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 "llvm/Assembly/Writer.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Constants.h"
19 #include "llvm/Module.h"
20 #include "llvm/CodeGen/DwarfWriter.h"
21 #include "llvm/CodeGen/GCMetadataPrinter.h"
22 #include "llvm/CodeGen/MachineConstantPool.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineJumpTableInfo.h"
26 #include "llvm/CodeGen/MachineLoopInfo.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/Analysis/ConstantFolding.h"
29 #include "llvm/Analysis/DebugInfo.h"
30 #include "llvm/MC/MCContext.h"
31 #include "llvm/MC/MCExpr.h"
32 #include "llvm/MC/MCInst.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/Target/Mangler.h"
38 #include "llvm/Target/TargetData.h"
39 #include "llvm/Target/TargetInstrInfo.h"
40 #include "llvm/Target/TargetLowering.h"
41 #include "llvm/Target/TargetLoweringObjectFile.h"
42 #include "llvm/Target/TargetOptions.h"
43 #include "llvm/Target/TargetRegisterInfo.h"
44 #include "llvm/ADT/SmallPtrSet.h"
45 #include "llvm/ADT/SmallString.h"
46 #include "llvm/ADT/Statistic.h"
47 #include "llvm/Support/CommandLine.h"
48 #include "llvm/Support/Debug.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/Format.h"
51 #include "llvm/Support/FormattedStream.h"
55 STATISTIC(EmittedInsts, "Number of machine instrs printed");
57 char AsmPrinter::ID = 0;
58 AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
59 MCContext &Ctx, MCStreamer &Streamer,
61 : MachineFunctionPass(&ID), O(o),
62 TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
63 OutContext(Ctx), OutStreamer(Streamer),
64 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0), PrevDLT(NULL) {
66 VerboseAsm = Streamer.isVerboseAsm();
69 AsmPrinter::~AsmPrinter() {
70 for (gcp_iterator I = GCMetadataPrinters.begin(),
71 E = GCMetadataPrinters.end(); I != E; ++I)
78 /// getFunctionNumber - Return a unique ID for the current function.
80 unsigned AsmPrinter::getFunctionNumber() const {
81 return MF->getFunctionNumber();
84 TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
85 return TM.getTargetLowering()->getObjFileLowering();
88 /// getCurrentSection() - Return the current section we are emitting to.
89 const MCSection *AsmPrinter::getCurrentSection() const {
90 return OutStreamer.getCurrentSection();
94 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
96 MachineFunctionPass::getAnalysisUsage(AU);
97 AU.addRequired<GCModuleInfo>();
99 AU.addRequired<MachineLoopInfo>();
102 bool AsmPrinter::doInitialization(Module &M) {
103 // Initialize TargetLoweringObjectFile.
104 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
105 .Initialize(OutContext, TM);
107 Mang = new Mangler(*MAI);
109 // Allow the target to emit any magic that it wants at the start of the file.
110 EmitStartOfAsmFile(M);
112 // Very minimal debug info. It is ignored if we emit actual debug info. If we
113 // don't, this at least helps the user find where a global came from.
114 if (MAI->hasSingleParameterDotFile()) {
116 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
119 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
120 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
121 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
122 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
123 MP->beginAssembly(O, *this, *MAI);
125 if (!M.getModuleInlineAsm().empty())
126 O << MAI->getCommentString() << " Start of file scope inline assembly\n"
127 << M.getModuleInlineAsm()
128 << '\n' << MAI->getCommentString()
129 << " End of file scope inline assembly\n";
131 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
133 MMI->AnalyzeModule(M);
134 DW = getAnalysisIfAvailable<DwarfWriter>();
136 DW->BeginModule(&M, MMI, O, this, MAI);
141 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
142 switch ((GlobalValue::LinkageTypes)Linkage) {
143 case GlobalValue::CommonLinkage:
144 case GlobalValue::LinkOnceAnyLinkage:
145 case GlobalValue::LinkOnceODRLinkage:
146 case GlobalValue::WeakAnyLinkage:
147 case GlobalValue::WeakODRLinkage:
148 case GlobalValue::LinkerPrivateLinkage:
149 if (MAI->getWeakDefDirective() != 0) {
151 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
152 // .weak_definition _foo
153 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
154 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
156 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
157 // FIXME: linkonce should be a section attribute, handled by COFF Section
159 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
161 // FIXME: It would be nice to use .linkonce samesize for non-common
166 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
169 case GlobalValue::DLLExportLinkage:
170 case GlobalValue::AppendingLinkage:
171 // FIXME: appending linkage variables should go into a section of
172 // their name or something. For now, just emit them as external.
173 case GlobalValue::ExternalLinkage:
174 // If external or appending, declare as a global symbol.
176 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
178 case GlobalValue::PrivateLinkage:
179 case GlobalValue::InternalLinkage:
182 llvm_unreachable("Unknown linkage type!");
187 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
188 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
189 if (!GV->hasInitializer()) // External globals require no code.
192 // Check to see if this is a special global used by LLVM, if so, emit it.
193 if (EmitSpecialLLVMGlobal(GV))
196 MCSymbol *GVSym = GetGlobalValueSymbol(GV);
197 EmitVisibility(GVSym, GV->getVisibility());
199 if (MAI->hasDotTypeDotSizeDirective())
200 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
202 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
204 const TargetData *TD = TM.getTargetData();
205 unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
206 unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
208 // Handle common and BSS local symbols (.lcomm).
209 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
210 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
213 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
214 /*PrintType=*/false, GV->getParent());
215 OutStreamer.GetCommentOS() << '\n';
218 // Handle common symbols.
219 if (GVKind.isCommon()) {
221 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
225 // Handle local BSS symbols.
226 if (MAI->hasMachoZeroFillDirective()) {
227 const MCSection *TheSection =
228 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
229 // .zerofill __DATA, __bss, _foo, 400, 5
230 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
234 if (MAI->hasLCOMMDirective()) {
236 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
241 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
243 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
247 const MCSection *TheSection =
248 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
250 // Handle the zerofill directive on darwin, which is a special form of BSS
252 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
254 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
255 // .zerofill __DATA, __common, _foo, 400, 5
256 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
260 OutStreamer.SwitchSection(TheSection);
262 EmitLinkage(GV->getLinkage(), GVSym);
263 EmitAlignment(AlignLog, GV);
266 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
267 /*PrintType=*/false, GV->getParent());
268 OutStreamer.GetCommentOS() << '\n';
270 OutStreamer.EmitLabel(GVSym);
272 EmitGlobalConstant(GV->getInitializer());
274 if (MAI->hasDotTypeDotSizeDirective())
276 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
278 OutStreamer.AddBlankLine();
281 /// EmitFunctionHeader - This method emits the header for the current
283 void AsmPrinter::EmitFunctionHeader() {
284 // Print out constants referenced by the function
287 // Print the 'header' of function.
288 const Function *F = MF->getFunction();
290 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
291 EmitVisibility(CurrentFnSym, F->getVisibility());
293 EmitLinkage(F->getLinkage(), CurrentFnSym);
294 EmitAlignment(MF->getAlignment(), F);
296 if (MAI->hasDotTypeDotSizeDirective())
297 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
300 WriteAsOperand(OutStreamer.GetCommentOS(), F,
301 /*PrintType=*/false, F->getParent());
302 OutStreamer.GetCommentOS() << '\n';
305 // Emit the CurrentFnSym. This is a virtual function to allow targets to
306 // do their wild and crazy things as required.
307 EmitFunctionEntryLabel();
309 // Add some workaround for linkonce linkage on Cygwin\MinGW.
310 if (MAI->getLinkOnceDirective() != 0 &&
311 (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
312 // FIXME: What is this?
313 O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
315 // Emit pre-function debug and/or EH information.
316 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
317 DW->BeginFunction(MF);
320 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
321 /// function. This can be overridden by targets as required to do custom stuff.
322 void AsmPrinter::EmitFunctionEntryLabel() {
323 OutStreamer.EmitLabel(CurrentFnSym);
327 /// EmitComments - Pretty-print comments for instructions.
328 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
329 const MachineFunction *MF = MI.getParent()->getParent();
330 const TargetMachine &TM = MF->getTarget();
332 if (!MI.getDebugLoc().isUnknown()) {
333 DILocation DLT = MF->getDILocation(MI.getDebugLoc());
335 // Print source line info.
336 DIScope Scope = DLT.getScope();
337 // Omit the directory, because it's likely to be long and uninteresting.
339 CommentOS << Scope.getFilename();
341 CommentOS << "<unknown>";
342 CommentOS << ':' << DLT.getLineNumber();
343 if (DLT.getColumnNumber() != 0)
344 CommentOS << ':' << DLT.getColumnNumber();
348 // Check for spills and reloads
351 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
353 // We assume a single instruction only has a spill or reload, not
355 const MachineMemOperand *MMO;
356 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
357 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
358 MMO = *MI.memoperands_begin();
359 CommentOS << MMO->getSize() << "-byte Reload\n";
361 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
362 if (FrameInfo->isSpillSlotObjectIndex(FI))
363 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
364 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
365 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
366 MMO = *MI.memoperands_begin();
367 CommentOS << MMO->getSize() << "-byte Spill\n";
369 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
370 if (FrameInfo->isSpillSlotObjectIndex(FI))
371 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
374 // Check for spill-induced copies
375 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
376 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
377 SrcSubIdx, DstSubIdx)) {
378 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
379 CommentOS << " Reload Reuse\n";
385 /// EmitFunctionBody - This method emits the body and trailer for a
387 void AsmPrinter::EmitFunctionBody() {
388 // Emit target-specific gunk before the function body.
389 EmitFunctionBodyStart();
391 // Print out code for the function.
392 bool HasAnyRealCode = false;
393 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
395 // Print a label for the basic block.
396 EmitBasicBlockStart(I);
397 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
399 // Print the assembly for the instruction.
401 HasAnyRealCode = true;
405 // FIXME: Clean up processDebugLoc.
406 processDebugLoc(II, true);
409 EmitComments(*II, OutStreamer.GetCommentOS());
411 switch (II->getOpcode()) {
412 case TargetOpcode::DBG_LABEL:
413 case TargetOpcode::EH_LABEL:
414 case TargetOpcode::GC_LABEL:
417 case TargetOpcode::INLINEASM:
420 case TargetOpcode::IMPLICIT_DEF:
421 printImplicitDef(II);
423 case TargetOpcode::KILL:
431 // FIXME: Clean up processDebugLoc.
432 processDebugLoc(II, false);
436 // If the function is empty and the object file uses .subsections_via_symbols,
437 // then we need to emit *something* to the function body to prevent the
438 // labels from collapsing together. Just emit a 0 byte.
439 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
440 OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
442 // Emit target-specific gunk after the function body.
443 EmitFunctionBodyEnd();
445 if (MAI->hasDotTypeDotSizeDirective())
446 O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
448 // Emit post-function debug information.
449 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
452 // Print out jump tables referenced by the function.
455 OutStreamer.AddBlankLine();
459 bool AsmPrinter::doFinalization(Module &M) {
460 // Emit global variables.
461 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
463 EmitGlobalVariable(I);
465 // Emit final debug information.
466 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
469 // If the target wants to know about weak references, print them all.
470 if (MAI->getWeakRefDirective()) {
471 // FIXME: This is not lazy, it would be nice to only print weak references
472 // to stuff that is actually used. Note that doing so would require targets
473 // to notice uses in operands (due to constant exprs etc). This should
474 // happen with the MC stuff eventually.
476 // Print out module-level global variables here.
477 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
479 if (!I->hasExternalWeakLinkage()) continue;
480 OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
484 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
485 if (!I->hasExternalWeakLinkage()) continue;
486 OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
491 if (MAI->hasSetDirective()) {
492 OutStreamer.AddBlankLine();
493 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
495 MCSymbol *Name = GetGlobalValueSymbol(I);
497 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
498 MCSymbol *Target = GetGlobalValueSymbol(GV);
500 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
501 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
502 else if (I->hasWeakLinkage())
503 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
505 assert(I->hasLocalLinkage() && "Invalid alias linkage");
507 EmitVisibility(Name, I->getVisibility());
509 // Emit the directives as assignments aka .set:
510 OutStreamer.EmitAssignment(Name,
511 MCSymbolRefExpr::Create(Target, OutContext));
515 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
516 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
517 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
518 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
519 MP->finishAssembly(O, *this, *MAI);
521 // If we don't have any trampolines, then we don't require stack memory
522 // to be executable. Some targets have a directive to declare this.
523 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
524 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
525 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
526 OutStreamer.SwitchSection(S);
528 // Allow the target to emit any magic that it wants at the end of the file,
529 // after everything else has gone out.
532 delete Mang; Mang = 0;
535 OutStreamer.Finish();
539 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
541 // Get the function symbol.
542 CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
545 LI = &getAnalysis<MachineLoopInfo>();
549 // SectionCPs - Keep track the alignment, constpool entries per Section.
553 SmallVector<unsigned, 4> CPEs;
554 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
558 /// EmitConstantPool - Print to the current output stream assembly
559 /// representations of the constants in the constant pool MCP. This is
560 /// used to print out constants which have been "spilled to memory" by
561 /// the code generator.
563 void AsmPrinter::EmitConstantPool() {
564 const MachineConstantPool *MCP = MF->getConstantPool();
565 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
566 if (CP.empty()) return;
568 // Calculate sections for constant pool entries. We collect entries to go into
569 // the same section together to reduce amount of section switch statements.
570 SmallVector<SectionCPs, 4> CPSections;
571 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
572 const MachineConstantPoolEntry &CPE = CP[i];
573 unsigned Align = CPE.getAlignment();
576 switch (CPE.getRelocationInfo()) {
577 default: llvm_unreachable("Unknown section kind");
578 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
580 Kind = SectionKind::getReadOnlyWithRelLocal();
583 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
584 case 4: Kind = SectionKind::getMergeableConst4(); break;
585 case 8: Kind = SectionKind::getMergeableConst8(); break;
586 case 16: Kind = SectionKind::getMergeableConst16();break;
587 default: Kind = SectionKind::getMergeableConst(); break;
591 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
593 // The number of sections are small, just do a linear search from the
594 // last section to the first.
596 unsigned SecIdx = CPSections.size();
597 while (SecIdx != 0) {
598 if (CPSections[--SecIdx].S == S) {
604 SecIdx = CPSections.size();
605 CPSections.push_back(SectionCPs(S, Align));
608 if (Align > CPSections[SecIdx].Alignment)
609 CPSections[SecIdx].Alignment = Align;
610 CPSections[SecIdx].CPEs.push_back(i);
613 // Now print stuff into the calculated sections.
614 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
615 OutStreamer.SwitchSection(CPSections[i].S);
616 EmitAlignment(Log2_32(CPSections[i].Alignment));
619 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
620 unsigned CPI = CPSections[i].CPEs[j];
621 MachineConstantPoolEntry CPE = CP[CPI];
623 // Emit inter-object padding for alignment.
624 unsigned AlignMask = CPE.getAlignment() - 1;
625 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
626 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
628 const Type *Ty = CPE.getType();
629 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
631 // Emit the label with a comment on it.
633 OutStreamer.GetCommentOS() << "constant pool ";
634 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
635 MF->getFunction()->getParent());
636 OutStreamer.GetCommentOS() << '\n';
638 OutStreamer.EmitLabel(GetCPISymbol(CPI));
640 if (CPE.isMachineConstantPoolEntry())
641 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
643 EmitGlobalConstant(CPE.Val.ConstVal);
648 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
649 /// by the current function to the current output stream.
651 void AsmPrinter::EmitJumpTableInfo() {
652 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
653 if (MJTI == 0) return;
654 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
655 if (JT.empty()) return;
657 // Pick the directive to use to print the jump table entries, and switch to
658 // the appropriate section.
659 const Function *F = MF->getFunction();
660 bool JTInDiffSection = false;
661 if (// In PIC mode, we need to emit the jump table to the same section as the
662 // function body itself, otherwise the label differences won't make sense.
663 // FIXME: Need a better predicate for this: what about custom entries?
664 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
665 // We should also do if the section name is NULL or function is declared
666 // in discardable section
667 // FIXME: this isn't the right predicate, should be based on the MCSection
669 F->isWeakForLinker()) {
670 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
672 // Otherwise, drop it in the readonly section.
673 const MCSection *ReadOnlySection =
674 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
675 OutStreamer.SwitchSection(ReadOnlySection);
676 JTInDiffSection = true;
679 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
681 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
682 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
684 // If this jump table was deleted, ignore it.
685 if (JTBBs.empty()) continue;
687 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
688 // .set directive for each unique entry. This reduces the number of
689 // relocations the assembler will generate for the jump table.
690 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
691 MAI->hasSetDirective()) {
692 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
693 const TargetLowering *TLI = TM.getTargetLowering();
694 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
695 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
696 const MachineBasicBlock *MBB = JTBBs[ii];
697 if (!EmittedSets.insert(MBB)) continue;
699 // .set LJTSet, LBB32-base
701 MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
702 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
703 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
707 // On some targets (e.g. Darwin) we want to emit two consequtive labels
708 // before each jump table. The first label is never referenced, but tells
709 // the assembler and linker the extents of the jump table object. The
710 // second label is actually referenced by the code.
711 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
712 // FIXME: This doesn't have to have any specific name, just any randomly
713 // named and numbered 'l' label would work. Simplify GetJTISymbol.
714 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
716 OutStreamer.EmitLabel(GetJTISymbol(JTI));
718 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
719 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
723 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
725 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
726 const MachineBasicBlock *MBB,
727 unsigned UID) const {
728 const MCExpr *Value = 0;
729 switch (MJTI->getEntryKind()) {
730 case MachineJumpTableInfo::EK_Custom32:
731 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
734 case MachineJumpTableInfo::EK_BlockAddress:
735 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
737 Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
739 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
740 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
741 // with a relocation as gp-relative, e.g.:
743 MCSymbol *MBBSym = MBB->getSymbol(OutContext);
744 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
748 case MachineJumpTableInfo::EK_LabelDifference32: {
749 // EK_LabelDifference32 - Each entry is the address of the block minus
750 // the address of the jump table. This is used for PIC jump tables where
751 // gprel32 is not supported. e.g.:
752 // .word LBB123 - LJTI1_2
753 // If the .set directive is supported, this is emitted as:
754 // .set L4_5_set_123, LBB123 - LJTI1_2
755 // .word L4_5_set_123
757 // If we have emitted set directives for the jump table entries, print
758 // them rather than the entries themselves. If we're emitting PIC, then
759 // emit the table entries as differences between two text section labels.
760 if (MAI->hasSetDirective()) {
761 // If we used .set, reference the .set's symbol.
762 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
766 // Otherwise, use the difference as the jump table entry.
767 Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
768 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
769 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
774 assert(Value && "Unknown entry kind!");
776 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
777 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
781 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
782 /// special global used by LLVM. If so, emit it and return true, otherwise
783 /// do nothing and return false.
784 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
785 if (GV->getName() == "llvm.used") {
786 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
787 EmitLLVMUsedList(GV->getInitializer());
791 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
792 if (GV->getSection() == "llvm.metadata" ||
793 GV->hasAvailableExternallyLinkage())
796 if (!GV->hasAppendingLinkage()) return false;
798 assert(GV->hasInitializer() && "Not a special LLVM global!");
800 const TargetData *TD = TM.getTargetData();
801 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
802 if (GV->getName() == "llvm.global_ctors") {
803 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
804 EmitAlignment(Align, 0);
805 EmitXXStructorList(GV->getInitializer());
807 if (TM.getRelocationModel() == Reloc::Static &&
808 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
809 StringRef Sym(".constructors_used");
810 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
816 if (GV->getName() == "llvm.global_dtors") {
817 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
818 EmitAlignment(Align, 0);
819 EmitXXStructorList(GV->getInitializer());
821 if (TM.getRelocationModel() == Reloc::Static &&
822 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
823 StringRef Sym(".destructors_used");
824 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
833 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
834 /// global in the specified llvm.used list for which emitUsedDirectiveFor
835 /// is true, as being used with this directive.
836 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
837 // Should be an array of 'i8*'.
838 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
839 if (InitList == 0) return;
841 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
842 const GlobalValue *GV =
843 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
844 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
845 OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
850 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
851 /// function pointers, ignoring the init priority.
852 void AsmPrinter::EmitXXStructorList(Constant *List) {
853 // Should be an array of '{ int, void ()* }' structs. The first value is the
854 // init priority, which we ignore.
855 if (!isa<ConstantArray>(List)) return;
856 ConstantArray *InitList = cast<ConstantArray>(List);
857 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
858 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
859 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
861 if (CS->getOperand(1)->isNullValue())
862 return; // Found a null terminator, exit printing.
863 // Emit the function pointer.
864 EmitGlobalConstant(CS->getOperand(1));
868 //===--------------------------------------------------------------------===//
869 // Emission and print routines
872 /// EmitInt8 - Emit a byte directive and value.
874 void AsmPrinter::EmitInt8(int Value) const {
875 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
878 /// EmitInt16 - Emit a short directive and value.
880 void AsmPrinter::EmitInt16(int Value) const {
881 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
884 /// EmitInt32 - Emit a long directive and value.
886 void AsmPrinter::EmitInt32(int Value) const {
887 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
890 /// EmitInt64 - Emit a long long directive and value.
892 void AsmPrinter::EmitInt64(uint64_t Value) const {
893 OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
896 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
897 /// in bytes of the directive is specified by Size and Hi/Lo specify the
898 /// labels. This implicitly uses .set if it is available.
899 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
900 unsigned Size) const {
901 // Get the Hi-Lo expression.
903 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
904 MCSymbolRefExpr::Create(Lo, OutContext),
907 if (!MAI->hasSetDirective()) {
908 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
912 // Otherwise, emit with .set (aka assignment).
914 OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
915 "set" + Twine(SetCounter++));
916 OutStreamer.EmitAssignment(SetLabel, Diff);
917 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
921 //===----------------------------------------------------------------------===//
923 // EmitAlignment - Emit an alignment directive to the specified power of
924 // two boundary. For example, if you pass in 3 here, you will get an 8
925 // byte alignment. If a global value is specified, and if that global has
926 // an explicit alignment requested, it will unconditionally override the
927 // alignment request. However, if ForcedAlignBits is specified, this value
928 // has final say: the ultimate alignment will be the max of ForcedAlignBits
929 // and the alignment computed with NumBits and the global.
933 // if (GV && GV->hasalignment) Align = GV->getalignment();
934 // Align = std::max(Align, ForcedAlignBits);
936 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
937 unsigned ForcedAlignBits,
938 bool UseFillExpr) const {
939 if (GV && GV->getAlignment())
940 NumBits = Log2_32(GV->getAlignment());
941 NumBits = std::max(NumBits, ForcedAlignBits);
943 if (NumBits == 0) return; // No need to emit alignment.
945 if (getCurrentSection()->getKind().isText())
946 OutStreamer.EmitCodeAlignment(1 << NumBits);
948 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
951 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
953 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
954 MCContext &Ctx = AP.OutContext;
956 if (CV->isNullValue() || isa<UndefValue>(CV))
957 return MCConstantExpr::Create(0, Ctx);
959 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
960 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
962 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
963 return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
964 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
965 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
967 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
969 llvm_unreachable("Unknown constant value to lower!");
970 return MCConstantExpr::Create(0, Ctx);
973 switch (CE->getOpcode()) {
975 // If the code isn't optimized, there may be outstanding folding
976 // opportunities. Attempt to fold the expression using TargetData as a
977 // last resort before giving up.
979 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
981 return LowerConstant(C, AP);
985 llvm_unreachable("FIXME: Don't support this constant expr");
986 case Instruction::GetElementPtr: {
987 const TargetData &TD = *AP.TM.getTargetData();
988 // Generate a symbolic expression for the byte address
989 const Constant *PtrVal = CE->getOperand(0);
990 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
991 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
994 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
998 // Truncate/sext the offset to the pointer size.
999 if (TD.getPointerSizeInBits() != 64) {
1000 int SExtAmount = 64-TD.getPointerSizeInBits();
1001 Offset = (Offset << SExtAmount) >> SExtAmount;
1004 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1008 case Instruction::Trunc:
1009 // We emit the value and depend on the assembler to truncate the generated
1010 // expression properly. This is important for differences between
1011 // blockaddress labels. Since the two labels are in the same function, it
1012 // is reasonable to treat their delta as a 32-bit value.
1014 case Instruction::BitCast:
1015 return LowerConstant(CE->getOperand(0), AP);
1017 case Instruction::IntToPtr: {
1018 const TargetData &TD = *AP.TM.getTargetData();
1019 // Handle casts to pointers by changing them into casts to the appropriate
1020 // integer type. This promotes constant folding and simplifies this code.
1021 Constant *Op = CE->getOperand(0);
1022 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1024 return LowerConstant(Op, AP);
1027 case Instruction::PtrToInt: {
1028 const TargetData &TD = *AP.TM.getTargetData();
1029 // Support only foldable casts to/from pointers that can be eliminated by
1030 // changing the pointer to the appropriately sized integer type.
1031 Constant *Op = CE->getOperand(0);
1032 const Type *Ty = CE->getType();
1034 const MCExpr *OpExpr = LowerConstant(Op, AP);
1036 // We can emit the pointer value into this slot if the slot is an
1037 // integer slot equal to the size of the pointer.
1038 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1041 // Otherwise the pointer is smaller than the resultant integer, mask off
1042 // the high bits so we are sure to get a proper truncation if the input is
1044 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1045 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1046 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1049 // The MC library also has a right-shift operator, but it isn't consistently
1050 // signed or unsigned between different targets.
1051 case Instruction::Add:
1052 case Instruction::Sub:
1053 case Instruction::Mul:
1054 case Instruction::SDiv:
1055 case Instruction::SRem:
1056 case Instruction::Shl:
1057 case Instruction::And:
1058 case Instruction::Or:
1059 case Instruction::Xor: {
1060 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1061 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1062 switch (CE->getOpcode()) {
1063 default: llvm_unreachable("Unknown binary operator constant cast expr");
1064 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1065 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1066 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1067 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1068 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1069 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1070 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1071 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1072 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1078 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1080 if (AddrSpace != 0 || !CA->isString()) {
1081 // Not a string. Print the values in successive locations
1082 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1083 AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1087 // Otherwise, it can be emitted as .ascii.
1088 SmallVector<char, 128> TmpVec;
1089 TmpVec.reserve(CA->getNumOperands());
1090 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1091 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1093 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1096 static void EmitGlobalConstantVector(const ConstantVector *CV,
1097 unsigned AddrSpace, AsmPrinter &AP) {
1098 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1099 AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1102 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1103 unsigned AddrSpace, AsmPrinter &AP) {
1104 // Print the fields in successive locations. Pad to align if needed!
1105 const TargetData *TD = AP.TM.getTargetData();
1106 unsigned Size = TD->getTypeAllocSize(CS->getType());
1107 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1108 uint64_t SizeSoFar = 0;
1109 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1110 const Constant *Field = CS->getOperand(i);
1112 // Check if padding is needed and insert one or more 0s.
1113 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1114 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1115 - Layout->getElementOffset(i)) - FieldSize;
1116 SizeSoFar += FieldSize + PadSize;
1118 // Now print the actual field value.
1119 AP.EmitGlobalConstant(Field, AddrSpace);
1121 // Insert padding - this may include padding to increase the size of the
1122 // current field up to the ABI size (if the struct is not packed) as well
1123 // as padding to ensure that the next field starts at the right offset.
1124 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1126 assert(SizeSoFar == Layout->getSizeInBytes() &&
1127 "Layout of constant struct may be incorrect!");
1130 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1132 // FP Constants are printed as integer constants to avoid losing
1134 if (CFP->getType()->isDoubleTy()) {
1135 if (AP.VerboseAsm) {
1136 double Val = CFP->getValueAPF().convertToDouble();
1137 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1140 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1141 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1145 if (CFP->getType()->isFloatTy()) {
1146 if (AP.VerboseAsm) {
1147 float Val = CFP->getValueAPF().convertToFloat();
1148 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1150 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1151 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1155 if (CFP->getType()->isX86_FP80Ty()) {
1156 // all long double variants are printed as hex
1157 // api needed to prevent premature destruction
1158 APInt API = CFP->getValueAPF().bitcastToAPInt();
1159 const uint64_t *p = API.getRawData();
1160 if (AP.VerboseAsm) {
1161 // Convert to double so we can print the approximate val as a comment.
1162 APFloat DoubleVal = CFP->getValueAPF();
1164 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1166 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1167 << DoubleVal.convertToDouble() << '\n';
1170 if (AP.TM.getTargetData()->isBigEndian()) {
1171 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1172 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1174 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1175 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1178 // Emit the tail padding for the long double.
1179 const TargetData &TD = *AP.TM.getTargetData();
1180 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1181 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1185 assert(CFP->getType()->isPPC_FP128Ty() &&
1186 "Floating point constant type not handled");
1187 // All long double variants are printed as hex api needed to prevent
1188 // premature destruction.
1189 APInt API = CFP->getValueAPF().bitcastToAPInt();
1190 const uint64_t *p = API.getRawData();
1191 if (AP.TM.getTargetData()->isBigEndian()) {
1192 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1193 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1195 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1196 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1200 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1201 unsigned AddrSpace, AsmPrinter &AP) {
1202 const TargetData *TD = AP.TM.getTargetData();
1203 unsigned BitWidth = CI->getBitWidth();
1204 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1206 // We don't expect assemblers to support integer data directives
1207 // for more than 64 bits, so we emit the data in at most 64-bit
1208 // quantities at a time.
1209 const uint64_t *RawData = CI->getValue().getRawData();
1210 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1211 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1212 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1216 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1217 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1218 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1219 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1220 if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1221 return OutStreamer.EmitZeros(Size, AddrSpace);
1224 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1225 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1232 OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1233 OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1236 EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1241 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1242 return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1244 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1245 return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1247 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1248 return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1250 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1251 return EmitGlobalConstantVector(V, AddrSpace, *this);
1253 if (isa<ConstantPointerNull>(CV)) {
1254 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1255 OutStreamer.EmitIntValue(0, Size, AddrSpace);
1259 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1260 // thread the streamer with EmitValue.
1261 OutStreamer.EmitValue(LowerConstant(CV, *this),
1262 TM.getTargetData()->getTypeAllocSize(CV->getType()),
1266 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1267 // Target doesn't support this yet!
1268 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1271 /// PrintSpecial - Print information related to the specified machine instr
1272 /// that is independent of the operand, and may be independent of the instr
1273 /// itself. This can be useful for portably encoding the comment character
1274 /// or other bits of target-specific knowledge into the asmstrings. The
1275 /// syntax used is ${:comment}. Targets can override this to add support
1276 /// for their own strange codes.
1277 void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1278 if (!strcmp(Code, "private")) {
1279 O << MAI->getPrivateGlobalPrefix();
1280 } else if (!strcmp(Code, "comment")) {
1282 O << MAI->getCommentString();
1283 } else if (!strcmp(Code, "uid")) {
1284 // Comparing the address of MI isn't sufficient, because machineinstrs may
1285 // be allocated to the same address across functions.
1286 const Function *ThisF = MI->getParent()->getParent()->getFunction();
1288 // If this is a new LastFn instruction, bump the counter.
1289 if (LastMI != MI || LastFn != ThisF) {
1297 raw_string_ostream Msg(msg);
1298 Msg << "Unknown special formatter '" << Code
1299 << "' for machine instr: " << *MI;
1300 llvm_report_error(Msg.str());
1304 /// processDebugLoc - Processes the debug information of each machine
1305 /// instruction's DebugLoc.
1306 void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1307 bool BeforePrintingInsn) {
1308 if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1309 || !DW->ShouldEmitDwarfDebug())
1311 DebugLoc DL = MI->getDebugLoc();
1314 DILocation CurDLT = MF->getDILocation(DL);
1315 if (!CurDLT.getScope().Verify())
1318 if (!BeforePrintingInsn) {
1319 // After printing instruction
1321 } else if (CurDLT.getNode() != PrevDLT) {
1322 MCSymbol *L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1323 CurDLT.getColumnNumber(),
1324 CurDLT.getScope().getNode());
1325 DW->BeginScope(MI, L);
1326 PrevDLT = CurDLT.getNode();
1331 /// printInlineAsm - This method formats and prints the specified machine
1332 /// instruction that is an inline asm.
1333 void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1334 unsigned NumOperands = MI->getNumOperands();
1336 // Count the number of register definitions.
1337 unsigned NumDefs = 0;
1338 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1340 assert(NumDefs != NumOperands-1 && "No asm string?");
1342 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1344 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1345 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1349 // If this asmstr is empty, just print the #APP/#NOAPP markers.
1350 // These are useful to see where empty asm's wound up.
1351 if (AsmStr[0] == 0) {
1352 O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1353 O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1357 O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1359 // The variant of the current asmprinter.
1360 int AsmPrinterVariant = MAI->getAssemblerDialect();
1362 int CurVariant = -1; // The number of the {.|.|.} region we are in.
1363 const char *LastEmitted = AsmStr; // One past the last character emitted.
1365 while (*LastEmitted) {
1366 switch (*LastEmitted) {
1368 // Not a special case, emit the string section literally.
1369 const char *LiteralEnd = LastEmitted+1;
1370 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1371 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1373 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1374 O.write(LastEmitted, LiteralEnd-LastEmitted);
1375 LastEmitted = LiteralEnd;
1379 ++LastEmitted; // Consume newline character.
1380 O << '\n'; // Indent code with newline.
1383 ++LastEmitted; // Consume '$' character.
1387 switch (*LastEmitted) {
1388 default: Done = false; break;
1389 case '$': // $$ -> $
1390 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1392 ++LastEmitted; // Consume second '$' character.
1394 case '(': // $( -> same as GCC's { character.
1395 ++LastEmitted; // Consume '(' character.
1396 if (CurVariant != -1) {
1397 llvm_report_error("Nested variants found in inline asm string: '"
1398 + std::string(AsmStr) + "'");
1400 CurVariant = 0; // We're in the first variant now.
1403 ++LastEmitted; // consume '|' character.
1404 if (CurVariant == -1)
1405 O << '|'; // this is gcc's behavior for | outside a variant
1407 ++CurVariant; // We're in the next variant.
1409 case ')': // $) -> same as GCC's } char.
1410 ++LastEmitted; // consume ')' character.
1411 if (CurVariant == -1)
1412 O << '}'; // this is gcc's behavior for } outside a variant
1419 bool HasCurlyBraces = false;
1420 if (*LastEmitted == '{') { // ${variable}
1421 ++LastEmitted; // Consume '{' character.
1422 HasCurlyBraces = true;
1425 // If we have ${:foo}, then this is not a real operand reference, it is a
1426 // "magic" string reference, just like in .td files. Arrange to call
1428 if (HasCurlyBraces && *LastEmitted == ':') {
1430 const char *StrStart = LastEmitted;
1431 const char *StrEnd = strchr(StrStart, '}');
1433 llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1434 + std::string(AsmStr) + "'");
1437 std::string Val(StrStart, StrEnd);
1438 PrintSpecial(MI, Val.c_str());
1439 LastEmitted = StrEnd+1;
1443 const char *IDStart = LastEmitted;
1446 long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1447 if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1448 llvm_report_error("Bad $ operand number in inline asm string: '"
1449 + std::string(AsmStr) + "'");
1451 LastEmitted = IDEnd;
1453 char Modifier[2] = { 0, 0 };
1455 if (HasCurlyBraces) {
1456 // If we have curly braces, check for a modifier character. This
1457 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1458 if (*LastEmitted == ':') {
1459 ++LastEmitted; // Consume ':' character.
1460 if (*LastEmitted == 0) {
1461 llvm_report_error("Bad ${:} expression in inline asm string: '"
1462 + std::string(AsmStr) + "'");
1465 Modifier[0] = *LastEmitted;
1466 ++LastEmitted; // Consume modifier character.
1469 if (*LastEmitted != '}') {
1470 llvm_report_error("Bad ${} expression in inline asm string: '"
1471 + std::string(AsmStr) + "'");
1473 ++LastEmitted; // Consume '}' character.
1476 if ((unsigned)Val >= NumOperands-1) {
1477 llvm_report_error("Invalid $ operand number in inline asm string: '"
1478 + std::string(AsmStr) + "'");
1481 // Okay, we finally have a value number. Ask the target to print this
1483 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1488 // Scan to find the machine operand number for the operand.
1489 for (; Val; --Val) {
1490 if (OpNo >= MI->getNumOperands()) break;
1491 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1492 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1495 if (OpNo >= MI->getNumOperands()) {
1498 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1499 ++OpNo; // Skip over the ID number.
1501 if (Modifier[0] == 'l') // labels are target independent
1502 O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1504 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1505 if ((OpFlags & 7) == 4) {
1506 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1507 Modifier[0] ? Modifier : 0);
1509 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1510 Modifier[0] ? Modifier : 0);
1516 raw_string_ostream Msg(msg);
1517 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1519 llvm_report_error(Msg.str());
1526 O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1527 OutStreamer.AddBlankLine();
1530 /// printImplicitDef - This method prints the specified machine instruction
1531 /// that is an implicit def.
1532 void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1533 if (!VerboseAsm) return;
1534 O.PadToColumn(MAI->getCommentColumn());
1535 O << MAI->getCommentString() << " implicit-def: "
1536 << TRI->getName(MI->getOperand(0).getReg());
1537 OutStreamer.AddBlankLine();
1540 void AsmPrinter::printKill(const MachineInstr *MI) const {
1541 if (!VerboseAsm) return;
1542 O.PadToColumn(MAI->getCommentColumn());
1543 O << MAI->getCommentString() << " kill:";
1544 for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1545 const MachineOperand &op = MI->getOperand(n);
1546 assert(op.isReg() && "KILL instruction must have only register operands");
1547 O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1549 OutStreamer.AddBlankLine();
1552 /// printLabel - This method prints a local label used by debug and
1553 /// exception handling tables.
1554 void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1556 OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1557 "label" + Twine(MI->getOperand(0).getImm()));
1558 OutStreamer.EmitLabel(Sym);
1561 void AsmPrinter::printLabel(unsigned Id) const {
1563 OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1564 "label" + Twine(Id));
1565 OutStreamer.EmitLabel(Sym);
1568 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1569 /// instruction, using the specified assembler variant. Targets should
1570 /// override this to format as appropriate.
1571 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1572 unsigned AsmVariant, const char *ExtraCode) {
1573 // Target doesn't support this yet!
1577 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1578 unsigned AsmVariant,
1579 const char *ExtraCode) {
1580 // Target doesn't support this yet!
1584 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1585 return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock());
1588 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1589 const BasicBlock *BB) const {
1590 assert(BB->hasName() &&
1591 "Address of anonymous basic block not supported yet!");
1593 // This code must use the function name itself, and not the function number,
1594 // since it must be possible to generate the label name from within other
1596 SmallString<60> FnName;
1597 Mang->getNameWithPrefix(FnName, F, false);
1599 // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1600 SmallString<60> NameResult;
1601 Mang->getNameWithPrefix(NameResult,
1602 StringRef("BA") + Twine((unsigned)FnName.size()) +
1603 "_" + FnName.str() + "_" + BB->getName(),
1606 return OutContext.GetOrCreateTemporarySymbol(NameResult.str());
1609 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1610 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1611 return OutContext.GetOrCreateTemporarySymbol
1612 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1613 + "_" + Twine(CPID));
1616 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1617 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1618 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1621 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1622 /// FIXME: privatize to AsmPrinter.
1623 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1624 return OutContext.GetOrCreateTemporarySymbol
1625 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1626 Twine(UID) + "_set_" + Twine(MBBID));
1629 /// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1631 MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1632 SmallString<60> NameStr;
1633 Mang->getNameWithPrefix(NameStr, GV, false);
1635 if (!GV->hasPrivateLinkage())
1636 return OutContext.GetOrCreateSymbol(NameStr.str());
1637 return OutContext.GetOrCreateTemporarySymbol(NameStr.str());
1640 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1641 /// global value name as its base, with the specified suffix, and where the
1642 /// symbol is forced to have private linkage if ForcePrivate is true.
1643 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1645 bool ForcePrivate) const {
1646 SmallString<60> NameStr;
1647 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1648 NameStr.append(Suffix.begin(), Suffix.end());
1649 if (!GV->hasPrivateLinkage() && !ForcePrivate)
1650 return OutContext.GetOrCreateSymbol(NameStr.str());
1651 return OutContext.GetOrCreateTemporarySymbol(NameStr.str());
1654 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1656 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1657 SmallString<60> NameStr;
1658 Mang->getNameWithPrefix(NameStr, Sym);
1659 return OutContext.GetOrCreateSymbol(NameStr.str());
1664 /// PrintParentLoopComment - Print comments about parent loops of this one.
1665 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1666 unsigned FunctionNumber) {
1667 if (Loop == 0) return;
1668 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1669 OS.indent(Loop->getLoopDepth()*2)
1670 << "Parent Loop BB" << FunctionNumber << "_"
1671 << Loop->getHeader()->getNumber()
1672 << " Depth=" << Loop->getLoopDepth() << '\n';
1676 /// PrintChildLoopComment - Print comments about child loops within
1677 /// the loop for this basic block, with nesting.
1678 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1679 unsigned FunctionNumber) {
1680 // Add child loop information
1681 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1682 OS.indent((*CL)->getLoopDepth()*2)
1683 << "Child Loop BB" << FunctionNumber << "_"
1684 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1686 PrintChildLoopComment(OS, *CL, FunctionNumber);
1690 /// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1691 static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1692 const MachineLoopInfo *LI,
1693 const AsmPrinter &AP) {
1694 // Add loop depth information
1695 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1696 if (Loop == 0) return;
1698 MachineBasicBlock *Header = Loop->getHeader();
1699 assert(Header && "No header for loop");
1701 // If this block is not a loop header, just print out what is the loop header
1703 if (Header != &MBB) {
1704 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1705 Twine(AP.getFunctionNumber())+"_" +
1706 Twine(Loop->getHeader()->getNumber())+
1707 " Depth="+Twine(Loop->getLoopDepth()));
1711 // Otherwise, it is a loop header. Print out information about child and
1713 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1715 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1718 OS.indent(Loop->getLoopDepth()*2-2);
1723 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1725 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1729 /// EmitBasicBlockStart - This method prints the label for the specified
1730 /// MachineBasicBlock, an alignment (if present) and a comment describing
1731 /// it if appropriate.
1732 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1733 // Emit an alignment directive for this block, if needed.
1734 if (unsigned Align = MBB->getAlignment())
1735 EmitAlignment(Log2_32(Align));
1737 // If the block has its address taken, emit a special label to satisfy
1738 // references to the block. This is done so that we don't need to
1739 // remember the number of this label, and so that we can make
1740 // forward references to labels without knowing what their numbers
1742 if (MBB->hasAddressTaken()) {
1743 const BasicBlock *BB = MBB->getBasicBlock();
1745 OutStreamer.AddComment("Address Taken");
1746 OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1749 // Print the main label for the block.
1750 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1752 // NOTE: Want this comment at start of line.
1753 O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1754 if (const BasicBlock *BB = MBB->getBasicBlock())
1756 OutStreamer.AddComment("%" + BB->getName());
1758 PrintBasicBlockLoopComments(*MBB, LI, *this);
1759 OutStreamer.AddBlankLine();
1763 if (const BasicBlock *BB = MBB->getBasicBlock())
1765 OutStreamer.AddComment("%" + BB->getName());
1766 PrintBasicBlockLoopComments(*MBB, LI, *this);
1769 OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1773 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1774 MCSymbolAttr Attr = MCSA_Invalid;
1776 switch (Visibility) {
1778 case GlobalValue::HiddenVisibility:
1779 Attr = MAI->getHiddenVisibilityAttr();
1781 case GlobalValue::ProtectedVisibility:
1782 Attr = MAI->getProtectedVisibilityAttr();
1786 if (Attr != MCSA_Invalid)
1787 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1790 void AsmPrinter::printOffset(int64_t Offset) const {
1793 else if (Offset < 0)
1797 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1798 /// exactly one predecessor and the control transfer mechanism between
1799 /// the predecessor and this block is a fall-through.
1800 bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1802 // If this is a landing pad, it isn't a fall through. If it has no preds,
1803 // then nothing falls through to it.
1804 if (MBB->isLandingPad() || MBB->pred_empty())
1807 // If there isn't exactly one predecessor, it can't be a fall through.
1808 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1810 if (PI2 != MBB->pred_end())
1813 // The predecessor has to be immediately before this block.
1814 const MachineBasicBlock *Pred = *PI;
1816 if (!Pred->isLayoutSuccessor(MBB))
1819 // If the block is completely empty, then it definitely does fall through.
1823 // Otherwise, check the last instruction.
1824 const MachineInstr &LastInst = Pred->back();
1825 return !LastInst.getDesc().isBarrier();
1830 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1831 if (!S->usesMetadata())
1834 gcp_iterator GCPI = GCMetadataPrinters.find(S);
1835 if (GCPI != GCMetadataPrinters.end())
1836 return GCPI->second;
1838 const char *Name = S->getName().c_str();
1840 for (GCMetadataPrinterRegistry::iterator
1841 I = GCMetadataPrinterRegistry::begin(),
1842 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1843 if (strcmp(Name, I->getName()) == 0) {
1844 GCMetadataPrinter *GMP = I->instantiate();
1846 GCMetadataPrinters.insert(std::make_pair(S, GMP));
1850 llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));