LLVM  14.0.0git
Public Member Functions | Static Public Member Functions | List of all members
llvm::M68kFrameLowering Class Reference

#include "Target/M68k/M68kFrameLowering.h"

Inheritance diagram for llvm::M68kFrameLowering:
Inheritance graph
[legend]
Collaboration diagram for llvm::M68kFrameLowering:
Collaboration graph
[legend]

Public Member Functions

 M68kFrameLowering (const M68kSubtarget &sti, Align Alignment)
 
MachineBasicBlock::iterator eliminateCallFramePseudoInstr (MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const override
 This method is called during prolog/epilog code insertion to eliminate call frame setup and destroy pseudo instructions (but only if the Target is using them). More...
 
void emitPrologue (MachineFunction &MF, MachineBasicBlock &MBB) const override
 Insert prolog code into the function. More...
 
void emitEpilogue (MachineFunction &MF, MachineBasicBlock &MBB) const override
 Insert epilog code into the function. More...
 
void determineCalleeSaves (MachineFunction &MF, BitVector &SavedRegs, RegScavenger *RS=nullptr) const override
 This method determines which of the registers reported by TargetRegisterInfo::getCalleeSavedRegs() should actually get saved. More...
 
bool assignCalleeSavedSpillSlots (MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI) const override
 Allows target to override spill slot assignment logic. More...
 
bool spillCalleeSavedRegisters (MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, ArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const override
 Issues instruction(s) to spill all callee saved registers and returns true if it isn't possible / profitable to do so by issuing a series of store instructions via storeRegToStackSlot(). More...
 
bool restoreCalleeSavedRegisters (MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, MutableArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const override
 Issues instruction(s) to restore all callee saved registers and returns true if it isn't possible / profitable to do so by issuing a series of load instructions via loadRegToStackSlot(). More...
 
bool hasFP (const MachineFunction &MF) const override
 Return true if the specified function should have a dedicated frame pointer register. More...
 
bool hasReservedCallFrame (const MachineFunction &MF) const override
 Under normal circumstances, when a frame pointer is not required, we reserve argument space for call sites in the function immediately on entry to the current function. More...
 
bool canSimplifyCallFramePseudos (const MachineFunction &MF) const override
 If there is a reserved call frame, the call frame pseudos can be simplified. More...
 
bool needsFrameIndexResolution (const MachineFunction &MF) const override
 
StackOffset getFrameIndexReference (const MachineFunction &MF, int FI, Register &FrameReg) const override
 This method should return the base register and offset used to reference a frame index location. More...
 
int mergeSPUpdates (MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, bool doMergeWithPrevious) const
 Check the instruction before/after the passed instruction. More...
 
void emitSPUpdate (MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, int64_t NumBytes, bool InEpilogue) const
 Emit a series of instructions to increment / decrement the stack pointer by a constant value. More...
 
- Public Member Functions inherited from llvm::TargetFrameLowering
 TargetFrameLowering (StackDirection D, Align StackAl, int LAO, Align TransAl=Align(1), bool StackReal=true)
 
virtual ~TargetFrameLowering ()
 
StackDirection getStackGrowthDirection () const
 getStackGrowthDirection - Return the direction the stack grows More...
 
unsigned getStackAlignment () const
 getStackAlignment - This method returns the number of bytes to which the stack pointer must be aligned on entry to a function. More...
 
Align getStackAlign () const
 getStackAlignment - This method returns the number of bytes to which the stack pointer must be aligned on entry to a function. More...
 
int alignSPAdjust (int SPAdj) const
 alignSPAdjust - This method aligns the stack adjustment to the correct alignment. More...
 
Align getTransientStackAlign () const
 getTransientStackAlignment - This method returns the number of bytes to which the stack pointer must be aligned at all times, even between calls. More...
 
bool isStackRealignable () const
 isStackRealignable - This method returns whether the stack can be realigned. More...
 
virtual unsigned getStackAlignmentSkew (const MachineFunction &MF) const
 Return the skew that has to be applied to stack alignment under certain conditions (e.g. More...
 
virtual bool isStackIdSafeForLocalArea (unsigned StackId) const
 This method returns whether or not it is safe for an object with the given stack id to be bundled into the local area. More...
 
int getOffsetOfLocalArea () const
 getOffsetOfLocalArea - This method returns the offset of the local area from the stack pointer on entrance to a function. More...
 
virtual bool allocateScavengingFrameIndexesNearIncomingSP (const MachineFunction &MF) const
 Control the placement of special register scavenging spill slots when allocating a stack frame. More...
 
virtual bool assignCalleeSavedSpillSlots (MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI, unsigned &MinCSFrameIndex, unsigned &MaxCSFrameIndex) const
 assignCalleeSavedSpillSlots - Allows target to override spill slot assignment logic. More...
 
virtual const SpillSlotgetCalleeSavedSpillSlots (unsigned &NumEntries) const
 getCalleeSavedSpillSlots - This method returns a pointer to an array of pairs, that contains an entry for each callee saved register that must be spilled to a particular stack location if it is spilled. More...
 
virtual bool targetHandlesStackFrameRounding () const
 targetHandlesStackFrameRounding - Returns true if the target is responsible for rounding up the stack frame (probably at emitPrologue time). More...
 
virtual bool enableShrinkWrapping (const MachineFunction &MF) const
 Returns true if the target will correctly handle shrink wrapping. More...
 
virtual bool enableStackSlotScavenging (const MachineFunction &MF) const
 Returns true if the stack slot holes in the fixed and callee-save stack area should be used when allocating other stack locations to reduce stack size. More...
 
virtual bool enableCalleeSaveSkip (const MachineFunction &MF) const
 Returns true if the target can safely skip saving callee-saved registers for noreturn nounwind functions. More...
 
virtual void emitCalleeSavedFrameMoves (MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI) const
 With basic block sections, emit callee saved frame moves for basic blocks that are in a different section. More...
 
virtual void inlineStackProbe (MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
 Replace a StackProbe stub (if any) with the actual probe code inline. More...
 
virtual bool stackProbeFunctionModifiesSP () const
 Does the stack probe function call return with a modified stack pointer? More...
 
virtual void adjustForSegmentedStacks (MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
 Adjust the prologue to have the function use segmented stacks. More...
 
virtual void adjustForHiPEPrologue (MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
 Adjust the prologue to add Erlang Run-Time System (ERTS) specific code in the assembly prologue to explicitly handle the stack. More...
 
virtual bool keepFramePointer (const MachineFunction &MF) const
 Return true if the target wants to keep the frame pointer regardless of the function attribute "frame-pointer". More...
 
virtual StackOffset getFrameIndexReferencePreferSP (const MachineFunction &MF, int FI, Register &FrameReg, bool IgnoreSPUpdates) const
 Same as getFrameIndexReference, except that the stack pointer (as opposed to the frame pointer) will be the preferred value for FrameReg. More...
 
virtual StackOffset getNonLocalFrameIndexReference (const MachineFunction &MF, int FI) const
 getNonLocalFrameIndexReference - This method returns the offset used to reference a frame index location. More...
 
virtual void getCalleeSaves (const MachineFunction &MF, BitVector &SavedRegs) const
 Returns the callee-saved registers as computed by determineCalleeSaves in the BitVector SavedRegs. More...
 
virtual void processFunctionBeforeFrameFinalized (MachineFunction &MF, RegScavenger *RS=nullptr) const
 processFunctionBeforeFrameFinalized - This method is called immediately before the specified function's frame layout (MF.getFrameInfo()) is finalized. More...
 
virtual void processFunctionBeforeFrameIndicesReplaced (MachineFunction &MF, RegScavenger *RS=nullptr) const
 processFunctionBeforeFrameIndicesReplaced - This method is called immediately before MO_FrameIndex operands are eliminated, but after the frame is finalized. More...
 
virtual unsigned getWinEHParentFrameOffset (const MachineFunction &MF) const
 
virtual void orderFrameObjects (const MachineFunction &MF, SmallVectorImpl< int > &objectsToAllocate) const
 Order the symbols in the local stack frame. More...
 
virtual bool canUseAsPrologue (const MachineBasicBlock &MBB) const
 Check whether or not the given MBB can be used as a prologue for the target. More...
 
virtual bool canUseAsEpilogue (const MachineBasicBlock &MBB) const
 Check whether or not the given MBB can be used as a epilogue for the target. More...
 
virtual TargetStackID::Value getStackIDForScalableVectors () const
 Returns the StackID that scalable vectors should be associated with. More...
 
virtual bool isSupportedStackID (TargetStackID::Value ID) const
 
virtual bool isProfitableForNoCSROpt (const Function &F) const
 Check if the no-CSR optimisation is profitable for the given function. More...
 
virtual int getInitialCFAOffset (const MachineFunction &MF) const
 Return initial CFA offset value i.e. More...
 
virtual Register getInitialCFARegister (const MachineFunction &MF) const
 Return initial CFA register value i.e. More...
 
virtual DwarfFrameBase getDwarfFrameBase (const MachineFunction &MF) const
 Return the frame base information to be encoded in the DWARF subprogram debug info. More...
 

Static Public Member Functions

static const M68kFrameLoweringcreate (const M68kSubtarget &ST)
 
- Static Public Member Functions inherited from llvm::TargetFrameLowering
static bool isSafeForNoCSROpt (const Function &F)
 Check if given function is safe for not having callee saved registers. More...
 

Additional Inherited Members

- Public Types inherited from llvm::TargetFrameLowering
enum  StackDirection { StackGrowsUp, StackGrowsDown }
 

Detailed Description

Definition at line 28 of file M68kFrameLowering.h.

Constructor & Destructor Documentation

◆ M68kFrameLowering()

M68kFrameLowering::M68kFrameLowering ( const M68kSubtarget sti,
Align  Alignment 
)
explicit

Member Function Documentation

◆ assignCalleeSavedSpillSlots()

bool M68kFrameLowering::assignCalleeSavedSpillSlots ( MachineFunction MF,
const TargetRegisterInfo TRI,
std::vector< CalleeSavedInfo > &  CSI 
) const
overridevirtual

Allows target to override spill slot assignment logic.

If implemented, assignCalleeSavedSpillSlots() should assign frame slots to all CSI entries and return true. If this method returns false, spill slots will be assigned using generic implementation. assignCalleeSavedSpillSlots() may add, delete or rearrange elements of CSI.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 806 of file M68kFrameLowering.cpp.

References llvm::MachineFrameInfo::CreateFixedSpillStackObject(), llvm::numbers::e, llvm::MachineFunction::getFrameInfo(), llvm::TargetRegisterInfo::getFrameRegister(), llvm::MachineFunction::getInfo(), llvm::TargetFrameLowering::getOffsetOfLocalArea(), llvm::M68kMachineFunctionInfo::getTCReturnAddrDelta(), hasFP(), i, llvm::TargetRegisterInfo::regsOverlap(), and TRI.

◆ canSimplifyCallFramePseudos()

bool M68kFrameLowering::canSimplifyCallFramePseudos ( const MachineFunction MF) const
overridevirtual

If there is a reserved call frame, the call frame pseudos can be simplified.

Having a FP, as in the default implementation, is not sufficient here since we can't always use it. Use a more nuanced condition.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 58 of file M68kFrameLowering.cpp.

References llvm::M68kRegisterInfo::hasBasePointer(), hasFP(), and hasReservedCallFrame().

◆ create()

static const M68kFrameLowering* llvm::M68kFrameLowering::create ( const M68kSubtarget ST)
static

◆ determineCalleeSaves()

void M68kFrameLowering::determineCalleeSaves ( MachineFunction MF,
BitVector SavedRegs,
RegScavenger RS = nullptr 
) const
overridevirtual

This method determines which of the registers reported by TargetRegisterInfo::getCalleeSavedRegs() should actually get saved.

The default implementation checks populates the SavedRegs bitset with all registers which are modified in the function, targets may override this function to save additional registers. This method also sets up the register scavenger ensuring there is a free register or a frameindex available.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 776 of file M68kFrameLowering.cpp.

References llvm::MachineFrameInfo::CreateFixedObject(), llvm::TargetFrameLowering::determineCalleeSaves(), llvm::M68kRegisterInfo::getBaseRegister(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getInfo(), llvm::M68kMachineFunctionInfo::getTCReturnAddrDelta(), llvm::M68kRegisterInfo::hasBasePointer(), and llvm::BitVector::set().

◆ eliminateCallFramePseudoInstr()

MachineBasicBlock::iterator M68kFrameLowering::eliminateCallFramePseudoInstr ( MachineFunction MF,
MachineBasicBlock MBB,
MachineBasicBlock::iterator  MI 
) const
overridevirtual

This method is called during prolog/epilog code insertion to eliminate call frame setup and destroy pseudo instructions (but only if the Target is using them).

It is responsible for eliminating these instructions, replacing them with concrete instructions. This method need only be implemented if using call frame setup/destroy pseudo instructions. Returns an iterator pointing to the instruction after the replaced one.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 227 of file M68kFrameLowering.cpp.

References llvm::alignTo(), B, llvm::MachineBasicBlock::begin(), llvm::MCCFIInstruction::createAdjustCfaOffset(), llvm::MCCFIInstruction::createGnuArgsSize(), DL, llvm::DwarfCFI, llvm::MachineBasicBlock::erase(), llvm::TargetInstrInfo::getCallFrameDestroyOpcode(), llvm::MachineFunction::getFunction(), llvm::M68kMachineFunctionInfo::getHasPushSequences(), llvm::MachineFunction::getInfo(), llvm::MachineFunction::getLandingPads(), llvm::MachineFunction::getMMI(), llvm::TargetFrameLowering::getStackAlignment(), llvm::MachineModuleInfo::hasDebugInfo(), hasFP(), hasReservedCallFrame(), I, MBB, mergeSPUpdates(), and llvm::ARM::WinEH::StackAdjustment().

◆ emitEpilogue()

void M68kFrameLowering::emitEpilogue ( MachineFunction MF,
MachineBasicBlock MBB 
) const
overridevirtual

◆ emitPrologue()

void M68kFrameLowering::emitPrologue ( MachineFunction MF,
MachineBasicBlock MBB 
) const
overridevirtual

◆ emitSPUpdate()

void M68kFrameLowering::emitSPUpdate ( MachineBasicBlock MBB,
MachineBasicBlock::iterator MBBI,
int64_t  NumBytes,
bool  InEpilogue 
) const

◆ getFrameIndexReference()

StackOffset M68kFrameLowering::getFrameIndexReference ( const MachineFunction MF,
int  FI,
Register FrameReg 
) const
overridevirtual

◆ hasFP()

bool M68kFrameLowering::hasFP ( const MachineFunction MF) const
overridevirtual

◆ hasReservedCallFrame()

bool M68kFrameLowering::hasReservedCallFrame ( const MachineFunction MF) const
overridevirtual

Under normal circumstances, when a frame pointer is not required, we reserve argument space for call sites in the function immediately on entry to the current function.

This eliminates the need for add/sub sp brackets around call sites. Returns true if the call frame is included as part of the stack frame.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 53 of file M68kFrameLowering.cpp.

References llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getInfo(), and llvm::MachineFrameInfo::hasVarSizedObjects().

Referenced by canSimplifyCallFramePseudos(), and eliminateCallFramePseudoInstr().

◆ mergeSPUpdates()

int M68kFrameLowering::mergeSPUpdates ( MachineBasicBlock MBB,
MachineBasicBlock::iterator MBBI,
bool  doMergeWithPrevious 
) const

Check the instruction before/after the passed instruction.

If it is an ADD/SUB/LEA instruction it is deleted argument and the stack adjustment is returned as a positive value for ADD/LEA and a negative for SUB.

Definition at line 384 of file M68kFrameLowering.cpp.

References assert(), llvm::MachineBasicBlock::begin(), llvm::MachineBasicBlock::end(), llvm::MachineBasicBlock::erase(), MBB, MBBI, and Offset.

Referenced by eliminateCallFramePseudoInstr(), emitEpilogue(), and emitPrologue().

◆ needsFrameIndexResolution()

bool M68kFrameLowering::needsFrameIndexResolution ( const MachineFunction MF) const
overridevirtual

◆ restoreCalleeSavedRegisters()

bool M68kFrameLowering::restoreCalleeSavedRegisters ( MachineBasicBlock MBB,
MachineBasicBlock::iterator  MI,
MutableArrayRef< CalleeSavedInfo CSI,
const TargetRegisterInfo TRI 
) const
overridevirtual

Issues instruction(s) to restore all callee saved registers and returns true if it isn't possible / profitable to do so by issuing a series of load instructions via loadRegToStackSlot().

Returns false otherwise.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 870 of file M68kFrameLowering.cpp.

References llvm::M68k::addFrameReference(), llvm::MachineInstrBuilder::addImm(), llvm::M68k::addMemOperand(), llvm::BuildMI(), DL, llvm::MachineBasicBlock::findDebugLoc(), llvm::MachineInstr::FrameDestroy, llvm::MCInstrInfo::get(), I, llvm::RegState::ImplicitDefine, Info, llvm::BitmaskEnumDetail::Mask(), llvm::max(), MBB, MI, MRI, Reg, llvm::MachineInstrBuilder::setMIFlag(), Shift, and TRI.

◆ spillCalleeSavedRegisters()

bool M68kFrameLowering::spillCalleeSavedRegisters ( MachineBasicBlock MBB,
MachineBasicBlock::iterator  MI,
ArrayRef< CalleeSavedInfo CSI,
const TargetRegisterInfo TRI 
) const
overridevirtual

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