LLVM  14.0.0git
Public Member Functions | List of all members
llvm::AVRAsmBackend Class Reference

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

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

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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< MCObjectTargetWritercreateObjectTargetWriter () 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. More...
 
const MCFixupKindInfogetFixupKindInfo (MCFixupKind Kind) const override
 Get information on a fixup kind. More...
 
unsigned getNumFixupKinds () const override
 Get the number of target specific fixup kinds. More...
 
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. More...
 
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. More...
 
bool shouldForceRelocation (const MCAssembler &Asm, const MCFixup &Fixup, const MCValue &Target) override
 Hook to check if a relocation is needed for some target specific reason. More...
 
- Public Member Functions inherited from llvm::MCAsmBackend
 MCAsmBackend (const MCAsmBackend &)=delete
 
MCAsmBackendoperator= (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. More...
 
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. More...
 
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. More...
 
virtual void emitInstructionEnd (MCObjectStreamer &OS, const MCInst &Inst)
 
virtual void reset ()
 lifetime management More...
 
std::unique_ptr< MCObjectWritercreateObjectWriter (raw_pwrite_stream &OS) const
 Create a new MCObjectWriter instance for use by the assembler backend to emit the final object file. More...
 
std::unique_ptr< MCObjectWritercreateDwoObjectWriter (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. More...
 
virtual unsigned getMinimumNopSize () const
 Returns the minimum size of a nop in bytes on this target. More...
 
virtual unsigned getMaximumNopSize (const MCSubtargetInfo &STI) const
 Returns the maximum size of a nop in bytes on this target. More...
 
virtual void finishLayout (MCAssembler const &Asm, MCAsmLayout &Layout) const
 Give backend an opportunity to finish layout after relaxation. More...
 
virtual void handleAssemblerFlag (MCAssemblerFlag Flag)
 Handle any target-specific assembler flags. By default, do nothing. More...
 
virtual uint32_t generateCompactUnwindEncoding (ArrayRef< MCCFIInstruction >) const
 Generate the compact unwind encoding for the CFI instructions. More...
 
virtual bool isMicroMips (const MCSymbol *Sym) const
 Check whether a given symbol has been flagged with MICROMIPS flag. More...
 
virtual Optional< MCFixupKindgetFixupKind (StringRef Name) const
 Map a relocation name used in .reloc to a fixup kind. More...
 
virtual bool shouldInsertExtraNopBytesForCodeAlign (const MCAlignFragment &AF, unsigned &Size)
 Hook to check if extra nop bytes must be inserted for alignment directive. More...
 
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. More...
 
virtual bool evaluateTargetFixup (const MCAssembler &Asm, const MCAsmLayout &Layout, const MCFixup &Fixup, const MCFragment *DF, const MCValue &Target, uint64_t &Value, bool &WasForced)
 
virtual bool mayNeedRelaxation (const MCInst &Inst, const MCSubtargetInfo &STI) const
 Check whether the given instruction may need relaxation. More...
 
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. More...
 
virtual void relaxInstruction (MCInst &Inst, const MCSubtargetInfo &STI) const
 Relax the instruction in the given fragment to the next wider instruction. More...
 
virtual bool relaxDwarfLineAddr (MCDwarfLineAddrFragment &DF, MCAsmLayout &Layout, bool &WasRelaxed) const
 
virtual bool relaxDwarfCFA (MCDwarfCallFrameFragment &DF, MCAsmLayout &Layout, bool &WasRelaxed) const
 

Additional Inherited Members

- Public Attributes inherited from llvm::MCAsmBackend
const support::endianness Endian
 
- Protected Member Functions inherited from llvm::MCAsmBackend
 MCAsmBackend (support::endianness Endian)
 

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

◆ 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 364 of file AVRAsmBackend.cpp.

References adjustFixupValue(), llvm::HexStyle::Asm, assert(), llvm::Data, Fixup, getFixupKindInfo(), i, Info, and Offset.

◆ createObjectTargetWriter()

std::unique_ptr< MCObjectTargetWriter > llvm::AVRAsmBackend::createObjectTargetWriter ( ) const
overridevirtual

◆ fixupNeedsRelaxation()

bool llvm::AVRAsmBackend::fixupNeedsRelaxation ( const MCFixup Fixup,
uint64_t  Value,
const MCRelaxableFragment DF,
const MCAsmLayout Layout 
) const
inlineoverridevirtual

Simple predicate for targets where !Resolved implies requiring relaxation.

Implements llvm::MCAsmBackend.

Definition at line 51 of file AVRAsmBackend.h.

References llvm_unreachable.

◆ getFixupKindInfo()

const MCFixupKindInfo & llvm::AVRAsmBackend::getFixupKindInfo ( MCFixupKind  Kind) const
overridevirtual

◆ getNumFixupKinds()

unsigned llvm::AVRAsmBackend::getNumFixupKinds ( ) const
inlineoverridevirtual

Get the number of target specific fixup kinds.

Implements llvm::MCAsmBackend.

Definition at line 47 of file AVRAsmBackend.h.

References llvm::AVR::NumTargetFixupKinds.

Referenced by getFixupKindInfo().

◆ shouldForceRelocation()

bool llvm::AVRAsmBackend::shouldForceRelocation ( const MCAssembler Asm,
const MCFixup Fixup,
const MCValue Target 
)
overridevirtual

Hook to check if a relocation is needed for some target specific reason.

Reimplemented from llvm::MCAsmBackend.

Definition at line 472 of file AVRAsmBackend.cpp.

References Fixup, llvm::AVR::fixup_13_pcrel, llvm::AVR::fixup_7_pcrel, and llvm::AVR::fixup_call.

◆ writeNopData()

bool llvm::AVRAsmBackend::writeNopData ( raw_ostream OS,
uint64_t  Count,
const MCSubtargetInfo STI 
) const
overridevirtual

Write an (optimal) nop sequence of Count bytes to the given output.

If the target cannot generate such a sequence, it should return an error.

Returns
- True on success.

Implements llvm::MCAsmBackend.

Definition at line 461 of file AVRAsmBackend.cpp.

References assert(), and llvm::raw_ostream::write_zeros().


The documentation for this class was generated from the following files: