91 lines · cpp
1//=-- BPFMCInstLower.cpp - Convert BPF MachineInstr to an MCInst ------------=//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file contains code to lower BPF MachineInstrs to their corresponding10// MCInst records.11//12//===----------------------------------------------------------------------===//13 14#include "BPFMCInstLower.h"15#include "BPFAsmPrinter.h"16#include "BPFISelLowering.h"17#include "llvm/CodeGen/AsmPrinter.h"18#include "llvm/CodeGen/MachineBasicBlock.h"19#include "llvm/CodeGen/MachineInstr.h"20#include "llvm/MC/MCAsmInfo.h"21#include "llvm/MC/MCContext.h"22#include "llvm/MC/MCExpr.h"23#include "llvm/MC/MCInst.h"24#include "llvm/MC/MCStreamer.h"25#include "llvm/Support/ErrorHandling.h"26#include "llvm/Support/raw_ostream.h"27using namespace llvm;28 29MCSymbol *30BPFMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const {31 return Printer.getSymbol(MO.getGlobal());32}33 34MCSymbol *35BPFMCInstLower::GetExternalSymbolSymbol(const MachineOperand &MO) const {36 return Printer.GetExternalSymbolSymbol(MO.getSymbolName());37}38 39MCOperand BPFMCInstLower::LowerSymbolOperand(const MachineOperand &MO,40 MCSymbol *Sym) const {41 42 const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);43 44 if (!MO.isJTI() && MO.getOffset())45 llvm_unreachable("unknown symbol op");46 47 return MCOperand::createExpr(Expr);48}49 50void BPFMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {51 OutMI.setOpcode(MI->getOpcode());52 53 for (const MachineOperand &MO : MI->operands()) {54 MCOperand MCOp;55 switch (MO.getType()) {56 default:57 MI->print(errs());58 llvm_unreachable("unknown operand type");59 case MachineOperand::MO_Register:60 // Ignore all implicit register operands.61 if (MO.isImplicit())62 continue;63 MCOp = MCOperand::createReg(MO.getReg());64 break;65 case MachineOperand::MO_Immediate:66 MCOp = MCOperand::createImm(MO.getImm());67 break;68 case MachineOperand::MO_MachineBasicBlock:69 MCOp = MCOperand::createExpr(70 MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));71 break;72 case MachineOperand::MO_RegisterMask:73 continue;74 case MachineOperand::MO_ExternalSymbol:75 MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));76 break;77 case MachineOperand::MO_GlobalAddress:78 MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));79 break;80 case MachineOperand::MO_ConstantPoolIndex:81 MCOp = LowerSymbolOperand(MO, Printer.GetCPISymbol(MO.getIndex()));82 break;83 case MachineOperand::MO_JumpTableIndex:84 MCOp = LowerSymbolOperand(MO, Printer.getJTPublicSymbol(MO.getIndex()));85 break;86 }87 88 OutMI.addOperand(MCOp);89 }90}91