llvm/lib/Target/X86/X86AsmPrinter.cpp

   1 //===-- X86AsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly --------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains a printer that converts from our internal representation
  10 // of machine-dependent LLVM code to X86 machine code.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "X86AsmPrinter.h"
  15 #include "MCTargetDesc/X86ATTInstPrinter.h"
  16 #include "MCTargetDesc/X86BaseInfo.h"
  17 #include "MCTargetDesc/X86TargetStreamer.h"
  18 #include "TargetInfo/X86TargetInfo.h"
  19 #include "X86InstrInfo.h"
  20 #include "X86MachineFunctionInfo.h"
  21 #include "X86Subtarget.h"
  22 #include "llvm/BinaryFormat/COFF.h"
  23 #include "llvm/BinaryFormat/ELF.h"
  24 #include "llvm/CodeGen/MachineConstantPool.h"
  25 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
  26 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
  27 #include "llvm/IR/DerivedTypes.h"
  28 #include "llvm/IR/InlineAsm.h"
  29 #include "llvm/IR/Mangler.h"
  30 #include "llvm/IR/Module.h"
  31 #include "llvm/IR/Type.h"
  32 #include "llvm/MC/MCCodeEmitter.h"
  33 #include "llvm/MC/MCContext.h"
  34 #include "llvm/MC/MCExpr.h"
  35 #include "llvm/MC/MCSectionCOFF.h"
  36 #include "llvm/MC/MCSectionELF.h"
  37 #include "llvm/MC/MCSectionMachO.h"
  38 #include "llvm/MC/MCStreamer.h"
  39 #include "llvm/MC/MCSymbol.h"
  40 #include "llvm/Support/Debug.h"
  41 #include "llvm/Support/ErrorHandling.h"
  42 #include "llvm/Support/MachineValueType.h"
  43 #include "llvm/Support/TargetRegistry.h"
  44 #include "llvm/Target/TargetMachine.h"
  45
  46 using namespace llvm;
  47
  48 X86AsmPrinter::X86AsmPrinter(TargetMachine &TM,
  49                              std::unique_ptr<MCStreamer> Streamer)
  50     : AsmPrinter(TM, std::move(Streamer)), SM(*this), FM(*this) {}
  51
  52 //===----------------------------------------------------------------------===//
  53 // Primitive Helper Functions.
  54 //===----------------------------------------------------------------------===//
  55
  56 /// runOnMachineFunction - Emit the function body.
  57 ///
  58 bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
  59   Subtarget = &MF.getSubtarget<X86Subtarget>();
  60
  61   SMShadowTracker.startFunction(MF);
  62   CodeEmitter.reset(TM.getTarget().createMCCodeEmitter(
  63       *Subtarget->getInstrInfo(), *Subtarget->getRegisterInfo(),
  64       MF.getContext()));
  65
  66   EmitFPOData =
  67       Subtarget->isTargetWin32() && MF.getMMI().getModule()->getCodeViewFlag();
  68
  69   SetupMachineFunction(MF);
  70
  71   if (Subtarget->isTargetCOFF()) {
  72     bool Local = MF.getFunction().hasLocalLinkage();
  73     OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
  74     OutStreamer->EmitCOFFSymbolStorageClass(
  75         Local ? COFF::IMAGE_SYM_CLASS_STATIC : COFF::IMAGE_SYM_CLASS_EXTERNAL);
  76     OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
  77                                                << COFF::SCT_COMPLEX_TYPE_SHIFT);
  78     OutStreamer->EndCOFFSymbolDef();
  79   }
  80
  81   // Emit the rest of the function body.
  82   emitFunctionBody();
  83
  84   // Emit the XRay table for this function.
  85   emitXRayTable();
  86
  87   EmitFPOData = false;
  88
  89   // We didn't modify anything.
  90   return false;
  91 }
  92
  93 void X86AsmPrinter::emitFunctionBodyStart() {
  94   if (EmitFPOData) {
  95     if (auto *XTS =
  96         static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
  97       XTS->emitFPOProc(
  98           CurrentFnSym,
  99           MF->getInfo<X86MachineFunctionInfo>()->getArgumentStackSize());
 100   }
 101 }
 102
 103 void X86AsmPrinter::emitFunctionBodyEnd() {
 104   if (EmitFPOData) {
 105     if (auto *XTS =
 106             static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
 107       XTS->emitFPOEndProc();
 108   }
 109 }
 110
 111 /// PrintSymbolOperand - Print a raw symbol reference operand.  This handles
 112 /// jump tables, constant pools, global address and external symbols, all of
 113 /// which print to a label with various suffixes for relocation types etc.
 114 void X86AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
 115                                        raw_ostream &O) {
 116   switch (MO.getType()) {
 117   default: llvm_unreachable("unknown symbol type!");
 118   case MachineOperand::MO_ConstantPoolIndex:
 119     GetCPISymbol(MO.getIndex())->print(O, MAI);
 120     printOffset(MO.getOffset(), O);
 121     break;
 122   case MachineOperand::MO_GlobalAddress: {
 123     const GlobalValue *GV = MO.getGlobal();
 124
 125     MCSymbol *GVSym;
 126     if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
 127         MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE)
 128       GVSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
 129     else
 130       GVSym = getSymbolPreferLocal(*GV);
 131
 132     // Handle dllimport linkage.
 133     if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
 134       GVSym = OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName());
 135     else if (MO.getTargetFlags() == X86II::MO_COFFSTUB)
 136       GVSym =
 137           OutContext.getOrCreateSymbol(Twine(".refptr.") + GVSym->getName());
 138
 139     if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
 140         MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
 141       MCSymbol *Sym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
 142       MachineModuleInfoImpl::StubValueTy &StubSym =
 143           MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
 144       if (!StubSym.getPointer())
 145         StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(GV),
 146                                                      !GV->hasInternalLinkage());
 147     }
 148
 149     // If the name begins with a dollar-sign, enclose it in parens.  We do this
 150     // to avoid having it look like an integer immediate to the assembler.
 151     if (GVSym->getName()[0] != '$')
 152       GVSym->print(O, MAI);
 153     else {
 154       O << '(';
 155       GVSym->print(O, MAI);
 156       O << ')';
 157     }
 158     printOffset(MO.getOffset(), O);
 159     break;
 160   }
 161   }
 162
 163   switch (MO.getTargetFlags()) {
 164   default:
 165     llvm_unreachable("Unknown target flag on GV operand");
 166   case X86II::MO_NO_FLAG:    // No flag.
 167     break;
 168   case X86II::MO_DARWIN_NONLAZY:
 169   case X86II::MO_DLLIMPORT:
 170   case X86II::MO_COFFSTUB:
 171     // These affect the name of the symbol, not any suffix.
 172     break;
 173   case X86II::MO_GOT_ABSOLUTE_ADDRESS:
 174     O << " + [.-";
 175     MF->getPICBaseSymbol()->print(O, MAI);
 176     O << ']';
 177     break;
 178   case X86II::MO_PIC_BASE_OFFSET:
 179   case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
 180     O << '-';
 181     MF->getPICBaseSymbol()->print(O, MAI);
 182     break;
 183   case X86II::MO_TLSGD:     O << "@TLSGD";     break;
 184   case X86II::MO_TLSLD:     O << "@TLSLD";     break;
 185   case X86II::MO_TLSLDM:    O << "@TLSLDM";    break;
 186   case X86II::MO_GOTTPOFF:  O << "@GOTTPOFF";  break;
 187   case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
 188   case X86II::MO_TPOFF:     O << "@TPOFF";     break;
 189   case X86II::MO_DTPOFF:    O << "@DTPOFF";    break;
 190   case X86II::MO_NTPOFF:    O << "@NTPOFF";    break;
 191   case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break;
 192   case X86II::MO_GOTPCREL:  O << "@GOTPCREL";  break;
 193   case X86II::MO_GOT:       O << "@GOT";       break;
 194   case X86II::MO_GOTOFF:    O << "@GOTOFF";    break;
 195   case X86II::MO_PLT:       O << "@PLT";       break;
 196   case X86II::MO_TLVP:      O << "@TLVP";      break;
 197   case X86II::MO_TLVP_PIC_BASE:
 198     O << "@TLVP" << '-';
 199     MF->getPICBaseSymbol()->print(O, MAI);
 200     break;
 201   case X86II::MO_SECREL:    O << "@SECREL32";  break;
 202   }
 203 }
 204
 205 void X86AsmPrinter::PrintOperand(const MachineInstr *MI, unsigned OpNo,
 206                                  raw_ostream &O) {
 207   const MachineOperand &MO = MI->getOperand(OpNo);
 208   const bool IsATT = MI->getInlineAsmDialect() == InlineAsm::AD_ATT;
 209   switch (MO.getType()) {
 210   default: llvm_unreachable("unknown operand type!");
 211   case MachineOperand::MO_Register: {
 212     if (IsATT)
 213       O << '%';
 214     O << X86ATTInstPrinter::getRegisterName(MO.getReg());
 215     return;
 216   }
 217
 218   case MachineOperand::MO_Immediate:
 219     if (IsATT)
 220       O << '$';
 221     O << MO.getImm();
 222     return;
 223
 224   case MachineOperand::MO_ConstantPoolIndex:
 225   case MachineOperand::MO_GlobalAddress: {
 226     switch (MI->getInlineAsmDialect()) {
 227     case InlineAsm::AD_ATT:
 228       O << '$';
 229       break;
 230     case InlineAsm::AD_Intel:
 231       O << "offset ";
 232       break;
 233     }
 234     PrintSymbolOperand(MO, O);
 235     break;
 236   }
 237   case MachineOperand::MO_BlockAddress: {
 238     MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
 239     Sym->print(O, MAI);
 240     break;
 241   }
 242   }
 243 }
 244
 245 /// PrintModifiedOperand - Print subregisters based on supplied modifier,
 246 /// deferring to PrintOperand() if no modifier was supplied or if operand is not
 247 /// a register.
 248 void X86AsmPrinter::PrintModifiedOperand(const MachineInstr *MI, unsigned OpNo,
 249                                          raw_ostream &O, const char *Modifier) {
 250   const MachineOperand &MO = MI->getOperand(OpNo);
 251   if (!Modifier || MO.getType() != MachineOperand::MO_Register)
 252     return PrintOperand(MI, OpNo, O);
 253   if (MI->getInlineAsmDialect() == InlineAsm::AD_ATT)
 254     O << '%';
 255   Register Reg = MO.getReg();
 256   if (strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
 257     unsigned Size = (strcmp(Modifier+6,"64") == 0) ? 64 :
 258         (strcmp(Modifier+6,"32") == 0) ? 32 :
 259         (strcmp(Modifier+6,"16") == 0) ? 16 : 8;
 260     Reg = getX86SubSuperRegister(Reg, Size);
 261   }
 262   O << X86ATTInstPrinter::getRegisterName(Reg);
 263 }
 264
 265 /// PrintPCRelImm - This is used to print an immediate value that ends up
 266 /// being encoded as a pc-relative value.  These print slightly differently, for
 267 /// example, a $ is not emitted.
 268 void X86AsmPrinter::PrintPCRelImm(const MachineInstr *MI, unsigned OpNo,
 269                                   raw_ostream &O) {
 270   const MachineOperand &MO = MI->getOperand(OpNo);
 271   switch (MO.getType()) {
 272   default: llvm_unreachable("Unknown pcrel immediate operand");
 273   case MachineOperand::MO_Register:
 274     // pc-relativeness was handled when computing the value in the reg.
 275     PrintOperand(MI, OpNo, O);
 276     return;
 277   case MachineOperand::MO_Immediate:
 278     O << MO.getImm();
 279     return;
 280   case MachineOperand::MO_GlobalAddress:
 281     PrintSymbolOperand(MO, O);
 282     return;
 283   }
 284 }
 285
 286 void X86AsmPrinter::PrintLeaMemReference(const MachineInstr *MI, unsigned OpNo,
 287                                          raw_ostream &O, const char *Modifier) {
 288   const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
 289   const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
 290   const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
 291
 292   // If we really don't want to print out (rip), don't.
 293   bool HasBaseReg = BaseReg.getReg() != 0;
 294   if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
 295       BaseReg.getReg() == X86::RIP)
 296     HasBaseReg = false;
 297
 298   // HasParenPart - True if we will print out the () part of the mem ref.
 299   bool HasParenPart = IndexReg.getReg() || HasBaseReg;
 300
 301   switch (DispSpec.getType()) {
 302   default:
 303     llvm_unreachable("unknown operand type!");
 304   case MachineOperand::MO_Immediate: {
 305     int DispVal = DispSpec.getImm();
 306     if (DispVal || !HasParenPart)
 307       O << DispVal;
 308     break;
 309   }
 310   case MachineOperand::MO_GlobalAddress:
 311   case MachineOperand::MO_ConstantPoolIndex:
 312     PrintSymbolOperand(DispSpec, O);
 313     break;
 314   }
 315
 316   if (Modifier && strcmp(Modifier, "H") == 0)
 317     O << "+8";
 318
 319   if (HasParenPart) {
 320     assert(IndexReg.getReg() != X86::ESP &&
 321            "X86 doesn't allow scaling by ESP");
 322
 323     O << '(';
 324     if (HasBaseReg)
 325       PrintModifiedOperand(MI, OpNo + X86::AddrBaseReg, O, Modifier);
 326
 327     if (IndexReg.getReg()) {
 328       O << ',';
 329       PrintModifiedOperand(MI, OpNo + X86::AddrIndexReg, O, Modifier);
 330       unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
 331       if (ScaleVal != 1)
 332         O << ',' << ScaleVal;
 333     }
 334     O << ')';
 335   }
 336 }
 337
 338 void X86AsmPrinter::PrintMemReference(const MachineInstr *MI, unsigned OpNo,
 339                                       raw_ostream &O, const char *Modifier) {
 340   assert(isMem(*MI, OpNo) && "Invalid memory reference!");
 341   const MachineOperand &Segment = MI->getOperand(OpNo + X86::AddrSegmentReg);
 342   if (Segment.getReg()) {
 343     PrintModifiedOperand(MI, OpNo + X86::AddrSegmentReg, O, Modifier);
 344     O << ':';
 345   }
 346   PrintLeaMemReference(MI, OpNo, O, Modifier);
 347 }
 348
 349
 350 void X86AsmPrinter::PrintIntelMemReference(const MachineInstr *MI,
 351                                            unsigned OpNo, raw_ostream &O,
 352                                            const char *Modifier) {
 353   const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
 354   unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
 355   const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
 356   const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
 357   const MachineOperand &SegReg = MI->getOperand(OpNo + X86::AddrSegmentReg);
 358
 359   // If we really don't want to print out (rip), don't.
 360   bool HasBaseReg = BaseReg.getReg() != 0;
 361   if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
 362       BaseReg.getReg() == X86::RIP)
 363     HasBaseReg = false;
 364
 365   // If this has a segment register, print it.
 366   if (SegReg.getReg()) {
 367     PrintOperand(MI, OpNo + X86::AddrSegmentReg, O);
 368     O << ':';
 369   }
 370
 371   O << '[';
 372
 373   bool NeedPlus = false;
 374   if (HasBaseReg) {
 375     PrintOperand(MI, OpNo + X86::AddrBaseReg, O);
 376     NeedPlus = true;
 377   }
 378
 379   if (IndexReg.getReg()) {
 380     if (NeedPlus) O << " + ";
 381     if (ScaleVal != 1)
 382       O << ScaleVal << '*';
 383     PrintOperand(MI, OpNo + X86::AddrIndexReg, O);
 384     NeedPlus = true;
 385   }
 386
 387   if (!DispSpec.isImm()) {
 388     if (NeedPlus) O << " + ";
 389     PrintOperand(MI, OpNo + X86::AddrDisp, O);
 390   } else {
 391     int64_t DispVal = DispSpec.getImm();
 392     if (DispVal || (!IndexReg.getReg() && !HasBaseReg)) {
 393       if (NeedPlus) {
 394         if (DispVal > 0)
 395           O << " + ";
 396         else {
 397           O << " - ";
 398           DispVal = -DispVal;
 399         }
 400       }
 401       O << DispVal;
 402     }
 403   }
 404   O << ']';
 405 }
 406
 407 static bool printAsmMRegister(const X86AsmPrinter &P, const MachineOperand &MO,
 408                               char Mode, raw_ostream &O) {
 409   Register Reg = MO.getReg();
 410   bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
 411
 412   if (!X86::GR8RegClass.contains(Reg) &&
 413       !X86::GR16RegClass.contains(Reg) &&
 414       !X86::GR32RegClass.contains(Reg) &&
 415       !X86::GR64RegClass.contains(Reg))
 416     return true;
 417
 418   switch (Mode) {
 419   default: return true;  // Unknown mode.
 420   case 'b': // Print QImode register
 421     Reg = getX86SubSuperRegister(Reg, 8);
 422     break;
 423   case 'h': // Print QImode high register
 424     Reg = getX86SubSuperRegister(Reg, 8, true);
 425     break;
 426   case 'w': // Print HImode register
 427     Reg = getX86SubSuperRegister(Reg, 16);
 428     break;
 429   case 'k': // Print SImode register
 430     Reg = getX86SubSuperRegister(Reg, 32);
 431     break;
 432   case 'V':
 433     EmitPercent = false;
 434     LLVM_FALLTHROUGH;
 435   case 'q':
 436     // Print 64-bit register names if 64-bit integer registers are available.
 437     // Otherwise, print 32-bit register names.
 438     Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32);
 439     break;
 440   }
 441
 442   if (EmitPercent)
 443     O << '%';
 444
 445   O << X86ATTInstPrinter::getRegisterName(Reg);
 446   return false;
 447 }
 448
 449 static bool printAsmVRegister(const MachineOperand &MO, char Mode,
 450                               raw_ostream &O) {
 451   Register Reg = MO.getReg();
 452   bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
 453
 454   unsigned Index;
 455   if (X86::VR128XRegClass.contains(Reg))
 456     Index = Reg - X86::XMM0;
 457   else if (X86::VR256XRegClass.contains(Reg))
 458     Index = Reg - X86::YMM0;
 459   else if (X86::VR512RegClass.contains(Reg))
 460     Index = Reg - X86::ZMM0;
 461   else
 462     return true;
 463
 464   switch (Mode) {
 465   default: // Unknown mode.
 466     return true;
 467   case 'x': // Print V4SFmode register
 468     Reg = X86::XMM0 + Index;
 469     break;
 470   case 't': // Print V8SFmode register
 471     Reg = X86::YMM0 + Index;
 472     break;
 473   case 'g': // Print V16SFmode register
 474     Reg = X86::ZMM0 + Index;
 475     break;
 476   }
 477
 478   if (EmitPercent)
 479     O << '%';
 480
 481   O << X86ATTInstPrinter::getRegisterName(Reg);
 482   return false;
 483 }
 484
 485 /// PrintAsmOperand - Print out an operand for an inline asm expression.
 486 ///
 487 bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
 488                                     const char *ExtraCode, raw_ostream &O) {
 489   // Does this asm operand have a single letter operand modifier?
 490   if (ExtraCode && ExtraCode[0]) {
 491     if (ExtraCode[1] != 0) return true; // Unknown modifier.
 492
 493     const MachineOperand &MO = MI->getOperand(OpNo);
 494
 495     switch (ExtraCode[0]) {
 496     default:
 497       // See if this is a generic print operand
 498       return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
 499     case 'a': // This is an address.  Currently only 'i' and 'r' are expected.
 500       switch (MO.getType()) {
 501       default:
 502         return true;
 503       case MachineOperand::MO_Immediate:
 504         O << MO.getImm();
 505         return false;
 506       case MachineOperand::MO_ConstantPoolIndex:
 507       case MachineOperand::MO_JumpTableIndex:
 508       case MachineOperand::MO_ExternalSymbol:
 509         llvm_unreachable("unexpected operand type!");
 510       case MachineOperand::MO_GlobalAddress:
 511         PrintSymbolOperand(MO, O);
 512         if (Subtarget->isPICStyleRIPRel())
 513           O << "(%rip)";
 514         return false;
 515       case MachineOperand::MO_Register:
 516         O << '(';
 517         PrintOperand(MI, OpNo, O);
 518         O << ')';
 519         return false;
 520       }
 521
 522     case 'c': // Don't print "$" before a global var name or constant.
 523       switch (MO.getType()) {
 524       default:
 525         PrintOperand(MI, OpNo, O);
 526         break;
 527       case MachineOperand::MO_Immediate:
 528         O << MO.getImm();
 529         break;
 530       case MachineOperand::MO_ConstantPoolIndex:
 531       case MachineOperand::MO_JumpTableIndex:
 532       case MachineOperand::MO_ExternalSymbol:
 533         llvm_unreachable("unexpected operand type!");
 534       case MachineOperand::MO_GlobalAddress:
 535         PrintSymbolOperand(MO, O);
 536         break;
 537       }
 538       return false;
 539
 540     case 'A': // Print '*' before a register (it must be a register)
 541       if (MO.isReg()) {
 542         O << '*';
 543         PrintOperand(MI, OpNo, O);
 544         return false;
 545       }
 546       return true;
 547
 548     case 'b': // Print QImode register
 549     case 'h': // Print QImode high register
 550     case 'w': // Print HImode register
 551     case 'k': // Print SImode register
 552     case 'q': // Print DImode register
 553     case 'V': // Print native register without '%'
 554       if (MO.isReg())
 555         return printAsmMRegister(*this, MO, ExtraCode[0], O);
 556       PrintOperand(MI, OpNo, O);
 557       return false;
 558
 559     case 'x': // Print V4SFmode register
 560     case 't': // Print V8SFmode register
 561     case 'g': // Print V16SFmode register
 562       if (MO.isReg())
 563         return printAsmVRegister(MO, ExtraCode[0], O);
 564       PrintOperand(MI, OpNo, O);
 565       return false;
 566
 567     case 'P': // This is the operand of a call, treat specially.
 568       PrintPCRelImm(MI, OpNo, O);
 569       return false;
 570
 571     case 'n': // Negate the immediate or print a '-' before the operand.
 572       // Note: this is a temporary solution. It should be handled target
 573       // independently as part of the 'MC' work.
 574       if (MO.isImm()) {
 575         O << -MO.getImm();
 576         return false;
 577       }
 578       O << '-';
 579     }
 580   }
 581
 582   PrintOperand(MI, OpNo, O);
 583   return false;
 584 }
 585
 586 bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
 587                                           const char *ExtraCode,
 588                                           raw_ostream &O) {
 589   if (ExtraCode && ExtraCode[0]) {
 590     if (ExtraCode[1] != 0) return true; // Unknown modifier.
 591
 592     switch (ExtraCode[0]) {
 593     default: return true;  // Unknown modifier.
 594     case 'b': // Print QImode register
 595     case 'h': // Print QImode high register
 596     case 'w': // Print HImode register
 597     case 'k': // Print SImode register
 598     case 'q': // Print SImode register
 599       // These only apply to registers, ignore on mem.
 600       break;
 601     case 'H':
 602       if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
 603         return true;  // Unsupported modifier in Intel inline assembly.
 604       } else {
 605         PrintMemReference(MI, OpNo, O, "H");
 606       }
 607       return false;
 608     case 'P': // Don't print @PLT, but do print as memory.
 609       if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
 610         PrintIntelMemReference(MI, OpNo, O, "no-rip");
 611       } else {
 612         PrintMemReference(MI, OpNo, O, "no-rip");
 613       }
 614       return false;
 615     }
 616   }
 617   if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
 618     PrintIntelMemReference(MI, OpNo, O, nullptr);
 619   } else {
 620     PrintMemReference(MI, OpNo, O, nullptr);
 621   }
 622   return false;
 623 }
 624
 625 void X86AsmPrinter::emitStartOfAsmFile(Module &M) {
 626   const Triple &TT = TM.getTargetTriple();
 627
 628   if (TT.isOSBinFormatELF()) {
 629     // Assemble feature flags that may require creation of a note section.
 630     unsigned FeatureFlagsAnd = 0;
 631     if (M.getModuleFlag("cf-protection-branch"))
 632       FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_IBT;
 633     if (M.getModuleFlag("cf-protection-return"))
 634       FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_SHSTK;
 635
 636     if (FeatureFlagsAnd) {
 637       // Emit a .note.gnu.property section with the flags.
 638       if (!TT.isArch32Bit() && !TT.isArch64Bit())
 639         llvm_unreachable("CFProtection used on invalid architecture!");
 640       MCSection *Cur = OutStreamer->getCurrentSectionOnly();
 641       MCSection *Nt = MMI->getContext().getELFSection(
 642           ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
 643       OutStreamer->SwitchSection(Nt);
 644
 645       // Emitting note header.
 646       const int WordSize = TT.isArch64Bit() && !TT.isX32() ? 8 : 4;
 647       emitAlignment(WordSize == 4 ? Align(4) : Align(8));
 648       OutStreamer->emitIntValue(4, 4 /*size*/); // data size for "GNU\0"
 649       OutStreamer->emitIntValue(8 + WordSize, 4 /*size*/); // Elf_Prop size
 650       OutStreamer->emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4 /*size*/);
 651       OutStreamer->emitBytes(StringRef("GNU", 4)); // note name
 652
 653       // Emitting an Elf_Prop for the CET properties.
 654       OutStreamer->emitInt32(ELF::GNU_PROPERTY_X86_FEATURE_1_AND);
 655       OutStreamer->emitInt32(4);                          // data size
 656       OutStreamer->emitInt32(FeatureFlagsAnd);            // data
 657       emitAlignment(WordSize == 4 ? Align(4) : Align(8)); // padding
 658
 659       OutStreamer->endSection(Nt);
 660       OutStreamer->SwitchSection(Cur);
 661     }
 662   }
 663
 664   if (TT.isOSBinFormatMachO())
 665     OutStreamer->SwitchSection(getObjFileLowering().getTextSection());
 666
 667   if (TT.isOSBinFormatCOFF()) {
 668     // Emit an absolute @feat.00 symbol.  This appears to be some kind of
 669     // compiler features bitfield read by link.exe.
 670     MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
 671     OutStreamer->BeginCOFFSymbolDef(S);
 672     OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
 673     OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
 674     OutStreamer->EndCOFFSymbolDef();
 675     int64_t Feat00Flags = 0;
 676
 677     if (TT.getArch() == Triple::x86) {
 678       // According to the PE-COFF spec, the LSB of this value marks the object
 679       // for "registered SEH".  This means that all SEH handler entry points
 680       // must be registered in .sxdata.  Use of any unregistered handlers will
 681       // cause the process to terminate immediately.  LLVM does not know how to
 682       // register any SEH handlers, so its object files should be safe.
 683       Feat00Flags |= 1;
 684     }
 685
 686     if (M.getModuleFlag("cfguard")) {
 687       Feat00Flags |= 0x800; // Object is CFG-aware.
 688     }
 689
 690     if (M.getModuleFlag("ehcontguard")) {
 691       Feat00Flags |= 0x4000; // Object also has EHCont.
 692     }
 693
 694     OutStreamer->emitSymbolAttribute(S, MCSA_Global);
 695     OutStreamer->emitAssignment(
 696         S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
 697   }
 698   OutStreamer->emitSyntaxDirective();
 699
 700   // If this is not inline asm and we're in 16-bit
 701   // mode prefix assembly with .code16.
 702   bool is16 = TT.getEnvironment() == Triple::CODE16;
 703   if (M.getModuleInlineAsm().empty() && is16)
 704     OutStreamer->emitAssemblerFlag(MCAF_Code16);
 705 }
 706
 707 static void
 708 emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
 709                          MachineModuleInfoImpl::StubValueTy &MCSym) {
 710   // L_foo$stub:
 711   OutStreamer.emitLabel(StubLabel);
 712   //   .indirect_symbol _foo
 713   OutStreamer.emitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
 714
 715   if (MCSym.getInt())
 716     // External to current translation unit.
 717     OutStreamer.emitIntValue(0, 4/*size*/);
 718   else
 719     // Internal to current translation unit.
 720     //
 721     // When we place the LSDA into the TEXT section, the type info
 722     // pointers need to be indirect and pc-rel. We accomplish this by
 723     // using NLPs; however, sometimes the types are local to the file.
 724     // We need to fill in the value for the NLP in those cases.
 725     OutStreamer.emitValue(
 726         MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
 727         4 /*size*/);
 728 }
 729
 730 static void emitNonLazyStubs(MachineModuleInfo *MMI, MCStreamer &OutStreamer) {
 731
 732   MachineModuleInfoMachO &MMIMacho =
 733       MMI->getObjFileInfo<MachineModuleInfoMachO>();
 734
 735   // Output stubs for dynamically-linked functions.
 736   MachineModuleInfoMachO::SymbolListTy Stubs;
 737
 738   // Output stubs for external and common global variables.
 739   Stubs = MMIMacho.GetGVStubList();
 740   if (!Stubs.empty()) {
 741     OutStreamer.SwitchSection(MMI->getContext().getMachOSection(
 742         "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS,
 743         SectionKind::getMetadata()));
 744
 745     for (auto &Stub : Stubs)
 746       emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
 747
 748     Stubs.clear();
 749     OutStreamer.AddBlankLine();
 750   }
 751 }
 752
 753 void X86AsmPrinter::emitEndOfAsmFile(Module &M) {
 754   const Triple &TT = TM.getTargetTriple();
 755
 756   if (TT.isOSBinFormatMachO()) {
 757     // Mach-O uses non-lazy symbol stubs to encode per-TU information into
 758     // global table for symbol lookup.
 759     emitNonLazyStubs(MMI, *OutStreamer);
 760
 761     // Emit stack and fault map information.
 762     emitStackMaps(SM);
 763     FM.serializeToFaultMapSection();
 764
 765     // This flag tells the linker that no global symbols contain code that fall
 766     // through to other global symbols (e.g. an implementation of multiple entry
 767     // points). If this doesn't occur, the linker can safely perform dead code
 768     // stripping. Since LLVM never generates code that does this, it is always
 769     // safe to set.
 770     OutStreamer->emitAssemblerFlag(MCAF_SubsectionsViaSymbols);
 771   } else if (TT.isOSBinFormatCOFF()) {
 772     if (MMI->usesMSVCFloatingPoint()) {
 773       // In Windows' libcmt.lib, there is a file which is linked in only if the
 774       // symbol _fltused is referenced. Linking this in causes some
 775       // side-effects:
 776       //
 777       // 1. For x86-32, it will set the x87 rounding mode to 53-bit instead of
 778       // 64-bit mantissas at program start.
 779       //
 780       // 2. It links in support routines for floating-point in scanf and printf.
 781       //
 782       // MSVC emits an undefined reference to _fltused when there are any
 783       // floating point operations in the program (including calls). A program
 784       // that only has: `scanf("%f", &global_float);` may fail to trigger this,
 785       // but oh well...that's a documented issue.
 786       StringRef SymbolName =
 787           (TT.getArch() == Triple::x86) ? "__fltused" : "_fltused";
 788       MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName);
 789       OutStreamer->emitSymbolAttribute(S, MCSA_Global);
 790       return;
 791     }
 792     emitStackMaps(SM);
 793   } else if (TT.isOSBinFormatELF()) {
 794     emitStackMaps(SM);
 795     FM.serializeToFaultMapSection();
 796   }
 797 }
 798
 799 //===----------------------------------------------------------------------===//
 800 // Target Registry Stuff
 801 //===----------------------------------------------------------------------===//
 802
 803 // Force static initialization.
 804 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86AsmPrinter() {
 805   RegisterAsmPrinter<X86AsmPrinter> X(getTheX86_32Target());
 806   RegisterAsmPrinter<X86AsmPrinter> Y(getTheX86_64Target());
 807 }