixup_ms8_ldi, llvm::AVR::fixup_ms8_ldi_neg, adjust::fixup_port5(), llvm::AVR::fixup_port5, adjust::fixup_port6(), llvm::AVR::fixup_port6, llvm::FK_Data_1, llvm::FK_Data_2, llvm::FK_Data_4, llvm::FK_Data_8, llvm::FK_GPRel_4, getFixupKindInfo(), adjust::ldi::hh8(), adjust::ldi::hi8(), llvm_unreachable, adjust::ldi::lo8(), adjust::ldi::ms8(), adjust::ldi::neg(), adjust::pm(), Size, llvm::MCFixupKindInfo::TargetSize, and adjust::unsigned_width().

Referenced by applyFixup().

◆ applyFixup()

void llvm::AVRAsmBackend::applyFixup	(	const MCAssembler &	Asm,
		const MCFixup &	Fixup,
		const MCValue &	Target,
		MutableArrayRef< char >	Data,
		uint64_t	Value,
		bool	IsResolved,
		const MCSubtargetInfo *	STI
	)		const

overridevirtual

Apply the Value for given Fixup into the provided data fragment, at the offset specified by the fixup and following the fixup kind as appropriate.

Errors (such as an out of range fixup value) should be reported via Ctx. The STI is present only for fragments of type MCRelaxableFragment and MCDataFragment with hasInstructions() == true.

Implements llvm::MCAsmBackend.

Definition at line 378 of file AVRAsmBackend.cpp.

References adjustFixupValue(), assert(), llvm::Data, llvm::FirstLiteralRelocationKind, Fixup, getFixupKindInfo(), Info, and llvm::Offset.