1 //===-- RISCVFrameLowering.h - Define frame lowering for RISCV -*- 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 // This class implements RISCV-specific bits of TargetFrameLowering class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H 14 #define LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H 15 16 #include "llvm/CodeGen/TargetFrameLowering.h" 17 #include "llvm/Support/TypeSize.h" 18 19 namespace llvm { 20 class RISCVSubtarget; 21 22 class RISCVFrameLowering : public TargetFrameLowering { 23 public: 24 explicit RISCVFrameLowering(const RISCVSubtarget &STI) 25 : TargetFrameLowering(StackGrowsDown, 26 /*StackAlignment=*/Align(16), 27 /*LocalAreaOffset=*/0, 28 /*TransientStackAlignment=*/Align(16)), 29 STI(STI) {} 30 31 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 32 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 33 34 uint64_t getStackSizeWithRVVPadding(const MachineFunction &MF) const; 35 36 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 37 Register &FrameReg) const override; 38 39 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 40 RegScavenger *RS) const override; 41 42 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 43 RegScavenger *RS) const override; 44 45 bool hasFP(const MachineFunction &MF) const override; 46 47 bool hasBP(const MachineFunction &MF) const; 48 49 bool hasReservedCallFrame(const MachineFunction &MF) const override; 50 MachineBasicBlock::iterator 51 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 52 MachineBasicBlock::iterator MI) const override; 53 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 54 MachineBasicBlock::iterator MI, 55 ArrayRef<CalleeSavedInfo> CSI, 56 const TargetRegisterInfo *TRI) const override; 57 bool 58 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 59 MachineBasicBlock::iterator MI, 60 MutableArrayRef<CalleeSavedInfo> CSI, 61 const TargetRegisterInfo *TRI) const override; 62 63 // Get the first stack adjustment amount for SplitSPAdjust. 64 // Return 0 if we don't want to to split the SP adjustment in prologue and 65 // epilogue. 66 uint64_t getFirstSPAdjustAmount(const MachineFunction &MF) const; 67 68 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override; 69 bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override; 70 71 bool enableShrinkWrapping(const MachineFunction &MF) const override; 72 73 bool isSupportedStackID(TargetStackID::Value ID) const override; 74 TargetStackID::Value getStackIDForScalableVectors() const override; 75 76 bool isStackIdSafeForLocalArea(unsigned StackId) const override { 77 // We don't support putting RISCV Vector objects into the pre-allocated 78 // local frame block at the moment. 79 return StackId != TargetStackID::ScalableVector; 80 } 81 82 protected: 83 const RISCVSubtarget &STI; 84 85 private: 86 void determineFrameLayout(MachineFunction &MF) const; 87 void adjustStackForRVV(MachineFunction &MF, MachineBasicBlock &MBB, 88 MachineBasicBlock::iterator MBBI, const DebugLoc &DL, 89 int64_t Amount, MachineInstr::MIFlag Flag) const; 90 std::pair<int64_t, Align> 91 assignRVVStackObjectOffsets(MachineFunction &MF) const; 92 }; 93 } // namespace llvm 94 #endif 95