LLVM  8.0.0svn
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llvm::AVRAsmBackend Class Reference

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

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

Inheritance diagram for llvm::AVRAsmBackend:
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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 mayNeedRelaxation (const MCInst &Inst, const MCSubtargetInfo &STI) const override
 Check whether the given instruction may need relaxation. 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...
 
void relaxInstruction (const MCInst &Inst, const MCSubtargetInfo &STI, MCInst &Res) const override
 Relax the instruction in the given fragment to the next wider instruction. More...
 
bool writeNopData (raw_ostream &OS, uint64_t Count) 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 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 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...
 
void handleCodePaddingBasicBlockStart (MCObjectStreamer *OS, const MCCodePaddingContext &Context)
 Handles all target related code padding when starting to write a new basic block to an object file. More...
 
void handleCodePaddingBasicBlockEnd (const MCCodePaddingContext &Context)
 Handles all target related code padding after writing a block to an object file. More...
 
void handleCodePaddingInstructionBegin (const MCInst &Inst)
 Handles all target related code padding before writing a new instruction to an object file. More...
 
void handleCodePaddingInstructionEnd (const MCInst &Inst)
 Handles all target related code padding after writing an instruction to an object file. More...
 
bool relaxFragment (MCPaddingFragment *PF, MCAsmLayout &Layout)
 Relaxes a fragment (changes the size of the padding) according to target requirements. More...
 
virtual Optional< MCFixupKindgetFixupKind (StringRef Name) const
 Map a relocation name used in .reloc to a fixup kind. More...
 
virtual bool requiresDiffExpressionRelocations () const
 Check whether the given target requires emitting differences of two symbols as a set of relocations. 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...
 

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 32 of file AVRAsmBackend.h.

Constructor & Destructor Documentation

◆ AVRAsmBackend()

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

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 360 of file AVRAsmBackend.cpp.

References adjustFixupValue(), assert(), llvm::MCAssembler::getContext(), llvm::MCFixup::getKind(), llvm::MCFixup::getOffset(), llvm::ArrayRef< T >::size(), llvm::MCFixupKindInfo::TargetOffset, and llvm::MCFixupKindInfo::TargetSize.

Referenced by AVRAsmBackend().

◆ 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 59 of file AVRAsmBackend.h.

References llvm_unreachable.

◆ getFixupKindInfo()

MCFixupKindInfo const & 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 50 of file AVRAsmBackend.h.

References llvm::AVR::NumTargetFixupKinds.

◆ mayNeedRelaxation()

bool llvm::AVRAsmBackend::mayNeedRelaxation ( const MCInst Inst,
const MCSubtargetInfo STI 
) const
inlineoverridevirtual

Check whether the given instruction may need relaxation.

Parameters
Inst- The instruction to test.
STI- The MCSubtargetInfo in effect when the instruction was encoded.

Implements llvm::MCAsmBackend.

Definition at line 54 of file AVRAsmBackend.h.

◆ relaxInstruction()

void llvm::AVRAsmBackend::relaxInstruction ( const MCInst Inst,
const MCSubtargetInfo STI,
MCInst Res 
) const
inlineoverridevirtual

Relax the instruction in the given fragment to the next wider instruction.

Parameters
InstThe instruction to relax, which may be the same as the output.
STIthe subtarget information for the associated instruction.
[out]ResOn return, the relaxed instruction.

Implements llvm::MCAsmBackend.

Definition at line 66 of file AVRAsmBackend.h.

References shouldForceRelocation(), and writeNopData().

◆ 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 467 of file AVRAsmBackend.cpp.

References adjust::fixup_13_pcrel(), adjust::fixup_7_pcrel(), adjust::fixup_call(), and llvm::MCFixup::getKind().

Referenced by relaxInstruction().

◆ writeNopData()

bool llvm::AVRAsmBackend::writeNopData ( raw_ostream OS,
uint64_t  Count 
) 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 457 of file AVRAsmBackend.cpp.

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

Referenced by relaxInstruction().


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