LLVM  3.7.0
Public Member Functions | List of all members
llvm::SystemZFrameLowering Class Reference

#include <SystemZFrameLowering.h>

Inheritance diagram for llvm::SystemZFrameLowering:
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Collaboration diagram for llvm::SystemZFrameLowering:
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Public Member Functions

 SystemZFrameLowering ()
 
bool isFPCloseToIncomingSP () const override
 isFPCloseToIncomingSP - Return true if the frame pointer is close to the incoming stack pointer, false if it is close to the post-prologue stack pointer. More...
 
const SpillSlotgetCalleeSavedSpillSlots (unsigned &NumEntries) const override
 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...
 
void determineCalleeSaves (MachineFunction &MF, BitVector &SavedRegs, RegScavenger *RS) const override
 This method determines which of the registers reported by TargetRegisterInfo::getCalleeSavedRegs() should actually get saved. More...
 
bool spillCalleeSavedRegisters (MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, const std::vector< CalleeSavedInfo > &CSI, const TargetRegisterInfo *TRI) const override
 spillCalleeSavedRegisters - 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 MBBII, const std::vector< CalleeSavedInfo > &CSI, const TargetRegisterInfo *TRI) const override
 restoreCalleeSavedRegisters - 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...
 
void processFunctionBeforeFrameFinalized (MachineFunction &MF, RegScavenger *RS) const override
 processFunctionBeforeFrameFinalized - This method is called immediately before the specified function's frame layout (MF.getFrameInfo()) is finalized. More...
 
void emitPrologue (MachineFunction &MF, MachineBasicBlock &MBB) const override
 emitProlog/emitEpilog - These methods insert prolog and epilog code into the function. More...
 
void emitEpilogue (MachineFunction &MF, MachineBasicBlock &MBB) const override
 
bool hasFP (const MachineFunction &MF) const override
 hasFP - Return true if the specified function should have a dedicated frame pointer register. More...
 
int getFrameIndexOffset (const MachineFunction &MF, int FI) const override
 getFrameIndexOffset - Returns the displacement from the frame register to the stack frame of the specified index. More...
 
bool hasReservedCallFrame (const MachineFunction &MF) const override
 hasReservedCallFrame - 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...
 
void eliminateCallFramePseudoInstr (MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const override
 eliminateCallFramePseudoInstr - 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...
 
uint64_t getAllocatedStackSize (const MachineFunction &MF) const
 
unsigned getRegSpillOffset (unsigned Reg) const
 
- Public Member Functions inherited from llvm::TargetFrameLowering
 TargetFrameLowering (StackDirection D, unsigned StackAl, int LAO, unsigned TransAl=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...
 
unsigned getTransientStackAlignment () 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...
 
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 assignCalleeSavedSpillSlots (MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI) const
 assignCalleeSavedSpillSlots - Allows target to override spill slot assignment logic. 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 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 void adjustForFrameAllocatePrologue (MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
 Adjust the prologue to add an allocation at a fixed offset from the frame pointer. More...
 
virtual bool noFramePointerElim (const MachineFunction &MF) const
 Return true if the target needs to disable frame pointer elimination. More...
 
virtual bool canSimplifyCallFramePseudos (const MachineFunction &MF) const
 canSimplifyCallFramePseudos - When possible, it's best to simplify the call frame pseudo ops before doing frame index elimination. More...
 
virtual bool needsFrameIndexResolution (const MachineFunction &MF) const
 
virtual int getFrameIndexReference (const MachineFunction &MF, int FI, unsigned &FrameReg) const
 getFrameIndexReference - This method should return the base register and offset used to reference a frame index location. More...
 
virtual int getFrameIndexReferenceFromSP (const MachineFunction &MF, int FI, unsigned &FrameReg) const
 Same as above, except that the 'base register' will always be RSP, not RBP on x86. 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...
 

Additional Inherited Members

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

Detailed Description

Definition at line 20 of file SystemZFrameLowering.h.

Constructor & Destructor Documentation

SystemZFrameLowering::SystemZFrameLowering ( )

Member Function Documentation

void SystemZFrameLowering::determineCalleeSaves ( MachineFunction MF,
BitVector SavedRegs,
RegScavenger RS 
) 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 64 of file SystemZFrameLowering.cpp.

References llvm::SystemZ::ArgGPRs, contains(), llvm::TargetFrameLowering::determineCalleeSaves(), llvm::TargetRegisterInfo::getCalleeSavedRegs(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getFunction(), llvm::MachineFunction::getInfo(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), llvm::SystemZMachineFunctionInfo::getVarArgsFirstGPR(), llvm::MachineFrameInfo::hasCalls(), hasFP(), I, llvm::Function::isVarArg(), llvm::SystemZ::NumArgGPRs, llvm::BitVector::set(), and llvm::BitVector::test().

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

eliminateCallFramePseudoInstr - 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.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 503 of file SystemZFrameLowering.cpp.

References llvm::MachineBasicBlock::erase(), hasReservedCallFrame(), and llvm_unreachable.

void SystemZFrameLowering::emitEpilogue ( MachineFunction MF,
MachineBasicBlock MBB 
) const
overridevirtual
void SystemZFrameLowering::emitPrologue ( MachineFunction MF,
MachineBasicBlock MBB 
) const
overridevirtual
uint64_t SystemZFrameLowering::getAllocatedStackSize ( const MachineFunction MF) const
const TargetFrameLowering::SpillSlot * SystemZFrameLowering::getCalleeSavedSpillSlots ( unsigned NumEntries) const
overridevirtual

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.

Each entry in this array contains a <register,offset> pair, indicating the fixed offset from the incoming stack pointer that each register should be spilled at. If a register is not listed here, the code generator is allowed to spill it anywhere it chooses.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 59 of file SystemZFrameLowering.cpp.

References llvm::array_lengthof().

int SystemZFrameLowering::getFrameIndexOffset ( const MachineFunction MF,
int  FI 
) const
overridevirtual

getFrameIndexOffset - Returns the displacement from the frame register to the stack frame of the specified index.

This is the default implementation which is overridden for some targets.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 458 of file SystemZFrameLowering.cpp.

References getAllocatedStackSize(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFrameInfo::getObjectOffset(), llvm::MachineFrameInfo::getOffsetAdjustment(), and llvm::TargetFrameLowering::getOffsetOfLocalArea().

Referenced by llvm::SystemZRegisterInfo::eliminateFrameIndex(), and emitPrologue().

unsigned llvm::SystemZFrameLowering::getRegSpillOffset ( unsigned  Reg) const
inline

Definition at line 58 of file SystemZFrameLowering.h.

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

hasFP - Return true if the specified function should have a dedicated frame pointer register.

For most targets this is true only if the function has variable sized allocas or if frame pointer elimination is disabled.

Implements llvm::TargetFrameLowering.

Definition at line 452 of file SystemZFrameLowering.cpp.

References llvm::TargetOptions::DisableFramePointerElim(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getInfo(), llvm::MachineFunction::getTarget(), llvm::MachineFrameInfo::hasVarSizedObjects(), and llvm::TargetMachine::Options.

Referenced by determineCalleeSaves(), emitPrologue(), llvm::SystemZRegisterInfo::getFrameRegister(), llvm::SystemZRegisterInfo::getReservedRegs(), and restoreCalleeSavedRegisters().

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

hasReservedCallFrame - 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 494 of file SystemZFrameLowering.cpp.

Referenced by eliminateCallFramePseudoInstr().

bool llvm::SystemZFrameLowering::isFPCloseToIncomingSP ( ) const
inlineoverridevirtual

isFPCloseToIncomingSP - Return true if the frame pointer is close to the incoming stack pointer, false if it is close to the post-prologue stack pointer.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 27 of file SystemZFrameLowering.h.

void SystemZFrameLowering::processFunctionBeforeFrameFinalized ( MachineFunction MF,
RegScavenger RS 
) const
overridevirtual

processFunctionBeforeFrameFinalized - This method is called immediately before the specified function's frame layout (MF.getFrameInfo()) is finalized.

Once the frame is finalized, MO_FrameIndex operands are replaced with direct constants. This method is optional.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 269 of file SystemZFrameLowering.cpp.

References llvm::RegScavenger::addScavengingFrameIndex(), llvm::SystemZMC::CallFrameSize, llvm::MachineFrameInfo::CreateStackObject(), llvm::MachineFrameInfo::estimateStackSize(), and llvm::MachineFunction::getFrameInfo().

bool SystemZFrameLowering::restoreCalleeSavedRegisters ( MachineBasicBlock MBB,
MachineBasicBlock::iterator  MI,
const std::vector< CalleeSavedInfo > &  CSI,
const TargetRegisterInfo TRI 
) const
overridevirtual
bool SystemZFrameLowering::spillCalleeSavedRegisters ( MachineBasicBlock MBB,
MachineBasicBlock::iterator  MI,
const std::vector< CalleeSavedInfo > &  CSI,
const TargetRegisterInfo TRI 
) const
overridevirtual

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