//===-- X86MCInstLower.cpp - Convert X86 MachineInstr to an MCInst --------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains code to lower X86 MachineInstrs to their corresponding // MCInst records. // //===----------------------------------------------------------------------===// #include "X86AsmPrinter.h" #include "InstPrinter/X86ATTInstPrinter.h" #include "MCTargetDesc/X86BaseInfo.h" #include "llvm/ADT/SmallString.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineModuleInfoImpls.h" #include "llvm/CodeGen/StackMaps.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/GlobalValue.h" #include "llvm/IR/Mangler.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCInstBuilder.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSymbol.h" using namespace llvm; namespace { /// X86MCInstLower - This class is used to lower an MachineInstr into an MCInst. class X86MCInstLower { MCContext &Ctx; const MachineFunction &MF; const TargetMachine &TM; const MCAsmInfo &MAI; X86AsmPrinter &AsmPrinter; public: X86MCInstLower(const MachineFunction &MF, X86AsmPrinter &asmprinter); void Lower(const MachineInstr *MI, MCInst &OutMI) const; MCSymbol *GetSymbolFromOperand(const MachineOperand &MO) const; MCOperand LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const; private: MachineModuleInfoMachO &getMachOMMI() const; Mangler *getMang() const { return AsmPrinter.Mang; } }; } // end anonymous namespace X86MCInstLower::X86MCInstLower(const MachineFunction &mf, X86AsmPrinter &asmprinter) : Ctx(mf.getContext()), MF(mf), TM(mf.getTarget()), MAI(*TM.getMCAsmInfo()), AsmPrinter(asmprinter) {} MachineModuleInfoMachO &X86MCInstLower::getMachOMMI() const { return MF.getMMI().getObjFileInfo(); } /// GetSymbolFromOperand - Lower an MO_GlobalAddress or MO_ExternalSymbol /// operand to an MCSymbol. MCSymbol *X86MCInstLower:: GetSymbolFromOperand(const MachineOperand &MO) const { const DataLayout *DL = TM.getDataLayout(); assert((MO.isGlobal() || MO.isSymbol() || MO.isMBB()) && "Isn't a symbol reference"); SmallString<128> Name; StringRef Suffix; switch (MO.getTargetFlags()) { case X86II::MO_DLLIMPORT: // Handle dllimport linkage. Name += "__imp_"; break; case X86II::MO_DARWIN_STUB: Suffix = "$stub"; break; case X86II::MO_DARWIN_NONLAZY: case X86II::MO_DARWIN_NONLAZY_PIC_BASE: case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: Suffix = "$non_lazy_ptr"; break; } if (!Suffix.empty()) Name += DL->getPrivateGlobalPrefix(); unsigned PrefixLen = Name.size(); if (MO.isGlobal()) { const GlobalValue *GV = MO.getGlobal(); AsmPrinter.getNameWithPrefix(Name, GV); } else if (MO.isSymbol()) { getMang()->getNameWithPrefix(Name, MO.getSymbolName()); } else if (MO.isMBB()) { Name += MO.getMBB()->getSymbol()->getName(); } unsigned OrigLen = Name.size() - PrefixLen; Name += Suffix; MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name); StringRef OrigName = StringRef(Name).substr(PrefixLen, OrigLen); // If the target flags on the operand changes the name of the symbol, do that // before we return the symbol. switch (MO.getTargetFlags()) { default: break; case X86II::MO_DARWIN_NONLAZY: case X86II::MO_DARWIN_NONLAZY_PIC_BASE: { MachineModuleInfoImpl::StubValueTy &StubSym = getMachOMMI().getGVStubEntry(Sym); if (StubSym.getPointer() == 0) { assert(MO.isGlobal() && "Extern symbol not handled yet"); StubSym = MachineModuleInfoImpl:: StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()), !MO.getGlobal()->hasInternalLinkage()); } break; } case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: { MachineModuleInfoImpl::StubValueTy &StubSym = getMachOMMI().getHiddenGVStubEntry(Sym); if (StubSym.getPointer() == 0) { assert(MO.isGlobal() && "Extern symbol not handled yet"); StubSym = MachineModuleInfoImpl:: StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()), !MO.getGlobal()->hasInternalLinkage()); } break; } case X86II::MO_DARWIN_STUB: { MachineModuleInfoImpl::StubValueTy &StubSym = getMachOMMI().getFnStubEntry(Sym); if (StubSym.getPointer()) return Sym; if (MO.isGlobal()) { StubSym = MachineModuleInfoImpl:: StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()), !MO.getGlobal()->hasInternalLinkage()); } else { StubSym = MachineModuleInfoImpl:: StubValueTy(Ctx.GetOrCreateSymbol(OrigName), false); } break; } } return Sym; } MCOperand X86MCInstLower::LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const { // FIXME: We would like an efficient form for this, so we don't have to do a // lot of extra uniquing. const MCExpr *Expr = 0; MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None; switch (MO.getTargetFlags()) { default: llvm_unreachable("Unknown target flag on GV operand"); case X86II::MO_NO_FLAG: // No flag. // These affect the name of the symbol, not any suffix. case X86II::MO_DARWIN_NONLAZY: case X86II::MO_DLLIMPORT: case X86II::MO_DARWIN_STUB: break; case X86II::MO_TLVP: RefKind = MCSymbolRefExpr::VK_TLVP; break; case X86II::MO_TLVP_PIC_BASE: Expr = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_TLVP, Ctx); // Subtract the pic base. Expr = MCBinaryExpr::CreateSub(Expr, MCSymbolRefExpr::Create(MF.getPICBaseSymbol(), Ctx), Ctx); break; case X86II::MO_SECREL: RefKind = MCSymbolRefExpr::VK_SECREL; break; case X86II::MO_TLSGD: RefKind = MCSymbolRefExpr::VK_TLSGD; break; case X86II::MO_TLSLD: RefKind = MCSymbolRefExpr::VK_TLSLD; break; case X86II::MO_TLSLDM: RefKind = MCSymbolRefExpr::VK_TLSLDM; break; case X86II::MO_GOTTPOFF: RefKind = MCSymbolRefExpr::VK_GOTTPOFF; break; case X86II::MO_INDNTPOFF: RefKind = MCSymbolRefExpr::VK_INDNTPOFF; break; case X86II::MO_TPOFF: RefKind = MCSymbolRefExpr::VK_TPOFF; break; case X86II::MO_DTPOFF: RefKind = MCSymbolRefExpr::VK_DTPOFF; break; case X86II::MO_NTPOFF: RefKind = MCSymbolRefExpr::VK_NTPOFF; break; case X86II::MO_GOTNTPOFF: RefKind = MCSymbolRefExpr::VK_GOTNTPOFF; break; case X86II::MO_GOTPCREL: RefKind = MCSymbolRefExpr::VK_GOTPCREL; break; case X86II::MO_GOT: RefKind = MCSymbolRefExpr::VK_GOT; break; case X86II::MO_GOTOFF: RefKind = MCSymbolRefExpr::VK_GOTOFF; break; case X86II::MO_PLT: RefKind = MCSymbolRefExpr::VK_PLT; break; case X86II::MO_PIC_BASE_OFFSET: case X86II::MO_DARWIN_NONLAZY_PIC_BASE: case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: Expr = MCSymbolRefExpr::Create(Sym, Ctx); // Subtract the pic base. Expr = MCBinaryExpr::CreateSub(Expr, MCSymbolRefExpr::Create(MF.getPICBaseSymbol(), Ctx), Ctx); if (MO.isJTI() && MAI.hasSetDirective()) { // If .set directive is supported, use it to reduce the number of // relocations the assembler will generate for differences between // local labels. This is only safe when the symbols are in the same // section so we are restricting it to jumptable references. MCSymbol *Label = Ctx.CreateTempSymbol(); AsmPrinter.OutStreamer.EmitAssignment(Label, Expr); Expr = MCSymbolRefExpr::Create(Label, Ctx); } break; } if (Expr == 0) Expr = MCSymbolRefExpr::Create(Sym, RefKind, Ctx); if (!MO.isJTI() && !MO.isMBB() && MO.getOffset()) Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(MO.getOffset(), Ctx), Ctx); return MCOperand::CreateExpr(Expr); } /// \brief Simplify FOO $imm, %{al,ax,eax,rax} to FOO $imm, for instruction with /// a short fixed-register form. static void SimplifyShortImmForm(MCInst &Inst, unsigned Opcode) { unsigned ImmOp = Inst.getNumOperands() - 1; assert(Inst.getOperand(0).isReg() && (Inst.getOperand(ImmOp).isImm() || Inst.getOperand(ImmOp).isExpr()) && ((Inst.getNumOperands() == 3 && Inst.getOperand(1).isReg() && Inst.getOperand(0).getReg() == Inst.getOperand(1).getReg()) || Inst.getNumOperands() == 2) && "Unexpected instruction!"); // Check whether the destination register can be fixed. unsigned Reg = Inst.getOperand(0).getReg(); if (Reg != X86::AL && Reg != X86::AX && Reg != X86::EAX && Reg != X86::RAX) return; // If so, rewrite the instruction. MCOperand Saved = Inst.getOperand(ImmOp); Inst = MCInst(); Inst.setOpcode(Opcode); Inst.addOperand(Saved); } /// \brief If a movsx instruction has a shorter encoding for the used register /// simplify the instruction to use it instead. static void SimplifyMOVSX(MCInst &Inst) { unsigned NewOpcode = 0; unsigned Op0 = Inst.getOperand(0).getReg(), Op1 = Inst.getOperand(1).getReg(); switch (Inst.getOpcode()) { default: llvm_unreachable("Unexpected instruction!"); case X86::MOVSX16rr8: // movsbw %al, %ax --> cbtw if (Op0 == X86::AX && Op1 == X86::AL) NewOpcode = X86::CBW; break; case X86::MOVSX32rr16: // movswl %ax, %eax --> cwtl if (Op0 == X86::EAX && Op1 == X86::AX) NewOpcode = X86::CWDE; break; case X86::MOVSX64rr32: // movslq %eax, %rax --> cltq if (Op0 == X86::RAX && Op1 == X86::EAX) NewOpcode = X86::CDQE; break; } if (NewOpcode != 0) { Inst = MCInst(); Inst.setOpcode(NewOpcode); } } /// \brief Simplify things like MOV32rm to MOV32o32a. static void SimplifyShortMoveForm(X86AsmPrinter &Printer, MCInst &Inst, unsigned Opcode) { // Don't make these simplifications in 64-bit mode; other assemblers don't // perform them because they make the code larger. if (Printer.getSubtarget().is64Bit()) return; bool IsStore = Inst.getOperand(0).isReg() && Inst.getOperand(1).isReg(); unsigned AddrBase = IsStore; unsigned RegOp = IsStore ? 0 : 5; unsigned AddrOp = AddrBase + 3; assert(Inst.getNumOperands() == 6 && Inst.getOperand(RegOp).isReg() && Inst.getOperand(AddrBase + X86::AddrBaseReg).isReg() && Inst.getOperand(AddrBase + X86::AddrScaleAmt).isImm() && Inst.getOperand(AddrBase + X86::AddrIndexReg).isReg() && Inst.getOperand(AddrBase + X86::AddrSegmentReg).isReg() && (Inst.getOperand(AddrOp).isExpr() || Inst.getOperand(AddrOp).isImm()) && "Unexpected instruction!"); // Check whether the destination register can be fixed. unsigned Reg = Inst.getOperand(RegOp).getReg(); if (Reg != X86::AL && Reg != X86::AX && Reg != X86::EAX && Reg != X86::RAX) return; // Check whether this is an absolute address. // FIXME: We know TLVP symbol refs aren't, but there should be a better way // to do this here. bool Absolute = true; if (Inst.getOperand(AddrOp).isExpr()) { const MCExpr *MCE = Inst.getOperand(AddrOp).getExpr(); if (const MCSymbolRefExpr *SRE = dyn_cast(MCE)) if (SRE->getKind() == MCSymbolRefExpr::VK_TLVP) Absolute = false; } if (Absolute && (Inst.getOperand(AddrBase + X86::AddrBaseReg).getReg() != 0 || Inst.getOperand(AddrBase + X86::AddrScaleAmt).getImm() != 1 || Inst.getOperand(AddrBase + X86::AddrIndexReg).getReg() != 0)) return; // If so, rewrite the instruction. MCOperand Saved = Inst.getOperand(AddrOp); MCOperand Seg = Inst.getOperand(AddrBase + X86::AddrSegmentReg); Inst = MCInst(); Inst.setOpcode(Opcode); Inst.addOperand(Saved); Inst.addOperand(Seg); } static unsigned getRetOpcode(const X86Subtarget &Subtarget) { return Subtarget.is64Bit() ? X86::RETQ : X86::RETL; } void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const { OutMI.setOpcode(MI->getOpcode()); for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { const MachineOperand &MO = MI->getOperand(i); MCOperand MCOp; switch (MO.getType()) { default: MI->dump(); llvm_unreachable("unknown operand type"); case MachineOperand::MO_Register: // Ignore all implicit register operands. if (MO.isImplicit()) continue; MCOp = MCOperand::CreateReg(MO.getReg()); break; case MachineOperand::MO_Immediate: MCOp = MCOperand::CreateImm(MO.getImm()); break; case MachineOperand::MO_MachineBasicBlock: case MachineOperand::MO_GlobalAddress: case MachineOperand::MO_ExternalSymbol: MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO)); break; case MachineOperand::MO_JumpTableIndex: MCOp = LowerSymbolOperand(MO, AsmPrinter.GetJTISymbol(MO.getIndex())); break; case MachineOperand::MO_ConstantPoolIndex: MCOp = LowerSymbolOperand(MO, AsmPrinter.GetCPISymbol(MO.getIndex())); break; case MachineOperand::MO_BlockAddress: MCOp = LowerSymbolOperand(MO, AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress())); break; case MachineOperand::MO_RegisterMask: // Ignore call clobbers. continue; } OutMI.addOperand(MCOp); } // Handle a few special cases to eliminate operand modifiers. ReSimplify: switch (OutMI.getOpcode()) { case X86::LEA64_32r: case X86::LEA64r: case X86::LEA16r: case X86::LEA32r: // LEA should have a segment register, but it must be empty. assert(OutMI.getNumOperands() == 1+X86::AddrNumOperands && "Unexpected # of LEA operands"); assert(OutMI.getOperand(1+X86::AddrSegmentReg).getReg() == 0 && "LEA has segment specified!"); break; case X86::MOV32ri64: OutMI.setOpcode(X86::MOV32ri); break; // Commute operands to get a smaller encoding by using VEX.R instead of VEX.B // if one of the registers is extended, but other isn't. case X86::VMOVAPDrr: case X86::VMOVAPDYrr: case X86::VMOVAPSrr: case X86::VMOVAPSYrr: case X86::VMOVDQArr: case X86::VMOVDQAYrr: case X86::VMOVDQUrr: case X86::VMOVDQUYrr: case X86::VMOVUPDrr: case X86::VMOVUPDYrr: case X86::VMOVUPSrr: case X86::VMOVUPSYrr: { if (!X86II::isX86_64ExtendedReg(OutMI.getOperand(0).getReg()) && X86II::isX86_64ExtendedReg(OutMI.getOperand(1).getReg())) { unsigned NewOpc; switch (OutMI.getOpcode()) { default: llvm_unreachable("Invalid opcode"); case X86::VMOVAPDrr: NewOpc = X86::VMOVAPDrr_REV; break; case X86::VMOVAPDYrr: NewOpc = X86::VMOVAPDYrr_REV; break; case X86::VMOVAPSrr: NewOpc = X86::VMOVAPSrr_REV; break; case X86::VMOVAPSYrr: NewOpc = X86::VMOVAPSYrr_REV; break; case X86::VMOVDQArr: NewOpc = X86::VMOVDQArr_REV; break; case X86::VMOVDQAYrr: NewOpc = X86::VMOVDQAYrr_REV; break; case X86::VMOVDQUrr: NewOpc = X86::VMOVDQUrr_REV; break; case X86::VMOVDQUYrr: NewOpc = X86::VMOVDQUYrr_REV; break; case X86::VMOVUPDrr: NewOpc = X86::VMOVUPDrr_REV; break; case X86::VMOVUPDYrr: NewOpc = X86::VMOVUPDYrr_REV; break; case X86::VMOVUPSrr: NewOpc = X86::VMOVUPSrr_REV; break; case X86::VMOVUPSYrr: NewOpc = X86::VMOVUPSYrr_REV; break; } OutMI.setOpcode(NewOpc); } break; } case X86::VMOVSDrr: case X86::VMOVSSrr: { if (!X86II::isX86_64ExtendedReg(OutMI.getOperand(0).getReg()) && X86II::isX86_64ExtendedReg(OutMI.getOperand(2).getReg())) { unsigned NewOpc; switch (OutMI.getOpcode()) { default: llvm_unreachable("Invalid opcode"); case X86::VMOVSDrr: NewOpc = X86::VMOVSDrr_REV; break; case X86::VMOVSSrr: NewOpc = X86::VMOVSSrr_REV; break; } OutMI.setOpcode(NewOpc); } break; } // TAILJMPr64, CALL64r, CALL64pcrel32 - These instructions have register // inputs modeled as normal uses instead of implicit uses. As such, truncate // off all but the first operand (the callee). FIXME: Change isel. case X86::TAILJMPr64: case X86::CALL64r: case X86::CALL64pcrel32: { unsigned Opcode = OutMI.getOpcode(); MCOperand Saved = OutMI.getOperand(0); OutMI = MCInst(); OutMI.setOpcode(Opcode); OutMI.addOperand(Saved); break; } case X86::EH_RETURN: case X86::EH_RETURN64: { OutMI = MCInst(); OutMI.setOpcode(getRetOpcode(AsmPrinter.getSubtarget())); break; } // TAILJMPd, TAILJMPd64 - Lower to the correct jump instructions. case X86::TAILJMPr: case X86::TAILJMPd: case X86::TAILJMPd64: { unsigned Opcode; switch (OutMI.getOpcode()) { default: llvm_unreachable("Invalid opcode"); case X86::TAILJMPr: Opcode = X86::JMP32r; break; case X86::TAILJMPd: case X86::TAILJMPd64: Opcode = X86::JMP_1; break; } MCOperand Saved = OutMI.getOperand(0); OutMI = MCInst(); OutMI.setOpcode(Opcode); OutMI.addOperand(Saved); break; } // These are pseudo-ops for OR to help with the OR->ADD transformation. We do // this with an ugly goto in case the resultant OR uses EAX and needs the // short form. case X86::ADD16rr_DB: OutMI.setOpcode(X86::OR16rr); goto ReSimplify; case X86::ADD32rr_DB: OutMI.setOpcode(X86::OR32rr); goto ReSimplify; case X86::ADD64rr_DB: OutMI.setOpcode(X86::OR64rr); goto ReSimplify; case X86::ADD16ri_DB: OutMI.setOpcode(X86::OR16ri); goto ReSimplify; case X86::ADD32ri_DB: OutMI.setOpcode(X86::OR32ri); goto ReSimplify; case X86::ADD64ri32_DB: OutMI.setOpcode(X86::OR64ri32); goto ReSimplify; case X86::ADD16ri8_DB: OutMI.setOpcode(X86::OR16ri8); goto ReSimplify; case X86::ADD32ri8_DB: OutMI.setOpcode(X86::OR32ri8); goto ReSimplify; case X86::ADD64ri8_DB: OutMI.setOpcode(X86::OR64ri8); goto ReSimplify; // The assembler backend wants to see branches in their small form and relax // them to their large form. The JIT can only handle the large form because // it does not do relaxation. For now, translate the large form to the // small one here. case X86::JMP_4: OutMI.setOpcode(X86::JMP_1); break; case X86::JO_4: OutMI.setOpcode(X86::JO_1); break; case X86::JNO_4: OutMI.setOpcode(X86::JNO_1); break; case X86::JB_4: OutMI.setOpcode(X86::JB_1); break; case X86::JAE_4: OutMI.setOpcode(X86::JAE_1); break; case X86::JE_4: OutMI.setOpcode(X86::JE_1); break; case X86::JNE_4: OutMI.setOpcode(X86::JNE_1); break; case X86::JBE_4: OutMI.setOpcode(X86::JBE_1); break; case X86::JA_4: OutMI.setOpcode(X86::JA_1); break; case X86::JS_4: OutMI.setOpcode(X86::JS_1); break; case X86::JNS_4: OutMI.setOpcode(X86::JNS_1); break; case X86::JP_4: OutMI.setOpcode(X86::JP_1); break; case X86::JNP_4: OutMI.setOpcode(X86::JNP_1); break; case X86::JL_4: OutMI.setOpcode(X86::JL_1); break; case X86::JGE_4: OutMI.setOpcode(X86::JGE_1); break; case X86::JLE_4: OutMI.setOpcode(X86::JLE_1); break; case X86::JG_4: OutMI.setOpcode(X86::JG_1); break; // Atomic load and store require a separate pseudo-inst because Acquire // implies mayStore and Release implies mayLoad; fix these to regular MOV // instructions here case X86::ACQUIRE_MOV8rm: OutMI.setOpcode(X86::MOV8rm); goto ReSimplify; case X86::ACQUIRE_MOV16rm: OutMI.setOpcode(X86::MOV16rm); goto ReSimplify; case X86::ACQUIRE_MOV32rm: OutMI.setOpcode(X86::MOV32rm); goto ReSimplify; case X86::ACQUIRE_MOV64rm: OutMI.setOpcode(X86::MOV64rm); goto ReSimplify; case X86::RELEASE_MOV8mr: OutMI.setOpcode(X86::MOV8mr); goto ReSimplify; case X86::RELEASE_MOV16mr: OutMI.setOpcode(X86::MOV16mr); goto ReSimplify; case X86::RELEASE_MOV32mr: OutMI.setOpcode(X86::MOV32mr); goto ReSimplify; case X86::RELEASE_MOV64mr: OutMI.setOpcode(X86::MOV64mr); goto ReSimplify; // We don't currently select the correct instruction form for instructions // which have a short %eax, etc. form. Handle this by custom lowering, for // now. // // Note, we are currently not handling the following instructions: // MOV64ao8, MOV64o8a // XCHG16ar, XCHG32ar, XCHG64ar case X86::MOV8mr_NOREX: case X86::MOV8mr: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV8ao8); break; case X86::MOV8rm_NOREX: case X86::MOV8rm: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV8o8a); break; case X86::MOV16mr: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV16ao16); break; case X86::MOV16rm: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV16o16a); break; case X86::MOV32mr: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV32ao32); break; case X86::MOV32rm: SimplifyShortMoveForm(AsmPrinter, OutMI, X86::MOV32o32a); break; case X86::ADC8ri: SimplifyShortImmForm(OutMI, X86::ADC8i8); break; case X86::ADC16ri: SimplifyShortImmForm(OutMI, X86::ADC16i16); break; case X86::ADC32ri: SimplifyShortImmForm(OutMI, X86::ADC32i32); break; case X86::ADC64ri32: SimplifyShortImmForm(OutMI, X86::ADC64i32); break; case X86::ADD8ri: SimplifyShortImmForm(OutMI, X86::ADD8i8); break; case X86::ADD16ri: SimplifyShortImmForm(OutMI, X86::ADD16i16); break; case X86::ADD32ri: SimplifyShortImmForm(OutMI, X86::ADD32i32); break; case X86::ADD64ri32: SimplifyShortImmForm(OutMI, X86::ADD64i32); break; case X86::AND8ri: SimplifyShortImmForm(OutMI, X86::AND8i8); break; case X86::AND16ri: SimplifyShortImmForm(OutMI, X86::AND16i16); break; case X86::AND32ri: SimplifyShortImmForm(OutMI, X86::AND32i32); break; case X86::AND64ri32: SimplifyShortImmForm(OutMI, X86::AND64i32); break; case X86::CMP8ri: SimplifyShortImmForm(OutMI, X86::CMP8i8); break; case X86::CMP16ri: SimplifyShortImmForm(OutMI, X86::CMP16i16); break; case X86::CMP32ri: SimplifyShortImmForm(OutMI, X86::CMP32i32); break; case X86::CMP64ri32: SimplifyShortImmForm(OutMI, X86::CMP64i32); break; case X86::OR8ri: SimplifyShortImmForm(OutMI, X86::OR8i8); break; case X86::OR16ri: SimplifyShortImmForm(OutMI, X86::OR16i16); break; case X86::OR32ri: SimplifyShortImmForm(OutMI, X86::OR32i32); break; case X86::OR64ri32: SimplifyShortImmForm(OutMI, X86::OR64i32); break; case X86::SBB8ri: SimplifyShortImmForm(OutMI, X86::SBB8i8); break; case X86::SBB16ri: SimplifyShortImmForm(OutMI, X86::SBB16i16); break; case X86::SBB32ri: SimplifyShortImmForm(OutMI, X86::SBB32i32); break; case X86::SBB64ri32: SimplifyShortImmForm(OutMI, X86::SBB64i32); break; case X86::SUB8ri: SimplifyShortImmForm(OutMI, X86::SUB8i8); break; case X86::SUB16ri: SimplifyShortImmForm(OutMI, X86::SUB16i16); break; case X86::SUB32ri: SimplifyShortImmForm(OutMI, X86::SUB32i32); break; case X86::SUB64ri32: SimplifyShortImmForm(OutMI, X86::SUB64i32); break; case X86::TEST8ri: SimplifyShortImmForm(OutMI, X86::TEST8i8); break; case X86::TEST16ri: SimplifyShortImmForm(OutMI, X86::TEST16i16); break; case X86::TEST32ri: SimplifyShortImmForm(OutMI, X86::TEST32i32); break; case X86::TEST64ri32: SimplifyShortImmForm(OutMI, X86::TEST64i32); break; case X86::XOR8ri: SimplifyShortImmForm(OutMI, X86::XOR8i8); break; case X86::XOR16ri: SimplifyShortImmForm(OutMI, X86::XOR16i16); break; case X86::XOR32ri: SimplifyShortImmForm(OutMI, X86::XOR32i32); break; case X86::XOR64ri32: SimplifyShortImmForm(OutMI, X86::XOR64i32); break; // Try to shrink some forms of movsx. case X86::MOVSX16rr8: case X86::MOVSX32rr16: case X86::MOVSX64rr32: SimplifyMOVSX(OutMI); break; } } static void LowerTlsAddr(MCStreamer &OutStreamer, X86MCInstLower &MCInstLowering, const MachineInstr &MI, const MCSubtargetInfo& STI) { bool is64Bits = MI.getOpcode() == X86::TLS_addr64 || MI.getOpcode() == X86::TLS_base_addr64; bool needsPadding = MI.getOpcode() == X86::TLS_addr64; MCContext &context = OutStreamer.getContext(); if (needsPadding) OutStreamer.EmitInstruction(MCInstBuilder(X86::DATA16_PREFIX), STI); MCSymbolRefExpr::VariantKind SRVK; switch (MI.getOpcode()) { case X86::TLS_addr32: case X86::TLS_addr64: SRVK = MCSymbolRefExpr::VK_TLSGD; break; case X86::TLS_base_addr32: SRVK = MCSymbolRefExpr::VK_TLSLDM; break; case X86::TLS_base_addr64: SRVK = MCSymbolRefExpr::VK_TLSLD; break; default: llvm_unreachable("unexpected opcode"); } MCSymbol *sym = MCInstLowering.GetSymbolFromOperand(MI.getOperand(3)); const MCSymbolRefExpr *symRef = MCSymbolRefExpr::Create(sym, SRVK, context); MCInst LEA; if (is64Bits) { LEA.setOpcode(X86::LEA64r); LEA.addOperand(MCOperand::CreateReg(X86::RDI)); // dest LEA.addOperand(MCOperand::CreateReg(X86::RIP)); // base LEA.addOperand(MCOperand::CreateImm(1)); // scale LEA.addOperand(MCOperand::CreateReg(0)); // index LEA.addOperand(MCOperand::CreateExpr(symRef)); // disp LEA.addOperand(MCOperand::CreateReg(0)); // seg } else if (SRVK == MCSymbolRefExpr::VK_TLSLDM) { LEA.setOpcode(X86::LEA32r); LEA.addOperand(MCOperand::CreateReg(X86::EAX)); // dest LEA.addOperand(MCOperand::CreateReg(X86::EBX)); // base LEA.addOperand(MCOperand::CreateImm(1)); // scale LEA.addOperand(MCOperand::CreateReg(0)); // index LEA.addOperand(MCOperand::CreateExpr(symRef)); // disp LEA.addOperand(MCOperand::CreateReg(0)); // seg } else { LEA.setOpcode(X86::LEA32r); LEA.addOperand(MCOperand::CreateReg(X86::EAX)); // dest LEA.addOperand(MCOperand::CreateReg(0)); // base LEA.addOperand(MCOperand::CreateImm(1)); // scale LEA.addOperand(MCOperand::CreateReg(X86::EBX)); // index LEA.addOperand(MCOperand::CreateExpr(symRef)); // disp LEA.addOperand(MCOperand::CreateReg(0)); // seg } OutStreamer.EmitInstruction(LEA, STI); if (needsPadding) { OutStreamer.EmitInstruction(MCInstBuilder(X86::DATA16_PREFIX), STI); OutStreamer.EmitInstruction(MCInstBuilder(X86::DATA16_PREFIX), STI); OutStreamer.EmitInstruction(MCInstBuilder(X86::REX64_PREFIX), STI); } StringRef name = is64Bits ? "__tls_get_addr" : "___tls_get_addr"; MCSymbol *tlsGetAddr = context.GetOrCreateSymbol(name); const MCSymbolRefExpr *tlsRef = MCSymbolRefExpr::Create(tlsGetAddr, MCSymbolRefExpr::VK_PLT, context); OutStreamer.EmitInstruction(MCInstBuilder(is64Bits ? X86::CALL64pcrel32 : X86::CALLpcrel32) .addExpr(tlsRef), STI); } /// \brief Emit the optimal amount of multi-byte nops on X86. static void EmitNops(MCStreamer &OS, unsigned NumBytes, bool Is64Bit, const MCSubtargetInfo &STI) { // This works only for 64bit. For 32bit we have to do additional checking if // the CPU supports multi-byte nops. assert(Is64Bit && "EmitNops only supports X86-64"); while (NumBytes) { unsigned Opc, BaseReg, ScaleVal, IndexReg, Displacement, SegmentReg; Opc = IndexReg = Displacement = SegmentReg = 0; BaseReg = X86::RAX; ScaleVal = 1; switch (NumBytes) { case 0: llvm_unreachable("Zero nops?"); break; case 1: NumBytes -= 1; Opc = X86::NOOP; break; case 2: NumBytes -= 2; Opc = X86::XCHG16ar; break; case 3: NumBytes -= 3; Opc = X86::NOOPL; break; case 4: NumBytes -= 4; Opc = X86::NOOPL; Displacement = 8; break; case 5: NumBytes -= 5; Opc = X86::NOOPL; Displacement = 8; IndexReg = X86::RAX; break; case 6: NumBytes -= 6; Opc = X86::NOOPW; Displacement = 8; IndexReg = X86::RAX; break; case 7: NumBytes -= 7; Opc = X86::NOOPL; Displacement = 512; break; case 8: NumBytes -= 8; Opc = X86::NOOPL; Displacement = 512; IndexReg = X86::RAX; break; case 9: NumBytes -= 9; Opc = X86::NOOPW; Displacement = 512; IndexReg = X86::RAX; break; default: NumBytes -= 10; Opc = X86::NOOPW; Displacement = 512; IndexReg = X86::RAX; SegmentReg = X86::CS; break; } unsigned NumPrefixes = std::min(NumBytes, 5U); NumBytes -= NumPrefixes; for (unsigned i = 0; i != NumPrefixes; ++i) OS.EmitBytes("\x66"); switch (Opc) { default: llvm_unreachable("Unexpected opcode"); break; case X86::NOOP: OS.EmitInstruction(MCInstBuilder(Opc), STI); break; case X86::XCHG16ar: OS.EmitInstruction(MCInstBuilder(Opc).addReg(X86::AX), STI); break; case X86::NOOPL: case X86::NOOPW: OS.EmitInstruction(MCInstBuilder(Opc).addReg(BaseReg).addImm(ScaleVal) .addReg(IndexReg) .addImm(Displacement) .addReg(SegmentReg), STI); break; } } // while (NumBytes) } // Lower a stackmap of the form: // , , ... static void LowerSTACKMAP(MCStreamer &OS, StackMaps &SM, const MachineInstr &MI, bool Is64Bit, const MCSubtargetInfo& STI) { unsigned NumBytes = MI.getOperand(1).getImm(); SM.recordStackMap(MI); // Emit padding. // FIXME: These nops ensure that the stackmap's shadow is covered by // instructions from the same basic block, but the nops should not be // necessary if instructions from the same block follow the stackmap. EmitNops(OS, NumBytes, Is64Bit, STI); } // Lower a patchpoint of the form: // [], , , , , , ... static void LowerPATCHPOINT(MCStreamer &OS, StackMaps &SM, const MachineInstr &MI, bool Is64Bit, const MCSubtargetInfo& STI) { assert(Is64Bit && "Patchpoint currently only supports X86-64"); SM.recordPatchPoint(MI); PatchPointOpers opers(&MI); unsigned ScratchIdx = opers.getNextScratchIdx(); unsigned EncodedBytes = 0; int64_t CallTarget = opers.getMetaOper(PatchPointOpers::TargetPos).getImm(); if (CallTarget) { // Emit MOV to materialize the target address and the CALL to target. // This is encoded with 12-13 bytes, depending on which register is used. unsigned ScratchReg = MI.getOperand(ScratchIdx).getReg(); if (X86II::isX86_64ExtendedReg(ScratchReg)) EncodedBytes = 13; else EncodedBytes = 12; OS.EmitInstruction(MCInstBuilder(X86::MOV64ri).addReg(ScratchReg) .addImm(CallTarget), STI); OS.EmitInstruction(MCInstBuilder(X86::CALL64r).addReg(ScratchReg), STI); } // Emit padding. unsigned NumBytes = opers.getMetaOper(PatchPointOpers::NBytesPos).getImm(); assert(NumBytes >= EncodedBytes && "Patchpoint can't request size less than the length of a call."); EmitNops(OS, NumBytes - EncodedBytes, Is64Bit, STI); } void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) { X86MCInstLower MCInstLowering(*MF, *this); switch (MI->getOpcode()) { case TargetOpcode::DBG_VALUE: llvm_unreachable("Should be handled target independently"); // Emit nothing here but a comment if we can. case X86::Int_MemBarrier: OutStreamer.emitRawComment("MEMBARRIER"); return; case X86::EH_RETURN: case X86::EH_RETURN64: { // Lower these as normal, but add some comments. unsigned Reg = MI->getOperand(0).getReg(); OutStreamer.AddComment(StringRef("eh_return, addr: %") + X86ATTInstPrinter::getRegisterName(Reg)); break; } case X86::TAILJMPr: case X86::TAILJMPd: case X86::TAILJMPd64: // Lower these as normal, but add some comments. OutStreamer.AddComment("TAILCALL"); break; case X86::TLS_addr32: case X86::TLS_addr64: case X86::TLS_base_addr32: case X86::TLS_base_addr64: return LowerTlsAddr(OutStreamer, MCInstLowering, *MI, getSubtargetInfo()); case X86::MOVPC32r: { // This is a pseudo op for a two instruction sequence with a label, which // looks like: // call "L1$pb" // "L1$pb": // popl %esi // Emit the call. MCSymbol *PICBase = MF->getPICBaseSymbol(); // FIXME: We would like an efficient form for this, so we don't have to do a // lot of extra uniquing. EmitToStreamer(OutStreamer, MCInstBuilder(X86::CALLpcrel32) .addExpr(MCSymbolRefExpr::Create(PICBase, OutContext))); // Emit the label. OutStreamer.EmitLabel(PICBase); // popl $reg EmitToStreamer(OutStreamer, MCInstBuilder(X86::POP32r) .addReg(MI->getOperand(0).getReg())); return; } case X86::ADD32ri: { // Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri. if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS) break; // Okay, we have something like: // EAX = ADD32ri EAX, MO_GOT_ABSOLUTE_ADDRESS(@MYGLOBAL) // For this, we want to print something like: // MYGLOBAL + (. - PICBASE) // However, we can't generate a ".", so just emit a new label here and refer // to it. MCSymbol *DotSym = OutContext.CreateTempSymbol(); OutStreamer.EmitLabel(DotSym); // Now that we have emitted the label, lower the complex operand expression. MCSymbol *OpSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2)); const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext); const MCExpr *PICBase = MCSymbolRefExpr::Create(MF->getPICBaseSymbol(), OutContext); DotExpr = MCBinaryExpr::CreateSub(DotExpr, PICBase, OutContext); DotExpr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(OpSym,OutContext), DotExpr, OutContext); EmitToStreamer(OutStreamer, MCInstBuilder(X86::ADD32ri) .addReg(MI->getOperand(0).getReg()) .addReg(MI->getOperand(1).getReg()) .addExpr(DotExpr)); return; } case TargetOpcode::STACKMAP: return LowerSTACKMAP(OutStreamer, SM, *MI, Subtarget->is64Bit(), getSubtargetInfo()); case TargetOpcode::PATCHPOINT: return LowerPATCHPOINT(OutStreamer, SM, *MI, Subtarget->is64Bit(), getSubtargetInfo()); case X86::MORESTACK_RET: EmitToStreamer(OutStreamer, MCInstBuilder(getRetOpcode(*Subtarget))); return; case X86::MORESTACK_RET_RESTORE_R10: // Return, then restore R10. EmitToStreamer(OutStreamer, MCInstBuilder(getRetOpcode(*Subtarget))); EmitToStreamer(OutStreamer, MCInstBuilder(X86::MOV64rr) .addReg(X86::R10) .addReg(X86::RAX)); return; } MCInst TmpInst; MCInstLowering.Lower(MI, TmpInst); EmitToStreamer(OutStreamer, TmpInst); }