85 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			85 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
| //=-- BPFMCInstLower.cpp - Convert BPF MachineInstr to an MCInst ------------=//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file contains code to lower BPF MachineInstrs to their corresponding
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| // MCInst records.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "BPFMCInstLower.h"
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| #include "llvm/CodeGen/AsmPrinter.h"
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| #include "llvm/CodeGen/MachineBasicBlock.h"
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| #include "llvm/CodeGen/MachineInstr.h"
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| #include "llvm/MC/MCAsmInfo.h"
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| #include "llvm/MC/MCContext.h"
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| #include "llvm/MC/MCExpr.h"
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| #include "llvm/MC/MCInst.h"
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| #include "llvm/Support/ErrorHandling.h"
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| #include "llvm/Support/raw_ostream.h"
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| using namespace llvm;
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| 
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| MCSymbol *
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| BPFMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const {
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|   return Printer.getSymbol(MO.getGlobal());
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| }
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| 
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| MCSymbol *
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| BPFMCInstLower::GetExternalSymbolSymbol(const MachineOperand &MO) const {
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|   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
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| }
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| 
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| MCOperand BPFMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
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|                                              MCSymbol *Sym) const {
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| 
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|   const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
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| 
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|   if (!MO.isJTI() && MO.getOffset())
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|     llvm_unreachable("unknown symbol op");
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| 
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|   return MCOperand::createExpr(Expr);
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| }
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| 
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| void BPFMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
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|   OutMI.setOpcode(MI->getOpcode());
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| 
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|   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
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|     const MachineOperand &MO = MI->getOperand(i);
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| 
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|     MCOperand MCOp;
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|     switch (MO.getType()) {
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|     default:
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|       MI->print(errs());
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|       llvm_unreachable("unknown operand type");
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|     case MachineOperand::MO_Register:
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|       // Ignore all implicit register operands.
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|       if (MO.isImplicit())
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|         continue;
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|       MCOp = MCOperand::createReg(MO.getReg());
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|       break;
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|     case MachineOperand::MO_Immediate:
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|       MCOp = MCOperand::createImm(MO.getImm());
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|       break;
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|     case MachineOperand::MO_MachineBasicBlock:
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|       MCOp = MCOperand::createExpr(
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|           MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
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|       break;
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|     case MachineOperand::MO_RegisterMask:
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|       continue;
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|     case MachineOperand::MO_ExternalSymbol:
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|       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
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|       break;
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|     case MachineOperand::MO_GlobalAddress:
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|       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
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|       break;
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|     }
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| 
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|     OutMI.addOperand(MCOp);
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|   }
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| }
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