1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
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 implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "llvm/Module.h"
19 #include "llvm/CodeGen/GCMetadataPrinter.h"
20 #include "llvm/CodeGen/MachineConstantPool.h"
21 #include "llvm/CodeGen/MachineFrameInfo.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineLoopInfo.h"
25 #include "llvm/CodeGen/MachineModuleInfo.h"
26 #include "llvm/Analysis/ConstantFolding.h"
27 #include "llvm/Analysis/DebugInfo.h"
28 #include "llvm/MC/MCAsmInfo.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCExpr.h"
31 #include "llvm/MC/MCInst.h"
32 #include "llvm/MC/MCSection.h"
33 #include "llvm/MC/MCStreamer.h"
34 #include "llvm/MC/MCSymbol.h"
35 #include "llvm/Target/Mangler.h"
36 #include "llvm/Target/TargetData.h"
37 #include "llvm/Target/TargetInstrInfo.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetLoweringObjectFile.h"
40 #include "llvm/Target/TargetRegisterInfo.h"
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/Statistic.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/Format.h"
45 #include "llvm/Support/Timer.h"
48 static const char *DWARFGroupName = "DWARF Emission";
49 static const char *DbgTimerName = "DWARF Debug Writer";
50 static const char *EHTimerName = "DWARF Exception Writer";
52 STATISTIC(EmittedInsts, "Number of machine instrs printed");
54 char AsmPrinter::ID = 0;
56 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
57 static gcp_map_type &getGCMap(void *&P) {
59 P = new gcp_map_type();
60 return *(gcp_map_type*)P;
64 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
65 /// value in log2 form. This rounds up to the preferred alignment if possible
67 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
68 unsigned InBits = 0) {
70 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
71 NumBits = TD.getPreferredAlignmentLog(GVar);
73 // If InBits is specified, round it to it.
77 // If the GV has a specified alignment, take it into account.
78 if (GV->getAlignment() == 0)
81 unsigned GVAlign = Log2_32(GV->getAlignment());
83 // If the GVAlign is larger than NumBits, or if we are required to obey
84 // NumBits because the GV has an assigned section, obey it.
85 if (GVAlign > NumBits || GV->hasSection())
93 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
94 : MachineFunctionPass(&ID),
95 TM(tm), MAI(tm.getMCAsmInfo()),
96 OutContext(Streamer.getContext()),
97 OutStreamer(Streamer),
98 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
99 DD = 0; DE = 0; MMI = 0; LI = 0;
100 GCMetadataPrinters = 0;
101 VerboseAsm = Streamer.isVerboseAsm();
104 AsmPrinter::~AsmPrinter() {
105 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
107 if (GCMetadataPrinters != 0) {
108 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
110 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
113 GCMetadataPrinters = 0;
119 /// getFunctionNumber - Return a unique ID for the current function.
121 unsigned AsmPrinter::getFunctionNumber() const {
122 return MF->getFunctionNumber();
125 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
126 return TM.getTargetLowering()->getObjFileLowering();
130 /// getTargetData - Return information about data layout.
131 const TargetData &AsmPrinter::getTargetData() const {
132 return *TM.getTargetData();
135 /// getCurrentSection() - Return the current section we are emitting to.
136 const MCSection *AsmPrinter::getCurrentSection() const {
137 return OutStreamer.getCurrentSection();
142 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
143 AU.setPreservesAll();
144 MachineFunctionPass::getAnalysisUsage(AU);
145 AU.addRequired<MachineModuleInfo>();
146 AU.addRequired<GCModuleInfo>();
148 AU.addRequired<MachineLoopInfo>();
151 bool AsmPrinter::doInitialization(Module &M) {
152 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
153 MMI->AnalyzeModule(M);
155 // Initialize TargetLoweringObjectFile.
156 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
157 .Initialize(OutContext, TM);
159 Mang = new Mangler(OutContext, *TM.getTargetData());
161 // Allow the target to emit any magic that it wants at the start of the file.
162 EmitStartOfAsmFile(M);
164 // Very minimal debug info. It is ignored if we emit actual debug info. If we
165 // don't, this at least helps the user find where a global came from.
166 if (MAI->hasSingleParameterDotFile()) {
168 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
171 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
172 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
173 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
174 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
175 MP->beginAssembly(*this);
177 // Emit module-level inline asm if it exists.
178 if (!M.getModuleInlineAsm().empty()) {
179 OutStreamer.AddComment("Start of file scope inline assembly");
180 OutStreamer.AddBlankLine();
181 EmitInlineAsm(M.getModuleInlineAsm(), 0/*no loc cookie*/);
182 OutStreamer.AddComment("End of file scope inline assembly");
183 OutStreamer.AddBlankLine();
186 if (MAI->doesSupportDebugInformation())
187 DD = new DwarfDebug(this, &M);
189 if (MAI->doesSupportExceptionHandling())
190 DE = new DwarfException(this);
195 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
196 switch ((GlobalValue::LinkageTypes)Linkage) {
197 case GlobalValue::CommonLinkage:
198 case GlobalValue::LinkOnceAnyLinkage:
199 case GlobalValue::LinkOnceODRLinkage:
200 case GlobalValue::WeakAnyLinkage:
201 case GlobalValue::WeakODRLinkage:
202 case GlobalValue::LinkerPrivateLinkage:
203 if (MAI->getWeakDefDirective() != 0) {
205 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
206 // .weak_definition _foo
207 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
208 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
210 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
211 // FIXME: linkonce should be a section attribute, handled by COFF Section
213 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
215 // FIXME: It would be nice to use .linkonce samesize for non-common
217 OutStreamer.EmitRawText(StringRef(LinkOnce));
220 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
223 case GlobalValue::DLLExportLinkage:
224 case GlobalValue::AppendingLinkage:
225 // FIXME: appending linkage variables should go into a section of
226 // their name or something. For now, just emit them as external.
227 case GlobalValue::ExternalLinkage:
228 // If external or appending, declare as a global symbol.
230 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
232 case GlobalValue::PrivateLinkage:
233 case GlobalValue::InternalLinkage:
236 llvm_unreachable("Unknown linkage type!");
241 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
242 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
243 if (!GV->hasInitializer()) // External globals require no code.
246 // Check to see if this is a special global used by LLVM, if so, emit it.
247 if (EmitSpecialLLVMGlobal(GV))
250 MCSymbol *GVSym = Mang->getSymbol(GV);
251 EmitVisibility(GVSym, GV->getVisibility());
253 if (MAI->hasDotTypeDotSizeDirective())
254 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
256 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
258 const TargetData *TD = TM.getTargetData();
259 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
261 // If the alignment is specified, we *must* obey it. Overaligning a global
262 // with a specified alignment is a prompt way to break globals emitted to
263 // sections and expected to be contiguous (e.g. ObjC metadata).
264 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
266 // Handle common and BSS local symbols (.lcomm).
267 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
268 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
271 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
272 /*PrintType=*/false, GV->getParent());
273 OutStreamer.GetCommentOS() << '\n';
276 // Handle common symbols.
277 if (GVKind.isCommon()) {
279 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
283 // Handle local BSS symbols.
284 if (MAI->hasMachoZeroFillDirective()) {
285 const MCSection *TheSection =
286 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
287 // .zerofill __DATA, __bss, _foo, 400, 5
288 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
292 if (MAI->hasLCOMMDirective()) {
294 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
299 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
301 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
305 const MCSection *TheSection =
306 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
308 // Handle the zerofill directive on darwin, which is a special form of BSS
310 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
311 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
314 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
315 // .zerofill __DATA, __common, _foo, 400, 5
316 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
320 OutStreamer.SwitchSection(TheSection);
322 EmitLinkage(GV->getLinkage(), GVSym);
323 EmitAlignment(AlignLog, GV);
326 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
327 /*PrintType=*/false, GV->getParent());
328 OutStreamer.GetCommentOS() << '\n';
330 OutStreamer.EmitLabel(GVSym);
332 EmitGlobalConstant(GV->getInitializer());
334 if (MAI->hasDotTypeDotSizeDirective())
336 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
338 OutStreamer.AddBlankLine();
341 /// EmitFunctionHeader - This method emits the header for the current
343 void AsmPrinter::EmitFunctionHeader() {
344 // Print out constants referenced by the function
347 // Print the 'header' of function.
348 const Function *F = MF->getFunction();
350 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
351 EmitVisibility(CurrentFnSym, F->getVisibility());
353 EmitLinkage(F->getLinkage(), CurrentFnSym);
354 EmitAlignment(MF->getAlignment(), F);
356 if (MAI->hasDotTypeDotSizeDirective())
357 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
360 WriteAsOperand(OutStreamer.GetCommentOS(), F,
361 /*PrintType=*/false, F->getParent());
362 OutStreamer.GetCommentOS() << '\n';
365 // Emit the CurrentFnSym. This is a virtual function to allow targets to
366 // do their wild and crazy things as required.
367 EmitFunctionEntryLabel();
369 // If the function had address-taken blocks that got deleted, then we have
370 // references to the dangling symbols. Emit them at the start of the function
371 // so that we don't get references to undefined symbols.
372 std::vector<MCSymbol*> DeadBlockSyms;
373 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
374 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
375 OutStreamer.AddComment("Address taken block that was later removed");
376 OutStreamer.EmitLabel(DeadBlockSyms[i]);
379 // Add some workaround for linkonce linkage on Cygwin\MinGW.
380 if (MAI->getLinkOnceDirective() != 0 &&
381 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
382 // FIXME: What is this?
384 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
385 CurrentFnSym->getName());
386 OutStreamer.EmitLabel(FakeStub);
389 // Emit pre-function debug and/or EH information.
391 if (TimePassesIsEnabled) {
392 NamedRegionTimer T(EHTimerName, DWARFGroupName);
393 DE->BeginFunction(MF);
395 DE->BeginFunction(MF);
399 if (TimePassesIsEnabled) {
400 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
401 DD->beginFunction(MF);
403 DD->beginFunction(MF);
408 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
409 /// function. This can be overridden by targets as required to do custom stuff.
410 void AsmPrinter::EmitFunctionEntryLabel() {
411 OutStreamer.EmitLabel(CurrentFnSym);
415 /// EmitComments - Pretty-print comments for instructions.
416 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
417 const MachineFunction *MF = MI.getParent()->getParent();
418 const TargetMachine &TM = MF->getTarget();
420 DebugLoc DL = MI.getDebugLoc();
421 if (!DL.isUnknown()) { // Print source line info.
422 DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
423 // Omit the directory, because it's likely to be long and uninteresting.
425 CommentOS << Scope.getFilename();
427 CommentOS << "<unknown>";
428 CommentOS << ':' << DL.getLine();
429 if (DL.getCol() != 0)
430 CommentOS << ':' << DL.getCol();
434 // Check for spills and reloads
437 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
439 // We assume a single instruction only has a spill or reload, not
441 const MachineMemOperand *MMO;
442 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
443 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
444 MMO = *MI.memoperands_begin();
445 CommentOS << MMO->getSize() << "-byte Reload\n";
447 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
448 if (FrameInfo->isSpillSlotObjectIndex(FI))
449 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
450 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
451 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
452 MMO = *MI.memoperands_begin();
453 CommentOS << MMO->getSize() << "-byte Spill\n";
455 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
456 if (FrameInfo->isSpillSlotObjectIndex(FI))
457 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
460 // Check for spill-induced copies
461 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
462 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
463 SrcSubIdx, DstSubIdx)) {
464 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
465 CommentOS << " Reload Reuse\n";
469 /// EmitImplicitDef - This method emits the specified machine instruction
470 /// that is an implicit def.
471 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
472 unsigned RegNo = MI->getOperand(0).getReg();
473 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
474 AP.TM.getRegisterInfo()->getName(RegNo));
475 AP.OutStreamer.AddBlankLine();
478 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
479 std::string Str = "kill:";
480 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
481 const MachineOperand &Op = MI->getOperand(i);
482 assert(Op.isReg() && "KILL instruction must have only register operands");
484 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
485 Str += (Op.isDef() ? "<def>" : "<kill>");
487 AP.OutStreamer.AddComment(Str);
488 AP.OutStreamer.AddBlankLine();
491 /// EmitDebugValueComment - This method handles the target-independent form
492 /// of DBG_VALUE, returning true if it was able to do so. A false return
493 /// means the target will need to handle MI in EmitInstruction.
494 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
495 // This code handles only the 3-operand target-independent form.
496 if (MI->getNumOperands() != 3)
499 SmallString<128> Str;
500 raw_svector_ostream OS(Str);
501 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
503 // cast away const; DIetc do not take const operands for some reason.
504 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
505 OS << V.getName() << " <- ";
507 // Register or immediate value. Register 0 means undef.
508 if (MI->getOperand(0).isFPImm()) {
509 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
510 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
511 OS << (double)APF.convertToFloat();
512 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
513 OS << APF.convertToDouble();
515 // There is no good way to print long double. Convert a copy to
516 // double. Ah well, it's only a comment.
518 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
520 OS << "(long double) " << APF.convertToDouble();
522 } else if (MI->getOperand(0).isImm()) {
523 OS << MI->getOperand(0).getImm();
525 assert(MI->getOperand(0).isReg() && "Unknown operand type");
526 if (MI->getOperand(0).getReg() == 0) {
527 // Suppress offset, it is not meaningful here.
529 // NOTE: Want this comment at start of line, don't emit with AddComment.
530 AP.OutStreamer.EmitRawText(OS.str());
533 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
536 OS << '+' << MI->getOperand(1).getImm();
537 // NOTE: Want this comment at start of line, don't emit with AddComment.
538 AP.OutStreamer.EmitRawText(OS.str());
542 /// EmitFunctionBody - This method emits the body and trailer for a
544 void AsmPrinter::EmitFunctionBody() {
545 // Emit target-specific gunk before the function body.
546 EmitFunctionBodyStart();
548 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
550 // Print out code for the function.
551 bool HasAnyRealCode = false;
552 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
554 // Print a label for the basic block.
555 EmitBasicBlockStart(I);
556 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
558 // Print the assembly for the instruction.
559 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill()) {
560 HasAnyRealCode = true;
564 if (ShouldPrintDebugScopes) {
565 if (TimePassesIsEnabled) {
566 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
574 EmitComments(*II, OutStreamer.GetCommentOS());
576 switch (II->getOpcode()) {
577 case TargetOpcode::DBG_LABEL:
578 case TargetOpcode::EH_LABEL:
579 case TargetOpcode::GC_LABEL:
580 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
582 case TargetOpcode::INLINEASM:
585 case TargetOpcode::DBG_VALUE:
587 if (!EmitDebugValueComment(II, *this))
591 case TargetOpcode::IMPLICIT_DEF:
592 if (isVerbose()) EmitImplicitDef(II, *this);
594 case TargetOpcode::KILL:
595 if (isVerbose()) EmitKill(II, *this);
602 if (ShouldPrintDebugScopes) {
603 if (TimePassesIsEnabled) {
604 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
613 // If the function is empty and the object file uses .subsections_via_symbols,
614 // then we need to emit *something* to the function body to prevent the
615 // labels from collapsing together. Just emit a noop.
616 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) {
618 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
619 if (Noop.getOpcode()) {
620 OutStreamer.AddComment("avoids zero-length function");
621 OutStreamer.EmitInstruction(Noop);
622 } else // Target not mc-ized yet.
623 OutStreamer.EmitRawText(StringRef("\tnop\n"));
626 // Emit target-specific gunk after the function body.
627 EmitFunctionBodyEnd();
629 // If the target wants a .size directive for the size of the function, emit
631 if (MAI->hasDotTypeDotSizeDirective()) {
632 // Create a symbol for the end of function, so we can get the size as
633 // difference between the function label and the temp label.
634 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
635 OutStreamer.EmitLabel(FnEndLabel);
637 const MCExpr *SizeExp =
638 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
639 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
641 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
644 // Emit post-function debug information.
646 if (TimePassesIsEnabled) {
647 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
654 if (TimePassesIsEnabled) {
655 NamedRegionTimer T(EHTimerName, DWARFGroupName);
663 // Print out jump tables referenced by the function.
666 OutStreamer.AddBlankLine();
669 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
671 MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
672 // Target specific DBG_VALUE instructions are handled by each target.
673 return MachineLocation();
676 bool AsmPrinter::doFinalization(Module &M) {
677 // Emit global variables.
678 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
680 EmitGlobalVariable(I);
682 // Finalize debug and EH information.
684 if (TimePassesIsEnabled) {
685 NamedRegionTimer T(EHTimerName, DWARFGroupName);
693 if (TimePassesIsEnabled) {
694 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
702 // If the target wants to know about weak references, print them all.
703 if (MAI->getWeakRefDirective()) {
704 // FIXME: This is not lazy, it would be nice to only print weak references
705 // to stuff that is actually used. Note that doing so would require targets
706 // to notice uses in operands (due to constant exprs etc). This should
707 // happen with the MC stuff eventually.
709 // Print out module-level global variables here.
710 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
712 if (!I->hasExternalWeakLinkage()) continue;
713 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
716 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
717 if (!I->hasExternalWeakLinkage()) continue;
718 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
722 if (MAI->hasSetDirective()) {
723 OutStreamer.AddBlankLine();
724 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
726 MCSymbol *Name = Mang->getSymbol(I);
728 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
729 MCSymbol *Target = Mang->getSymbol(GV);
731 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
732 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
733 else if (I->hasWeakLinkage())
734 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
736 assert(I->hasLocalLinkage() && "Invalid alias linkage");
738 EmitVisibility(Name, I->getVisibility());
740 // Emit the directives as assignments aka .set:
741 OutStreamer.EmitAssignment(Name,
742 MCSymbolRefExpr::Create(Target, OutContext));
746 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
747 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
748 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
749 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
750 MP->finishAssembly(*this);
752 // If we don't have any trampolines, then we don't require stack memory
753 // to be executable. Some targets have a directive to declare this.
754 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
755 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
756 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
757 OutStreamer.SwitchSection(S);
759 // Allow the target to emit any magic that it wants at the end of the file,
760 // after everything else has gone out.
763 delete Mang; Mang = 0;
766 OutStreamer.Finish();
770 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
772 // Get the function symbol.
773 CurrentFnSym = Mang->getSymbol(MF.getFunction());
776 LI = &getAnalysis<MachineLoopInfo>();
780 // SectionCPs - Keep track the alignment, constpool entries per Section.
784 SmallVector<unsigned, 4> CPEs;
785 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
789 /// EmitConstantPool - Print to the current output stream assembly
790 /// representations of the constants in the constant pool MCP. This is
791 /// used to print out constants which have been "spilled to memory" by
792 /// the code generator.
794 void AsmPrinter::EmitConstantPool() {
795 const MachineConstantPool *MCP = MF->getConstantPool();
796 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
797 if (CP.empty()) return;
799 // Calculate sections for constant pool entries. We collect entries to go into
800 // the same section together to reduce amount of section switch statements.
801 SmallVector<SectionCPs, 4> CPSections;
802 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
803 const MachineConstantPoolEntry &CPE = CP[i];
804 unsigned Align = CPE.getAlignment();
807 switch (CPE.getRelocationInfo()) {
808 default: llvm_unreachable("Unknown section kind");
809 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
811 Kind = SectionKind::getReadOnlyWithRelLocal();
814 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
815 case 4: Kind = SectionKind::getMergeableConst4(); break;
816 case 8: Kind = SectionKind::getMergeableConst8(); break;
817 case 16: Kind = SectionKind::getMergeableConst16();break;
818 default: Kind = SectionKind::getMergeableConst(); break;
822 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
824 // The number of sections are small, just do a linear search from the
825 // last section to the first.
827 unsigned SecIdx = CPSections.size();
828 while (SecIdx != 0) {
829 if (CPSections[--SecIdx].S == S) {
835 SecIdx = CPSections.size();
836 CPSections.push_back(SectionCPs(S, Align));
839 if (Align > CPSections[SecIdx].Alignment)
840 CPSections[SecIdx].Alignment = Align;
841 CPSections[SecIdx].CPEs.push_back(i);
844 // Now print stuff into the calculated sections.
845 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
846 OutStreamer.SwitchSection(CPSections[i].S);
847 EmitAlignment(Log2_32(CPSections[i].Alignment));
850 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
851 unsigned CPI = CPSections[i].CPEs[j];
852 MachineConstantPoolEntry CPE = CP[CPI];
854 // Emit inter-object padding for alignment.
855 unsigned AlignMask = CPE.getAlignment() - 1;
856 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
857 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
859 const Type *Ty = CPE.getType();
860 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
862 // Emit the label with a comment on it.
864 OutStreamer.GetCommentOS() << "constant pool ";
865 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
866 MF->getFunction()->getParent());
867 OutStreamer.GetCommentOS() << '\n';
869 OutStreamer.EmitLabel(GetCPISymbol(CPI));
871 if (CPE.isMachineConstantPoolEntry())
872 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
874 EmitGlobalConstant(CPE.Val.ConstVal);
879 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
880 /// by the current function to the current output stream.
882 void AsmPrinter::EmitJumpTableInfo() {
883 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
884 if (MJTI == 0) return;
885 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
886 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
887 if (JT.empty()) return;
889 // Pick the directive to use to print the jump table entries, and switch to
890 // the appropriate section.
891 const Function *F = MF->getFunction();
892 bool JTInDiffSection = false;
893 if (// In PIC mode, we need to emit the jump table to the same section as the
894 // function body itself, otherwise the label differences won't make sense.
895 // FIXME: Need a better predicate for this: what about custom entries?
896 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
897 // We should also do if the section name is NULL or function is declared
898 // in discardable section
899 // FIXME: this isn't the right predicate, should be based on the MCSection
901 F->isWeakForLinker()) {
902 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
904 // Otherwise, drop it in the readonly section.
905 const MCSection *ReadOnlySection =
906 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
907 OutStreamer.SwitchSection(ReadOnlySection);
908 JTInDiffSection = true;
911 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
913 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
914 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
916 // If this jump table was deleted, ignore it.
917 if (JTBBs.empty()) continue;
919 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
920 // .set directive for each unique entry. This reduces the number of
921 // relocations the assembler will generate for the jump table.
922 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
923 MAI->hasSetDirective()) {
924 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
925 const TargetLowering *TLI = TM.getTargetLowering();
926 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
927 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
928 const MachineBasicBlock *MBB = JTBBs[ii];
929 if (!EmittedSets.insert(MBB)) continue;
931 // .set LJTSet, LBB32-base
933 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
934 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
935 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
939 // On some targets (e.g. Darwin) we want to emit two consequtive labels
940 // before each jump table. The first label is never referenced, but tells
941 // the assembler and linker the extents of the jump table object. The
942 // second label is actually referenced by the code.
943 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
944 // FIXME: This doesn't have to have any specific name, just any randomly
945 // named and numbered 'l' label would work. Simplify GetJTISymbol.
946 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
948 OutStreamer.EmitLabel(GetJTISymbol(JTI));
950 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
951 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
955 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
957 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
958 const MachineBasicBlock *MBB,
959 unsigned UID) const {
960 const MCExpr *Value = 0;
961 switch (MJTI->getEntryKind()) {
962 case MachineJumpTableInfo::EK_Inline:
963 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
964 case MachineJumpTableInfo::EK_Custom32:
965 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
968 case MachineJumpTableInfo::EK_BlockAddress:
969 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
971 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
973 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
974 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
975 // with a relocation as gp-relative, e.g.:
977 MCSymbol *MBBSym = MBB->getSymbol();
978 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
982 case MachineJumpTableInfo::EK_LabelDifference32: {
983 // EK_LabelDifference32 - Each entry is the address of the block minus
984 // the address of the jump table. This is used for PIC jump tables where
985 // gprel32 is not supported. e.g.:
986 // .word LBB123 - LJTI1_2
987 // If the .set directive is supported, this is emitted as:
988 // .set L4_5_set_123, LBB123 - LJTI1_2
989 // .word L4_5_set_123
991 // If we have emitted set directives for the jump table entries, print
992 // them rather than the entries themselves. If we're emitting PIC, then
993 // emit the table entries as differences between two text section labels.
994 if (MAI->hasSetDirective()) {
995 // If we used .set, reference the .set's symbol.
996 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1000 // Otherwise, use the difference as the jump table entry.
1001 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1002 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1003 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1008 assert(Value && "Unknown entry kind!");
1010 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1011 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1015 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1016 /// special global used by LLVM. If so, emit it and return true, otherwise
1017 /// do nothing and return false.
1018 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1019 if (GV->getName() == "llvm.used") {
1020 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1021 EmitLLVMUsedList(GV->getInitializer());
1025 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1026 if (GV->getSection() == "llvm.metadata" ||
1027 GV->hasAvailableExternallyLinkage())
1030 if (!GV->hasAppendingLinkage()) return false;
1032 assert(GV->hasInitializer() && "Not a special LLVM global!");
1034 const TargetData *TD = TM.getTargetData();
1035 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1036 if (GV->getName() == "llvm.global_ctors") {
1037 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1038 EmitAlignment(Align);
1039 EmitXXStructorList(GV->getInitializer());
1041 if (TM.getRelocationModel() == Reloc::Static &&
1042 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1043 StringRef Sym(".constructors_used");
1044 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1050 if (GV->getName() == "llvm.global_dtors") {
1051 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1052 EmitAlignment(Align);
1053 EmitXXStructorList(GV->getInitializer());
1055 if (TM.getRelocationModel() == Reloc::Static &&
1056 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1057 StringRef Sym(".destructors_used");
1058 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1067 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1068 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1069 /// is true, as being used with this directive.
1070 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1071 // Should be an array of 'i8*'.
1072 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1073 if (InitList == 0) return;
1075 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1076 const GlobalValue *GV =
1077 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1078 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1079 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1083 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1084 /// function pointers, ignoring the init priority.
1085 void AsmPrinter::EmitXXStructorList(Constant *List) {
1086 // Should be an array of '{ int, void ()* }' structs. The first value is the
1087 // init priority, which we ignore.
1088 if (!isa<ConstantArray>(List)) return;
1089 ConstantArray *InitList = cast<ConstantArray>(List);
1090 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1091 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1092 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1094 if (CS->getOperand(1)->isNullValue())
1095 return; // Found a null terminator, exit printing.
1096 // Emit the function pointer.
1097 EmitGlobalConstant(CS->getOperand(1));
1101 //===--------------------------------------------------------------------===//
1102 // Emission and print routines
1105 /// EmitInt8 - Emit a byte directive and value.
1107 void AsmPrinter::EmitInt8(int Value) const {
1108 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1111 /// EmitInt16 - Emit a short directive and value.
1113 void AsmPrinter::EmitInt16(int Value) const {
1114 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1117 /// EmitInt32 - Emit a long directive and value.
1119 void AsmPrinter::EmitInt32(int Value) const {
1120 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1123 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1124 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1125 /// labels. This implicitly uses .set if it is available.
1126 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1127 unsigned Size) const {
1128 // Get the Hi-Lo expression.
1129 const MCExpr *Diff =
1130 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1131 MCSymbolRefExpr::Create(Lo, OutContext),
1134 if (!MAI->hasSetDirective()) {
1135 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1139 // Otherwise, emit with .set (aka assignment).
1140 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1141 OutStreamer.EmitAssignment(SetLabel, Diff);
1142 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1145 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1146 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1147 /// specify the labels. This implicitly uses .set if it is available.
1148 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1149 const MCSymbol *Lo, unsigned Size)
1152 // Emit Hi+Offset - Lo
1153 // Get the Hi+Offset expression.
1154 const MCExpr *Plus =
1155 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1156 MCConstantExpr::Create(Offset, OutContext),
1159 // Get the Hi+Offset-Lo expression.
1160 const MCExpr *Diff =
1161 MCBinaryExpr::CreateSub(Plus,
1162 MCSymbolRefExpr::Create(Lo, OutContext),
1165 if (!MAI->hasSetDirective())
1166 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1168 // Otherwise, emit with .set (aka assignment).
1169 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1170 OutStreamer.EmitAssignment(SetLabel, Diff);
1171 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1176 //===----------------------------------------------------------------------===//
1178 // EmitAlignment - Emit an alignment directive to the specified power of
1179 // two boundary. For example, if you pass in 3 here, you will get an 8
1180 // byte alignment. If a global value is specified, and if that global has
1181 // an explicit alignment requested, it will override the alignment request
1182 // if required for correctness.
1184 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1185 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1187 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1189 if (getCurrentSection()->getKind().isText())
1190 OutStreamer.EmitCodeAlignment(1 << NumBits);
1192 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1195 //===----------------------------------------------------------------------===//
1196 // Constant emission.
1197 //===----------------------------------------------------------------------===//
1199 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1201 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1202 MCContext &Ctx = AP.OutContext;
1204 if (CV->isNullValue() || isa<UndefValue>(CV))
1205 return MCConstantExpr::Create(0, Ctx);
1207 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1208 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1210 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1211 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1212 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1213 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1215 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1217 llvm_unreachable("Unknown constant value to lower!");
1218 return MCConstantExpr::Create(0, Ctx);
1221 switch (CE->getOpcode()) {
1223 // If the code isn't optimized, there may be outstanding folding
1224 // opportunities. Attempt to fold the expression using TargetData as a
1225 // last resort before giving up.
1227 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1229 return LowerConstant(C, AP);
1233 llvm_unreachable("FIXME: Don't support this constant expr");
1234 case Instruction::GetElementPtr: {
1235 const TargetData &TD = *AP.TM.getTargetData();
1236 // Generate a symbolic expression for the byte address
1237 const Constant *PtrVal = CE->getOperand(0);
1238 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1239 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1242 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1246 // Truncate/sext the offset to the pointer size.
1247 if (TD.getPointerSizeInBits() != 64) {
1248 int SExtAmount = 64-TD.getPointerSizeInBits();
1249 Offset = (Offset << SExtAmount) >> SExtAmount;
1252 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1256 case Instruction::Trunc:
1257 // We emit the value and depend on the assembler to truncate the generated
1258 // expression properly. This is important for differences between
1259 // blockaddress labels. Since the two labels are in the same function, it
1260 // is reasonable to treat their delta as a 32-bit value.
1262 case Instruction::BitCast:
1263 return LowerConstant(CE->getOperand(0), AP);
1265 case Instruction::IntToPtr: {
1266 const TargetData &TD = *AP.TM.getTargetData();
1267 // Handle casts to pointers by changing them into casts to the appropriate
1268 // integer type. This promotes constant folding and simplifies this code.
1269 Constant *Op = CE->getOperand(0);
1270 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1272 return LowerConstant(Op, AP);
1275 case Instruction::PtrToInt: {
1276 const TargetData &TD = *AP.TM.getTargetData();
1277 // Support only foldable casts to/from pointers that can be eliminated by
1278 // changing the pointer to the appropriately sized integer type.
1279 Constant *Op = CE->getOperand(0);
1280 const Type *Ty = CE->getType();
1282 const MCExpr *OpExpr = LowerConstant(Op, AP);
1284 // We can emit the pointer value into this slot if the slot is an
1285 // integer slot equal to the size of the pointer.
1286 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1289 // Otherwise the pointer is smaller than the resultant integer, mask off
1290 // the high bits so we are sure to get a proper truncation if the input is
1292 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1293 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1294 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1297 // The MC library also has a right-shift operator, but it isn't consistently
1298 // signed or unsigned between different targets.
1299 case Instruction::Add:
1300 case Instruction::Sub:
1301 case Instruction::Mul:
1302 case Instruction::SDiv:
1303 case Instruction::SRem:
1304 case Instruction::Shl:
1305 case Instruction::And:
1306 case Instruction::Or:
1307 case Instruction::Xor: {
1308 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1309 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1310 switch (CE->getOpcode()) {
1311 default: llvm_unreachable("Unknown binary operator constant cast expr");
1312 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1313 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1314 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1315 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1316 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1317 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1318 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1319 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1320 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1326 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1329 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1331 if (AddrSpace != 0 || !CA->isString()) {
1332 // Not a string. Print the values in successive locations
1333 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1334 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1338 // Otherwise, it can be emitted as .ascii.
1339 SmallVector<char, 128> TmpVec;
1340 TmpVec.reserve(CA->getNumOperands());
1341 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1342 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1344 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1347 static void EmitGlobalConstantVector(const ConstantVector *CV,
1348 unsigned AddrSpace, AsmPrinter &AP) {
1349 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1350 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1353 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1354 unsigned AddrSpace, AsmPrinter &AP) {
1355 // Print the fields in successive locations. Pad to align if needed!
1356 const TargetData *TD = AP.TM.getTargetData();
1357 unsigned Size = TD->getTypeAllocSize(CS->getType());
1358 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1359 uint64_t SizeSoFar = 0;
1360 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1361 const Constant *Field = CS->getOperand(i);
1363 // Check if padding is needed and insert one or more 0s.
1364 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1365 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1366 - Layout->getElementOffset(i)) - FieldSize;
1367 SizeSoFar += FieldSize + PadSize;
1369 // Now print the actual field value.
1370 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1372 // Insert padding - this may include padding to increase the size of the
1373 // current field up to the ABI size (if the struct is not packed) as well
1374 // as padding to ensure that the next field starts at the right offset.
1375 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1377 assert(SizeSoFar == Layout->getSizeInBytes() &&
1378 "Layout of constant struct may be incorrect!");
1381 static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1382 unsigned AddrSpace, AsmPrinter &AP) {
1383 const TargetData *TD = AP.TM.getTargetData();
1384 unsigned Size = TD->getTypeAllocSize(CU->getType());
1386 const Constant *Contents = CU->getOperand(0);
1387 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1389 // Print the actually filled part
1390 EmitGlobalConstantImpl(Contents, AddrSpace, AP);
1392 // And pad with enough zeroes
1393 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1396 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1398 // FP Constants are printed as integer constants to avoid losing
1400 if (CFP->getType()->isDoubleTy()) {
1401 if (AP.isVerbose()) {
1402 double Val = CFP->getValueAPF().convertToDouble();
1403 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1406 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1407 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1411 if (CFP->getType()->isFloatTy()) {
1412 if (AP.isVerbose()) {
1413 float Val = CFP->getValueAPF().convertToFloat();
1414 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1416 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1417 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1421 if (CFP->getType()->isX86_FP80Ty()) {
1422 // all long double variants are printed as hex
1423 // API needed to prevent premature destruction
1424 APInt API = CFP->getValueAPF().bitcastToAPInt();
1425 const uint64_t *p = API.getRawData();
1426 if (AP.isVerbose()) {
1427 // Convert to double so we can print the approximate val as a comment.
1428 APFloat DoubleVal = CFP->getValueAPF();
1430 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1432 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1433 << DoubleVal.convertToDouble() << '\n';
1436 if (AP.TM.getTargetData()->isBigEndian()) {
1437 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1438 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1440 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1441 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1444 // Emit the tail padding for the long double.
1445 const TargetData &TD = *AP.TM.getTargetData();
1446 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1447 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1451 assert(CFP->getType()->isPPC_FP128Ty() &&
1452 "Floating point constant type not handled");
1453 // All long double variants are printed as hex
1454 // API needed to prevent premature destruction.
1455 APInt API = CFP->getValueAPF().bitcastToAPInt();
1456 const uint64_t *p = API.getRawData();
1457 if (AP.TM.getTargetData()->isBigEndian()) {
1458 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1459 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1461 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1462 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1466 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1467 unsigned AddrSpace, AsmPrinter &AP) {
1468 const TargetData *TD = AP.TM.getTargetData();
1469 unsigned BitWidth = CI->getBitWidth();
1470 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1472 // We don't expect assemblers to support integer data directives
1473 // for more than 64 bits, so we emit the data in at most 64-bit
1474 // quantities at a time.
1475 const uint64_t *RawData = CI->getValue().getRawData();
1476 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1477 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1478 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1482 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1484 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1485 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1486 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1489 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1490 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1497 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1498 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1501 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1506 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1507 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1509 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1510 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1512 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1513 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1515 if (isa<ConstantPointerNull>(CV)) {
1516 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1517 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1521 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1522 return EmitGlobalConstantUnion(CVU, AddrSpace, AP);
1524 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1525 return EmitGlobalConstantVector(V, AddrSpace, AP);
1527 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1528 // thread the streamer with EmitValue.
1529 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1530 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1534 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1535 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1536 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1538 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1539 else if (MAI->hasSubsectionsViaSymbols()) {
1540 // If the global has zero size, emit a single byte so that two labels don't
1541 // look like they are at the same location.
1542 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1546 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1547 // Target doesn't support this yet!
1548 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1551 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1553 OS << '+' << Offset;
1554 else if (Offset < 0)
1558 //===----------------------------------------------------------------------===//
1559 // Symbol Lowering Routines.
1560 //===----------------------------------------------------------------------===//
1562 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1563 /// temporary label with the specified stem and unique ID.
1564 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1565 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1569 /// GetTempSymbol - Return an assembler temporary label with the specified
1571 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1572 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1577 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1578 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1581 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1582 return MMI->getAddrLabelSymbol(BB);
1585 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1586 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1587 return OutContext.GetOrCreateSymbol
1588 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1589 + "_" + Twine(CPID));
1592 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1593 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1594 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1597 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1598 /// FIXME: privatize to AsmPrinter.
1599 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1600 return OutContext.GetOrCreateSymbol
1601 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1602 Twine(UID) + "_set_" + Twine(MBBID));
1605 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1606 /// global value name as its base, with the specified suffix, and where the
1607 /// symbol is forced to have private linkage if ForcePrivate is true.
1608 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1610 bool ForcePrivate) const {
1611 SmallString<60> NameStr;
1612 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1613 NameStr.append(Suffix.begin(), Suffix.end());
1614 return OutContext.GetOrCreateSymbol(NameStr.str());
1617 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1619 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1620 SmallString<60> NameStr;
1621 Mang->getNameWithPrefix(NameStr, Sym);
1622 return OutContext.GetOrCreateSymbol(NameStr.str());
1627 /// PrintParentLoopComment - Print comments about parent loops of this one.
1628 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1629 unsigned FunctionNumber) {
1630 if (Loop == 0) return;
1631 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1632 OS.indent(Loop->getLoopDepth()*2)
1633 << "Parent Loop BB" << FunctionNumber << "_"
1634 << Loop->getHeader()->getNumber()
1635 << " Depth=" << Loop->getLoopDepth() << '\n';
1639 /// PrintChildLoopComment - Print comments about child loops within
1640 /// the loop for this basic block, with nesting.
1641 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1642 unsigned FunctionNumber) {
1643 // Add child loop information
1644 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1645 OS.indent((*CL)->getLoopDepth()*2)
1646 << "Child Loop BB" << FunctionNumber << "_"
1647 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1649 PrintChildLoopComment(OS, *CL, FunctionNumber);
1653 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1654 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1655 const MachineLoopInfo *LI,
1656 const AsmPrinter &AP) {
1657 // Add loop depth information
1658 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1659 if (Loop == 0) return;
1661 MachineBasicBlock *Header = Loop->getHeader();
1662 assert(Header && "No header for loop");
1664 // If this block is not a loop header, just print out what is the loop header
1666 if (Header != &MBB) {
1667 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1668 Twine(AP.getFunctionNumber())+"_" +
1669 Twine(Loop->getHeader()->getNumber())+
1670 " Depth="+Twine(Loop->getLoopDepth()));
1674 // Otherwise, it is a loop header. Print out information about child and
1676 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1678 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1681 OS.indent(Loop->getLoopDepth()*2-2);
1686 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1688 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1692 /// EmitBasicBlockStart - This method prints the label for the specified
1693 /// MachineBasicBlock, an alignment (if present) and a comment describing
1694 /// it if appropriate.
1695 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1696 // Emit an alignment directive for this block, if needed.
1697 if (unsigned Align = MBB->getAlignment())
1698 EmitAlignment(Log2_32(Align));
1700 // If the block has its address taken, emit any labels that were used to
1701 // reference the block. It is possible that there is more than one label
1702 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1703 // the references were generated.
1704 if (MBB->hasAddressTaken()) {
1705 const BasicBlock *BB = MBB->getBasicBlock();
1707 OutStreamer.AddComment("Block address taken");
1709 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1711 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1712 OutStreamer.EmitLabel(Syms[i]);
1715 // Print the main label for the block.
1716 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1717 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1718 if (const BasicBlock *BB = MBB->getBasicBlock())
1720 OutStreamer.AddComment("%" + BB->getName());
1722 EmitBasicBlockLoopComments(*MBB, LI, *this);
1724 // NOTE: Want this comment at start of line, don't emit with AddComment.
1725 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1726 Twine(MBB->getNumber()) + ":");
1730 if (const BasicBlock *BB = MBB->getBasicBlock())
1732 OutStreamer.AddComment("%" + BB->getName());
1733 EmitBasicBlockLoopComments(*MBB, LI, *this);
1736 OutStreamer.EmitLabel(MBB->getSymbol());
1740 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1741 MCSymbolAttr Attr = MCSA_Invalid;
1743 switch (Visibility) {
1745 case GlobalValue::HiddenVisibility:
1746 Attr = MAI->getHiddenVisibilityAttr();
1748 case GlobalValue::ProtectedVisibility:
1749 Attr = MAI->getProtectedVisibilityAttr();
1753 if (Attr != MCSA_Invalid)
1754 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1757 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1758 /// exactly one predecessor and the control transfer mechanism between
1759 /// the predecessor and this block is a fall-through.
1761 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1762 // If this is a landing pad, it isn't a fall through. If it has no preds,
1763 // then nothing falls through to it.
1764 if (MBB->isLandingPad() || MBB->pred_empty())
1767 // If there isn't exactly one predecessor, it can't be a fall through.
1768 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1770 if (PI2 != MBB->pred_end())
1773 // The predecessor has to be immediately before this block.
1774 const MachineBasicBlock *Pred = *PI;
1776 if (!Pred->isLayoutSuccessor(MBB))
1779 // If the block is completely empty, then it definitely does fall through.
1783 // Otherwise, check the last instruction.
1784 const MachineInstr &LastInst = Pred->back();
1785 return !LastInst.getDesc().isBarrier();
1790 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1791 if (!S->usesMetadata())
1794 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1795 gcp_map_type::iterator GCPI = GCMap.find(S);
1796 if (GCPI != GCMap.end())
1797 return GCPI->second;
1799 const char *Name = S->getName().c_str();
1801 for (GCMetadataPrinterRegistry::iterator
1802 I = GCMetadataPrinterRegistry::begin(),
1803 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1804 if (strcmp(Name, I->getName()) == 0) {
1805 GCMetadataPrinter *GMP = I->instantiate();
1807 GCMap.insert(std::make_pair(S, GMP));
1811 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));