| Ulrich Weigand | 1d09d56 | 2013-05-06 16:15:19 +0000 | [diff] [blame] | 1 | //===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | |
| 10 | #ifndef SYSTEMZFRAMELOWERING_H |
| 11 | #define SYSTEMZFRAMELOWERING_H |
| 12 | |
| 13 | #include "SystemZSubtarget.h" |
| 14 | #include "llvm/ADT/IndexedMap.h" |
| 15 | #include "llvm/Target/TargetFrameLowering.h" |
| 16 | |
| 17 | namespace llvm { |
| 18 | class SystemZTargetMachine; |
| 19 | class SystemZSubtarget; |
| 20 | |
| 21 | class SystemZFrameLowering : public TargetFrameLowering { |
| 22 | IndexedMap<unsigned> RegSpillOffsets; |
| 23 | |
| 24 | protected: |
| 25 | const SystemZTargetMachine &TM; |
| 26 | const SystemZSubtarget &STI; |
| 27 | |
| 28 | public: |
| 29 | SystemZFrameLowering(const SystemZTargetMachine &tm, |
| 30 | const SystemZSubtarget &sti); |
| 31 | |
| 32 | // Override FrameLowering. |
| 33 | virtual void |
| 34 | processFunctionBeforeCalleeSavedScan(MachineFunction &MF, |
| 35 | RegScavenger *RS) const LLVM_OVERRIDE; |
| 36 | virtual bool |
| 37 | spillCalleeSavedRegisters(MachineBasicBlock &MBB, |
| 38 | MachineBasicBlock::iterator MBBI, |
| 39 | const std::vector<CalleeSavedInfo> &CSI, |
| 40 | const TargetRegisterInfo *TRI) const |
| 41 | LLVM_OVERRIDE; |
| 42 | virtual bool |
| 43 | restoreCalleeSavedRegisters(MachineBasicBlock &MBB, |
| 44 | MachineBasicBlock::iterator MBBII, |
| 45 | const std::vector<CalleeSavedInfo> &CSI, |
| 46 | const TargetRegisterInfo *TRI) const |
| 47 | LLVM_OVERRIDE; |
| 48 | virtual void emitPrologue(MachineFunction &MF) const LLVM_OVERRIDE; |
| 49 | virtual void emitEpilogue(MachineFunction &MF, |
| 50 | MachineBasicBlock &MBB) const LLVM_OVERRIDE; |
| 51 | virtual bool hasFP(const MachineFunction &MF) const LLVM_OVERRIDE; |
| 52 | virtual int getFrameIndexOffset(const MachineFunction &MF, |
| 53 | int FI) const LLVM_OVERRIDE; |
| 54 | virtual bool hasReservedCallFrame(const MachineFunction &MF) const |
| 55 | LLVM_OVERRIDE; |
| 56 | virtual void |
| 57 | eliminateCallFramePseudoInstr(MachineFunction &MF, |
| 58 | MachineBasicBlock &MBB, |
| 59 | MachineBasicBlock::iterator MI) const |
| 60 | LLVM_OVERRIDE; |
| 61 | |
| 62 | // The target-independent code automatically allocates save slots for |
| 63 | // call-saved GPRs. However, we don't need those slots for SystemZ, |
| 64 | // because the ABI sets aside GPR save slots in the caller-allocated part |
| 65 | // of the frame. Since the target-independent code puts this unneeded |
| 66 | // area at the top of the callee-allocated part of frame, we choose not |
| 67 | // to allocate it and adjust the offsets accordingly. Return the |
| 68 | // size of this unallocated area. |
| 69 | // FIXME: seems a bit hackish. |
| 70 | uint64_t getUnallocatedTopBytes(const MachineFunction &MF) const; |
| 71 | |
| 72 | // Return the number of bytes in the callee-allocated part of the frame. |
| 73 | uint64_t getAllocatedStackSize(const MachineFunction &MF) const; |
| 74 | |
| 75 | // Return the number of frame bytes that should be reserved for |
| 76 | // an emergency spill slot, for use by the register scaveneger. |
| 77 | // Return 0 if register scaveging won't be needed. |
| 78 | unsigned getEmergencySpillSlotSize(const MachineFunction &MF) const; |
| 79 | |
| 80 | // Return the offset from the frame pointer of the emergency spill slot, |
| 81 | // which always fits within a 12-bit unsigned displacement field. |
| 82 | // Only valid if getEmergencySpillSlotSize(MF) returns nonzero. |
| 83 | unsigned getEmergencySpillSlotOffset(const MachineFunction &MF) const; |
| 84 | |
| 85 | // Return the byte offset from the incoming stack pointer of Reg's |
| 86 | // ABI-defined save slot. Return 0 if no slot is defined for Reg. |
| 87 | unsigned getRegSpillOffset(unsigned Reg) const { |
| 88 | return RegSpillOffsets[Reg]; |
| 89 | } |
| 90 | }; |
| 91 | } // end namespace llvm |
| 92 | |
| 93 | #endif |