LLVM  6.0.0svn
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llvm::SystemZFrameLowering Class Reference

#include "Target/SystemZ/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, 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 getFrameIndexReference (const MachineFunction &MF, int FI, unsigned &FrameReg) const override
 getFrameIndexReference - This method should return the base register and offset used to reference a frame index location. 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...
 
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...
 
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...
 
int alignSPAdjust (int SPAdj) const
 alignSPAdjust - This method aligns the stack adjustment to the correct alignment. 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...
 
virtual unsigned getStackAlignmentSkew (const MachineFunction &MF) const
 Return the skew that has to be applied to stack alignment under certain conditions (e.g. 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 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 void inlineStackProbe (MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
 Replace a StackProbe stub (if any) with the actual probe code inline. 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 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 getFrameIndexReferencePreferSP (const MachineFunction &MF, int FI, unsigned &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 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...
 

Additional Inherited Members

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

Detailed Description

Definition at line 20 of file SystemZFrameLowering.h.

Constructor & Destructor Documentation

◆ SystemZFrameLowering()

SystemZFrameLowering::SystemZFrameLowering ( )

Member Function Documentation

◆ determineCalleeSaves()

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 65 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::MachineFunction::getLandingPads(), 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().

Referenced by isFPCloseToIncomingSP().

◆ eliminateCallFramePseudoInstr()

MachineBasicBlock::iterator SystemZFrameLowering::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 548 of file SystemZFrameLowering.cpp.

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

Referenced by hasReservedCallFrame(), and isFPCloseToIncomingSP().

◆ emitEpilogue()

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

◆ emitPrologue()

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

◆ getAllocatedStackSize()

uint64_t SystemZFrameLowering::getAllocatedStackSize ( const MachineFunction MF) const

◆ getCalleeSavedSpillSlots()

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 60 of file SystemZFrameLowering.cpp.

References llvm::array_lengthof().

Referenced by isFPCloseToIncomingSP().

◆ getFrameIndexReference()

int SystemZFrameLowering::getFrameIndexReference ( const MachineFunction MF,
int  FI,
unsigned FrameReg 
) const
overridevirtual

getFrameIndexReference - This method should return the base register and offset used to reference a frame index location.

Returns the displacement from the frame register to the stack frame of the specified index, along with the frame register used (in output arg FrameReg).

The offset is returned directly, and the base register is returned via FrameReg.

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

Reimplemented from llvm::TargetFrameLowering.

Definition at line 498 of file SystemZFrameLowering.cpp.

References getAllocatedStackSize(), llvm::MachineFunction::getFrameInfo(), llvm::TargetRegisterInfo::getFrameRegister(), llvm::MachineFrameInfo::getObjectOffset(), llvm::MachineFrameInfo::getOffsetAdjustment(), llvm::TargetFrameLowering::getOffsetOfLocalArea(), llvm::TargetSubtargetInfo::getRegisterInfo(), and llvm::MachineFunction::getSubtarget().

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

◆ getRegSpillOffset()

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

Definition at line 58 of file SystemZFrameLowering.h.

◆ hasFP()

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 492 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(), isFPCloseToIncomingSP(), and restoreCalleeSavedRegisters().

◆ hasReservedCallFrame()

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 539 of file SystemZFrameLowering.cpp.

References eliminateCallFramePseudoInstr().

Referenced by eliminateCallFramePseudoInstr(), and isFPCloseToIncomingSP().

◆ isFPCloseToIncomingSP()

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.

References determineCalleeSaves(), eliminateCallFramePseudoInstr(), emitEpilogue(), emitPrologue(), getAllocatedStackSize(), getCalleeSavedSpillSlots(), getFrameIndexReference(), hasFP(), hasReservedCallFrame(), MI, processFunctionBeforeFrameFinalized(), restoreCalleeSavedRegisters(), and spillCalleeSavedRegisters().

◆ processFunctionBeforeFrameFinalized()

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 277 of file SystemZFrameLowering.cpp.

References llvm::RegScavenger::addScavengingFrameIndex(), llvm::SystemZMC::CallFrameSize, llvm::MachineFrameInfo::CreateStackObject(), llvm::MachineFrameInfo::estimateStackSize(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFrameInfo::getObjectIndexBegin(), llvm::MachineFrameInfo::getObjectOffset(), llvm::MachineFrameInfo::getObjectSize(), I, and llvm::max().

Referenced by isFPCloseToIncomingSP(), and restoreCalleeSavedRegisters().

◆ restoreCalleeSavedRegisters()

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

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().

If it returns true, and any of the registers in CSI is not restored, it sets the corresponding Restored flag in CSI to false. Returns false otherwise.

Reimplemented from llvm::TargetFrameLowering.

Definition at line 221 of file SystemZFrameLowering.cpp.

References llvm::MachineInstrBuilder::addImm(), llvm::MachineInstrBuilder::addReg(), assert(), llvm::BuildMI(), contains(), llvm::RegState::Define, E, llvm::MachineBasicBlock::end(), llvm::MCInstrInfo::get(), llvm::SystemZMachineFunctionInfo::getHighSavedGPR(), llvm::MachineFunction::getInfo(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::SystemZMachineFunctionInfo::getLowSavedGPR(), llvm::MachineBasicBlock::getParent(), llvm::MachineFunction::getSubtarget(), hasFP(), I, llvm::RegState::ImplicitDefine, llvm::TargetInstrInfo::loadRegFromStackSlot(), processFunctionBeforeFrameFinalized(), and TII.

Referenced by isFPCloseToIncomingSP(), and spillCalleeSavedRegisters().

◆ spillCalleeSavedRegisters()

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: