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
X86AsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)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 ///
runOnMachineFunction(MachineFunction & MF)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
emitFunctionBodyStart()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
emitFunctionBodyEnd()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.
PrintSymbolOperand(const MachineOperand & MO,raw_ostream & O)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
PrintOperand(const MachineInstr * MI,unsigned OpNo,raw_ostream & O)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.
PrintModifiedOperand(const MachineInstr * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)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.
PrintPCRelImm(const MachineInstr * MI,unsigned OpNo,raw_ostream & O)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
PrintLeaMemReference(const MachineInstr * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)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
PrintMemReference(const MachineInstr * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)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
PrintIntelMemReference(const MachineInstr * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)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
printAsmMRegister(const X86AsmPrinter & P,const MachineOperand & MO,char Mode,raw_ostream & O)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
printAsmVRegister(const MachineOperand & MO,char Mode,raw_ostream & O)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 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)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
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)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
emitStartOfAsmFile(Module & M)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 int WordSize = TT.isArch64Bit() ? 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 OutStreamer->emitSymbolAttribute(S, MCSA_Global);
690 OutStreamer->emitAssignment(
691 S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
692 }
693 OutStreamer->emitSyntaxDirective();
694
695 // If this is not inline asm and we're in 16-bit
696 // mode prefix assembly with .code16.
697 bool is16 = TT.getEnvironment() == Triple::CODE16;
698 if (M.getModuleInlineAsm().empty() && is16)
699 OutStreamer->emitAssemblerFlag(MCAF_Code16);
700 }
701
702 static void
emitNonLazySymbolPointer(MCStreamer & OutStreamer,MCSymbol * StubLabel,MachineModuleInfoImpl::StubValueTy & MCSym)703 emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
704 MachineModuleInfoImpl::StubValueTy &MCSym) {
705 // L_foo$stub:
706 OutStreamer.emitLabel(StubLabel);
707 // .indirect_symbol _foo
708 OutStreamer.emitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
709
710 if (MCSym.getInt())
711 // External to current translation unit.
712 OutStreamer.emitIntValue(0, 4/*size*/);
713 else
714 // Internal to current translation unit.
715 //
716 // When we place the LSDA into the TEXT section, the type info
717 // pointers need to be indirect and pc-rel. We accomplish this by
718 // using NLPs; however, sometimes the types are local to the file.
719 // We need to fill in the value for the NLP in those cases.
720 OutStreamer.emitValue(
721 MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
722 4 /*size*/);
723 }
724
emitNonLazyStubs(MachineModuleInfo * MMI,MCStreamer & OutStreamer)725 static void emitNonLazyStubs(MachineModuleInfo *MMI, MCStreamer &OutStreamer) {
726
727 MachineModuleInfoMachO &MMIMacho =
728 MMI->getObjFileInfo<MachineModuleInfoMachO>();
729
730 // Output stubs for dynamically-linked functions.
731 MachineModuleInfoMachO::SymbolListTy Stubs;
732
733 // Output stubs for external and common global variables.
734 Stubs = MMIMacho.GetGVStubList();
735 if (!Stubs.empty()) {
736 OutStreamer.SwitchSection(MMI->getContext().getMachOSection(
737 "__IMPORT", "__pointers", MachO::S_NON_LAZY_SYMBOL_POINTERS,
738 SectionKind::getMetadata()));
739
740 for (auto &Stub : Stubs)
741 emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
742
743 Stubs.clear();
744 OutStreamer.AddBlankLine();
745 }
746 }
747
emitEndOfAsmFile(Module & M)748 void X86AsmPrinter::emitEndOfAsmFile(Module &M) {
749 const Triple &TT = TM.getTargetTriple();
750
751 if (TT.isOSBinFormatMachO()) {
752 // Mach-O uses non-lazy symbol stubs to encode per-TU information into
753 // global table for symbol lookup.
754 emitNonLazyStubs(MMI, *OutStreamer);
755
756 // Emit stack and fault map information.
757 emitStackMaps(SM);
758 FM.serializeToFaultMapSection();
759
760 // This flag tells the linker that no global symbols contain code that fall
761 // through to other global symbols (e.g. an implementation of multiple entry
762 // points). If this doesn't occur, the linker can safely perform dead code
763 // stripping. Since LLVM never generates code that does this, it is always
764 // safe to set.
765 OutStreamer->emitAssemblerFlag(MCAF_SubsectionsViaSymbols);
766 } else if (TT.isOSBinFormatCOFF()) {
767 if (MMI->usesMSVCFloatingPoint()) {
768 // In Windows' libcmt.lib, there is a file which is linked in only if the
769 // symbol _fltused is referenced. Linking this in causes some
770 // side-effects:
771 //
772 // 1. For x86-32, it will set the x87 rounding mode to 53-bit instead of
773 // 64-bit mantissas at program start.
774 //
775 // 2. It links in support routines for floating-point in scanf and printf.
776 //
777 // MSVC emits an undefined reference to _fltused when there are any
778 // floating point operations in the program (including calls). A program
779 // that only has: `scanf("%f", &global_float);` may fail to trigger this,
780 // but oh well...that's a documented issue.
781 StringRef SymbolName =
782 (TT.getArch() == Triple::x86) ? "__fltused" : "_fltused";
783 MCSymbol *S = MMI->getContext().getOrCreateSymbol(SymbolName);
784 OutStreamer->emitSymbolAttribute(S, MCSA_Global);
785 return;
786 }
787 emitStackMaps(SM);
788 } else if (TT.isOSBinFormatELF()) {
789 emitStackMaps(SM);
790 FM.serializeToFaultMapSection();
791 }
792 }
793
794 //===----------------------------------------------------------------------===//
795 // Target Registry Stuff
796 //===----------------------------------------------------------------------===//
797
798 // Force static initialization.
LLVMInitializeX86AsmPrinter()799 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86AsmPrinter() {
800 RegisterAsmPrinter<X86AsmPrinter> X(getTheX86_32Target());
801 RegisterAsmPrinter<X86AsmPrinter> Y(getTheX86_64Target());
802 }
803