| //===-- 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/PassManager.h" |
| #include "llvm/CodeGen/MachineCodeEmitter.h" |
| #include "llvm/CodeGen/JITCodeEmitter.h" |
| #include "llvm/CodeGen/ObjectCodeEmitter.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/Support/Compiler.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 VISIBILITY_HIDDEN Emitter : public MachineFunctionPass { |
| const X86InstrInfo *II; |
| const TargetData *TD; |
| X86TargetMachine &TM; |
| CodeEmitter &MCE; |
| 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(const MachineInstr &MI, |
| const TargetInstrDesc *Desc); |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesAll(); |
| AU.addRequired<MachineModuleInfo>(); |
| MachineFunctionPass::getAnalysisUsage(AU); |
| } |
| |
| private: |
| void emitPCRelativeBlockAddress(MachineBasicBlock *MBB); |
| void emitGlobalAddress(GlobalValue *GV, unsigned Reloc, |
| intptr_t Disp = 0, intptr_t PCAdj = 0, |
| bool NeedStub = false, 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); |
| |
| unsigned getX86RegNum(unsigned RegNo) const; |
| }; |
| |
| 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::createX86CodeEmitterPass(X86TargetMachine &TM, |
| MachineCodeEmitter &MCE) { |
| return new Emitter<MachineCodeEmitter>(TM, MCE); |
| } |
| FunctionPass *llvm::createX86JITCodeEmitterPass(X86TargetMachine &TM, |
| JITCodeEmitter &JCE) { |
| return new Emitter<JITCodeEmitter>(TM, JCE); |
| } |
| FunctionPass *llvm::createX86ObjectCodeEmitterPass(X86TargetMachine &TM, |
| ObjectCodeEmitter &OCE) { |
| return new Emitter<ObjectCodeEmitter>(TM, OCE); |
| } |
| |
| template<class CodeEmitter> |
| bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) { |
| |
| MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>()); |
| |
| II = TM.getInstrInfo(); |
| TD = TM.getTargetData(); |
| Is64BitMode = TM.getSubtarget<X86Subtarget>().is64Bit(); |
| IsPIC = TM.getRelocationModel() == Reloc::PIC_; |
| |
| do { |
| DEBUG(errs() << "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::const_iterator I = MBB->begin(), E = MBB->end(); |
| I != E; ++I) { |
| const TargetInstrDesc &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; |
| } |
| |
| /// 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(GlobalValue *GV, unsigned Reloc, |
| intptr_t Disp /* = 0 */, |
| intptr_t PCAdj /* = 0 */, |
| bool NeedStub /* = false */, |
| 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, |
| GV, RelocCST, NeedStub) |
| : MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, |
| GV, RelocCST, NeedStub); |
| 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; |
| MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(), |
| Reloc, ES, RelocCST)); |
| 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); |
| } |
| |
| template<class CodeEmitter> |
| unsigned Emitter<CodeEmitter>::getX86RegNum(unsigned RegNo) const { |
| return II->getRegisterInfo().getX86RegNum(RegNo); |
| } |
| |
| 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, 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. |
| 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 |
| unsigned rt = Is64BitMode ? |
| (IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext) |
| : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| bool NeedStub = isa<Function>(RelocOp->getGlobal()); |
| bool Indirect = gvNeedsNonLazyPtr(*RelocOp, TM); |
| emitGlobalAddress(RelocOp->getGlobal(), rt, RelocOp->getOffset(), |
| Adj, NeedStub, Indirect); |
| } else if (RelocOp->isCPI()) { |
| unsigned rt = Is64BitMode ? |
| (IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext) |
| : (IsPCRel ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| emitConstPoolAddress(RelocOp->getIndex(), rt, |
| RelocOp->getOffset(), Adj); |
| } else if (RelocOp->isJTI()) { |
| unsigned rt = Is64BitMode ? |
| (IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext) |
| : (IsPCRel ? X86::reloc_picrel_word : X86::reloc_absolute_word); |
| emitJumpTableAddress(RelocOp->getIndex(), rt, Adj); |
| } else { |
| llvm_unreachable("Unknown value to relocate!"); |
| } |
| } |
| |
| 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.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(); |
| |
| // 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. |
| if ((!Is64BitMode || DispForReloc || BaseReg != 0) && |
| IndexReg.getReg() == 0 && |
| ((BaseReg == 0 && MCE.earlyResolveAddresses()) || BaseReg == X86::RIP || |
| (BaseReg != 0 && getX86RegNum(BaseReg) != N86::ESP))) { |
| if (BaseReg == 0 || BaseReg == X86::RIP) { // Just a displacement? |
| // Emit special case [disp32] encoding |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, 5)); |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, true); |
| } else { |
| unsigned BaseRegNo = getX86RegNum(BaseReg); |
| if (!DispForReloc && DispVal == 0 && BaseRegNo != N86::EBP) { |
| // Emit simple indirect register encoding... [EAX] f.e. |
| MCE.emitByte(ModRMByte(0, RegOpcodeField, BaseRegNo)); |
| } else if (!DispForReloc && isDisp8(DispVal)) { |
| // Emit the disp8 encoding... [REG+disp8] |
| MCE.emitByte(ModRMByte(1, RegOpcodeField, BaseRegNo)); |
| emitConstant(DispVal, 1); |
| } else { |
| // Emit the most general non-SIB encoding: [REG+disp32] |
| MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo)); |
| emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel); |
| } |
| } |
| |
| } else { // 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=5, 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 && getX86RegNum(BaseReg) != 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[] = { ~0, 0, 1, ~0, 2, ~0, ~0, ~0, 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 = 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 = getX86RegNum(BaseReg); |
| unsigned IndexRegNo; |
| if (IndexReg.getReg()) |
| IndexRegNo = 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); |
| } |
| } |
| } |
| |
| template<class CodeEmitter> |
| void Emitter<CodeEmitter>::emitInstruction(const MachineInstr &MI, |
| const TargetInstrDesc *Desc) { |
| DEBUG(errs() << MI); |
| |
| MCE.processDebugLoc(MI.getDebugLoc()); |
| |
| 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 |
| 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 = X86InstrInfo::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; |
| } |
| |
| // 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, TOI::TIED_TO) != -1) |
| ++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; |
| |
| unsigned char BaseOpcode = II->getBaseOpcodeFor(Desc); |
| 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("psuedo instructions should be removed before code" |
| " emission"); |
| break; |
| case TargetInstrInfo::INLINEASM: |
| // We allow inline assembler nodes with empty bodies - they can |
| // implicitly define registers, which is ok for JIT. |
| assert(MI.getOperand(0).getSymbolName()[0] == 0 && |
| "JIT does not support inline asm!"); |
| break; |
| case TargetInstrInfo::DBG_LABEL: |
| case TargetInstrInfo::EH_LABEL: |
| MCE.emitLabel(MI.getOperand(0).getImm()); |
| break; |
| case TargetInstrInfo::IMPLICIT_DEF: |
| case TargetInstrInfo::DECLARE: |
| case X86::DWARF_LOC: |
| case X86::FP_REG_KILL: |
| break; |
| case X86::MOVPC32r: { |
| // This emits the "call" portion of this pseudo instruction. |
| MCE.emitByte(BaseOpcode); |
| emitConstant(0, X86InstrInfo::sizeOfImm(Desc)); |
| // 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(errs() << "RawFrm CurOp " << CurOp << "\n"); |
| DEBUG(errs() << "isMBB " << MO.isMBB() << "\n"); |
| DEBUG(errs() << "isGlobal " << MO.isGlobal() << "\n"); |
| DEBUG(errs() << "isSymbol " << MO.isSymbol() << "\n"); |
| DEBUG(errs() << "isImm " << MO.isImm() << "\n"); |
| |
| if (MO.isMBB()) { |
| emitPCRelativeBlockAddress(MO.getMBB()); |
| break; |
| } |
| |
| if (MO.isGlobal()) { |
| // Assume undefined functions may be outside the Small codespace. |
| bool NeedStub = |
| (Is64BitMode && |
| (TM.getCodeModel() == CodeModel::Large || |
| TM.getSubtarget<X86Subtarget>().isTargetDarwin())) || |
| Opcode == X86::TAILJMPd; |
| emitGlobalAddress(MO.getGlobal(), X86::reloc_pcrel_word, |
| MO.getOffset(), 0, NeedStub); |
| break; |
| } |
| |
| if (MO.isSymbol()) { |
| emitExternalSymbolAddress(MO.getSymbolName(), X86::reloc_pcrel_word); |
| break; |
| } |
| |
| assert(MO.isImm() && "Unknown RawFrm operand!"); |
| if (Opcode == X86::CALLpcrel32 || Opcode == X86::CALL64pcrel32) { |
| // Fix up immediate operand for pc relative calls. |
| intptr_t Imm = (intptr_t)MO.getImm(); |
| Imm = Imm - MCE.getCurrentPCValue() - 4; |
| emitConstant(Imm, X86InstrInfo::sizeOfImm(Desc)); |
| } else |
| emitConstant(MO.getImm(), X86InstrInfo::sizeOfImm(Desc)); |
| break; |
| } |
| |
| case X86II::AddRegFrm: { |
| MCE.emitByte(BaseOpcode + getX86RegNum(MI.getOperand(CurOp++).getReg())); |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO1 = MI.getOperand(CurOp++); |
| unsigned Size = X86InstrInfo::sizeOfImm(Desc); |
| 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 NeedStub = isa<Function>(MO1.getGlobal()); |
| bool Indirect = gvNeedsNonLazyPtr(MO1, TM); |
| emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0, |
| NeedStub, 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(), |
| getX86RegNum(MI.getOperand(CurOp+1).getReg())); |
| CurOp += 2; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86InstrInfo::sizeOfImm(Desc)); |
| break; |
| } |
| case X86II::MRMDestMem: { |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp, |
| getX86RegNum(MI.getOperand(CurOp + X86AddrNumOperands) |
| .getReg())); |
| CurOp += X86AddrNumOperands + 1; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86InstrInfo::sizeOfImm(Desc)); |
| break; |
| } |
| |
| case X86II::MRMSrcReg: |
| MCE.emitByte(BaseOpcode); |
| emitRegModRMByte(MI.getOperand(CurOp+1).getReg(), |
| getX86RegNum(MI.getOperand(CurOp).getReg())); |
| CurOp += 2; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86InstrInfo::sizeOfImm(Desc)); |
| break; |
| |
| case X86II::MRMSrcMem: { |
| // FIXME: Maybe lea should have its own form? |
| int AddrOperands; |
| if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r || |
| Opcode == X86::LEA16r || Opcode == X86::LEA32r) |
| AddrOperands = X86AddrNumOperands - 1; // No segment register |
| else |
| AddrOperands = X86AddrNumOperands; |
| |
| intptr_t PCAdj = (CurOp + AddrOperands + 1 != NumOps) ? |
| X86InstrInfo::sizeOfImm(Desc) : 0; |
| |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp+1, getX86RegNum(MI.getOperand(CurOp).getReg()), |
| PCAdj); |
| CurOp += AddrOperands + 1; |
| if (CurOp != NumOps) |
| emitConstant(MI.getOperand(CurOp++).getImm(), |
| X86InstrInfo::sizeOfImm(Desc)); |
| 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); |
| |
| // Special handling of lfence, mfence, monitor, and mwait. |
| if (Desc->getOpcode() == X86::LFENCE || |
| Desc->getOpcode() == X86::MFENCE || |
| Desc->getOpcode() == X86::MONITOR || |
| Desc->getOpcode() == X86::MWAIT) { |
| emitRegModRMByte((Desc->TSFlags & X86II::FormMask)-X86II::MRM0r); |
| |
| switch (Desc->getOpcode()) { |
| default: break; |
| case X86::MONITOR: |
| MCE.emitByte(0xC8); |
| break; |
| case X86::MWAIT: |
| MCE.emitByte(0xC9); |
| break; |
| } |
| } else { |
| emitRegModRMByte(MI.getOperand(CurOp++).getReg(), |
| (Desc->TSFlags & X86II::FormMask)-X86II::MRM0r); |
| } |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO1 = MI.getOperand(CurOp++); |
| unsigned Size = X86InstrInfo::sizeOfImm(Desc); |
| 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 NeedStub = isa<Function>(MO1.getGlobal()); |
| bool Indirect = gvNeedsNonLazyPtr(MO1, TM); |
| emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0, |
| NeedStub, 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 + X86AddrNumOperands != NumOps) ? |
| (MI.getOperand(CurOp+X86AddrNumOperands).isImm() ? |
| X86InstrInfo::sizeOfImm(Desc) : 4) : 0; |
| |
| MCE.emitByte(BaseOpcode); |
| emitMemModRMByte(MI, CurOp, (Desc->TSFlags & X86II::FormMask)-X86II::MRM0m, |
| PCAdj); |
| CurOp += X86AddrNumOperands; |
| |
| if (CurOp == NumOps) |
| break; |
| |
| const MachineOperand &MO = MI.getOperand(CurOp++); |
| unsigned Size = X86InstrInfo::sizeOfImm(Desc); |
| 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 NeedStub = isa<Function>(MO.getGlobal()); |
| bool Indirect = gvNeedsNonLazyPtr(MO, TM); |
| emitGlobalAddress(MO.getGlobal(), rt, MO.getOffset(), 0, |
| NeedStub, 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(), |
| getX86RegNum(MI.getOperand(CurOp).getReg())); |
| ++CurOp; |
| break; |
| } |
| |
| if (!Desc->isVariadic() && CurOp != NumOps) { |
| #ifndef NDEBUG |
| errs() << "Cannot encode all operands of: " << MI << "\n"; |
| #endif |
| llvm_unreachable(0); |
| } |
| } |
