| //===-- X86/X86CodeEmitter.cpp - Convert X86 code to machine code ---------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains the pass that transforms the X86 machine instructions into |
| // relocatable machine code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "x86-emitter" |
| #include "X86InstrInfo.h" |
| #include "X86JITInfo.h" |
| #include "X86Subtarget.h" |
| #include "X86TargetMachine.h" |
| #include "X86Relocations.h" |
| #include "X86.h" |
| #include "llvm/LLVMContext.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/CodeGen/JITCodeEmitter.h" |
| #include "llvm/CodeGen/MachineFunctionPass.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineModuleInfo.h" |
| #include "llvm/CodeGen/Passes.h" |
| #include "llvm/Function.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/MC/MCCodeEmitter.h" |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetOptions.h" |
| using namespace llvm; |
| |
| STATISTIC(NumEmitted, "Number of machine instructions emitted"); |
| |
| namespace { |
| template<class CodeEmitter> |
| class Emitter : public MachineFunctionPass { |
| const X86InstrInfo *II; |
| const TargetData *TD; |
| X86TargetMachine &TM; |
| CodeEmitter &MCE; |
| MachineModuleInfo *MMI; |
| intptr_t PICBaseOffset; |
| bool Is64BitMode; |
| bool IsPIC; |
| public: |
| static char ID; |
| explicit Emitter(X86TargetMachine &tm, CodeEmitter &mce) |
| : MachineFunctionPass(ID), II(0), TD(0), TM(tm), |
| MCE(mce), PICBaseOffset(0), Is64BitMode(false), |
| IsPIC(TM.getRelocationModel() == Reloc::PIC_) {} |
| Emitter(X86TargetMachine &tm, CodeEmitter &mce, |
| const X86InstrInfo &ii, const TargetData &td, bool is64) |
| : MachineFunctionPass(ID), II(&ii), TD(&td), TM(tm), |
| MCE(mce), PICBaseOffset(0), Is64BitMode(is64), |
| IsPIC(TM.getRelocationModel() == Reloc::PIC_) {} |
| |
| bool runOnMachineFunction(MachineFunction &MF); |
| |
| virtual const char *getPassName() const { |
| return "X86 Machine Code Emitter"; |
| } |
| |
| void emitInstruction(MachineInstr &MI, const MCInstrDesc *Desc); |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesAll(); |
| AU.addRequired<MachineModuleInfo>(); |
| MachineFunctionPass::getAnalysisUsage(AU); |
| } |
| |
| private: |
| void emitPCRelativeBlockAddress(MachineBasicBlock *MBB); |
| void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc, |
| intptr_t Disp = 0, intptr_t PCAdj = 0, |
| bool Indirect = false); |
| void emitExternalSymbolAddress(const char *ES, unsigned Reloc); |
| void emitConstPoolAddress(unsigned CPI, unsigned Reloc, intptr_t Disp = 0, |
| intptr_t PCAdj = 0); |
| void emitJumpTableAddress(unsigned JTI, unsigned Reloc, |
| intptr_t PCAdj = 0); |
| |
| void emitDisplacementField(const MachineOperand *RelocOp, int DispVal, |
| intptr_t Adj = 0, bool IsPCRel = true); |
| |
| void emitRegModRMByte(unsigned ModRMReg, unsigned RegOpcodeField); |
| void emitRegModRMByte(unsigned RegOpcodeField); |
| void emitSIBByte(unsigned SS, unsigned Index, unsigned Base); |
| void emitConstant(uint64_t Val, unsigned Size); |
| |
| void emitMemModRMByte(const MachineInstr &MI, |
| unsigned Op, unsigned RegOpcodeField, |
| intptr_t PCAdj = 0); |
| }; |
| |
| template<class CodeEmitter> |
| char Emitter<CodeEmitter>::ID = 0; |
| } // end anonymous namespace. |
| |
| /// createX86CodeEmitterPass - Return a pass that emits the collected X86 code |
| /// to the specified templated MachineCodeEmitter object. |
| FunctionPass *llvm::createX86JITCodeEmitterPass(X86TargetMachine &TM, |
| JITCodeEmitter &JCE) { |
| return new Emitter<JITCodeEmitter>(TM, JCE); |
| } |
| |
| template<class CodeEmitter> |
| bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) { |
| MMI = &getAnalysis<MachineModuleInfo>(); |
| MCE.setModuleInfo(MMI); |
| |
| II = TM.getInstrInfo(); |
| TD = TM.getTargetData(); |
| Is64BitMode = TM.getSubtarget<X86Subtarget>().is64Bit(); |
| IsPIC = TM.getRelocationModel() == Reloc::PIC_; |
| |
| do { |
| DEBUG(dbgs() << "JITTing function '" |
| << MF.getFunction()->getName() << "'\n"); |
| MCE.startFunction(MF); |
| for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); |
| MBB != E; ++MBB) { |
| MCE.StartMachineBasicBlock(MBB); |
| for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); |
| I != E; ++I) { |
| const MCInstrDesc &Desc = I->getDesc(); |
| emitInstruction(*I, &Desc); |
| // MOVPC32r is basically a call plus a pop instruction. |
| if (Desc.getOpcode() == X86::MOVPC32r) |
| emitInstruction(*I, &II->get(X86::POP32r)); |
| ++NumEmitted; // Keep track of the # of mi's emitted |
| } |
| } |
| } while (MCE.finishFunction(MF)); |
| |
| return false; |
| } |
| |
| /// determineREX - Determine if the MachineInstr has to be encoded with a X86-64 |
| /// REX prefix which specifies 1) 64-bit instructions, 2) non-default operand |
| /// size, and 3) use of X86-64 extended registers. |
| static unsigned determineREX(const MachineInstr &MI) { |
| unsigned REX = 0; |
| const MCInstrDesc &Desc = MI.getDesc(); |
| |
| // Pseudo instructions do not need REX prefix byte. |
| if ((Desc.TSFlags & X86II::FormMask) == X86II::Pseudo) |
| return 0; |
| if (Desc.TSFlags & X86II::REX_W) |
| REX |= 1 << 3; |
| |
| unsigned NumOps = Desc.getNumOperands(); |
| if (NumOps) { |
| bool isTwoAddr = NumOps > 1 && |
| Desc.getOperandConstraint(1, MCOI::TIED_TO) != -1; |
| |
| // If it accesses SPL, BPL, SIL, or DIL, then it requires a 0x40 REX prefix. |
| unsigned i = isTwoAddr ? 1 : 0; |
| for (unsigned e = NumOps; i != e; ++i) { |
| const MachineOperand& MO = MI.getOperand(i); |
| if (MO.isReg()) { |
| unsigned Reg = MO.getReg(); |
| if (X86II::isX86_64NonExtLowByteReg(Reg)) |
| REX |= 0x40; |
| } |
| } |
| |
| switch (Desc.TSFlags & X86II::FormMask) { |
| case X86II::MRMInitReg: |
| if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0))) |
| REX |= (1 << 0) | (1 << 2); |
| break; |
| case X86II::MRMSrcReg: { |
| if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0))) |
| REX |= 1 << 2; |
| i = isTwoAddr ? 2 : 1; |
| for (unsigned e = NumOps; i != e; ++i) { |
| const MachineOperand& MO = MI.getOperand(i); |
| if (X86InstrInfo::isX86_64ExtendedReg(MO)) |
| REX |= 1 << 0; |
| } |
| break; |
| } |
| case X86II::MRMSrcMem: { |
| if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0))) |
| REX |= 1 << 2; |
| unsigned Bit = 0; |
| i = isTwoAddr ? 2 : 1; |
| for (; i != NumOps; ++i) { |
| const MachineOperand& MO = MI.getOperand(i); |
| if (MO.isReg()) { |
| if (X86InstrInfo::isX86_64ExtendedReg(MO)) |
| REX |= 1 << Bit; |
| Bit++; |
| } |
| } |
| 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: |
| case X86II::MRMDestMem: { |
| unsigned e = (isTwoAddr ? X86::AddrNumOperands+1 : X86::AddrNumOperands); |
| i = isTwoAddr ? 1 : 0; |
| if (NumOps > e && X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(e))) |
| REX |= 1 << 2; |
| unsigned Bit = 0; |
| for (; i != e; ++i) { |
| const MachineOperand& MO = MI.getOperand(i); |
| if (MO.isReg()) { |
| if (X86InstrInfo::isX86_64ExtendedReg(MO)) |
| REX |= 1 << Bit; |
| Bit++; |
| } |
| } |
| break; |
| } |
| default: { |
| if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0))) |
| REX |= 1 << 0; |
| i = isTwoAddr ? 2 : 1; |
| for (unsigned e = NumOps; i != e; ++i) { |
| const MachineOperand& MO = MI.getOperand(i); |
| if (X86InstrInfo::isX86_64ExtendedReg(MO)) |
| REX |= 1 << 2; |
| } |
| break; |
| } |
| } |
| } |
| return REX; |
| } |
| |
| |
| /// emitPCRelativeBlockAddress - This method keeps track of the information |
| /// necessary to resolve the address of this block later and emits a dummy |
| /// value. |
| /// |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitPCRelativeBlockAddress(MachineBasicBlock *MBB) { |
| // Remember where this reference was and where it is to so we can |
| // deal with it later. |
| MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(), |
| X86::reloc_pcrel_word, MBB)); |
| MCE.emitWordLE(0); |
| } |
| |
| /// emitGlobalAddress - Emit the specified address to the code stream assuming |
| /// this is part of a "take the address of a global" instruction. |
| /// |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitGlobalAddress(const GlobalValue *GV, |
| unsigned Reloc, |
| intptr_t Disp /* = 0 */, |
| intptr_t PCAdj /* = 0 */, |
| bool Indirect /* = false */) { |
| intptr_t RelocCST = Disp; |
| if (Reloc == X86::reloc_picrel_word) |
| RelocCST = PICBaseOffset; |
| else if (Reloc == X86::reloc_pcrel_word) |
| RelocCST = PCAdj; |
| MachineRelocation MR = Indirect |
| ? MachineRelocation::getIndirectSymbol(MCE.getCurrentPCOffset(), Reloc, |
| const_cast<GlobalValue *>(GV), |
| RelocCST, false) |
| : MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, |
| const_cast<GlobalValue *>(GV), RelocCST, false); |
| MCE.addRelocation(MR); |
| // The relocated value will be added to the displacement |
| if (Reloc == X86::reloc_absolute_dword) |
| MCE.emitDWordLE(Disp); |
| else |
| MCE.emitWordLE((int32_t)Disp); |
| } |
| |
| /// emitExternalSymbolAddress - Arrange for the address of an external symbol to |
| /// be emitted to the current location in the function, and allow it to be PC |
| /// relative. |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitExternalSymbolAddress(const char *ES, |
| unsigned Reloc) { |
| intptr_t RelocCST = (Reloc == X86::reloc_picrel_word) ? PICBaseOffset : 0; |
| |
| // X86 never needs stubs because instruction selection will always pick |
| // an instruction sequence that is large enough to hold any address |
| // to a symbol. |
| // (see X86ISelLowering.cpp, near 2039: X86TargetLowering::LowerCall) |
| bool NeedStub = false; |
| MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(), |
| Reloc, ES, RelocCST, |
| 0, NeedStub)); |
| if (Reloc == X86::reloc_absolute_dword) |
| MCE.emitDWordLE(0); |
| else |
| MCE.emitWordLE(0); |
| } |
| |
| /// emitConstPoolAddress - Arrange for the address of an constant pool |
| /// to be emitted to the current location in the function, and allow it to be PC |
| /// relative. |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitConstPoolAddress(unsigned CPI, unsigned Reloc, |
| intptr_t Disp /* = 0 */, |
| intptr_t PCAdj /* = 0 */) { |
| intptr_t RelocCST = 0; |
| if (Reloc == X86::reloc_picrel_word) |
| RelocCST = PICBaseOffset; |
| else if (Reloc == X86::reloc_pcrel_word) |
| RelocCST = PCAdj; |
| MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(), |
| Reloc, CPI, RelocCST)); |
| // The relocated value will be added to the displacement |
| if (Reloc == X86::reloc_absolute_dword) |
| MCE.emitDWordLE(Disp); |
| else |
| MCE.emitWordLE((int32_t)Disp); |
| } |
| |
| /// emitJumpTableAddress - Arrange for the address of a jump table to |
| /// be emitted to the current location in the function, and allow it to be PC |
| /// relative. |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitJumpTableAddress(unsigned JTI, unsigned Reloc, |
| intptr_t PCAdj /* = 0 */) { |
| intptr_t RelocCST = 0; |
| if (Reloc == X86::reloc_picrel_word) |
| RelocCST = PICBaseOffset; |
| else if (Reloc == X86::reloc_pcrel_word) |
| RelocCST = PCAdj; |
| MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(), |
| Reloc, JTI, RelocCST)); |
| // The relocated value will be added to the displacement |
| if (Reloc == X86::reloc_absolute_dword) |
| MCE.emitDWordLE(0); |
| else |
| MCE.emitWordLE(0); |
| } |
| |
| inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode, |
| unsigned RM) { |
| assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!"); |
| return RM | (RegOpcode << 3) | (Mod << 6); |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitRegModRMByte(unsigned ModRMReg, |
| unsigned RegOpcodeFld){ |
| MCE.emitByte(ModRMByte(3, RegOpcodeFld, X86_MC::getX86RegNum(ModRMReg))); |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitRegModRMByte(unsigned RegOpcodeFld) { |
| MCE.emitByte(ModRMByte(3, RegOpcodeFld, 0)); |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitSIBByte(unsigned SS, |
| unsigned Index, |
| unsigned Base) { |
| // SIB byte is in the same format as the ModRMByte... |
| MCE.emitByte(ModRMByte(SS, Index, Base)); |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitConstant(uint64_t Val, unsigned Size) { |
| // Output the constant in little endian byte order... |
| for (unsigned i = 0; i != Size; ++i) { |
| MCE.emitByte(Val & 255); |
| Val >>= 8; |
| } |
| } |
| |
| /// isDisp8 - Return true if this signed displacement fits in a 8-bit |
| /// sign-extended field. |
| static bool isDisp8(int Value) { |
| return Value == (signed char)Value; |
| } |
| |
| static bool gvNeedsNonLazyPtr(const MachineOperand &GVOp, |
| const TargetMachine &TM) { |
| // For Darwin-64, simulate the linktime GOT by using the same non-lazy-pointer |
| // mechanism as 32-bit mode. |
| if (TM.getSubtarget<X86Subtarget>().is64Bit() && |
| !TM.getSubtarget<X86Subtarget>().isTargetDarwin()) |
| return false; |
| |
| // Return true if this is a reference to a stub containing the address of the |
| // global, not the global itself. |
| return isGlobalStubReference(GVOp.getTargetFlags()); |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitDisplacementField(const MachineOperand *RelocOp, |
| int DispVal, |
| intptr_t Adj /* = 0 */, |
| bool IsPCRel /* = true */) { |
| // If this is a simple integer displacement that doesn't require a relocation, |
| // emit it now. |
| if (!RelocOp) { |
| emitConstant(DispVal, 4); |
| return; |
| } |
| |
| // Otherwise, this is something that requires a relocation. Emit it as such |
| // now. |
| unsigned RelocType = Is64BitMode ? |
| (IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext) |
| : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| if (RelocOp->isGlobal()) { |
| // In 64-bit static small code model, we could potentially emit absolute. |
| // But it's probably not beneficial. If the MCE supports using RIP directly |
| // do it, otherwise fallback to absolute (this is determined by IsPCRel). |
| // 89 05 00 00 00 00 mov %eax,0(%rip) # PC-relative |
| // 89 04 25 00 00 00 00 mov %eax,0x0 # Absolute |
| bool Indirect = gvNeedsNonLazyPtr(*RelocOp, TM); |
| emitGlobalAddress(RelocOp->getGlobal(), RelocType, RelocOp->getOffset(), |
| Adj, Indirect); |
| } else if (RelocOp->isSymbol()) { |
| emitExternalSymbolAddress(RelocOp->getSymbolName(), RelocType); |
| } else if (RelocOp->isCPI()) { |
| emitConstPoolAddress(RelocOp->getIndex(), RelocType, |
| RelocOp->getOffset(), Adj); |
| } else { |
| assert(RelocOp->isJTI() && "Unexpected machine operand!"); |
| emitJumpTableAddress(RelocOp->getIndex(), RelocType, Adj); |
| } |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitMemModRMByte(const MachineInstr &MI, |
| unsigned Op,unsigned RegOpcodeField, |
| intptr_t PCAdj) { |
| const MachineOperand &Op3 = MI.getOperand(Op+3); |
| int DispVal = 0; |
| const MachineOperand *DispForReloc = 0; |
| |
| // Figure out what sort of displacement we have to handle here. |
| if (Op3.isGlobal()) { |
| DispForReloc = &Op3; |
| } else if (Op3.isSymbol()) { |
| DispForReloc = &Op3; |
| } else if (Op3.isCPI()) { |
| if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) { |
| DispForReloc = &Op3; |
| } else { |
| DispVal += MCE.getConstantPoolEntryAddress(Op3.getIndex()); |
| DispVal += Op3.getOffset(); |
| } |
| } else if (Op3.isJTI()) { |
| if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) { |
| DispForReloc = &Op3; |
| } else { |
| DispVal += MCE.getJumpTableEntryAddress(Op3.getIndex()); |
| } |
| } else { |
| DispVal = Op3.getImm(); |
| } |
| |
| const MachineOperand &Base = MI.getOperand(Op); |
| const MachineOperand &Scale = MI.getOperand(Op+1); |
| const MachineOperand &IndexReg = MI.getOperand(Op+2); |
| |
| unsigned BaseReg = Base.getReg(); |
| |
| // Handle %rip relative addressing. |
| if (BaseReg == X86::RIP || |
| (Is64BitMode && DispForReloc)) { // [disp32+RIP] in X86-64 mode |
| assert(IndexReg.getReg() == 0 && Is64BitMode && |
| "Invalid rip-relative address"); |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, 5)); |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, true); |
| return; |
| } |
| |
| // Indicate that the displacement will use an pcrel or absolute reference |
| // by default. MCEs able to resolve addresses on-the-fly use pcrel by default |
| // while others, unless explicit asked to use RIP, use absolute references. |
| bool IsPCRel = MCE.earlyResolveAddresses() ? true : false; |
| |
| // Is a SIB byte needed? |
| // If no BaseReg, issue a RIP relative instruction only if the MCE can |
| // resolve addresses on-the-fly, otherwise use SIB (Intel Manual 2A, table |
| // 2-7) and absolute references. |
| unsigned BaseRegNo = -1U; |
| if (BaseReg != 0 && BaseReg != X86::RIP) |
| BaseRegNo = X86_MC::getX86RegNum(BaseReg); |
| |
| if (// The SIB byte must be used if there is an index register. |
| IndexReg.getReg() == 0 && |
| // The SIB byte must be used if the base is ESP/RSP/R12, all of which |
| // encode to an R/M value of 4, which indicates that a SIB byte is |
| // present. |
| BaseRegNo != N86::ESP && |
| // If there is no base register and we're in 64-bit mode, we need a SIB |
| // byte to emit an addr that is just 'disp32' (the non-RIP relative form). |
| (!Is64BitMode || BaseReg != 0)) { |
| if (BaseReg == 0 || // [disp32] in X86-32 mode |
| BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, 5)); |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, true); |
| return; |
| } |
| |
| // If the base is not EBP/ESP and there is no displacement, use simple |
| // indirect register encoding, this handles addresses like [EAX]. The |
| // encoding for [EBP] with no displacement means [disp32] so we handle it |
| // by emitting a displacement of 0 below. |
| if (!DispForReloc && DispVal == 0 && BaseRegNo != N86::EBP) { |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, BaseRegNo)); |
| return; |
| } |
| |
| // Otherwise, if the displacement fits in a byte, encode as [REG+disp8]. |
| if (!DispForReloc && isDisp8(DispVal)) { |
| MCE.emitByte(ModRMByte(1, RegOpcodeField, BaseRegNo)); |
| emitConstant(DispVal, 1); |
| return; |
| } |
| |
| // Otherwise, emit the most general non-SIB encoding: [REG+disp32] |
| MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo)); |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel); |
| return; |
| } |
| |
| // Otherwise we need a SIB byte, so start by outputting the ModR/M byte first. |
| assert(IndexReg.getReg() != X86::ESP && |
| IndexReg.getReg() != X86::RSP && "Cannot use ESP as index reg!"); |
| |
| bool ForceDisp32 = false; |
| bool ForceDisp8 = false; |
| if (BaseReg == 0) { |
| // If there is no base register, we emit the special case SIB byte with |
| // MOD=0, BASE=4, to JUST get the index, scale, and displacement. |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, 4)); |
| ForceDisp32 = true; |
| } else if (DispForReloc) { |
| // Emit the normal disp32 encoding. |
| MCE.emitByte(ModRMByte(2, RegOpcodeField, 4)); |
| ForceDisp32 = true; |
| } else if (DispVal == 0 && BaseRegNo != N86::EBP) { |
| // Emit no displacement ModR/M byte |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, 4)); |
| } else if (isDisp8(DispVal)) { |
| // Emit the disp8 encoding... |
| MCE.emitByte(ModRMByte(1, RegOpcodeField, 4)); |
| ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP |
| } else { |
| // Emit the normal disp32 encoding... |
| MCE.emitByte(ModRMByte(2, RegOpcodeField, 4)); |
| } |
| |
| // Calculate what the SS field value should be... |
| static const unsigned SSTable[] = { ~0U, 0, 1, ~0U, 2, ~0U, ~0U, ~0U, 3 }; |
| unsigned SS = SSTable[Scale.getImm()]; |
| |
| if (BaseReg == 0) { |
| // Handle the SIB byte for the case where there is no base, see Intel |
| // Manual 2A, table 2-7. The displacement has already been output. |
| unsigned IndexRegNo; |
| if (IndexReg.getReg()) |
| IndexRegNo = X86_MC::getX86RegNum(IndexReg.getReg()); |
| else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5) |
| IndexRegNo = 4; |
| emitSIBByte(SS, IndexRegNo, 5); |
| } else { |
| unsigned BaseRegNo = X86_MC::getX86RegNum(BaseReg); |
| unsigned IndexRegNo; |
| if (IndexReg.getReg()) |
| IndexRegNo = X86_MC::getX86RegNum(IndexReg.getReg()); |
| else |
| IndexRegNo = 4; // For example [ESP+1*<noreg>+4] |
| emitSIBByte(SS, IndexRegNo, BaseRegNo); |
| } |
| |
| // Do we need to output a displacement? |
| if (ForceDisp8) { |
| emitConstant(DispVal, 1); |
| } else if (DispVal != 0 || ForceDisp32) { |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel); |
| } |
| } |
| |
| static const MCInstrDesc *UpdateOp(MachineInstr &MI, const X86InstrInfo *II, |
| unsigned Opcode) { |
| const MCInstrDesc *Desc = &II->get(Opcode); |
| MI.setDesc(*Desc); |
| return Desc; |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitInstruction(MachineInstr &MI, |
| const MCInstrDesc *Desc) { |
| DEBUG(dbgs() << MI); |
| |
| // If this is a pseudo instruction, lower it. |
| switch (Desc->getOpcode()) { |
| case X86::ADD16rr_DB: Desc = UpdateOp(MI, II, X86::OR16rr); break; |
| case X86::ADD32rr_DB: Desc = UpdateOp(MI, II, X86::OR32rr); break; |
| case X86::ADD64rr_DB: Desc = UpdateOp(MI, II, X86::OR64rr); break; |
| case X86::ADD16ri_DB: Desc = UpdateOp(MI, II, X86::OR16ri); break; |
| case X86::ADD32ri_DB: Desc = UpdateOp(MI, II, X86::OR32ri); break; |
| case X86::ADD64ri32_DB: Desc = UpdateOp(MI, II, X86::OR64ri32); break; |
| case X86::ADD16ri8_DB: Desc = UpdateOp(MI, II, X86::OR16ri8); break; |
| case X86::ADD32ri8_DB: Desc = UpdateOp(MI, II, X86::OR32ri8); break; |
| case X86::ADD64ri8_DB: Desc = UpdateOp(MI, II, X86::OR64ri8); break; |
| case X86::ACQUIRE_MOV8rm: Desc = UpdateOp(MI, II, X86::MOV8rm); break; |
| case X86::ACQUIRE_MOV16rm: Desc = UpdateOp(MI, II, X86::MOV16rm); break; |
| case X86::ACQUIRE_MOV32rm: Desc = UpdateOp(MI, II, X86::MOV32rm); break; |
| case X86::ACQUIRE_MOV64rm: Desc = UpdateOp(MI, II, X86::MOV64rm); break; |
| case X86::RELEASE_MOV8mr: Desc = UpdateOp(MI, II, X86::MOV8mr); break; |
| case X86::RELEASE_MOV16mr: Desc = UpdateOp(MI, II, X86::MOV16mr); break; |
| case X86::RELEASE_MOV32mr: Desc = UpdateOp(MI, II, X86::MOV32mr); break; |
| case X86::RELEASE_MOV64mr: Desc = UpdateOp(MI, II, X86::MOV64mr); break; |
| } |
| |
| |
| MCE.processDebugLoc(MI.getDebugLoc(), true); |
| |
| unsigned Opcode = Desc->Opcode; |
| |
| // Emit the lock opcode prefix as needed. |
| if (Desc->TSFlags & X86II::LOCK) |
| MCE.emitByte(0xF0); |
| |
| // Emit segment override opcode prefix as needed. |
| switch (Desc->TSFlags & X86II::SegOvrMask) { |
| case X86II::FS: |
| MCE.emitByte(0x64); |
| break; |
| case X86II::GS: |
| MCE.emitByte(0x65); |
| break; |
| default: llvm_unreachable("Invalid segment!"); |
| case 0: break; // No segment override! |
| } |
| |
| // Emit the repeat opcode prefix as needed. |
| if ((Desc->TSFlags & X86II::Op0Mask) == X86II::REP) |
| MCE.emitByte(0xF3); |
| |
| // Emit the operand size opcode prefix as needed. |
| if (Desc->TSFlags & X86II::OpSize) |
| MCE.emitByte(0x66); |
| |
| // Emit the address size opcode prefix as needed. |
| if (Desc->TSFlags & X86II::AdSize) |
| MCE.emitByte(0x67); |
| |
| bool Need0FPrefix = false; |
| switch (Desc->TSFlags & X86II::Op0Mask) { |
| case X86II::TB: // Two-byte opcode prefix |
| case X86II::T8: // 0F 38 |
| case X86II::TA: // 0F 3A |
| case X86II::A6: // 0F A6 |
| case X86II::A7: // 0F A7 |
| Need0FPrefix = true; |
| break; |
| case X86II::TF: // F2 0F 38 |
| MCE.emitByte(0xF2); |
| Need0FPrefix = true; |
| break; |
| case X86II::REP: break; // already handled. |
| case X86II::XS: // F3 0F |
| MCE.emitByte(0xF3); |
| Need0FPrefix = true; |
| break; |
| case X86II::XD: // F2 0F |
| MCE.emitByte(0xF2); |
| Need0FPrefix = true; |
| break; |
| case X86II::D8: case X86II::D9: case X86II::DA: case X86II::DB: |
| case X86II::DC: case X86II::DD: case X86II::DE: case X86II::DF: |
| MCE.emitByte(0xD8+ |
| (((Desc->TSFlags & X86II::Op0Mask)-X86II::D8) |
| >> X86II::Op0Shift)); |
| break; // Two-byte opcode prefix |
| default: llvm_unreachable("Invalid prefix!"); |
| case 0: break; // No prefix! |
| } |
| |
| // Handle REX prefix. |
| if (Is64BitMode) { |
| if (unsigned REX = determineREX(MI)) |
| MCE.emitByte(0x40 | REX); |
| } |
| |
| // 0x0F escape code must be emitted just before the opcode. |
| if (Need0FPrefix) |
| MCE.emitByte(0x0F); |
| |
| switch (Desc->TSFlags & X86II::Op0Mask) { |
| case X86II::TF: // F2 0F 38 |
| case X86II::T8: // 0F 38 |
| MCE.emitByte(0x38); |
| break; |
| case X86II::TA: // 0F 3A |
| MCE.emitByte(0x3A); |
| break; |
| case X86II::A6: // 0F A6 |
| MCE.emitByte(0xA6); |
| break; |
| case X86II::A7: // 0F A7 |
| MCE.emitByte(0xA7); |
| break; |
| } |
| |
| // If this is a two-address instruction, skip one of the register operands. |
| unsigned NumOps = Desc->getNumOperands(); |
| unsigned CurOp = 0; |
| if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) != -1) |
| ++CurOp; |
| else if (NumOps > 2 && Desc->getOperandConstraint(NumOps-1,MCOI::TIED_TO)== 0) |
| // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32 |
| --NumOps; |
| |
| unsigned char BaseOpcode = X86II::getBaseOpcodeFor(Desc->TSFlags); |
| switch (Desc->TSFlags & X86II::FormMask) { |
| default: |
| llvm_unreachable("Unknown FormMask value in X86 MachineCodeEmitter!"); |
| case X86II::Pseudo: |
| // Remember the current PC offset, this is the PIC relocation |
| // base address. |
| switch (Opcode) { |
| default: |
| llvm_unreachable("pseudo instructions should be removed before code" |
| " emission"); |
| break; |
| // Do nothing for Int_MemBarrier - it's just a comment. Add a debug |
| // to make it slightly easier to see. |
| case X86::Int_MemBarrier: |
| DEBUG(dbgs() << "#MEMBARRIER\n"); |
| break; |
| |
| case TargetOpcode::INLINEASM: |
| // We allow inline assembler nodes with empty bodies - they can |
| // implicitly define registers, which is ok for JIT. |
| if (MI.getOperand(0).getSymbolName()[0]) |
| report_fatal_error("JIT does not support inline asm!"); |
| break; |
| case TargetOpcode::PROLOG_LABEL: |
| case TargetOpcode::GC_LABEL: |
| case TargetOpcode::EH_LABEL: |
| MCE.emitLabel(MI.getOperand(0).getMCSymbol()); |
| break; |
| |
| case TargetOpcode::IMPLICIT_DEF: |
| case TargetOpcode::KILL: |
| break; |
| case X86::MOVPC32r: { |
| // This emits the "call" portion of this pseudo instruction. |
| MCE.emitByte(BaseOpcode); |
| emitConstant(0, X86II::getSizeOfImm(Desc->TSFlags)); |
| // Remember PIC base. |
| PICBaseOffset = (intptr_t) MCE.getCurrentPCOffset(); |
| X86JITInfo *JTI = TM.getJITInfo(); |
| JTI->setPICBase(MCE.getCurrentPCValue()); |
| break; |
| } |
| } |
| CurOp = NumOps; |
| break; |
| case X86II::RawFrm: { |
| MCE.emitByte(BaseOpcode); |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO = MI.getOperand(CurOp++); |
| |
| DEBUG(dbgs() << "RawFrm CurOp " << CurOp << "\n"); |
| DEBUG(dbgs() << "isMBB " << MO.isMBB() << "\n"); |
| DEBUG(dbgs() << "isGlobal " << MO.isGlobal() << "\n"); |
| DEBUG(dbgs() << "isSymbol " << MO.isSymbol() << "\n"); |
| DEBUG(dbgs() << "isImm " << MO.isImm() << "\n"); |
| |
| if (MO.isMBB()) { |
| emitPCRelativeBlockAddress(MO.getMBB()); |
| break; |
| } |
| |
| if (MO.isGlobal()) { |
| emitGlobalAddress(MO.getGlobal(), X86::reloc_pcrel_word, |
| MO.getOffset(), 0); |
| break; |
| } |
| |
| if (MO.isSymbol()) { |
| emitExternalSymbolAddress(MO.getSymbolName(), X86::reloc_pcrel_word); |
| break; |
| } |
| |
| // FIXME: Only used by hackish MCCodeEmitter, remove when dead. |
| if (MO.isJTI()) { |
| emitJumpTableAddress(MO.getIndex(), X86::reloc_pcrel_word); |
| break; |
| } |
| |
| assert(MO.isImm() && "Unknown RawFrm operand!"); |
| if (Opcode == X86::CALLpcrel32 || Opcode == X86::CALL64pcrel32 || |
| Opcode == X86::WINCALL64pcrel32) { |
| // Fix up immediate operand for pc relative calls. |
| intptr_t Imm = (intptr_t)MO.getImm(); |
| Imm = Imm - MCE.getCurrentPCValue() - 4; |
| emitConstant(Imm, X86II::getSizeOfImm(Desc->TSFlags)); |
| } else |
| emitConstant(MO.getImm(), X86II::getSizeOfImm(Desc->TSFlags)); |
| break; |
| } |
| |
| case X86II::AddRegFrm: { |
| MCE.emitByte(BaseOpcode + |
| X86_MC::getX86RegNum(MI.getOperand(CurOp++).getReg())); |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO1 = MI.getOperand(CurOp++); |
| unsigned Size = X86II::getSizeOfImm(Desc->TSFlags); |
| if (MO1.isImm()) { |
| emitConstant(MO1.getImm(), Size); |
| break; |
| } |
| |
| unsigned rt = Is64BitMode ? X86::reloc_pcrel_word |
| : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| if (Opcode == X86::MOV64ri64i32) |
| rt = X86::reloc_absolute_word; // FIXME: add X86II flag? |
| // This should not occur on Darwin for relocatable objects. |
| if (Opcode == X86::MOV64ri) |
| rt = X86::reloc_absolute_dword; // FIXME: add X86II flag? |
| if (MO1.isGlobal()) { |
| bool Indirect = gvNeedsNonLazyPtr(MO1, TM); |
| emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0, |
| Indirect); |
| } else if (MO1.isSymbol()) |
| emitExternalSymbolAddress(MO1.getSymbolName(), rt); |
| else if (MO1.isCPI()) |
| emitConstPoolAddress(MO1.getIndex(), rt); |
| else if (MO1.isJTI()) |
| emitJumpTableAddress(MO1.getIndex(), rt); |
| break; |
| } |
| |
| case X86II::MRMDestReg: { |
| MCE.emitByte(BaseOpcode); |
| emitRegModRMByte(MI.getOperand(CurOp).getReg(), |
| X86_MC::getX86RegNum(MI.getOperand(CurOp+1).getReg())); |
| CurOp += 2; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86II::getSizeOfImm(Desc->TSFlags)); |
| break; |
| } |
| case X86II::MRMDestMem: { |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp, |
| X86_MC::getX86RegNum(MI.getOperand(CurOp + X86::AddrNumOperands) |
| .getReg())); |
| CurOp += X86::AddrNumOperands + 1; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86II::getSizeOfImm(Desc->TSFlags)); |
| break; |
| } |
| |
| case X86II::MRMSrcReg: |
| MCE.emitByte(BaseOpcode); |
| emitRegModRMByte(MI.getOperand(CurOp+1).getReg(), |
| X86_MC::getX86RegNum(MI.getOperand(CurOp).getReg())); |
| CurOp += 2; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86II::getSizeOfImm(Desc->TSFlags)); |
| break; |
| |
| case X86II::MRMSrcMem: { |
| int AddrOperands = X86::AddrNumOperands; |
| |
| intptr_t PCAdj = (CurOp + AddrOperands + 1 != NumOps) ? |
| X86II::getSizeOfImm(Desc->TSFlags) : 0; |
| |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp+1, |
| X86_MC::getX86RegNum(MI.getOperand(CurOp).getReg()),PCAdj); |
| CurOp += AddrOperands + 1; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86II::getSizeOfImm(Desc->TSFlags)); |
| 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: { |
| MCE.emitByte(BaseOpcode); |
| emitRegModRMByte(MI.getOperand(CurOp++).getReg(), |
| (Desc->TSFlags & X86II::FormMask)-X86II::MRM0r); |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO1 = MI.getOperand(CurOp++); |
| unsigned Size = X86II::getSizeOfImm(Desc->TSFlags); |
| if (MO1.isImm()) { |
| emitConstant(MO1.getImm(), Size); |
| break; |
| } |
| |
| unsigned rt = Is64BitMode ? X86::reloc_pcrel_word |
| : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| if (Opcode == X86::MOV64ri32) |
| rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag? |
| if (MO1.isGlobal()) { |
| bool Indirect = gvNeedsNonLazyPtr(MO1, TM); |
| emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0, |
| Indirect); |
| } else if (MO1.isSymbol()) |
| emitExternalSymbolAddress(MO1.getSymbolName(), rt); |
| else if (MO1.isCPI()) |
| emitConstPoolAddress(MO1.getIndex(), rt); |
| else if (MO1.isJTI()) |
| emitJumpTableAddress(MO1.getIndex(), rt); |
| 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: { |
| intptr_t PCAdj = (CurOp + X86::AddrNumOperands != NumOps) ? |
| (MI.getOperand(CurOp+X86::AddrNumOperands).isImm() ? |
| X86II::getSizeOfImm(Desc->TSFlags) : 4) : 0; |
| |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp, (Desc->TSFlags & X86II::FormMask)-X86II::MRM0m, |
| PCAdj); |
| CurOp += X86::AddrNumOperands; |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO = MI.getOperand(CurOp++); |
| unsigned Size = X86II::getSizeOfImm(Desc->TSFlags); |
| if (MO.isImm()) { |
| emitConstant(MO.getImm(), Size); |
| break; |
| } |
| |
| unsigned rt = Is64BitMode ? X86::reloc_pcrel_word |
| : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| if (Opcode == X86::MOV64mi32) |
| rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag? |
| if (MO.isGlobal()) { |
| bool Indirect = gvNeedsNonLazyPtr(MO, TM); |
| emitGlobalAddress(MO.getGlobal(), rt, MO.getOffset(), 0, |
| Indirect); |
| } else if (MO.isSymbol()) |
| emitExternalSymbolAddress(MO.getSymbolName(), rt); |
| else if (MO.isCPI()) |
| emitConstPoolAddress(MO.getIndex(), rt); |
| else if (MO.isJTI()) |
| emitJumpTableAddress(MO.getIndex(), rt); |
| break; |
| } |
| |
| case X86II::MRMInitReg: |
| MCE.emitByte(BaseOpcode); |
| // Duplicate register, used by things like MOV8r0 (aka xor reg,reg). |
| emitRegModRMByte(MI.getOperand(CurOp).getReg(), |
| X86_MC::getX86RegNum(MI.getOperand(CurOp).getReg())); |
| ++CurOp; |
| break; |
| |
| case X86II::MRM_C1: |
| MCE.emitByte(BaseOpcode); |
| MCE.emitByte(0xC1); |
| break; |
| case X86II::MRM_C8: |
| MCE.emitByte(BaseOpcode); |
| MCE.emitByte(0xC8); |
| break; |
| case X86II::MRM_C9: |
| MCE.emitByte(BaseOpcode); |
| MCE.emitByte(0xC9); |
| break; |
| case X86II::MRM_E8: |
| MCE.emitByte(BaseOpcode); |
| MCE.emitByte(0xE8); |
| break; |
| case X86II::MRM_F0: |
| MCE.emitByte(BaseOpcode); |
| MCE.emitByte(0xF0); |
| break; |
| } |
| |
| if (!Desc->isVariadic() && CurOp != NumOps) { |
| #ifndef NDEBUG |
| dbgs() << "Cannot encode all operands of: " << MI << "\n"; |
| #endif |
| llvm_unreachable(0); |
| } |
| |
| MCE.processDebugLoc(MI.getDebugLoc(), false); |
| } |
