llvm/lib/Target/AArch64/AArch64FrameLowering.h

   1 //==-- AArch64FrameLowering.h - TargetFrameLowering for AArch64 --*- 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 //
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H
  14 #define LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H
  15
  16 #include "llvm/Support/TypeSize.h"
  17 #include "llvm/CodeGen/TargetFrameLowering.h"
  18
  19 namespace llvm {
  20
  21 class MCCFIInstruction;
  22
  23 class AArch64FrameLowering : public TargetFrameLowering {
  24 public:
  25   explicit AArch64FrameLowering()
  26       : TargetFrameLowering(StackGrowsDown, Align(16), 0, Align(16),
  27                             true /*StackRealignable*/) {}
  28
  29   void
  30   emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
  31                             MachineBasicBlock::iterator MBBI) const override;
  32
  33   MachineBasicBlock::iterator
  34   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
  35                                 MachineBasicBlock::iterator I) const override;
  36
  37   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
  38   /// the function.
  39   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  40   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  41
  42   bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
  43
  44   StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
  45                                      Register &FrameReg) const override;
  46   StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI,
  47                                          Register &FrameReg, bool PreferFP,
  48                                          bool ForSimm) const;
  49   StackOffset resolveFrameOffsetReference(const MachineFunction &MF,
  50                                           int64_t ObjectOffset, bool isFixed,
  51                                           bool isSVE, Register &FrameReg,
  52                                           bool PreferFP, bool ForSimm) const;
  53   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
  54                                  MachineBasicBlock::iterator MI,
  55                                  ArrayRef<CalleeSavedInfo> CSI,
  56                                  const TargetRegisterInfo *TRI) const override;
  57
  58   bool
  59   restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
  60                               MachineBasicBlock::iterator MI,
  61                               MutableArrayRef<CalleeSavedInfo> CSI,
  62                               const TargetRegisterInfo *TRI) const override;
  63
  64   /// Can this function use the red zone for local allocations.
  65   bool canUseRedZone(const MachineFunction &MF) const;
  66
  67   bool hasFP(const MachineFunction &MF) const override;
  68   bool hasReservedCallFrame(const MachineFunction &MF) const override;
  69
  70   bool hasSwiftExtendedFrame(const MachineFunction &MF) const;
  71
  72   bool assignCalleeSavedSpillSlots(MachineFunction &MF,
  73                                    const TargetRegisterInfo *TRI,
  74                                    std::vector<CalleeSavedInfo> &CSI,
  75                                    unsigned &MinCSFrameIndex,
  76                                    unsigned &MaxCSFrameIndex) const override;
  77
  78   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
  79                             RegScavenger *RS) const override;
  80
  81   /// Returns true if the target will correctly handle shrink wrapping.
  82   bool enableShrinkWrapping(const MachineFunction &MF) const override {
  83     return true;
  84   }
  85
  86   bool enableStackSlotScavenging(const MachineFunction &MF) const override;
  87   TargetStackID::Value getStackIDForScalableVectors() const override;
  88
  89   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
  90                                            RegScavenger *RS) const override;
  91
  92   void
  93   processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF,
  94                                             RegScavenger *RS) const override;
  95
  96   unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
  97
  98   unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
  99
 100   StackOffset
 101   getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI,
 102                                  Register &FrameReg,
 103                                  bool IgnoreSPUpdates) const override;
 104   StackOffset getNonLocalFrameIndexReference(const MachineFunction &MF,
 105                                              int FI) const override;
 106   int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const;
 107
 108   bool isSupportedStackID(TargetStackID::Value ID) const override {
 109     switch (ID) {
 110     default:
 111       return false;
 112     case TargetStackID::Default:
 113     case TargetStackID::ScalableVector:
 114     case TargetStackID::NoAlloc:
 115       return true;
 116     }
 117   }
 118
 119   bool isStackIdSafeForLocalArea(unsigned StackId) const override {
 120     // We don't support putting SVE objects into the pre-allocated local
 121     // frame block at the moment.
 122     return StackId != TargetStackID::ScalableVector;
 123   }
 124
 125   void
 126   orderFrameObjects(const MachineFunction &MF,
 127                     SmallVectorImpl<int> &ObjectsToAllocate) const override;
 128
 129 private:
 130   /// Returns true if a homogeneous prolog or epilog code can be emitted
 131   /// for the size optimization. If so, HOM_Prolog/HOM_Epilog pseudo
 132   /// instructions are emitted in place. When Exit block is given, this check is
 133   /// for epilog.
 134   bool homogeneousPrologEpilog(MachineFunction &MF,
 135                                MachineBasicBlock *Exit = nullptr) const;
 136
 137   /// Returns true if CSRs should be paired.
 138   bool producePairRegisters(MachineFunction &MF) const;
 139
 140   bool shouldCombineCSRLocalStackBump(MachineFunction &MF,
 141                                       uint64_t StackBumpBytes) const;
 142
 143   int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const;
 144   int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF,
 145                                       int &MinCSFrameIndex,
 146                                       int &MaxCSFrameIndex) const;
 147   MCCFIInstruction
 148   createDefCFAExpressionFromSP(const TargetRegisterInfo &TRI,
 149                                const StackOffset &OffsetFromSP) const;
 150   MCCFIInstruction createCfaOffset(const TargetRegisterInfo &MRI, unsigned DwarfReg,
 151                                    const StackOffset &OffsetFromDefCFA) const;
 152   bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB,
 153                                                 unsigned StackBumpBytes) const;
 154 };
 155
 156 } // End llvm namespace
 157
 158 #endif