07f7c00208
This patch adds the support required for using the __riscv_save and __riscv_restore libcalls to implement a size-optimization for prologue and epilogue code, whereby the spill and restore code of callee-saved registers is implemented by common functions to reduce code duplication. Logic is also included to ensure that if both this optimization and shrink wrapping are enabled then the prologue and epilogue code can be safely inserted into the basic blocks chosen by shrink wrapping. Differential Revision: https://reviews.llvm.org/D62686
78 lines
3.1 KiB
C++
78 lines
3.1 KiB
C++
//===-- RISCVFrameLowering.h - Define frame lowering for RISCV -*- C++ -*--===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This class implements RISCV-specific bits of TargetFrameLowering class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H
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#define LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H
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#include "llvm/CodeGen/TargetFrameLowering.h"
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namespace llvm {
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class RISCVSubtarget;
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class RISCVFrameLowering : public TargetFrameLowering {
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public:
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explicit RISCVFrameLowering(const RISCVSubtarget &STI)
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: TargetFrameLowering(StackGrowsDown,
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/*StackAlignment=*/Align(16),
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/*LocalAreaOffset=*/0),
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STI(STI) {}
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void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
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void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
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int getFrameIndexReference(const MachineFunction &MF, int FI,
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unsigned &FrameReg) const override;
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void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
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RegScavenger *RS) const override;
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void processFunctionBeforeFrameFinalized(MachineFunction &MF,
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RegScavenger *RS) const override;
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bool hasFP(const MachineFunction &MF) const override;
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bool hasBP(const MachineFunction &MF) const;
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bool hasReservedCallFrame(const MachineFunction &MF) const override;
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MachineBasicBlock::iterator
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eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI) const override;
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bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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ArrayRef<CalleeSavedInfo> CSI,
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const TargetRegisterInfo *TRI) const override;
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bool
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restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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std::vector<CalleeSavedInfo> &CSI,
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const TargetRegisterInfo *TRI) const override;
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// Get the first stack adjustment amount for SplitSPAdjust.
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// Return 0 if we don't want to to split the SP adjustment in prologue and
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// epilogue.
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uint64_t getFirstSPAdjustAmount(const MachineFunction &MF) const;
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bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
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bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
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protected:
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const RISCVSubtarget &STI;
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private:
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void determineFrameLayout(MachineFunction &MF) const;
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void adjustReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
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const DebugLoc &DL, Register DestReg, Register SrcReg,
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int64_t Val, MachineInstr::MIFlag Flag) const;
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};
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}
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#endif
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