From da8bc76b4bf7d1a7b025d6c8ef5809551467dcc7 Mon Sep 17 00:00:00 2001 From: Richard-Qin-X Date: Sun, 9 Aug 2026 13:23:48 +0800 Subject: [CodeGen] Implement RV64GC frame lowering --- .../include/rcc/CodeGen/FrameIndexElimination.h | 22 +++++++ backend/include/rcc/CodeGen/MachineInstr.h | 2 + .../rcc/CodeGen/PrologueEpilogueInsertion.h | 30 +++++++++ backend/include/rcc/CodeGen/RegisterScavenger.h | 42 +++++++++++++ backend/include/rcc/CodeGen/TargetFrameLowering.h | 73 ++++++++++++++++++++++ .../rcc/CodeGen/TargetRegisterAllocationInfo.h | 5 ++ 6 files changed, 174 insertions(+) create mode 100644 backend/include/rcc/CodeGen/FrameIndexElimination.h create mode 100644 backend/include/rcc/CodeGen/PrologueEpilogueInsertion.h create mode 100644 backend/include/rcc/CodeGen/RegisterScavenger.h create mode 100644 backend/include/rcc/CodeGen/TargetFrameLowering.h (limited to 'backend/include/rcc/CodeGen') diff --git a/backend/include/rcc/CodeGen/FrameIndexElimination.h b/backend/include/rcc/CodeGen/FrameIndexElimination.h new file mode 100644 index 0000000..df67479 --- /dev/null +++ b/backend/include/rcc/CodeGen/FrameIndexElimination.h @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef RCC_CODEGEN_FRAMEINDEXELIMINATION_H +#define RCC_CODEGEN_FRAMEINDEXELIMINATION_H + +#include "rcc/Support/Error.h" + +namespace rcc { + +class MachineFunction; +class RegisterScavenger; +class TargetDescription; +class TargetFrameLowering; + +[[nodiscard]] Expected eliminateFrameIndices(MachineFunction &Function, + const TargetDescription &Target, + const TargetFrameLowering &FrameLowering, + RegisterScavenger &Scavenger); + +} // namespace rcc + +#endif // RCC_CODEGEN_FRAMEINDEXELIMINATION_H diff --git a/backend/include/rcc/CodeGen/MachineInstr.h b/backend/include/rcc/CodeGen/MachineInstr.h index e7294b4..84d2f0e 100644 --- a/backend/include/rcc/CodeGen/MachineInstr.h +++ b/backend/include/rcc/CodeGen/MachineInstr.h @@ -98,6 +98,8 @@ public: [[nodiscard]] Expected untieOperand(std::size_t Index); [[nodiscard]] Expected addMemOperand(const MachineMemOperand &MemOperand); + [[nodiscard]] Expected replaceMemOperand(std::size_t Index, + const MachineMemOperand &MemOperand); [[nodiscard]] Expected eraseMemOperand(std::size_t Index); [[nodiscard]] std::span memOperands() const noexcept { return MemOperands; diff --git a/backend/include/rcc/CodeGen/PrologueEpilogueInsertion.h b/backend/include/rcc/CodeGen/PrologueEpilogueInsertion.h new file mode 100644 index 0000000..b94715a --- /dev/null +++ b/backend/include/rcc/CodeGen/PrologueEpilogueInsertion.h @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef RCC_CODEGEN_PROLOGUEEPILOGUEINSERTION_H +#define RCC_CODEGEN_PROLOGUEEPILOGUEINSERTION_H + +#include "rcc/CodeGen/MachinePass.h" + +namespace rcc { + +class TargetFrameLowering; + +class PrologueEpilogueInsertionPass final : public MachineFunctionPass { +public: + explicit PrologueEpilogueInsertionPass(const TargetFrameLowering &Info) noexcept : Info(&Info) {} + + [[nodiscard]] const MachinePassContract &contract() const noexcept override; + [[nodiscard]] Expected run(MachineFunction &Function, + const TargetDescription &Target, + MachineAnalysisManager &Analyses) override; + +private: + [[nodiscard]] Expected + runImplementation(MachineFunction &Function, const TargetDescription &Target) const; + + const TargetFrameLowering *Info; +}; + +} // namespace rcc + +#endif // RCC_CODEGEN_PROLOGUEEPILOGUEINSERTION_H diff --git a/backend/include/rcc/CodeGen/RegisterScavenger.h b/backend/include/rcc/CodeGen/RegisterScavenger.h new file mode 100644 index 0000000..6351b98 --- /dev/null +++ b/backend/include/rcc/CodeGen/RegisterScavenger.h @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef RCC_CODEGEN_REGISTERSCAVENGER_H +#define RCC_CODEGEN_REGISTERSCAVENGER_H + +#include "rcc/CodeGen/Register.h" +#include "rcc/Support/Error.h" + +#include + +namespace rcc { + +class MachineFunction; +class MachineInstr; +class TargetDescription; + +struct ScavengedRegister final { + PhysicalRegister Reg; + bool RequiresSpill = false; +}; + +class RegisterScavenger final { +public: + RegisterScavenger(const MachineFunction &Function, const TargetDescription &Target) noexcept + : Function(&Function), Target(&Target) {} + + [[nodiscard]] Expected + scavenge(const MachineInstr &Instruction, std::span Candidates) const; + +private: + [[nodiscard]] Expected isLiveBefore(const MachineInstr &Instruction, + PhysicalRegister Reg) const; + [[nodiscard]] bool instructionUses(const MachineInstr &Instruction, + PhysicalRegister Reg) const noexcept; + + const MachineFunction *Function; + const TargetDescription *Target; +}; + +} // namespace rcc + +#endif // RCC_CODEGEN_REGISTERSCAVENGER_H diff --git a/backend/include/rcc/CodeGen/TargetFrameLowering.h b/backend/include/rcc/CodeGen/TargetFrameLowering.h new file mode 100644 index 0000000..1712616 --- /dev/null +++ b/backend/include/rcc/CodeGen/TargetFrameLowering.h @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef RCC_CODEGEN_TARGETFRAMELOWERING_H +#define RCC_CODEGEN_TARGETFRAMELOWERING_H + +#include "rcc/CodeGen/MachineIRTypes.h" +#include "rcc/CodeGen/Register.h" +#include "rcc/Support/Error.h" + +#include +#include + +namespace rcc { + +class MachineBasicBlock; +class MachineFunction; +class MachineInstr; +class RegisterScavenger; +class TargetDescription; + +struct FrameIndexReference final { + PhysicalRegister BaseRegister; + std::int64_t Offset = 0; +}; + +class TargetFrameLowering { +public: + virtual ~TargetFrameLowering() = default; + + [[nodiscard]] virtual Expected prepareFrame(MachineFunction &Function, + const TargetDescription &Target) const = 0; + [[nodiscard]] virtual Expected + insertCalleeSavedSpillsAndRestores(MachineFunction &Function, + const TargetDescription &Target) const = 0; + [[nodiscard]] virtual Expected + processFunctionBeforeFrameFinalized(MachineFunction &, const TargetDescription &) const { + return {}; + } + [[nodiscard]] virtual Expected finalizeFrame(MachineFunction &Function, + const TargetDescription &Target) const = 0; + + [[nodiscard]] virtual bool isCallFramePseudo(const MachineInstr &Instruction) const noexcept = 0; + [[nodiscard]] virtual Expected + eliminateCallFramePseudo(MachineInstr &Instruction, MachineFunction &Function, + const TargetDescription &Target, RegisterScavenger &Scavenger) const = 0; + + [[nodiscard]] virtual Expected emitPrologue(MachineFunction &Function, + const TargetDescription &Target, + RegisterScavenger &Scavenger) const = 0; + [[nodiscard]] virtual bool + isEpilogueTerminator(const MachineInstr &Instruction, + const TargetDescription &Target) const noexcept = 0; + [[nodiscard]] virtual Expected + emitEpilogue(MachineBasicBlock &Block, MachineInstr &Terminator, MachineFunction &Function, + const TargetDescription &Target, RegisterScavenger &Scavenger) const = 0; + [[nodiscard]] virtual Expected + processFunctionBeforeFrameIndexElimination(MachineFunction &, const TargetDescription &) const { + return {}; + } + + [[nodiscard]] virtual Expected + getFrameIndexReference(const MachineFunction &Function, const MachineInstr &Instruction, + FrameIndex Index, std::int64_t OperandOffset) const = 0; + [[nodiscard]] virtual Expected eliminateFrameIndex(MachineInstr &Instruction, + std::size_t OperandIndex, + MachineFunction &Function, + const TargetDescription &Target, + RegisterScavenger &Scavenger) const = 0; +}; + +} // namespace rcc + +#endif // RCC_CODEGEN_TARGETFRAMELOWERING_H diff --git a/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h b/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h index 6e25465..4448933 100644 --- a/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h +++ b/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h @@ -51,6 +51,11 @@ public: RegisterClassID) const noexcept { return 1; } + + [[nodiscard]] virtual bool isReservedForFunction(const MachineFunction &, PhysicalRegister, + const TargetDescription &) const noexcept { + return false; + } }; } // namespace rcc -- cgit v1.2.3