llvm/lib/Target/SystemZ/SystemZFrameLowering.h

   1 //===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
  10 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
  11
  12 #include "MCTargetDesc/SystemZMCTargetDesc.h"
  13 #include "llvm/ADT/IndexedMap.h"
  14 #include "llvm/CodeGen/TargetFrameLowering.h"
  15 #include "llvm/Support/TypeSize.h"
  16
  17 namespace llvm {
  18 class SystemZTargetMachine;
  19 class SystemZSubtarget;
  20
  21 class SystemZFrameLowering : public TargetFrameLowering {
  22   IndexedMap<unsigned> RegSpillOffsets;
  23
  24 public:
  25   SystemZFrameLowering();
  26
  27   // Override TargetFrameLowering.
  28   bool isFPCloseToIncomingSP() const override { return false; }
  29   bool
  30   assignCalleeSavedSpillSlots(MachineFunction &MF,
  31                               const TargetRegisterInfo *TRI,
  32                               std::vector<CalleeSavedInfo> &CSI) const override;
  33   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
  34                             RegScavenger *RS) const override;
  35   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
  36                                  MachineBasicBlock::iterator MBBI,
  37                                  ArrayRef<CalleeSavedInfo> CSI,
  38                                  const TargetRegisterInfo *TRI) const override;
  39   bool
  40   restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
  41                               MachineBasicBlock::iterator MBBII,
  42                               MutableArrayRef<CalleeSavedInfo> CSI,
  43                               const TargetRegisterInfo *TRI) const override;
  44   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
  45                                            RegScavenger *RS) const override;
  46   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  47   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  48   void inlineStackProbe(MachineFunction &MF,
  49                         MachineBasicBlock &PrologMBB) const override;
  50   bool hasFP(const MachineFunction &MF) const override;
  51   bool hasReservedCallFrame(const MachineFunction &MF) const override;
  52   StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
  53                                      Register &FrameReg) const override;
  54   MachineBasicBlock::iterator
  55   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
  56                                 MachineBasicBlock::iterator MI) const override;
  57
  58   // Return the byte offset from the incoming stack pointer of Reg's
  59   // ABI-defined save slot.  Return 0 if no slot is defined for Reg.  Adjust
  60   // the offset in case MF has packed-stack.
  61   unsigned getRegSpillOffset(MachineFunction &MF, Register Reg) const;
  62
  63   // Get or create the frame index of where the old frame pointer is stored.
  64   int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const;
  65
  66   bool usePackedStack(MachineFunction &MF) const;
  67
  68   // Return the offset of the backchain.
  69   unsigned getBackchainOffset(MachineFunction &MF) const {
  70     // The back chain is stored topmost with packed-stack.
  71     return usePackedStack(MF) ? SystemZMC::ELFCallFrameSize - 8 : 0;
  72   }
  73 };
  74 } // end namespace llvm
  75
  76 #endif