| // WebAssemblyFrameLowering.h - TargetFrameLowering for WebAssembly -*- C++ -*-/ |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// \file |
| /// This class implements WebAssembly-specific bits of |
| /// TargetFrameLowering class. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYFRAMELOWERING_H |
| #define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYFRAMELOWERING_H |
| |
| #include "llvm/CodeGen/TargetFrameLowering.h" |
| |
| namespace llvm { |
| |
| class WebAssemblyFrameLowering final : public TargetFrameLowering { |
| public: |
| /// Size of the red zone for the user stack (leaf functions can use this much |
| /// space below the stack pointer without writing it back to __stack_pointer |
| /// global). |
| // TODO: (ABI) Revisit and decide how large it should be. |
| static const size_t RedZoneSize = 128; |
| |
| WebAssemblyFrameLowering() |
| : TargetFrameLowering(StackGrowsDown, /*StackAlignment=*/Align(16), |
| /*LocalAreaOffset=*/0, |
| /*TransientStackAlignment=*/Align(16), |
| /*StackRealignable=*/true) {} |
| |
| MachineBasicBlock::iterator |
| eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I) const override; |
| |
| /// These methods insert prolog and epilog code into the function. |
| void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; |
| void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; |
| |
| bool hasFP(const MachineFunction &MF) const override; |
| bool hasReservedCallFrame(const MachineFunction &MF) const override; |
| bool isSupportedStackID(TargetStackID::Value ID) const override; |
| DwarfFrameBase getDwarfFrameBase(const MachineFunction &MF) const override; |
| |
| bool needsPrologForEH(const MachineFunction &MF) const; |
| |
| /// Write SP back to __stack_pointer global. |
| void writeSPToGlobal(unsigned SrcReg, MachineFunction &MF, |
| MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator &InsertStore, |
| const DebugLoc &DL) const; |
| |
| // Returns the index of the WebAssembly local to which the stack object |
| // FrameIndex in MF should be allocated, or None. |
| static Optional<unsigned> getLocalForStackObject(MachineFunction &MF, |
| int FrameIndex); |
| |
| static unsigned getSPReg(const MachineFunction &MF); |
| static unsigned getFPReg(const MachineFunction &MF); |
| static unsigned getOpcConst(const MachineFunction &MF); |
| static unsigned getOpcAdd(const MachineFunction &MF); |
| static unsigned getOpcSub(const MachineFunction &MF); |
| static unsigned getOpcAnd(const MachineFunction &MF); |
| static unsigned getOpcGlobGet(const MachineFunction &MF); |
| static unsigned getOpcGlobSet(const MachineFunction &MF); |
| |
| private: |
| bool hasBP(const MachineFunction &MF) const; |
| bool needsSPForLocalFrame(const MachineFunction &MF) const; |
| bool needsSP(const MachineFunction &MF) const; |
| bool needsSPWriteback(const MachineFunction &MF) const; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif |