X86AsmPrinter.cpp revision 363496 
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 "llvm/BinaryFormat/COFF.h"
22#include "llvm/BinaryFormat/ELF.h"
23#include "llvm/CodeGen/MachineConstantPool.h"
24#include "llvm/CodeGen/MachineModuleInfoImpls.h"
25#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
26#include "llvm/IR/DerivedTypes.h"
27#include "llvm/IR/InlineAsm.h"
28#include "llvm/IR/Mangler.h"
29#include "llvm/IR/Module.h"
30#include "llvm/IR/Type.h"
31#include "llvm/MC/MCCodeEmitter.h"
32#include "llvm/MC/MCContext.h"
33#include "llvm/MC/MCExpr.h"
34#include "llvm/MC/MCSectionCOFF.h"
35#include "llvm/MC/MCSectionELF.h"
36#include "llvm/MC/MCSectionMachO.h"
37#include "llvm/MC/MCStreamer.h"
38#include "llvm/MC/MCSymbol.h"
39#include "llvm/Support/Debug.h"
40#include "llvm/Support/ErrorHandling.h"
41#include "llvm/Support/MachineValueType.h"
42#include "llvm/Support/TargetRegistry.h"
43using namespace llvm;
44
45X86AsmPrinter::X86AsmPrinter(TargetMachine &TM,
46                             std::unique_ptr<MCStreamer> Streamer)
47    : AsmPrinter(TM, std::move(Streamer)), SM(*this), FM(*this) {}
48
49//===----------------------------------------------------------------------===//
50// Primitive Helper Functions.
51//===----------------------------------------------------------------------===//
52
53/// runOnMachineFunction - Emit the function body.
54///
55bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
56  Subtarget = &MF.getSubtarget<X86Subtarget>();
57
58  SMShadowTracker.startFunction(MF);
59  CodeEmitter.reset(TM.getTarget().createMCCodeEmitter(
60      *Subtarget->getInstrInfo(), *Subtarget->getRegisterInfo(),
61      MF.getContext()));
62
63  EmitFPOData =
64      Subtarget->isTargetWin32() && MF.getMMI().getModule()->getCodeViewFlag();
65
66  SetupMachineFunction(MF);
67
68  if (Subtarget->isTargetCOFF()) {
69    bool Local = MF.getFunction().hasLocalLinkage();
70    OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
71    OutStreamer->EmitCOFFSymbolStorageClass(
72        Local ? COFF::IMAGE_SYM_CLASS_STATIC : COFF::IMAGE_SYM_CLASS_EXTERNAL);
73    OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
74                                               << COFF::SCT_COMPLEX_TYPE_SHIFT);
75    OutStreamer->EndCOFFSymbolDef();
76  }
77
78  // Emit the rest of the function body.
79  EmitFunctionBody();
80
81  // Emit the XRay table for this function.
82  emitXRayTable();
83
84  EmitFPOData = false;
85
86  // We didn't modify anything.
87  return false;
88}
89
90void X86AsmPrinter::EmitFunctionBodyStart() {
91  if (EmitFPOData) {
92    if (auto *XTS =
93        static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
94      XTS->emitFPOProc(
95          CurrentFnSym,
96          MF->getInfo<X86MachineFunctionInfo>()->getArgumentStackSize());
97  }
98}
99
100void X86AsmPrinter::EmitFunctionBodyEnd() {
101  if (EmitFPOData) {
102    if (auto *XTS =
103            static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer()))
104      XTS->emitFPOEndProc();
105  }
106}
107
108/// PrintSymbolOperand - Print a raw symbol reference operand.  This handles
109/// jump tables, constant pools, global address and external symbols, all of
110/// which print to a label with various suffixes for relocation types etc.
111void X86AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
112                                       raw_ostream &O) {
113  switch (MO.getType()) {
114  default: llvm_unreachable("unknown symbol type!");
115  case MachineOperand::MO_ConstantPoolIndex:
116    GetCPISymbol(MO.getIndex())->print(O, MAI);
117    printOffset(MO.getOffset(), O);
118    break;
119  case MachineOperand::MO_GlobalAddress: {
120    const GlobalValue *GV = MO.getGlobal();
121
122    MCSymbol *GVSym;
123    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
124        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE)
125      GVSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
126    else
127      GVSym = getSymbol(GV);
128
129    // Handle dllimport linkage.
130    if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
131      GVSym = OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName());
132    else if (MO.getTargetFlags() == X86II::MO_COFFSTUB)
133      GVSym =
134          OutContext.getOrCreateSymbol(Twine(".refptr.") + GVSym->getName());
135
136    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
137        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
138      MCSymbol *Sym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
139      MachineModuleInfoImpl::StubValueTy &StubSym =
140          MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
141      if (!StubSym.getPointer())
142        StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(GV),
143                                                     !GV->hasInternalLinkage());
144    }
145
146    // If the name begins with a dollar-sign, enclose it in parens.  We do this
147    // to avoid having it look like an integer immediate to the assembler.
148    if (GVSym->getName()[0] != '$')
149      GVSym->print(O, MAI);
150    else {
151      O << '(';
152      GVSym->print(O, MAI);
153      O << ')';
154    }
155    printOffset(MO.getOffset(), O);
156    break;
157  }
158  }
159
160  switch (MO.getTargetFlags()) {
161  default:
162    llvm_unreachable("Unknown target flag on GV operand");
163  case X86II::MO_NO_FLAG:    // No flag.
164    break;
165  case X86II::MO_DARWIN_NONLAZY:
166  case X86II::MO_DLLIMPORT:
167  case X86II::MO_COFFSTUB:
168    // These affect the name of the symbol, not any suffix.
169    break;
170  case X86II::MO_GOT_ABSOLUTE_ADDRESS:
171    O << " + [.-";
172    MF->getPICBaseSymbol()->print(O, MAI);
173    O << ']';
174    break;
175  case X86II::MO_PIC_BASE_OFFSET:
176  case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
177    O << '-';
178    MF->getPICBaseSymbol()->print(O, MAI);
179    break;
180  case X86II::MO_TLSGD:     O << "@TLSGD";     break;
181  case X86II::MO_TLSLD:     O << "@TLSLD";     break;
182  case X86II::MO_TLSLDM:    O << "@TLSLDM";    break;
183  case X86II::MO_GOTTPOFF:  O << "@GOTTPOFF";  break;
184  case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
185  case X86II::MO_TPOFF:     O << "@TPOFF";     break;
186  case X86II::MO_DTPOFF:    O << "@DTPOFF";    break;
187  case X86II::MO_NTPOFF:    O << "@NTPOFF";    break;
188  case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break;
189  case X86II::MO_GOTPCREL:  O << "@GOTPCREL";  break;
190  case X86II::MO_GOT:       O << "@GOT";       break;
191  case X86II::MO_GOTOFF:    O << "@GOTOFF";    break;
192  case X86II::MO_PLT:       O << "@PLT";       break;
193  case X86II::MO_TLVP:      O << "@TLVP";      break;
194  case X86II::MO_TLVP_PIC_BASE:
195    O << "@TLVP" << '-';
196    MF->getPICBaseSymbol()->print(O, MAI);
197    break;
198  case X86II::MO_SECREL:    O << "@SECREL32";  break;
199  }
200}
201
202void X86AsmPrinter::PrintOperand(const MachineInstr *MI, unsigned OpNo,
203                                 raw_ostream &O) {
204  const MachineOperand &MO = MI->getOperand(OpNo);
205  const bool IsATT = MI->getInlineAsmDialect() == InlineAsm::AD_ATT;
206  switch (MO.getType()) {
207  default: llvm_unreachable("unknown operand type!");
208  case MachineOperand::MO_Register: {
209    if (IsATT)
210      O << '%';
211    O << X86ATTInstPrinter::getRegisterName(MO.getReg());
212    return;
213  }
214
215  case MachineOperand::MO_Immediate:
216    if (IsATT)
217      O << '$';
218    O << MO.getImm();
219    return;
220
221  case MachineOperand::MO_ConstantPoolIndex:
222  case MachineOperand::MO_GlobalAddress: {
223    switch (MI->getInlineAsmDialect()) {
224    case InlineAsm::AD_ATT:
225      O << '$';
226      break;
227    case InlineAsm::AD_Intel:
228      O << "offset ";
229      break;
230    }
231    PrintSymbolOperand(MO, O);
232    break;
233  }
234  case MachineOperand::MO_BlockAddress: {
235    MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
236    Sym->print(O, MAI);
237    break;
238  }
239  }
240}
241
242/// PrintModifiedOperand - Print subregisters based on supplied modifier,
243/// deferring to PrintOperand() if no modifier was supplied or if operand is not
244/// a register.
245void X86AsmPrinter::PrintModifiedOperand(const MachineInstr *MI, unsigned OpNo,
246                                         raw_ostream &O, const char *Modifier) {
247  const MachineOperand &MO = MI->getOperand(OpNo);
248  if (!Modifier || MO.getType() != MachineOperand::MO_Register)
249    return PrintOperand(MI, OpNo, O);
250  if (MI->getInlineAsmDialect() == InlineAsm::AD_ATT)
251    O << '%';
252  Register Reg = MO.getReg();
253  if (strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
254    unsigned Size = (strcmp(Modifier+6,"64") == 0) ? 64 :
255        (strcmp(Modifier+6,"32") == 0) ? 32 :
256        (strcmp(Modifier+6,"16") == 0) ? 16 : 8;
257    Reg = getX86SubSuperRegister(Reg, Size);
258  }
259  O << X86ATTInstPrinter::getRegisterName(Reg);
260}
261
262/// PrintPCRelImm - This is used to print an immediate value that ends up
263/// being encoded as a pc-relative value.  These print slightly differently, for
264/// example, a $ is not emitted.
265void X86AsmPrinter::PrintPCRelImm(const MachineInstr *MI, unsigned OpNo,
266                                  raw_ostream &O) {
267  const MachineOperand &MO = MI->getOperand(OpNo);
268  switch (MO.getType()) {
269  default: llvm_unreachable("Unknown pcrel immediate operand");
270  case MachineOperand::MO_Register:
271    // pc-relativeness was handled when computing the value in the reg.
272    PrintOperand(MI, OpNo, O);
273    return;
274  case MachineOperand::MO_Immediate:
275    O << MO.getImm();
276    return;
277  case MachineOperand::MO_GlobalAddress:
278    PrintSymbolOperand(MO, O);
279    return;
280  }
281}
282
283void X86AsmPrinter::PrintLeaMemReference(const MachineInstr *MI, unsigned OpNo,
284                                         raw_ostream &O, const char *Modifier) {
285  const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
286  const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
287  const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
288
289  // If we really don't want to print out (rip), don't.
290  bool HasBaseReg = BaseReg.getReg() != 0;
291  if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
292      BaseReg.getReg() == X86::RIP)
293    HasBaseReg = false;
294
295  // HasParenPart - True if we will print out the () part of the mem ref.
296  bool HasParenPart = IndexReg.getReg() || HasBaseReg;
297
298  switch (DispSpec.getType()) {
299  default:
300    llvm_unreachable("unknown operand type!");
301  case MachineOperand::MO_Immediate: {
302    int DispVal = DispSpec.getImm();
303    if (DispVal || !HasParenPart)
304      O << DispVal;
305    break;
306  }
307  case MachineOperand::MO_GlobalAddress:
308  case MachineOperand::MO_ConstantPoolIndex:
309    PrintSymbolOperand(DispSpec, O);
310    break;
311  }
312
313  if (Modifier && strcmp(Modifier, "H") == 0)
314    O << "+8";
315
316  if (HasParenPart) {
317    assert(IndexReg.getReg() != X86::ESP &&
318           "X86 doesn't allow scaling by ESP");
319
320    O << '(';
321    if (HasBaseReg)
322      PrintModifiedOperand(MI, OpNo + X86::AddrBaseReg, O, Modifier);
323
324    if (IndexReg.getReg()) {
325      O << ',';
326      PrintModifiedOperand(MI, OpNo + X86::AddrIndexReg, O, Modifier);
327      unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
328      if (ScaleVal != 1)
329        O << ',' << ScaleVal;
330    }
331    O << ')';
332  }
333}
334
335void X86AsmPrinter::PrintMemReference(const MachineInstr *MI, unsigned OpNo,
336                                      raw_ostream &O, const char *Modifier) {
337  assert(isMem(*MI, OpNo) && "Invalid memory reference!");
338  const MachineOperand &Segment = MI->getOperand(OpNo + X86::AddrSegmentReg);
339  if (Segment.getReg()) {
340    PrintModifiedOperand(MI, OpNo + X86::AddrSegmentReg, O, Modifier);
341    O << ':';
342  }
343  PrintLeaMemReference(MI, OpNo, O, Modifier);
344}
345
346
347void X86AsmPrinter::PrintIntelMemReference(const MachineInstr *MI,
348                                           unsigned OpNo, raw_ostream &O,
349                                           const char *Modifier) {
350  const MachineOperand &BaseReg = MI->getOperand(OpNo + X86::AddrBaseReg);
351  unsigned ScaleVal = MI->getOperand(OpNo + X86::AddrScaleAmt).getImm();
352  const MachineOperand &IndexReg = MI->getOperand(OpNo + X86::AddrIndexReg);
353  const MachineOperand &DispSpec = MI->getOperand(OpNo + X86::AddrDisp);
354  const MachineOperand &SegReg = MI->getOperand(OpNo + X86::AddrSegmentReg);
355
356  // If we really don't want to print out (rip), don't.
357  bool HasBaseReg = BaseReg.getReg() != 0;
358  if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
359      BaseReg.getReg() == X86::RIP)
360    HasBaseReg = false;
361
362  // If this has a segment register, print it.
363  if (SegReg.getReg()) {
364    PrintOperand(MI, OpNo + X86::AddrSegmentReg, O);
365    O << ':';
366  }
367
368  O << '[';
369
370  bool NeedPlus = false;
371  if (HasBaseReg) {
372    PrintOperand(MI, OpNo + X86::AddrBaseReg, O);
373    NeedPlus = true;
374  }
375
376  if (IndexReg.getReg()) {
377    if (NeedPlus) O << " + ";
378    if (ScaleVal != 1)
379      O << ScaleVal << '*';
380    PrintOperand(MI, OpNo + X86::AddrIndexReg, O);
381    NeedPlus = true;
382  }
383
384  if (!DispSpec.isImm()) {
385    if (NeedPlus) O << " + ";
386    PrintOperand(MI, OpNo + X86::AddrDisp, O);
387  } else {
388    int64_t DispVal = DispSpec.getImm();
389    if (DispVal || (!IndexReg.getReg() && !HasBaseReg)) {
390      if (NeedPlus) {
391        if (DispVal > 0)
392          O << " + ";
393        else {
394          O << " - ";
395          DispVal = -DispVal;
396        }
397      }
398      O << DispVal;
399    }
400  }
401  O << ']';
402}
403
404static bool printAsmMRegister(X86AsmPrinter &P, const MachineOperand &MO,
405                              char Mode, raw_ostream &O) {
406  Register Reg = MO.getReg();
407  bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
408
409  if (!X86::GR8RegClass.contains(Reg) &&
410      !X86::GR16RegClass.contains(Reg) &&
411      !X86::GR32RegClass.contains(Reg) &&
412      !X86::GR64RegClass.contains(Reg))
413    return true;
414
415  switch (Mode) {
416  default: return true;  // Unknown mode.
417  case 'b': // Print QImode register
418    Reg = getX86SubSuperRegister(Reg, 8);
419    break;
420  case 'h': // Print QImode high register
421    Reg = getX86SubSuperRegister(Reg, 8, true);
422    break;
423  case 'w': // Print HImode register
424    Reg = getX86SubSuperRegister(Reg, 16);
425    break;
426  case 'k': // Print SImode register
427    Reg = getX86SubSuperRegister(Reg, 32);
428    break;
429  case 'V':
430    EmitPercent = false;
431    LLVM_FALLTHROUGH;
432  case 'q':
433    // Print 64-bit register names if 64-bit integer registers are available.
434    // Otherwise, print 32-bit register names.
435    Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32);
436    break;
437  }
438
439  if (EmitPercent)
440    O << '%';
441
442  O << X86ATTInstPrinter::getRegisterName(Reg);
443  return false;
444}
445
446static bool printAsmVRegister(X86AsmPrinter &P, const MachineOperand &MO,
447                              char Mode, raw_ostream &O) {
448  unsigned Reg = MO.getReg();
449  bool EmitPercent = MO.getParent()->getInlineAsmDialect() == InlineAsm::AD_ATT;
450
451  unsigned Index;
452  if (X86::VR128XRegClass.contains(Reg))
453    Index = Reg - X86::XMM0;
454  else if (X86::VR256XRegClass.contains(Reg))
455    Index = Reg - X86::YMM0;
456  else if (X86::VR512RegClass.contains(Reg))
457    Index = Reg - X86::ZMM0;
458  else
459    return true;
460
461  switch (Mode) {
462  default: // Unknown mode.
463    return true;
464  case 'x': // Print V4SFmode register
465    Reg = X86::XMM0 + Index;
466    break;
467  case 't': // Print V8SFmode register
468    Reg = X86::YMM0 + Index;
469    break;
470  case 'g': // Print V16SFmode register
471    Reg = X86::ZMM0 + Index;
472    break;
473  }
474
475  if (EmitPercent)
476    O << '%';
477
478  O << X86ATTInstPrinter::getRegisterName(Reg);
479  return false;
480}
481
482/// PrintAsmOperand - Print out an operand for an inline asm expression.
483///
484bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
485                                    const char *ExtraCode, raw_ostream &O) {
486  // Does this asm operand have a single letter operand modifier?
487  if (ExtraCode && ExtraCode[0]) {
488    if (ExtraCode[1] != 0) return true; // Unknown modifier.
489
490    const MachineOperand &MO = MI->getOperand(OpNo);
491
492    switch (ExtraCode[0]) {
493    default:
494      // See if this is a generic print operand
495      return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
496    case 'a': // This is an address.  Currently only 'i' and 'r' are expected.
497      switch (MO.getType()) {
498      default:
499        return true;
500      case MachineOperand::MO_Immediate:
501        O << MO.getImm();
502        return false;
503      case MachineOperand::MO_ConstantPoolIndex:
504      case MachineOperand::MO_JumpTableIndex:
505      case MachineOperand::MO_ExternalSymbol:
506        llvm_unreachable("unexpected operand type!");
507      case MachineOperand::MO_GlobalAddress:
508        PrintSymbolOperand(MO, O);
509        if (Subtarget->isPICStyleRIPRel())
510          O << "(%rip)";
511        return false;
512      case MachineOperand::MO_Register:
513        O << '(';
514        PrintOperand(MI, OpNo, O);
515        O << ')';
516        return false;
517      }
518
519    case 'c': // Don't print "$" before a global var name or constant.
520      switch (MO.getType()) {
521      default:
522        PrintOperand(MI, OpNo, O);
523        break;
524      case MachineOperand::MO_Immediate:
525        O << MO.getImm();
526        break;
527      case MachineOperand::MO_ConstantPoolIndex:
528      case MachineOperand::MO_JumpTableIndex:
529      case MachineOperand::MO_ExternalSymbol:
530        llvm_unreachable("unexpected operand type!");
531      case MachineOperand::MO_GlobalAddress:
532        PrintSymbolOperand(MO, O);
533        break;
534      }
535      return false;
536
537    case 'A': // Print '*' before a register (it must be a register)
538      if (MO.isReg()) {
539        O << '*';
540        PrintOperand(MI, OpNo, O);
541        return false;
542      }
543      return true;
544
545    case 'b': // Print QImode register
546    case 'h': // Print QImode high register
547    case 'w': // Print HImode register
548    case 'k': // Print SImode register
549    case 'q': // Print DImode register
550    case 'V': // Print native register without '%'
551      if (MO.isReg())
552        return printAsmMRegister(*this, MO, ExtraCode[0], O);
553      PrintOperand(MI, OpNo, O);
554      return false;
555
556    case 'x': // Print V4SFmode register
557    case 't': // Print V8SFmode register
558    case 'g': // Print V16SFmode register
559      if (MO.isReg())
560        return printAsmVRegister(*this, MO, ExtraCode[0], O);
561      PrintOperand(MI, OpNo, O);
562      return false;
563
564    case 'P': // This is the operand of a call, treat specially.
565      PrintPCRelImm(MI, OpNo, O);
566      return false;
567
568    case 'n': // Negate the immediate or print a '-' before the operand.
569      // Note: this is a temporary solution. It should be handled target
570      // independently as part of the 'MC' work.
571      if (MO.isImm()) {
572        O << -MO.getImm();
573        return false;
574      }
575      O << '-';
576    }
577  }
578
579  PrintOperand(MI, OpNo, O);
580  return false;
581}
582
583bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
584                                          const char *ExtraCode,
585                                          raw_ostream &O) {
586  if (ExtraCode && ExtraCode[0]) {
587    if (ExtraCode[1] != 0) return true; // Unknown modifier.
588
589    switch (ExtraCode[0]) {
590    default: return true;  // Unknown modifier.
591    case 'b': // Print QImode register
592    case 'h': // Print QImode high register
593    case 'w': // Print HImode register
594    case 'k': // Print SImode register
595    case 'q': // Print SImode register
596      // These only apply to registers, ignore on mem.
597      break;
598    case 'H':
599      if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
600        return true;  // Unsupported modifier in Intel inline assembly.
601      } else {
602        PrintMemReference(MI, OpNo, O, "H");
603      }
604      return false;
605    case 'P': // Don't print @PLT, but do print as memory.
606      if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
607        PrintIntelMemReference(MI, OpNo, O, "no-rip");
608      } else {
609        PrintMemReference(MI, OpNo, O, "no-rip");
610      }
611      return false;
612    }
613  }
614  if (MI->getInlineAsmDialect() == InlineAsm::AD_Intel) {
615    PrintIntelMemReference(MI, OpNo, O, nullptr);
616  } else {
617    PrintMemReference(MI, OpNo, O, nullptr);
618  }
619  return false;
620}
621
622void X86AsmPrinter::EmitStartOfAsmFile(Module &M) {
623  const Triple &TT = TM.getTargetTriple();
624
625  if (TT.isOSBinFormatELF()) {
626    // Assemble feature flags that may require creation of a note section.
627    unsigned FeatureFlagsAnd = 0;
628    if (M.getModuleFlag("cf-protection-branch"))
629      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_IBT;
630    if (M.getModuleFlag("cf-protection-return"))
631      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_SHSTK;
632
633    if (FeatureFlagsAnd) {
634      // Emit a .note.gnu.property section with the flags.
635      if (!TT.isArch32Bit() && !TT.isArch64Bit())
636        llvm_unreachable("CFProtection used on invalid architecture!");
637      MCSection *Cur = OutStreamer->getCurrentSectionOnly();
638      MCSection *Nt = MMI->getContext().getELFSection(
639          ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
640      OutStreamer->SwitchSection(Nt);
641
642      // Emitting note header.
643      int WordSize = TT.isArch64Bit() ? 8 : 4;
644      EmitAlignment(WordSize == 4 ? Align(4) : Align(8));
645      OutStreamer->EmitIntValue(4, 4 /*size*/); // data size for "GNU\0"
646      OutStreamer->EmitIntValue(8 + WordSize, 4 /*size*/); // Elf_Prop size
647      OutStreamer->EmitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4 /*size*/);
648      OutStreamer->EmitBytes(StringRef("GNU", 4)); // note name
649
650      // Emitting an Elf_Prop for the CET properties.
651      OutStreamer->EmitIntValue(ELF::GNU_PROPERTY_X86_FEATURE_1_AND, 4);
652      OutStreamer->EmitIntValue(4, 4);               // data size
653      OutStreamer->EmitIntValue(FeatureFlagsAnd, 4); // data
654      EmitAlignment(WordSize == 4 ? Align(4) : Align(8)); // padding
655
656      OutStreamer->endSection(Nt);
657      OutStreamer->SwitchSection(Cur);
658    }
659  }
660
661  if (TT.isOSBinFormatMachO())
662    OutStreamer->SwitchSection(getObjFileLowering().getTextSection());
663
664  if (TT.isOSBinFormatCOFF()) {
665    // Emit an absolute @feat.00 symbol.  This appears to be some kind of
666    // compiler features bitfield read by link.exe.
667    MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
668    OutStreamer->BeginCOFFSymbolDef(S);
669    OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
670    OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
671    OutStreamer->EndCOFFSymbolDef();
672    int64_t Feat00Flags = 0;
673
674    if (TT.getArch() == Triple::x86) {
675      // According to the PE-COFF spec, the LSB of this value marks the object
676      // for "registered SEH".  This means that all SEH handler entry points
677      // must be registered in .sxdata.  Use of any unregistered handlers will
678      // cause the process to terminate immediately.  LLVM does not know how to
679      // register any SEH handlers, so its object files should be safe.
680      Feat00Flags |= 1;
681    }
682
683    if (M.getModuleFlag("cfguard"))
684      Feat00Flags |= 0x800; // Object is CFG-aware.
685
686    OutStreamer->EmitSymbolAttribute(S, MCSA_Global);
687    OutStreamer->EmitAssignment(
688        S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
689  }
690  OutStreamer->EmitSyntaxDirective();
691
692  // If this is not inline asm and we're in 16-bit
693  // mode prefix assembly with .code16.
694  bool is16 = TT.getEnvironment() == Triple::CODE16;
695  if (M.getModuleInlineAsm().empty() && is16)
696    OutStreamer->EmitAssemblerFlag(MCAF_Code16);
697}
698
699static void
700emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
701                         MachineModuleInfoImpl::StubValueTy &MCSym) {
702  // L_foo$stub:
703  OutStreamer.EmitLabel(StubLabel);
704  //   .indirect_symbol _foo
705  OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
706
707  if (MCSym.getInt())
708    // External to current translation unit.
709    OutStreamer.EmitIntValue(0, 4/*size*/);
710  else
711    // Internal to current translation unit.
712    //
713    // When we place the LSDA into the TEXT section, the type info
714    // pointers need to be indirect and pc-rel. We accomplish this by
715    // using NLPs; however, sometimes the types are local to the file.
716    // We need to fill in the value for the NLP in those cases.
717    OutStreamer.EmitValue(
718        MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
719        4 /*size*/);
720}
721
722static void emitNonLazyStubs(MachineModuleInfo *MMI, MCStreamer &OutStreamer) {
723
724  MachineModuleInfoMachO &MMIMacho =
725      MMI->getObjFileInfo<MachineModuleInfoMachO>();
726
727  // Output stubs for dynamically-linked functions.
728  MachineModuleInfoMachO::SymbolListTy Stubs;
729
730  // Output stubs for external and common global variables.
731  Stubs = MMIMacho.GetGVStubList();
732  if (!Stubs.empty()) {
733    OutStreamer.SwitchSection(MMI->getContext().getMachOSection(
734        "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS,
735        SectionKind::getMetadata()));
736
737    for (auto &Stub : Stubs)
738      emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
739
740    Stubs.clear();
741    OutStreamer.AddBlankLine();
742  }
743}
744
745void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
746  const Triple &TT = TM.getTargetTriple();
747
748  if (TT.isOSBinFormatMachO()) {
749    // Mach-O uses non-lazy symbol stubs to encode per-TU information into
750    // global table for symbol lookup.
751    emitNonLazyStubs(MMI, *OutStreamer);
752
753    // Emit stack and fault map information.
754    emitStackMaps(SM);
755    FM.serializeToFaultMapSection();
756
757    // This flag tells the linker that no global symbols contain code that fall
758    // through to other global symbols (e.g. an implementation of multiple entry
759    // points). If this doesn't occur, the linker can safely perform dead code
760    // stripping. Since LLVM never generates code that does this, it is always
761    // safe to set.
762    OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
763  } else if (TT.isOSBinFormatCOFF()) {
764    if (MMI->usesMSVCFloatingPoint()) {
765      // In Windows' libcmt.lib, there is a file which is linked in only if the
766      // symbol _fltused is referenced. Linking this in causes some
767      // side-effects:
768      //
769      // 1. For x86-32, it will set the x87 rounding mode to 53-bit instead of
770      // 64-bit mantissas at program start.
771      //
772      // 2. It links in support routines for floating-point in scanf and printf.
773      //
774      // MSVC emits an undefined reference to _fltused when there are any
775      // floating point operations in the program (including calls). A program
776      // that only has: `scanf("%f", &global_float);` may fail to trigger this,
777      // but oh well...that's a documented issue.
778      StringRef SymbolName =
779          (TT.getArch() == Triple::x86) ? "__fltused" : "_fltused";
780      MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName);
781      OutStreamer->EmitSymbolAttribute(S, MCSA_Global);
782      return;
783    }
784    emitStackMaps(SM);
785  } else if (TT.isOSBinFormatELF()) {
786    emitStackMaps(SM);
787    FM.serializeToFaultMapSection();
788  }
789}
790
791//===----------------------------------------------------------------------===//
792// Target Registry Stuff
793//===----------------------------------------------------------------------===//
794
795// Force static initialization.
796extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86AsmPrinter() {
797  RegisterAsmPrinter<X86AsmPrinter> X(getTheX86_32Target());
798  RegisterAsmPrinter<X86AsmPrinter> Y(getTheX86_64Target());
799}
800