-
-// Adapt the Emitter / CodeEmitter interfaces to MCCodeEmitter.
-//
-// FIXME: This is a total hack designed to allow work on llvm-mc to proceed
-// without being blocked on various cleanups needed to support a clean interface
-// to instruction encoding.
-//
-// Look away!
-
-#include "llvm/DerivedTypes.h"
-
-namespace {
-class MCSingleInstructionCodeEmitter : public MachineCodeEmitter {
- uint8_t Data[256];
-
-public:
- MCSingleInstructionCodeEmitter() { reset(); }
-
- void reset() {
- BufferBegin = Data;
- BufferEnd = array_endof(Data);
- CurBufferPtr = Data;
- }
-
- StringRef str() {
- return StringRef(reinterpret_cast<char*>(BufferBegin),
- CurBufferPtr - BufferBegin);
- }
-
- virtual void startFunction(MachineFunction &F) {}
- virtual bool finishFunction(MachineFunction &F) { return false; }
- virtual void emitLabel(uint64_t LabelID) {}
- virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {}
- virtual bool earlyResolveAddresses() const { return false; }
- virtual void addRelocation(const MachineRelocation &MR) { }
- virtual uintptr_t getConstantPoolEntryAddress(unsigned Index) const {
- return 0;
- }
- virtual uintptr_t getJumpTableEntryAddress(unsigned Index) const {
- return 0;
- }
- virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
- return 0;
- }
- virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
- return 0;
- }
- virtual void setModuleInfo(MachineModuleInfo* Info) {}
-};
-
-class X86MCCodeEmitter : public MCCodeEmitter {
- X86MCCodeEmitter(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
- void operator=(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
-
-private:
- X86TargetMachine &TM;
- llvm::Function *DummyF;
- TargetData *DummyTD;
- mutable llvm::MachineFunction *DummyMF;
- llvm::MachineBasicBlock *DummyMBB;
-
- MCSingleInstructionCodeEmitter *InstrEmitter;
- Emitter<MachineCodeEmitter> *Emit;
-
-public:
- X86MCCodeEmitter(X86TargetMachine &_TM) : TM(_TM) {
- // Verily, thou shouldst avert thine eyes.
- const llvm::FunctionType *FTy =
- FunctionType::get(llvm::Type::getVoidTy(getGlobalContext()), false);
- DummyF = Function::Create(FTy, GlobalValue::InternalLinkage);
- DummyTD = new TargetData("");
- DummyMF = new MachineFunction(DummyF, TM);
- DummyMBB = DummyMF->CreateMachineBasicBlock();
-
- InstrEmitter = new MCSingleInstructionCodeEmitter();
- Emit = new Emitter<MachineCodeEmitter>(TM, *InstrEmitter,
- *TM.getInstrInfo(),
- *DummyTD, false);
- }
- ~X86MCCodeEmitter() {
- delete Emit;
- delete InstrEmitter;
- delete DummyMF;
- delete DummyF;
- }
-
- bool AddRegToInstr(const MCInst &MI, MachineInstr *Instr,
- unsigned Start) const {
- if (Start + 1 > MI.getNumOperands())
- return false;
-
- const MCOperand &Op = MI.getOperand(Start);
- if (!Op.isReg()) return false;
-
- Instr->addOperand(MachineOperand::CreateReg(Op.getReg(), false));
- return true;
- }
-
- bool AddImmToInstr(const MCInst &MI, MachineInstr *Instr,
- unsigned Start) const {
- if (Start + 1 > MI.getNumOperands())
- return false;
-
- const MCOperand &Op = MI.getOperand(Start);
- if (Op.isImm()) {
- Instr->addOperand(MachineOperand::CreateImm(Op.getImm()));
- return true;
- }
- if (!Op.isExpr())
- return false;
-
- const MCExpr *Expr = Op.getExpr();
- if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Expr)) {
- Instr->addOperand(MachineOperand::CreateImm(CE->getValue()));
- return true;
- }
-
- // FIXME: Relocation / fixup.
- Instr->addOperand(MachineOperand::CreateImm(0));
- return true;
- }
-
- bool AddLMemToInstr(const MCInst &MI, MachineInstr *Instr,
- unsigned Start) const {
- return (AddRegToInstr(MI, Instr, Start + 0) &&
- AddImmToInstr(MI, Instr, Start + 1) &&
- AddRegToInstr(MI, Instr, Start + 2) &&
- AddImmToInstr(MI, Instr, Start + 3));
- }
-
- bool AddMemToInstr(const MCInst &MI, MachineInstr *Instr,
- unsigned Start) const {
- return (AddRegToInstr(MI, Instr, Start + 0) &&
- AddImmToInstr(MI, Instr, Start + 1) &&
- AddRegToInstr(MI, Instr, Start + 2) &&
- AddImmToInstr(MI, Instr, Start + 3) &&
- AddRegToInstr(MI, Instr, Start + 4));
- }
-
- void EncodeInstruction(const MCInst &MI, raw_ostream &OS) const {
- // Don't look yet!
-
- // Convert the MCInst to a MachineInstr so we can (ab)use the regular
- // emitter.
- const X86InstrInfo &II = *TM.getInstrInfo();
- const TargetInstrDesc &Desc = II.get(MI.getOpcode());
- MachineInstr *Instr = DummyMF->CreateMachineInstr(Desc, DebugLoc());
- DummyMBB->push_back(Instr);
-
- unsigned Opcode = MI.getOpcode();
- unsigned NumOps = MI.getNumOperands();
- unsigned CurOp = 0;
- if (NumOps > 1 && Desc.getOperandConstraint(1, TOI::TIED_TO) != -1) {
- Instr->addOperand(MachineOperand::CreateReg(0, false));
- ++CurOp;
- } else if (NumOps > 2 &&
- Desc.getOperandConstraint(NumOps-1, TOI::TIED_TO)== 0)
- // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
- --NumOps;
-
- bool OK = true;
- switch (Desc.TSFlags & X86II::FormMask) {
- case X86II::MRMDestReg:
- case X86II::MRMSrcReg:
- // Matching doesn't fill this in completely, we have to choose operand 0
- // for a tied register.
- OK &= AddRegToInstr(MI, Instr, 0); CurOp++;
- OK &= AddRegToInstr(MI, Instr, CurOp++);
- if (CurOp < NumOps)
- OK &= AddImmToInstr(MI, Instr, CurOp);
- break;
-
- case X86II::RawFrm:
- if (CurOp < NumOps) {
- // Hack to make branches work.
- if (!(Desc.TSFlags & X86II::ImmMask) &&
- MI.getOperand(0).isExpr() &&
- isa<MCSymbolRefExpr>(MI.getOperand(0).getExpr()))
- Instr->addOperand(MachineOperand::CreateMBB(DummyMBB));
- else
- OK &= AddImmToInstr(MI, Instr, CurOp);
- }
- break;
-
- case X86II::AddRegFrm:
- OK &= AddRegToInstr(MI, Instr, CurOp++);
- if (CurOp < NumOps)
- OK &= AddImmToInstr(MI, Instr, CurOp);
- break;
-
- case X86II::MRM0r: case X86II::MRM1r:
- case X86II::MRM2r: case X86II::MRM3r:
- case X86II::MRM4r: case X86II::MRM5r:
- case X86II::MRM6r: case X86II::MRM7r:
- // Matching doesn't fill this in completely, we have to choose operand 0
- // for a tied register.
- OK &= AddRegToInstr(MI, Instr, 0); CurOp++;
- if (CurOp < NumOps)
- OK &= AddImmToInstr(MI, Instr, CurOp);
- break;
-
- case X86II::MRM0m: case X86II::MRM1m:
- case X86II::MRM2m: case X86II::MRM3m:
- case X86II::MRM4m: case X86II::MRM5m:
- case X86II::MRM6m: case X86II::MRM7m:
- OK &= AddMemToInstr(MI, Instr, CurOp); CurOp += 5;
- if (CurOp < NumOps)
- OK &= AddImmToInstr(MI, Instr, CurOp);
- break;
-
- case X86II::MRMSrcMem:
- OK &= AddRegToInstr(MI, Instr, CurOp++);
- if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r ||
- Opcode == X86::LEA16r || Opcode == X86::LEA32r)
- OK &= AddLMemToInstr(MI, Instr, CurOp);
- else
- OK &= AddMemToInstr(MI, Instr, CurOp);
- break;
-
- case X86II::MRMDestMem:
- OK &= AddMemToInstr(MI, Instr, CurOp); CurOp += 5;
- OK &= AddRegToInstr(MI, Instr, CurOp);
- break;
-
- default:
- case X86II::MRMInitReg:
- case X86II::Pseudo:
- OK = false;
- break;
- }
-
- if (!OK) {
- errs() << "couldn't convert inst '";
- MI.dump();
- errs() << "' to machine instr:\n";
- Instr->dump();
- }
-
- InstrEmitter->reset();
- if (OK)
- Emit->emitInstruction(*Instr, &Desc);
- OS << InstrEmitter->str();
-
- Instr->eraseFromParent();
- }
-};
-}
-
-// Ok, now you can look.
-MCCodeEmitter *llvm::createX86MCCodeEmitter(const Target &,
- TargetMachine &TM) {
- return new X86MCCodeEmitter(static_cast<X86TargetMachine&>(TM));
-}