1 //===-- AArch64AsmPrinter.cpp - AArch64 LLVM assembly writer --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains a printer that converts from our internal representation
11 // of machine-dependent LLVM code to the AArch64 assembly language.
13 //===----------------------------------------------------------------------===//
15 #include "MCTargetDesc/AArch64AddressingModes.h"
17 #include "AArch64MCInstLower.h"
18 #include "AArch64MachineFunctionInfo.h"
19 #include "AArch64RegisterInfo.h"
20 #include "AArch64Subtarget.h"
21 #include "InstPrinter/AArch64InstPrinter.h"
22 #include "MCTargetDesc/AArch64MCExpr.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/StringSwitch.h"
25 #include "llvm/ADT/Twine.h"
26 #include "llvm/CodeGen/AsmPrinter.h"
27 #include "llvm/CodeGen/MachineInstr.h"
28 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
29 #include "llvm/CodeGen/StackMaps.h"
30 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/MC/MCContext.h"
35 #include "llvm/MC/MCInst.h"
36 #include "llvm/MC/MCInstBuilder.h"
37 #include "llvm/MC/MCLinkerOptimizationHint.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/TargetRegistry.h"
42 #include "llvm/Support/raw_ostream.h"
45 #define DEBUG_TYPE "asm-printer"
49 class AArch64AsmPrinter : public AsmPrinter {
50 AArch64MCInstLower MCInstLowering;
52 const AArch64Subtarget *STI;
55 AArch64AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
56 : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this),
57 SM(*this), AArch64FI(nullptr) {}
59 const char *getPassName() const override {
60 return "AArch64 Assembly Printer";
63 /// \brief Wrapper for MCInstLowering.lowerOperand() for the
64 /// tblgen'erated pseudo lowering.
65 bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const {
66 return MCInstLowering.lowerOperand(MO, MCOp);
69 void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
70 const MachineInstr &MI);
71 void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
72 const MachineInstr &MI);
73 /// \brief tblgen'erated driver function for lowering simple MI->MC
74 /// pseudo instructions.
75 bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
76 const MachineInstr *MI);
78 void EmitInstruction(const MachineInstr *MI) override;
80 void getAnalysisUsage(AnalysisUsage &AU) const override {
81 AsmPrinter::getAnalysisUsage(AU);
85 bool runOnMachineFunction(MachineFunction &F) override {
86 AArch64FI = F.getInfo<AArch64FunctionInfo>();
87 STI = static_cast<const AArch64Subtarget*>(&F.getSubtarget());
88 return AsmPrinter::runOnMachineFunction(F);
92 void printOperand(const MachineInstr *MI, unsigned OpNum, raw_ostream &O);
93 bool printAsmMRegister(const MachineOperand &MO, char Mode, raw_ostream &O);
94 bool printAsmRegInClass(const MachineOperand &MO,
95 const TargetRegisterClass *RC, bool isVector,
98 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
99 unsigned AsmVariant, const char *ExtraCode,
100 raw_ostream &O) override;
101 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
102 unsigned AsmVariant, const char *ExtraCode,
103 raw_ostream &O) override;
105 void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
107 void EmitFunctionBodyEnd() override;
109 MCSymbol *GetCPISymbol(unsigned CPID) const override;
110 void EmitEndOfAsmFile(Module &M) override;
111 AArch64FunctionInfo *AArch64FI;
113 /// \brief Emit the LOHs contained in AArch64FI.
116 /// Emit instruction to set float register to zero.
117 void EmitFMov0(const MachineInstr &MI);
119 typedef std::map<const MachineInstr *, MCSymbol *> MInstToMCSymbol;
120 MInstToMCSymbol LOHInstToLabel;
123 } // end of anonymous namespace
125 //===----------------------------------------------------------------------===//
127 void AArch64AsmPrinter::EmitEndOfAsmFile(Module &M) {
128 const Triple &TT = TM.getTargetTriple();
129 if (TT.isOSBinFormatMachO()) {
130 // Funny Darwin hack: This flag tells the linker that no global symbols
131 // contain code that falls through to other global symbols (e.g. the obvious
132 // implementation of multiple entry points). If this doesn't occur, the
133 // linker can safely perform dead code stripping. Since LLVM never
134 // generates code that does this, it is always safe to set.
135 OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
136 SM.serializeToStackMapSection();
140 void AArch64AsmPrinter::EmitLOHs() {
141 SmallVector<MCSymbol *, 3> MCArgs;
143 for (const auto &D : AArch64FI->getLOHContainer()) {
144 for (const MachineInstr *MI : D.getArgs()) {
145 MInstToMCSymbol::iterator LabelIt = LOHInstToLabel.find(MI);
146 assert(LabelIt != LOHInstToLabel.end() &&
147 "Label hasn't been inserted for LOH related instruction");
148 MCArgs.push_back(LabelIt->second);
150 OutStreamer->EmitLOHDirective(D.getKind(), MCArgs);
155 void AArch64AsmPrinter::EmitFunctionBodyEnd() {
156 if (!AArch64FI->getLOHRelated().empty())
160 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
161 MCSymbol *AArch64AsmPrinter::GetCPISymbol(unsigned CPID) const {
162 // Darwin uses a linker-private symbol name for constant-pools (to
163 // avoid addends on the relocation?), ELF has no such concept and
164 // uses a normal private symbol.
165 if (getDataLayout().getLinkerPrivateGlobalPrefix()[0])
166 return OutContext.getOrCreateSymbol(
167 Twine(getDataLayout().getLinkerPrivateGlobalPrefix()) + "CPI" +
168 Twine(getFunctionNumber()) + "_" + Twine(CPID));
170 return OutContext.getOrCreateSymbol(
171 Twine(getDataLayout().getPrivateGlobalPrefix()) + "CPI" +
172 Twine(getFunctionNumber()) + "_" + Twine(CPID));
175 void AArch64AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNum,
177 const MachineOperand &MO = MI->getOperand(OpNum);
178 switch (MO.getType()) {
180 llvm_unreachable("<unknown operand type>");
181 case MachineOperand::MO_Register: {
182 unsigned Reg = MO.getReg();
183 assert(TargetRegisterInfo::isPhysicalRegister(Reg));
184 assert(!MO.getSubReg() && "Subregs should be eliminated!");
185 O << AArch64InstPrinter::getRegisterName(Reg);
188 case MachineOperand::MO_Immediate: {
189 int64_t Imm = MO.getImm();
193 case MachineOperand::MO_GlobalAddress: {
194 const GlobalValue *GV = MO.getGlobal();
195 MCSymbol *Sym = getSymbol(GV);
197 // FIXME: Can we get anything other than a plain symbol here?
198 assert(!MO.getTargetFlags() && "Unknown operand target flag!");
201 printOffset(MO.getOffset(), O);
207 bool AArch64AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
209 unsigned Reg = MO.getReg();
212 return true; // Unknown mode.
214 Reg = getWRegFromXReg(Reg);
217 Reg = getXRegFromWReg(Reg);
221 O << AArch64InstPrinter::getRegisterName(Reg);
225 // Prints the register in MO using class RC using the offset in the
226 // new register class. This should not be used for cross class
228 bool AArch64AsmPrinter::printAsmRegInClass(const MachineOperand &MO,
229 const TargetRegisterClass *RC,
230 bool isVector, raw_ostream &O) {
231 assert(MO.isReg() && "Should only get here with a register!");
232 const TargetRegisterInfo *RI = STI->getRegisterInfo();
233 unsigned Reg = MO.getReg();
234 unsigned RegToPrint = RC->getRegister(RI->getEncodingValue(Reg));
235 assert(RI->regsOverlap(RegToPrint, Reg));
236 O << AArch64InstPrinter::getRegisterName(
237 RegToPrint, isVector ? AArch64::vreg : AArch64::NoRegAltName);
241 bool AArch64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
243 const char *ExtraCode, raw_ostream &O) {
244 const MachineOperand &MO = MI->getOperand(OpNum);
246 // First try the generic code, which knows about modifiers like 'c' and 'n'.
247 if (!AsmPrinter::PrintAsmOperand(MI, OpNum, AsmVariant, ExtraCode, O))
250 // Does this asm operand have a single letter operand modifier?
251 if (ExtraCode && ExtraCode[0]) {
252 if (ExtraCode[1] != 0)
253 return true; // Unknown modifier.
255 switch (ExtraCode[0]) {
257 return true; // Unknown modifier.
258 case 'w': // Print W register
259 case 'x': // Print X register
261 return printAsmMRegister(MO, ExtraCode[0], O);
262 if (MO.isImm() && MO.getImm() == 0) {
263 unsigned Reg = ExtraCode[0] == 'w' ? AArch64::WZR : AArch64::XZR;
264 O << AArch64InstPrinter::getRegisterName(Reg);
267 printOperand(MI, OpNum, O);
269 case 'b': // Print B register.
270 case 'h': // Print H register.
271 case 's': // Print S register.
272 case 'd': // Print D register.
273 case 'q': // Print Q register.
275 const TargetRegisterClass *RC;
276 switch (ExtraCode[0]) {
278 RC = &AArch64::FPR8RegClass;
281 RC = &AArch64::FPR16RegClass;
284 RC = &AArch64::FPR32RegClass;
287 RC = &AArch64::FPR64RegClass;
290 RC = &AArch64::FPR128RegClass;
295 return printAsmRegInClass(MO, RC, false /* vector */, O);
297 printOperand(MI, OpNum, O);
302 // According to ARM, we should emit x and v registers unless we have a
305 unsigned Reg = MO.getReg();
307 // If this is a w or x register, print an x register.
308 if (AArch64::GPR32allRegClass.contains(Reg) ||
309 AArch64::GPR64allRegClass.contains(Reg))
310 return printAsmMRegister(MO, 'x', O);
312 // If this is a b, h, s, d, or q register, print it as a v register.
313 return printAsmRegInClass(MO, &AArch64::FPR128RegClass, true /* vector */,
317 printOperand(MI, OpNum, O);
321 bool AArch64AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
324 const char *ExtraCode,
326 if (ExtraCode && ExtraCode[0])
327 return true; // Unknown modifier.
329 const MachineOperand &MO = MI->getOperand(OpNum);
330 assert(MO.isReg() && "unexpected inline asm memory operand");
331 O << "[" << AArch64InstPrinter::getRegisterName(MO.getReg()) << "]";
335 void AArch64AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
337 unsigned NOps = MI->getNumOperands();
339 OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
340 // cast away const; DIetc do not take const operands for some reason.
341 OS << cast<DILocalVariable>(MI->getOperand(NOps - 2).getMetadata())
344 // Frame address. Currently handles register +- offset only.
345 assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
347 printOperand(MI, 0, OS);
349 printOperand(MI, 1, OS);
352 printOperand(MI, NOps - 2, OS);
355 void AArch64AsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
356 const MachineInstr &MI) {
357 unsigned NumNOPBytes = MI.getOperand(1).getImm();
359 SM.recordStackMap(MI);
360 assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
362 // Scan ahead to trim the shadow.
363 const MachineBasicBlock &MBB = *MI.getParent();
364 MachineBasicBlock::const_iterator MII(MI);
366 while (NumNOPBytes > 0) {
367 if (MII == MBB.end() || MII->isCall() ||
368 MII->getOpcode() == AArch64::DBG_VALUE ||
369 MII->getOpcode() == TargetOpcode::PATCHPOINT ||
370 MII->getOpcode() == TargetOpcode::STACKMAP)
377 for (unsigned i = 0; i < NumNOPBytes; i += 4)
378 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
381 // Lower a patchpoint of the form:
382 // [<def>], <id>, <numBytes>, <target>, <numArgs>
383 void AArch64AsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
384 const MachineInstr &MI) {
385 SM.recordPatchPoint(MI);
387 PatchPointOpers Opers(&MI);
389 int64_t CallTarget = Opers.getMetaOper(PatchPointOpers::TargetPos).getImm();
390 unsigned EncodedBytes = 0;
392 assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
393 "High 16 bits of call target should be zero.");
394 unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
396 // Materialize the jump address:
397 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZXi)
399 .addImm((CallTarget >> 32) & 0xFFFF)
401 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
404 .addImm((CallTarget >> 16) & 0xFFFF)
406 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
409 .addImm(CallTarget & 0xFFFF)
411 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::BLR).addReg(ScratchReg));
414 unsigned NumBytes = Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
415 assert(NumBytes >= EncodedBytes &&
416 "Patchpoint can't request size less than the length of a call.");
417 assert((NumBytes - EncodedBytes) % 4 == 0 &&
418 "Invalid number of NOP bytes requested!");
419 for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
420 EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
423 void AArch64AsmPrinter::EmitFMov0(const MachineInstr &MI) {
424 unsigned DestReg = MI.getOperand(0).getReg();
425 if (STI->hasZeroCycleZeroing()) {
426 // Convert S/D register to corresponding Q register
427 if (AArch64::S0 <= DestReg && DestReg <= AArch64::S31) {
428 DestReg = AArch64::Q0 + (DestReg - AArch64::S0);
430 assert(AArch64::D0 <= DestReg && DestReg <= AArch64::D31);
431 DestReg = AArch64::Q0 + (DestReg - AArch64::D0);
434 MOVI.setOpcode(AArch64::MOVIv2d_ns);
435 MOVI.addOperand(MCOperand::createReg(DestReg));
436 MOVI.addOperand(MCOperand::createImm(0));
437 EmitToStreamer(*OutStreamer, MOVI);
440 switch (MI.getOpcode()) {
441 default: llvm_unreachable("Unexpected opcode");
442 case AArch64::FMOVS0:
443 FMov.setOpcode(AArch64::FMOVWSr);
444 FMov.addOperand(MCOperand::createReg(DestReg));
445 FMov.addOperand(MCOperand::createReg(AArch64::WZR));
447 case AArch64::FMOVD0:
448 FMov.setOpcode(AArch64::FMOVXDr);
449 FMov.addOperand(MCOperand::createReg(DestReg));
450 FMov.addOperand(MCOperand::createReg(AArch64::XZR));
453 EmitToStreamer(*OutStreamer, FMov);
457 // Simple pseudo-instructions have their lowering (with expansion to real
458 // instructions) auto-generated.
459 #include "AArch64GenMCPseudoLowering.inc"
461 void AArch64AsmPrinter::EmitInstruction(const MachineInstr *MI) {
462 // Do any auto-generated pseudo lowerings.
463 if (emitPseudoExpansionLowering(*OutStreamer, MI))
466 if (AArch64FI->getLOHRelated().count(MI)) {
467 // Generate a label for LOH related instruction
468 MCSymbol *LOHLabel = createTempSymbol("loh");
469 // Associate the instruction with the label
470 LOHInstToLabel[MI] = LOHLabel;
471 OutStreamer->EmitLabel(LOHLabel);
474 // Do any manual lowerings.
475 switch (MI->getOpcode()) {
478 case AArch64::DBG_VALUE: {
479 if (isVerbose() && OutStreamer->hasRawTextSupport()) {
480 SmallString<128> TmpStr;
481 raw_svector_ostream OS(TmpStr);
482 PrintDebugValueComment(MI, OS);
483 OutStreamer->EmitRawText(StringRef(OS.str()));
488 // Tail calls use pseudo instructions so they have the proper code-gen
489 // attributes (isCall, isReturn, etc.). We lower them to the real
491 case AArch64::TCRETURNri: {
493 TmpInst.setOpcode(AArch64::BR);
494 TmpInst.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
495 EmitToStreamer(*OutStreamer, TmpInst);
498 case AArch64::TCRETURNdi: {
500 MCInstLowering.lowerOperand(MI->getOperand(0), Dest);
502 TmpInst.setOpcode(AArch64::B);
503 TmpInst.addOperand(Dest);
504 EmitToStreamer(*OutStreamer, TmpInst);
507 case AArch64::TLSDESC_CALLSEQ: {
509 /// adrp x0, :tlsdesc:var
510 /// ldr x1, [x0, #:tlsdesc_lo12:var]
511 /// add x0, x0, #:tlsdesc_lo12:var
514 /// (TPIDR_EL0 offset now in x0)
515 const MachineOperand &MO_Sym = MI->getOperand(0);
516 MachineOperand MO_TLSDESC_LO12(MO_Sym), MO_TLSDESC(MO_Sym);
517 MCOperand Sym, SymTLSDescLo12, SymTLSDesc;
518 MO_TLSDESC_LO12.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGEOFF |
520 MO_TLSDESC.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGE);
521 MCInstLowering.lowerOperand(MO_Sym, Sym);
522 MCInstLowering.lowerOperand(MO_TLSDESC_LO12, SymTLSDescLo12);
523 MCInstLowering.lowerOperand(MO_TLSDESC, SymTLSDesc);
526 Adrp.setOpcode(AArch64::ADRP);
527 Adrp.addOperand(MCOperand::createReg(AArch64::X0));
528 Adrp.addOperand(SymTLSDesc);
529 EmitToStreamer(*OutStreamer, Adrp);
532 Ldr.setOpcode(AArch64::LDRXui);
533 Ldr.addOperand(MCOperand::createReg(AArch64::X1));
534 Ldr.addOperand(MCOperand::createReg(AArch64::X0));
535 Ldr.addOperand(SymTLSDescLo12);
536 Ldr.addOperand(MCOperand::createImm(0));
537 EmitToStreamer(*OutStreamer, Ldr);
540 Add.setOpcode(AArch64::ADDXri);
541 Add.addOperand(MCOperand::createReg(AArch64::X0));
542 Add.addOperand(MCOperand::createReg(AArch64::X0));
543 Add.addOperand(SymTLSDescLo12);
544 Add.addOperand(MCOperand::createImm(AArch64_AM::getShiftValue(0)));
545 EmitToStreamer(*OutStreamer, Add);
547 // Emit a relocation-annotation. This expands to no code, but requests
548 // the following instruction gets an R_AARCH64_TLSDESC_CALL.
550 TLSDescCall.setOpcode(AArch64::TLSDESCCALL);
551 TLSDescCall.addOperand(Sym);
552 EmitToStreamer(*OutStreamer, TLSDescCall);
555 Blr.setOpcode(AArch64::BLR);
556 Blr.addOperand(MCOperand::createReg(AArch64::X1));
557 EmitToStreamer(*OutStreamer, Blr);
562 case AArch64::FMOVS0:
563 case AArch64::FMOVD0:
567 case TargetOpcode::STACKMAP:
568 return LowerSTACKMAP(*OutStreamer, SM, *MI);
570 case TargetOpcode::PATCHPOINT:
571 return LowerPATCHPOINT(*OutStreamer, SM, *MI);
574 // Finally, do the automated lowerings for everything else.
576 MCInstLowering.Lower(MI, TmpInst);
577 EmitToStreamer(*OutStreamer, TmpInst);
580 // Force static initialization.
581 extern "C" void LLVMInitializeAArch64AsmPrinter() {
582 RegisterAsmPrinter<AArch64AsmPrinter> X(TheAArch64leTarget);
583 RegisterAsmPrinter<AArch64AsmPrinter> Y(TheAArch64beTarget);
584 RegisterAsmPrinter<AArch64AsmPrinter> Z(TheARM64Target);