ff55e2e047
We would like to split the SP adjustment to reduce the instructions in
prologue and epilogue as the following case. In this way, the offset of
the callee saved register could fit in a single store.
add sp,sp,-2032
sw ra,2028(sp)
sw s0,2024(sp)
sw s1,2020(sp)
sw s3,2012(sp)
sw s4,2008(sp)
add sp,sp,-64
Differential Revision: https://reviews.llvm.org/D68011
llvm-svn: 373688
64 lines
2.4 KiB
C++
64 lines
2.4 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=*/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 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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// 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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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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