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 "SystemZInstrBuilder.h" 14 #include "SystemZMachineFunctionInfo.h" 15 #include "llvm/ADT/IndexedMap.h" 16 #include "llvm/CodeGen/TargetFrameLowering.h" 17 #include "llvm/Support/TypeSize.h" 18 19 namespace llvm { 20 class SystemZSubtarget; 21 22 class SystemZFrameLowering : public TargetFrameLowering { 23 public: 24 SystemZFrameLowering(StackDirection D, Align StackAl, int LAO, Align TransAl, 25 bool StackReal); 26 27 static std::unique_ptr<SystemZFrameLowering> 28 create(const SystemZSubtarget &STI); 29 30 // Override TargetFrameLowering. 31 bool allocateScavengingFrameIndexesNearIncomingSP( 32 const MachineFunction &MF) const override { 33 // SystemZ wants normal register scavenging slots, as close to the stack or 34 // frame pointer as possible. 35 // The default implementation assumes an x86-like layout, where the frame 36 // pointer is at the opposite end of the frame from the stack pointer. 37 // This meant that when frame pointer elimination was disabled, 38 // the slots ended up being as close as possible to the incoming 39 // stack pointer, which is the opposite of what we want on SystemZ. 40 return false; 41 } 42 43 bool hasReservedCallFrame(const MachineFunction &MF) const override; 44 MachineBasicBlock::iterator 45 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 46 MachineBasicBlock::iterator MI) const override; 47 }; 48 49 class SystemZELFFrameLowering : public SystemZFrameLowering { 50 IndexedMap<unsigned> RegSpillOffsets; 51 52 public: 53 SystemZELFFrameLowering(); 54 55 // Override TargetFrameLowering. 56 bool 57 assignCalleeSavedSpillSlots(MachineFunction &MF, 58 const TargetRegisterInfo *TRI, 59 std::vector<CalleeSavedInfo> &CSI) const override; 60 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 61 RegScavenger *RS) const override; 62 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 63 MachineBasicBlock::iterator MBBI, 64 ArrayRef<CalleeSavedInfo> CSI, 65 const TargetRegisterInfo *TRI) const override; 66 bool 67 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 68 MachineBasicBlock::iterator MBBII, 69 MutableArrayRef<CalleeSavedInfo> CSI, 70 const TargetRegisterInfo *TRI) const override; 71 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 72 RegScavenger *RS) const override; 73 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 74 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 75 void inlineStackProbe(MachineFunction &MF, 76 MachineBasicBlock &PrologMBB) const override; 77 bool hasFP(const MachineFunction &MF) const override; 78 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 79 Register &FrameReg) const override; 80 void 81 orderFrameObjects(const MachineFunction &MF, 82 SmallVectorImpl<int> &ObjectsToAllocate) const override; 83 84 // Return the byte offset from the incoming stack pointer of Reg's 85 // ABI-defined save slot. Return 0 if no slot is defined for Reg. Adjust 86 // the offset in case MF has packed-stack. 87 unsigned getRegSpillOffset(MachineFunction &MF, Register Reg) const; 88 89 bool usePackedStack(MachineFunction &MF) const; 90 91 // Return the offset of the backchain. 92 unsigned getBackchainOffset(MachineFunction &MF) const { 93 // The back chain is stored topmost with packed-stack. 94 return usePackedStack(MF) ? SystemZMC::ELFCallFrameSize - 8 : 0; 95 } 96 97 // Get or create the frame index of where the old frame pointer is stored. 98 int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const; 99 }; 100 101 class SystemZXPLINKFrameLowering : public SystemZFrameLowering { 102 IndexedMap<unsigned> RegSpillOffsets; 103 104 public: 105 SystemZXPLINKFrameLowering(); 106 107 bool 108 assignCalleeSavedSpillSlots(MachineFunction &MF, 109 const TargetRegisterInfo *TRI, 110 std::vector<CalleeSavedInfo> &CSI) const override; 111 112 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 113 RegScavenger *RS) const override; 114 115 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 116 MachineBasicBlock::iterator MBBI, 117 ArrayRef<CalleeSavedInfo> CSI, 118 const TargetRegisterInfo *TRI) const override; 119 120 bool 121 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 122 MachineBasicBlock::iterator MBBII, 123 MutableArrayRef<CalleeSavedInfo> CSI, 124 const TargetRegisterInfo *TRI) const override; 125 126 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 127 128 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 129 130 bool hasFP(const MachineFunction &MF) const override; 131 132 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 133 RegScavenger *RS) const override; 134 }; 135 } // end namespace llvm 136 137 #endif 138