1 //=-- BPFMCInstLower.cpp - Convert BPF MachineInstr to an MCInst ------------=// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains code to lower BPF MachineInstrs to their corresponding 11 // MCInst records. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "BPFMCInstLower.h" 16 #include "llvm/CodeGen/AsmPrinter.h" 17 #include "llvm/CodeGen/MachineBasicBlock.h" 18 #include "llvm/CodeGen/MachineInstr.h" 19 #include "llvm/MC/MCAsmInfo.h" 20 #include "llvm/MC/MCContext.h" 21 #include "llvm/MC/MCExpr.h" 22 #include "llvm/MC/MCInst.h" 23 #include "llvm/Support/ErrorHandling.h" 24 #include "llvm/Support/raw_ostream.h" 25 using namespace llvm; 26 27 MCSymbol * 28 BPFMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const { 29 return Printer.getSymbol(MO.getGlobal()); 30 } 31 32 MCOperand BPFMCInstLower::LowerSymbolOperand(const MachineOperand &MO, 33 MCSymbol *Sym) const { 34 35 const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx); 36 37 if (!MO.isJTI() && MO.getOffset()) 38 llvm_unreachable("unknown symbol op"); 39 40 return MCOperand::createExpr(Expr); 41 } 42 43 void BPFMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const { 44 OutMI.setOpcode(MI->getOpcode()); 45 46 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 47 const MachineOperand &MO = MI->getOperand(i); 48 49 MCOperand MCOp; 50 switch (MO.getType()) { 51 default: 52 MI->dump(); 53 llvm_unreachable("unknown operand type"); 54 case MachineOperand::MO_Register: 55 // Ignore all implicit register operands. 56 if (MO.isImplicit()) 57 continue; 58 MCOp = MCOperand::createReg(MO.getReg()); 59 break; 60 case MachineOperand::MO_Immediate: 61 MCOp = MCOperand::createImm(MO.getImm()); 62 break; 63 case MachineOperand::MO_MachineBasicBlock: 64 MCOp = MCOperand::createExpr( 65 MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx)); 66 break; 67 case MachineOperand::MO_RegisterMask: 68 continue; 69 case MachineOperand::MO_GlobalAddress: 70 MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO)); 71 break; 72 } 73 74 OutMI.addOperand(MCOp); 75 } 76 } 77
