+ /// 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(). Returns
+ /// false otherwise.
+ virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI) const {
+ return false;
+ }
+
+ /// 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().
+ /// Returns false otherwise.
+ virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI) const {
+ return false;
+ }
+
+ virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned SrcReg, int FrameIndex,
+ const TargetRegisterClass *RC) const = 0;
+
+ virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned DestReg, int FrameIndex,
+ const TargetRegisterClass *RC) const = 0;
+
+ virtual void copyRegToReg(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned DestReg, unsigned SrcReg,
+ const TargetRegisterClass *RC) const = 0;
+
+ /// reMaterialize - Re-issue the specified 'original' instruction at the
+ /// specific location targeting a new destination register.
+ virtual void reMaterialize(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned DestReg,
+ const MachineInstr *Orig) const = 0;
+
+ /// foldMemoryOperand - Attempt to fold a load or store of the
+ /// specified stack slot into the specified machine instruction for
+ /// the specified operand. If this is possible, a new instruction
+ /// is returned with the specified operand folded, otherwise NULL is
+ /// returned. The client is responsible for removing the old
+ /// instruction and adding the new one in the instruction stream
+ virtual MachineInstr* foldMemoryOperand(MachineInstr* MI,
+ unsigned OpNum,
+ int FrameIndex) const {
+ return 0;
+ }
+
+ /// targetHandlesStackFrameRounding - Returns true if the target is responsible
+ /// for rounding up the stack frame (probably at emitPrologue time).
+ virtual bool targetHandlesStackFrameRounding() const {
+ return false;
+ }
+
+ /// requiresRegisterScavenging - returns true if the target requires (and
+ /// can make use of) the register scavenger.
+ virtual bool requiresRegisterScavenging(const MachineFunction &MF) const {
+ return false;
+ }
+
+ /// 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.
+ virtual bool hasFP(const MachineFunction &MF) const = 0;
+
+ /// getCallFrameSetup/DestroyOpcode - These methods return the opcode of the
+ /// frame setup/destroy instructions if they exist (-1 otherwise). Some
+ /// targets use pseudo instructions in order to abstract away the difference
+ /// between operating with a frame pointer and operating without, through the
+ /// use of these two instructions.
+ ///
+ int getCallFrameSetupOpcode() const { return CallFrameSetupOpcode; }
+ int getCallFrameDestroyOpcode() const { return CallFrameDestroyOpcode; }
+
+
+ /// 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.
+ ///
+ virtual void
+ eliminateCallFramePseudoInstr(MachineFunction &MF,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI) const {
+ assert(getCallFrameSetupOpcode()== -1 && getCallFrameDestroyOpcode()== -1 &&
+ "eliminateCallFramePseudoInstr must be implemented if using"
+ " call frame setup/destroy pseudo instructions!");
+ assert(0 && "Call Frame Pseudo Instructions do not exist on this target!");
+ }
+
+ /// processFunctionBeforeCalleeSavedScan - This method is called immediately
+ /// before PrologEpilogInserter scans the physical registers used to determine
+ /// what callee saved registers should be spilled. This method is optional.
+ virtual void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+ RegScavenger *RS = NULL) const {
+
+ }
+
+ /// processFunctionBeforeFrameFinalized - This method is called immediately
+ /// before the specified functions frame layout (MF.getFrameInfo()) is
+ /// finalized. Once the frame is finalized, MO_FrameIndex operands are
+ /// replaced with direct constants. This method is optional.
+ ///
+ virtual void processFunctionBeforeFrameFinalized(MachineFunction &MF) const {
+ }
+
+ /// eliminateFrameIndex - This method must be overriden to eliminate abstract
+ /// frame indices from instructions which may use them. The instruction
+ /// referenced by the iterator contains an MO_FrameIndex operand which must be
+ /// eliminated by this method. This method may modify or replace the
+ /// specified instruction, as long as it keeps the iterator pointing the the
+ /// finished product. The return value is the number of instructions
+ /// added to (negative if removed from) the basic block.
+ ///
+ virtual void eliminateFrameIndex(MachineBasicBlock::iterator MI,
+ RegScavenger *RS = NULL) const = 0;
+
+ /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
+ /// the function. The return value is the number of instructions
+ /// added to (negative if removed from) the basic block (entry for prologue).
+ ///
+ virtual void emitPrologue(MachineFunction &MF) const = 0;
+ virtual void emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const = 0;
+
+ //===--------------------------------------------------------------------===//
+ /// Debug information queries.
+
+ /// getDwarfRegNum - Map a target register to an equivalent dwarf register
+ /// number. Returns -1 if there is no equivalent value.
+ virtual int getDwarfRegNum(unsigned RegNum) const = 0;
+
+ /// getFrameRegister - This method should return the register used as a base
+ /// for values allocated in the current stack frame.
+ virtual unsigned getFrameRegister(MachineFunction &MF) const = 0;
+
+ /// getRARegister - This method should return the register where the return
+ /// address can be found.
+ virtual unsigned getRARegister() const = 0;
+
+ /// getLocation - This method should return the actual location of a frame
+ /// variable given the frame index. The location is returned in ML.
+ /// Subclasses should override this method for special handling of frame
+ /// variables and call MRegisterInfo::getLocation for the default action.
+ virtual void getLocation(MachineFunction &MF, unsigned Index,
+ MachineLocation &ML) const;
+
+ /// getInitialFrameState - Returns a list of machine moves that are assumed
+ /// on entry to all functions. Note that LabelID is ignored (assumed to be
+ /// the beginning of the function.)
+ virtual void getInitialFrameState(std::vector<MachineMove> &Moves) const;
+};
+
+// This is useful when building IndexedMaps keyed on virtual registers
+struct VirtReg2IndexFunctor : std::unary_function<unsigned, unsigned> {
+ unsigned operator()(unsigned Reg) const {
+ return Reg - MRegisterInfo::FirstVirtualRegister;
+ }