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//===-- X86MCInstLower.cpp - Convert X86 MachineInstr to an MCInst --------===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file contains code to lower X86 MachineInstrs to their corresponding
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//===----------------------------------------------------------------------===//
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#include "X86MCInstLower.h"
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#include "X86AsmPrinter.h"
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#include "X86COFFMachineModuleInfo.h"
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#include "X86MCAsmInfo.h"
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#include "X86MCTargetExpr.h"
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#include "llvm/Analysis/DebugInfo.h"
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#include "llvm/CodeGen/MachineModuleInfoImpls.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/Target/Mangler.h"
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#include "llvm/Support/FormattedStream.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/Type.h"
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const X86Subtarget &X86MCInstLower::getSubtarget() const {
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return AsmPrinter.getSubtarget();
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MachineModuleInfoMachO &X86MCInstLower::getMachOMMI() const {
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assert(getSubtarget().isTargetDarwin() &&"Can only get MachO info on darwin");
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return AsmPrinter.MMI->getObjFileInfo<MachineModuleInfoMachO>();
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MCSymbol *X86MCInstLower::GetPICBaseSymbol() const {
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const TargetLowering *TLI = AsmPrinter.TM.getTargetLowering();
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return static_cast<const X86TargetLowering*>(TLI)->
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getPICBaseSymbol(AsmPrinter.MF, Ctx);
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/// GetSymbolFromOperand - Lower an MO_GlobalAddress or MO_ExternalSymbol
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/// operand to an MCSymbol.
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MCSymbol *X86MCInstLower::
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GetSymbolFromOperand(const MachineOperand &MO) const {
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assert((MO.isGlobal() || MO.isSymbol()) && "Isn't a symbol reference");
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SmallString<128> Name;
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bool isImplicitlyPrivate = false;
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if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB ||
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MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
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MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
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MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
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isImplicitlyPrivate = true;
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const GlobalValue *GV = MO.getGlobal();
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Mang->getNameWithPrefix(Name, GV, isImplicitlyPrivate);
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if (getSubtarget().isTargetCygMing()) {
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X86COFFMachineModuleInfo &COFFMMI =
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AsmPrinter.MMI->getObjFileInfo<X86COFFMachineModuleInfo>();
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COFFMMI.DecorateCygMingName(Name, GV, *AsmPrinter.TM.getTargetData());
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assert(MO.isSymbol());
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Name += AsmPrinter.MAI->getGlobalPrefix();
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Name += MO.getSymbolName();
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// If the target flags on the operand changes the name of the symbol, do that
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// before we return the symbol.
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switch (MO.getTargetFlags()) {
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case X86II::MO_DLLIMPORT: {
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// Handle dllimport linkage.
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const char *Prefix = "__imp_";
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Name.insert(Name.begin(), Prefix, Prefix+strlen(Prefix));
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case X86II::MO_DARWIN_NONLAZY:
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case X86II::MO_DARWIN_NONLAZY_PIC_BASE: {
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Name += "$non_lazy_ptr";
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MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name.str());
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MCSymbol *&StubSym = getMachOMMI().getGVStubEntry(Sym);
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assert(MO.isGlobal() && "Extern symbol not handled yet");
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StubSym = AsmPrinter.GetGlobalValueSymbol(MO.getGlobal());
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case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: {
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Name += "$non_lazy_ptr";
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MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name.str());
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MCSymbol *&StubSym = getMachOMMI().getHiddenGVStubEntry(Sym);
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assert(MO.isGlobal() && "Extern symbol not handled yet");
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StubSym = AsmPrinter.GetGlobalValueSymbol(MO.getGlobal());
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case X86II::MO_DARWIN_STUB: {
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MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name.str());
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MCSymbol *&StubSym = getMachOMMI().getFnStubEntry(Sym);
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StubSym = AsmPrinter.GetGlobalValueSymbol(MO.getGlobal());
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Name.erase(Name.end()-5, Name.end());
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StubSym = Ctx.GetOrCreateSymbol(Name.str());
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return Ctx.GetOrCreateSymbol(Name.str());
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MCOperand X86MCInstLower::LowerSymbolOperand(const MachineOperand &MO,
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MCSymbol *Sym) const {
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// FIXME: We would like an efficient form for this, so we don't have to do a
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// lot of extra uniquing.
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const MCExpr *Expr = 0;
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X86MCTargetExpr::VariantKind RefKind = X86MCTargetExpr::Invalid;
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switch (MO.getTargetFlags()) {
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default: llvm_unreachable("Unknown target flag on GV operand");
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case X86II::MO_NO_FLAG: // No flag.
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// These affect the name of the symbol, not any suffix.
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case X86II::MO_DARWIN_NONLAZY:
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case X86II::MO_DLLIMPORT:
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case X86II::MO_DARWIN_STUB:
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case X86II::MO_TLSGD: RefKind = X86MCTargetExpr::TLSGD; break;
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case X86II::MO_GOTTPOFF: RefKind = X86MCTargetExpr::GOTTPOFF; break;
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case X86II::MO_INDNTPOFF: RefKind = X86MCTargetExpr::INDNTPOFF; break;
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case X86II::MO_TPOFF: RefKind = X86MCTargetExpr::TPOFF; break;
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case X86II::MO_NTPOFF: RefKind = X86MCTargetExpr::NTPOFF; break;
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case X86II::MO_GOTPCREL: RefKind = X86MCTargetExpr::GOTPCREL; break;
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case X86II::MO_GOT: RefKind = X86MCTargetExpr::GOT; break;
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case X86II::MO_GOTOFF: RefKind = X86MCTargetExpr::GOTOFF; break;
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case X86II::MO_PLT: RefKind = X86MCTargetExpr::PLT; break;
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case X86II::MO_PIC_BASE_OFFSET:
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case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
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case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
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Expr = MCSymbolRefExpr::Create(Sym, Ctx);
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// Subtract the pic base.
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Expr = MCBinaryExpr::CreateSub(Expr,
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MCSymbolRefExpr::Create(GetPICBaseSymbol(), Ctx),
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if (RefKind == X86MCTargetExpr::Invalid)
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Expr = MCSymbolRefExpr::Create(Sym, Ctx);
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Expr = X86MCTargetExpr::Create(Sym, RefKind, Ctx);
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if (!MO.isJTI() && MO.getOffset())
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Expr = MCBinaryExpr::CreateAdd(Expr,
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MCConstantExpr::Create(MO.getOffset(), Ctx),
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return MCOperand::CreateExpr(Expr);
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static void lower_subreg32(MCInst *MI, unsigned OpNo) {
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// Convert registers in the addr mode according to subreg32.
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unsigned Reg = MI->getOperand(OpNo).getReg();
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MI->getOperand(OpNo).setReg(getX86SubSuperRegister(Reg, MVT::i32));
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static void lower_lea64_32mem(MCInst *MI, unsigned OpNo) {
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// Convert registers in the addr mode according to subreg64.
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for (unsigned i = 0; i != 4; ++i) {
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if (!MI->getOperand(OpNo+i).isReg()) continue;
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unsigned Reg = MI->getOperand(OpNo+i).getReg();
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if (Reg == 0) continue;
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MI->getOperand(OpNo+i).setReg(getX86SubSuperRegister(Reg, MVT::i64));
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/// LowerSubReg32_Op0 - Things like MOVZX16rr8 -> MOVZX32rr8.
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static void LowerSubReg32_Op0(MCInst &OutMI, unsigned NewOpc) {
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OutMI.setOpcode(NewOpc);
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lower_subreg32(&OutMI, 0);
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/// LowerUnaryToTwoAddr - R = setb -> R = sbb R, R
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static void LowerUnaryToTwoAddr(MCInst &OutMI, unsigned NewOpc) {
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OutMI.setOpcode(NewOpc);
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OutMI.addOperand(OutMI.getOperand(0));
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OutMI.addOperand(OutMI.getOperand(0));
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void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
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OutMI.setOpcode(MI->getOpcode());
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for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
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const MachineOperand &MO = MI->getOperand(i);
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switch (MO.getType()) {
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llvm_unreachable("unknown operand type");
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case MachineOperand::MO_Register:
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// Ignore all implicit register operands.
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if (MO.isImplicit()) continue;
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MCOp = MCOperand::CreateReg(MO.getReg());
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case MachineOperand::MO_Immediate:
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MCOp = MCOperand::CreateImm(MO.getImm());
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case MachineOperand::MO_MachineBasicBlock:
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MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
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MO.getMBB()->getSymbol(Ctx), Ctx));
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case MachineOperand::MO_GlobalAddress:
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MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
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case MachineOperand::MO_ExternalSymbol:
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MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
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case MachineOperand::MO_JumpTableIndex:
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MCOp = LowerSymbolOperand(MO, AsmPrinter.GetJTISymbol(MO.getIndex()));
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case MachineOperand::MO_ConstantPoolIndex:
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MCOp = LowerSymbolOperand(MO, AsmPrinter.GetCPISymbol(MO.getIndex()));
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case MachineOperand::MO_BlockAddress:
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MCOp = LowerSymbolOperand(MO,
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AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress()));
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OutMI.addOperand(MCOp);
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// Handle a few special cases to eliminate operand modifiers.
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switch (OutMI.getOpcode()) {
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case X86::LEA64_32r: // Handle 'subreg rewriting' for the lea64_32mem operand.
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lower_lea64_32mem(&OutMI, 1);
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case X86::MOVZX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
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case X86::MOVZX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
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case X86::MOVSX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rr8); break;
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case X86::MOVSX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rm8); break;
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case X86::MOVZX64rr32: LowerSubReg32_Op0(OutMI, X86::MOV32rr); break;
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case X86::MOVZX64rm32: LowerSubReg32_Op0(OutMI, X86::MOV32rm); break;
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case X86::MOV64ri64i32: LowerSubReg32_Op0(OutMI, X86::MOV32ri); break;
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case X86::MOVZX64rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
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case X86::MOVZX64rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
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case X86::MOVZX64rr16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr16); break;
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case X86::MOVZX64rm16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm16); break;
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case X86::SETB_C8r: LowerUnaryToTwoAddr(OutMI, X86::SBB8rr); break;
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case X86::SETB_C16r: LowerUnaryToTwoAddr(OutMI, X86::SBB16rr); break;
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case X86::SETB_C32r: LowerUnaryToTwoAddr(OutMI, X86::SBB32rr); break;
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case X86::SETB_C64r: LowerUnaryToTwoAddr(OutMI, X86::SBB64rr); break;
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case X86::MOV8r0: LowerUnaryToTwoAddr(OutMI, X86::XOR8rr); break;
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case X86::MOV32r0: LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); break;
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case X86::MMX_V_SET0: LowerUnaryToTwoAddr(OutMI, X86::MMX_PXORrr); break;
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case X86::MMX_V_SETALLONES:
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LowerUnaryToTwoAddr(OutMI, X86::MMX_PCMPEQDrr); break;
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case X86::FsFLD0SS: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
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case X86::FsFLD0SD: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
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case X86::V_SET0: LowerUnaryToTwoAddr(OutMI, X86::XORPSrr); break;
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case X86::V_SETALLONES: LowerUnaryToTwoAddr(OutMI, X86::PCMPEQDrr); break;
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LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV16r0 -> MOV32r0
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LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
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LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV64r0 -> MOV32r0
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LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
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void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
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X86MCInstLower MCInstLowering(OutContext, Mang, *this);
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switch (MI->getOpcode()) {
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case TargetOpcode::DBG_VALUE: {
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// FIXME: if this is implemented for another target before it goes
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// away completely, the common part should be moved into AsmPrinter.
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O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
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unsigned NOps = MI->getNumOperands();
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// cast away const; DIetc do not take const operands for some reason.
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DIVariable V((MDNode*)(MI->getOperand(NOps-1).getMetadata()));
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// Register or immediate value. Register 0 means undef.
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assert(MI->getOperand(0).getType()==MachineOperand::MO_Register ||
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MI->getOperand(0).getType()==MachineOperand::MO_Immediate ||
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MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate);
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if (MI->getOperand(0).getType()==MachineOperand::MO_Register &&
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MI->getOperand(0).getReg()==0) {
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// Suppress offset in this case, it is not meaningful.
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OutStreamer.AddBlankLine();
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} else if (MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate) {
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// This is more naturally done in printOperand, but since the only use
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// of such an operand is in this comment and that is temporary (and it's
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// ugly), we prefer to keep this localized.
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// The include of Type.h may be removable when this code is.
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if (MI->getOperand(0).getFPImm()->getType()->isFloatTy() ||
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MI->getOperand(0).getFPImm()->getType()->isDoubleTy())
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MI->getOperand(0).print(O, &TM);
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// There is no good way to print long double. Convert a copy to
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// double. Ah well, it's only a comment.
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APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
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APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
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O << "(long double) " << APF.convertToDouble();
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// Frame address. Currently handles register +- offset only.
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assert(MI->getOperand(0).getType()==MachineOperand::MO_Register);
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assert(MI->getOperand(3).getType()==MachineOperand::MO_Immediate);
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O << '['; printOperand(MI, 0); O << '+'; printOperand(MI, 3); O << ']';
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printOperand(MI, NOps-2);
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OutStreamer.AddBlankLine();
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case X86::MOVPC32r: {
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// This is a pseudo op for a two instruction sequence with a label, which
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MCSymbol *PICBase = MCInstLowering.GetPICBaseSymbol();
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TmpInst.setOpcode(X86::CALLpcrel32);
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// FIXME: We would like an efficient form for this, so we don't have to do a
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// lot of extra uniquing.
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TmpInst.addOperand(MCOperand::CreateExpr(MCSymbolRefExpr::Create(PICBase,
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OutStreamer.EmitInstruction(TmpInst);
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OutStreamer.EmitLabel(PICBase);
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TmpInst.setOpcode(X86::POP32r);
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TmpInst.getOperand(0) = MCOperand::CreateReg(MI->getOperand(0).getReg());
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OutStreamer.EmitInstruction(TmpInst);
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// Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri.
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if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS)
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// Okay, we have something like:
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// EAX = ADD32ri EAX, MO_GOT_ABSOLUTE_ADDRESS(@MYGLOBAL)
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// For this, we want to print something like:
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// MYGLOBAL + (. - PICBASE)
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// However, we can't generate a ".", so just emit a new label here and refer
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// to it. We know that this operand flag occurs at most once per function.
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const char *Prefix = MAI->getPrivateGlobalPrefix();
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MCSymbol *DotSym = OutContext.GetOrCreateSymbol(Twine(Prefix)+"picbaseref"+
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Twine(getFunctionNumber()));
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OutStreamer.EmitLabel(DotSym);
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// Now that we have emitted the label, lower the complex operand expression.
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MCSymbol *OpSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2));
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const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext);
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const MCExpr *PICBase =
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MCSymbolRefExpr::Create(MCInstLowering.GetPICBaseSymbol(), OutContext);
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DotExpr = MCBinaryExpr::CreateSub(DotExpr, PICBase, OutContext);
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DotExpr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(OpSym,OutContext),
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DotExpr, OutContext);
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TmpInst.setOpcode(X86::ADD32ri);
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TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
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TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
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TmpInst.addOperand(MCOperand::CreateExpr(DotExpr));
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OutStreamer.EmitInstruction(TmpInst);
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MCInstLowering.Lower(MI, TmpInst);
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OutStreamer.EmitInstruction(TmpInst);