1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the AsmPrinter class.
11 //
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/Assembly/Writer.h"
22 #include "llvm/CodeGen/GCMetadataPrinter.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineJumpTableInfo.h"
27 #include "llvm/CodeGen/MachineLoopInfo.h"
28 #include "llvm/CodeGen/MachineModuleInfo.h"
29 #include "llvm/DebugInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/Operator.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/MC/MCContext.h"
35 #include "llvm/MC/MCExpr.h"
36 #include "llvm/MC/MCInst.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/Format.h"
42 #include "llvm/Support/MathExtras.h"
43 #include "llvm/Support/Timer.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetInstrInfo.h"
46 #include "llvm/Target/TargetLowering.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetOptions.h"
49 #include "llvm/Target/TargetRegisterInfo.h"
50 using namespace llvm;
52 static const char *DWARFGroupName = "DWARF Emission";
53 static const char *DbgTimerName = "DWARF Debug Writer";
54 static const char *EHTimerName = "DWARF Exception Writer";
56 STATISTIC(EmittedInsts, "Number of machine instrs printed");
58 char AsmPrinter::ID = 0;
60 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
61 static gcp_map_type &getGCMap(void *&P) {
62 if (P == 0)
63 P = new gcp_map_type();
64 return *(gcp_map_type*)P;
65 }
68 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
69 /// value in log2 form. This rounds up to the preferred alignment if possible
70 /// and legal.
71 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
72 unsigned InBits = 0) {
73 unsigned NumBits = 0;
74 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
75 NumBits = TD.getPreferredAlignmentLog(GVar);
77 // If InBits is specified, round it to it.
78 if (InBits > NumBits)
79 NumBits = InBits;
81 // If the GV has a specified alignment, take it into account.
82 if (GV->getAlignment() == 0)
83 return NumBits;
85 unsigned GVAlign = Log2_32(GV->getAlignment());
87 // If the GVAlign is larger than NumBits, or if we are required to obey
88 // NumBits because the GV has an assigned section, obey it.
89 if (GVAlign > NumBits || GV->hasSection())
90 NumBits = GVAlign;
91 return NumBits;
92 }
94 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
95 : MachineFunctionPass(ID),
96 TM(tm), MAI(tm.getMCAsmInfo()),
97 OutContext(Streamer.getContext()),
98 OutStreamer(Streamer),
99 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
100 DD = 0; DE = 0; MMI = 0; LI = 0;
101 CurrentFnSym = CurrentFnSymForSize = 0;
102 GCMetadataPrinters = 0;
103 VerboseAsm = Streamer.isVerboseAsm();
104 }
106 AsmPrinter::~AsmPrinter() {
107 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
109 if (GCMetadataPrinters != 0) {
110 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
112 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
113 delete I->second;
114 delete &GCMap;
115 GCMetadataPrinters = 0;
116 }
118 delete &OutStreamer;
119 }
121 /// getFunctionNumber - Return a unique ID for the current function.
122 ///
123 unsigned AsmPrinter::getFunctionNumber() const {
124 return MF->getFunctionNumber();
125 }
127 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
128 return TM.getTargetLowering()->getObjFileLowering();
129 }
131 /// getDataLayout - Return information about data layout.
132 const DataLayout &AsmPrinter::getDataLayout() const {
133 return *TM.getDataLayout();
134 }
136 /// getCurrentSection() - Return the current section we are emitting to.
137 const MCSection *AsmPrinter::getCurrentSection() const {
138 return OutStreamer.getCurrentSection().first;
139 }
143 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
144 AU.setPreservesAll();
145 MachineFunctionPass::getAnalysisUsage(AU);
146 AU.addRequired<MachineModuleInfo>();
147 AU.addRequired<GCModuleInfo>();
148 if (isVerbose())
149 AU.addRequired<MachineLoopInfo>();
150 }
152 bool AsmPrinter::doInitialization(Module &M) {
153 OutStreamer.InitStreamer();
155 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
156 MMI->AnalyzeModule(M);
158 // Initialize TargetLoweringObjectFile.
159 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
160 .Initialize(OutContext, TM);
162 Mang = new Mangler(OutContext, *TM.getDataLayout());
164 // Allow the target to emit any magic that it wants at the start of the file.
165 EmitStartOfAsmFile(M);
167 // Very minimal debug info. It is ignored if we emit actual debug info. If we
168 // don't, this at least helps the user find where a global came from.
169 if (MAI->hasSingleParameterDotFile()) {
170 // .file "foo.c"
171 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
172 }
174 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
175 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
176 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
177 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
178 MP->beginAssembly(*this);
180 // Emit module-level inline asm if it exists.
181 if (!M.getModuleInlineAsm().empty()) {
182 OutStreamer.AddComment("Start of file scope inline assembly");
183 OutStreamer.AddBlankLine();
184 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
185 OutStreamer.AddComment("End of file scope inline assembly");
186 OutStreamer.AddBlankLine();
187 }
189 if (MAI->doesSupportDebugInformation())
190 DD = new DwarfDebug(this, &M);
192 switch (MAI->getExceptionHandlingType()) {
193 case ExceptionHandling::None:
194 return false;
195 case ExceptionHandling::SjLj:
196 case ExceptionHandling::DwarfCFI:
197 DE = new DwarfCFIException(this);
198 return false;
199 case ExceptionHandling::ARM:
200 DE = new ARMException(this);
201 return false;
202 case ExceptionHandling::Win64:
203 DE = new Win64Exception(this);
204 return false;
205 }
207 llvm_unreachable("Unknown exception type.");
208 }
210 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
211 switch ((GlobalValue::LinkageTypes)Linkage) {
212 case GlobalValue::CommonLinkage:
213 case GlobalValue::LinkOnceAnyLinkage:
214 case GlobalValue::LinkOnceODRLinkage:
215 case GlobalValue::LinkOnceODRAutoHideLinkage:
216 case GlobalValue::WeakAnyLinkage:
217 case GlobalValue::WeakODRLinkage:
218 case GlobalValue::LinkerPrivateWeakLinkage:
219 if (MAI->getWeakDefDirective() != 0) {
220 // .globl _foo
221 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
223 if ((GlobalValue::LinkageTypes)Linkage !=
224 GlobalValue::LinkOnceODRAutoHideLinkage)
225 // .weak_definition _foo
226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
227 else
228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
229 } else if (MAI->getLinkOnceDirective() != 0) {
230 // .globl _foo
231 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
232 //NOTE: linkonce is handled by the section the symbol was assigned to.
233 } else {
234 // .weak _foo
235 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
236 }
237 break;
238 case GlobalValue::DLLExportLinkage:
239 case GlobalValue::AppendingLinkage:
240 // FIXME: appending linkage variables should go into a section of
241 // their name or something. For now, just emit them as external.
242 case GlobalValue::ExternalLinkage:
243 // If external or appending, declare as a global symbol.
244 // .globl _foo
245 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
246 break;
247 case GlobalValue::PrivateLinkage:
248 case GlobalValue::InternalLinkage:
249 case GlobalValue::LinkerPrivateLinkage:
250 break;
251 default:
252 llvm_unreachable("Unknown linkage type!");
253 }
254 }
257 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
258 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
259 if (GV->hasInitializer()) {
260 // Check to see if this is a special global used by LLVM, if so, emit it.
261 if (EmitSpecialLLVMGlobal(GV))
262 return;
264 if (isVerbose()) {
265 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
266 /*PrintType=*/false, GV->getParent());
267 OutStreamer.GetCommentOS() << '\n';
268 }
269 }
271 MCSymbol *GVSym = Mang->getSymbol(GV);
272 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
274 if (!GV->hasInitializer()) // External globals require no extra code.
275 return;
277 if (MAI->hasDotTypeDotSizeDirective())
278 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
280 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
282 const DataLayout *TD = TM.getDataLayout();
283 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
285 // If the alignment is specified, we *must* obey it. Overaligning a global
286 // with a specified alignment is a prompt way to break globals emitted to
287 // sections and expected to be contiguous (e.g. ObjC metadata).
288 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
290 // Handle common and BSS local symbols (.lcomm).
291 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
292 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
293 unsigned Align = 1 << AlignLog;
295 // Handle common symbols.
296 if (GVKind.isCommon()) {
297 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
298 Align = 0;
300 // .comm _foo, 42, 4
301 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
302 return;
303 }
305 // Handle local BSS symbols.
306 if (MAI->hasMachoZeroFillDirective()) {
307 const MCSection *TheSection =
308 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
309 // .zerofill __DATA, __bss, _foo, 400, 5
310 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
311 return;
312 }
314 // Use .lcomm only if it supports user-specified alignment.
315 // Otherwise, while it would still be correct to use .lcomm in some
316 // cases (e.g. when Align == 1), the external assembler might enfore
317 // some -unknown- default alignment behavior, which could cause
318 // spurious differences between external and integrated assembler.
319 // Prefer to simply fall back to .local / .comm in this case.
320 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
321 // .lcomm _foo, 42
322 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
323 return;
324 }
326 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
327 Align = 0;
329 // .local _foo
330 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
331 // .comm _foo, 42, 4
332 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
333 return;
334 }
336 const MCSection *TheSection =
337 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
339 // Handle the zerofill directive on darwin, which is a special form of BSS
340 // emission.
341 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
342 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
344 // .globl _foo
345 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
346 // .zerofill __DATA, __common, _foo, 400, 5
347 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
348 return;
349 }
351 // Handle thread local data for mach-o which requires us to output an
352 // additional structure of data and mangle the original symbol so that we
353 // can reference it later.
354 //
355 // TODO: This should become an "emit thread local global" method on TLOF.
356 // All of this macho specific stuff should be sunk down into TLOFMachO and
357 // stuff like "TLSExtraDataSection" should no longer be part of the parent
358 // TLOF class. This will also make it more obvious that stuff like
359 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
360 // specific code.
361 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
362 // Emit the .tbss symbol
363 MCSymbol *MangSym =
364 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
366 if (GVKind.isThreadBSS())
367 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
368 else if (GVKind.isThreadData()) {
369 OutStreamer.SwitchSection(TheSection);
371 EmitAlignment(AlignLog, GV);
372 OutStreamer.EmitLabel(MangSym);
374 EmitGlobalConstant(GV->getInitializer());
375 }
377 OutStreamer.AddBlankLine();
379 // Emit the variable struct for the runtime.
380 const MCSection *TLVSect
381 = getObjFileLowering().getTLSExtraDataSection();
383 OutStreamer.SwitchSection(TLVSect);
384 // Emit the linkage here.
385 EmitLinkage(GV->getLinkage(), GVSym);
386 OutStreamer.EmitLabel(GVSym);
388 // Three pointers in size:
389 // - __tlv_bootstrap - used to make sure support exists
390 // - spare pointer, used when mapped by the runtime
391 // - pointer to mangled symbol above with initializer
392 unsigned PtrSize = TD->getPointerSizeInBits()/8;
393 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
394 PtrSize);
395 OutStreamer.EmitIntValue(0, PtrSize);
396 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
398 OutStreamer.AddBlankLine();
399 return;
400 }
402 OutStreamer.SwitchSection(TheSection);
404 EmitLinkage(GV->getLinkage(), GVSym);
405 EmitAlignment(AlignLog, GV);
407 OutStreamer.EmitLabel(GVSym);
409 EmitGlobalConstant(GV->getInitializer());
411 if (MAI->hasDotTypeDotSizeDirective())
412 // .size foo, 42
413 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
415 OutStreamer.AddBlankLine();
416 }
418 /// EmitFunctionHeader - This method emits the header for the current
419 /// function.
420 void AsmPrinter::EmitFunctionHeader() {
421 // Print out constants referenced by the function
422 EmitConstantPool();
424 // Print the 'header' of function.
425 const Function *F = MF->getFunction();
427 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
428 EmitVisibility(CurrentFnSym, F->getVisibility());
430 EmitLinkage(F->getLinkage(), CurrentFnSym);
431 EmitAlignment(MF->getAlignment(), F);
433 if (MAI->hasDotTypeDotSizeDirective())
434 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
436 if (isVerbose()) {
437 WriteAsOperand(OutStreamer.GetCommentOS(), F,
438 /*PrintType=*/false, F->getParent());
439 OutStreamer.GetCommentOS() << '\n';
440 }
442 // Emit the CurrentFnSym. This is a virtual function to allow targets to
443 // do their wild and crazy things as required.
444 EmitFunctionEntryLabel();
446 // If the function had address-taken blocks that got deleted, then we have
447 // references to the dangling symbols. Emit them at the start of the function
448 // so that we don't get references to undefined symbols.
449 std::vector<MCSymbol*> DeadBlockSyms;
450 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
451 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
452 OutStreamer.AddComment("Address taken block that was later removed");
453 OutStreamer.EmitLabel(DeadBlockSyms[i]);
454 }
456 // Add some workaround for linkonce linkage on Cygwin\MinGW.
457 if (MAI->getLinkOnceDirective() != 0 &&
458 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
459 // FIXME: What is this?
460 MCSymbol *FakeStub =
461 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
462 CurrentFnSym->getName());
463 OutStreamer.EmitLabel(FakeStub);
464 }
466 // Emit pre-function debug and/or EH information.
467 if (DE) {
468 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
469 DE->BeginFunction(MF);
470 }
471 if (DD) {
472 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
473 DD->beginFunction(MF);
474 }
475 }
477 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
478 /// function. This can be overridden by targets as required to do custom stuff.
479 void AsmPrinter::EmitFunctionEntryLabel() {
480 // The function label could have already been emitted if two symbols end up
481 // conflicting due to asm renaming. Detect this and emit an error.
482 if (CurrentFnSym->isUndefined())
483 return OutStreamer.EmitLabel(CurrentFnSym);
485 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
486 "' label emitted multiple times to assembly file");
487 }
489 /// emitComments - Pretty-print comments for instructions.
490 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
491 const MachineFunction *MF = MI.getParent()->getParent();
492 const TargetMachine &TM = MF->getTarget();
494 // Check for spills and reloads
495 int FI;
497 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
499 // We assume a single instruction only has a spill or reload, not
500 // both.
501 const MachineMemOperand *MMO;
502 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
503 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
504 MMO = *MI.memoperands_begin();
505 CommentOS << MMO->getSize() << "-byte Reload\n";
506 }
507 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
508 if (FrameInfo->isSpillSlotObjectIndex(FI))
509 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
510 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
511 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
512 MMO = *MI.memoperands_begin();
513 CommentOS << MMO->getSize() << "-byte Spill\n";
514 }
515 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
516 if (FrameInfo->isSpillSlotObjectIndex(FI))
517 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
518 }
520 // Check for spill-induced copies
521 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
522 CommentOS << " Reload Reuse\n";
523 }
525 /// emitImplicitDef - This method emits the specified machine instruction
526 /// that is an implicit def.
527 static void emitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
528 unsigned RegNo = MI->getOperand(0).getReg();
529 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
530 AP.TM.getRegisterInfo()->getName(RegNo));
531 AP.OutStreamer.AddBlankLine();
532 }
534 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
535 std::string Str = "kill:";
536 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
537 const MachineOperand &Op = MI->getOperand(i);
538 assert(Op.isReg() && "KILL instruction must have only register operands");
539 Str += ' ';
540 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
541 Str += (Op.isDef() ? "<def>" : "<kill>");
542 }
543 AP.OutStreamer.AddComment(Str);
544 AP.OutStreamer.AddBlankLine();
545 }
547 /// emitDebugValueComment - This method handles the target-independent form
548 /// of DBG_VALUE, returning true if it was able to do so. A false return
549 /// means the target will need to handle MI in EmitInstruction.
550 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
551 // This code handles only the 3-operand target-independent form.
552 if (MI->getNumOperands() != 3)
553 return false;
555 SmallString<128> Str;
556 raw_svector_ostream OS(Str);
557 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
559 // cast away const; DIetc do not take const operands for some reason.
560 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
561 if (V.getContext().isSubprogram())
562 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
563 OS << V.getName() << " <- ";
565 // Register or immediate value. Register 0 means undef.
566 if (MI->getOperand(0).isFPImm()) {
567 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
568 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
569 OS << (double)APF.convertToFloat();
570 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
571 OS << APF.convertToDouble();
572 } else {
573 // There is no good way to print long double. Convert a copy to
574 // double. Ah well, it's only a comment.
575 bool ignored;
576 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
577 &ignored);
578 OS << "(long double) " << APF.convertToDouble();
579 }
580 } else if (MI->getOperand(0).isImm()) {
581 OS << MI->getOperand(0).getImm();
582 } else if (MI->getOperand(0).isCImm()) {
583 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
584 } else {
585 assert(MI->getOperand(0).isReg() && "Unknown operand type");
586 if (MI->getOperand(0).getReg() == 0) {
587 // Suppress offset, it is not meaningful here.
588 OS << "undef";
589 // NOTE: Want this comment at start of line, don't emit with AddComment.
590 AP.OutStreamer.EmitRawText(OS.str());
591 return true;
592 }
593 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
594 }
596 OS << '+' << MI->getOperand(1).getImm();
597 // NOTE: Want this comment at start of line, don't emit with AddComment.
598 AP.OutStreamer.EmitRawText(OS.str());
599 return true;
600 }
602 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
603 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
604 MF->getFunction()->needsUnwindTableEntry())
605 return CFI_M_EH;
607 if (MMI->hasDebugInfo())
608 return CFI_M_Debug;
610 return CFI_M_None;
611 }
613 bool AsmPrinter::needsSEHMoves() {
614 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
615 MF->getFunction()->needsUnwindTableEntry();
616 }
618 bool AsmPrinter::needsRelocationsForDwarfStringPool() const {
619 return MAI->doesDwarfUseRelocationsAcrossSections();
620 }
622 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
623 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
625 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
626 return;
628 if (needsCFIMoves() == CFI_M_None)
629 return;
631 if (MMI->getCompactUnwindEncoding() != 0)
632 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
634 MachineModuleInfo &MMI = MF->getMMI();
635 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
636 bool FoundOne = false;
637 (void)FoundOne;
638 for (std::vector<MachineMove>::iterator I = Moves.begin(),
639 E = Moves.end(); I != E; ++I) {
640 if (I->getLabel() == Label) {
641 EmitCFIFrameMove(*I);
642 FoundOne = true;
643 }
644 }
645 assert(FoundOne);
646 }
648 /// EmitFunctionBody - This method emits the body and trailer for a
649 /// function.
650 void AsmPrinter::EmitFunctionBody() {
651 // Emit target-specific gunk before the function body.
652 EmitFunctionBodyStart();
654 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
656 // Print out code for the function.
657 bool HasAnyRealCode = false;
658 const MachineInstr *LastMI = 0;
659 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
660 I != E; ++I) {
661 // Print a label for the basic block.
662 EmitBasicBlockStart(I);
663 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
664 II != IE; ++II) {
665 LastMI = II;
667 // Print the assembly for the instruction.
668 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
669 !II->isDebugValue()) {
670 HasAnyRealCode = true;
671 ++EmittedInsts;
672 }
674 if (ShouldPrintDebugScopes) {
675 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
676 DD->beginInstruction(II);
677 }
679 if (isVerbose())
680 emitComments(*II, OutStreamer.GetCommentOS());
682 switch (II->getOpcode()) {
683 case TargetOpcode::PROLOG_LABEL:
684 emitPrologLabel(*II);
685 break;
687 case TargetOpcode::EH_LABEL:
688 case TargetOpcode::GC_LABEL:
689 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
690 break;
691 case TargetOpcode::INLINEASM:
692 EmitInlineAsm(II);
693 break;
694 case TargetOpcode::DBG_VALUE:
695 if (isVerbose()) {
696 if (!emitDebugValueComment(II, *this))
697 EmitInstruction(II);
698 }
699 break;
700 case TargetOpcode::IMPLICIT_DEF:
701 if (isVerbose()) emitImplicitDef(II, *this);
702 break;
703 case TargetOpcode::KILL:
704 if (isVerbose()) emitKill(II, *this);
705 break;
706 default:
707 if (!TM.hasMCUseLoc())
708 MCLineEntry::Make(&OutStreamer, getCurrentSection());
710 EmitInstruction(II);
711 break;
712 }
714 if (ShouldPrintDebugScopes) {
715 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
716 DD->endInstruction(II);
717 }
718 }
719 }
721 // If the last instruction was a prolog label, then we have a situation where
722 // we emitted a prolog but no function body. This results in the ending prolog
723 // label equaling the end of function label and an invalid "row" in the
724 // FDE. We need to emit a noop in this situation so that the FDE's rows are
725 // valid.
726 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
728 // If the function is empty and the object file uses .subsections_via_symbols,
729 // then we need to emit *something* to the function body to prevent the
730 // labels from collapsing together. Just emit a noop.
731 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
732 MCInst Noop;
733 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
734 if (Noop.getOpcode()) {
735 OutStreamer.AddComment("avoids zero-length function");
736 OutStreamer.EmitInstruction(Noop);
737 } else // Target not mc-ized yet.
738 OutStreamer.EmitRawText(StringRef("\tnop\n"));
739 }
741 const Function *F = MF->getFunction();
742 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
743 const BasicBlock *BB = i;
744 if (!BB->hasAddressTaken())
745 continue;
746 MCSymbol *Sym = GetBlockAddressSymbol(BB);
747 if (Sym->isDefined())
748 continue;
749 OutStreamer.AddComment("Address of block that was removed by CodeGen");
750 OutStreamer.EmitLabel(Sym);
751 }
753 // Emit target-specific gunk after the function body.
754 EmitFunctionBodyEnd();
756 // If the target wants a .size directive for the size of the function, emit
757 // it.
758 if (MAI->hasDotTypeDotSizeDirective()) {
759 // Create a symbol for the end of function, so we can get the size as
760 // difference between the function label and the temp label.
761 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
762 OutStreamer.EmitLabel(FnEndLabel);
764 const MCExpr *SizeExp =
765 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
766 MCSymbolRefExpr::Create(CurrentFnSymForSize,
767 OutContext),
768 OutContext);
769 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
770 }
772 // Emit post-function debug information.
773 if (DD) {
774 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
775 DD->endFunction(MF);
776 }
777 if (DE) {
778 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
779 DE->EndFunction();
780 }
781 MMI->EndFunction();
783 // Print out jump tables referenced by the function.
784 EmitJumpTableInfo();
786 OutStreamer.AddBlankLine();
787 }
789 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
790 /// operands.
791 MachineLocation AsmPrinter::
792 getDebugValueLocation(const MachineInstr *MI) const {
793 // Target specific DBG_VALUE instructions are handled by each target.
794 return MachineLocation();
795 }
797 /// EmitDwarfRegOp - Emit dwarf register operation.
798 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
799 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
800 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
802 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
803 ++SR) {
804 Reg = TRI->getDwarfRegNum(*SR, false);
805 // FIXME: Get the bit range this register uses of the superregister
806 // so that we can produce a DW_OP_bit_piece
807 }
809 // FIXME: Handle cases like a super register being encoded as
810 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
812 // FIXME: We have no reasonable way of handling errors in here. The
813 // caller might be in the middle of an dwarf expression. We should
814 // probably assert that Reg >= 0 once debug info generation is more mature.
816 if (int Offset = MLoc.getOffset()) {
817 if (Reg < 32) {
818 OutStreamer.AddComment(
819 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
820 EmitInt8(dwarf::DW_OP_breg0 + Reg);
821 } else {
822 OutStreamer.AddComment("DW_OP_bregx");
823 EmitInt8(dwarf::DW_OP_bregx);
824 OutStreamer.AddComment(Twine(Reg));
825 EmitULEB128(Reg);
826 }
827 EmitSLEB128(Offset);
828 } else {
829 if (Reg < 32) {
830 OutStreamer.AddComment(
831 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
832 EmitInt8(dwarf::DW_OP_reg0 + Reg);
833 } else {
834 OutStreamer.AddComment("DW_OP_regx");
835 EmitInt8(dwarf::DW_OP_regx);
836 OutStreamer.AddComment(Twine(Reg));
837 EmitULEB128(Reg);
838 }
839 }
841 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
842 }
844 bool AsmPrinter::doFinalization(Module &M) {
845 // Emit global variables.
846 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
847 I != E; ++I)
848 EmitGlobalVariable(I);
850 // Emit visibility info for declarations
851 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
852 const Function &F = *I;
853 if (!F.isDeclaration())
854 continue;
855 GlobalValue::VisibilityTypes V = F.getVisibility();
856 if (V == GlobalValue::DefaultVisibility)
857 continue;
859 MCSymbol *Name = Mang->getSymbol(&F);
860 EmitVisibility(Name, V, false);
861 }
863 // Emit module flags.
864 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
865 M.getModuleFlagsMetadata(ModuleFlags);
866 if (!ModuleFlags.empty())
867 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
869 // Finalize debug and EH information.
870 if (DE) {
871 {
872 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
873 DE->EndModule();
874 }
875 delete DE; DE = 0;
876 }
877 if (DD) {
878 {
879 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
880 DD->endModule();
881 }
882 delete DD; DD = 0;
883 }
885 // If the target wants to know about weak references, print them all.
886 if (MAI->getWeakRefDirective()) {
887 // FIXME: This is not lazy, it would be nice to only print weak references
888 // to stuff that is actually used. Note that doing so would require targets
889 // to notice uses in operands (due to constant exprs etc). This should
890 // happen with the MC stuff eventually.
892 // Print out module-level global variables here.
893 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
894 I != E; ++I) {
895 if (!I->hasExternalWeakLinkage()) continue;
896 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
897 }
899 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
900 if (!I->hasExternalWeakLinkage()) continue;
901 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
902 }
903 }
905 if (MAI->hasSetDirective()) {
906 OutStreamer.AddBlankLine();
907 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
908 I != E; ++I) {
909 MCSymbol *Name = Mang->getSymbol(I);
911 const GlobalValue *GV = I->getAliasedGlobal();
912 MCSymbol *Target = Mang->getSymbol(GV);
914 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
915 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
916 else if (I->hasWeakLinkage())
917 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
918 else
919 assert(I->hasLocalLinkage() && "Invalid alias linkage");
921 EmitVisibility(Name, I->getVisibility());
923 // Emit the directives as assignments aka .set:
924 OutStreamer.EmitAssignment(Name,
925 MCSymbolRefExpr::Create(Target, OutContext));
926 }
927 }
929 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
930 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
931 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
932 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
933 MP->finishAssembly(*this);
935 // If we don't have any trampolines, then we don't require stack memory
936 // to be executable. Some targets have a directive to declare this.
937 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
938 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
939 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
940 OutStreamer.SwitchSection(S);
942 // Allow the target to emit any magic that it wants at the end of the file,
943 // after everything else has gone out.
944 EmitEndOfAsmFile(M);
946 delete Mang; Mang = 0;
947 MMI = 0;
949 OutStreamer.Finish();
950 OutStreamer.reset();
952 return false;
953 }
955 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
956 this->MF = &MF;
957 // Get the function symbol.
958 CurrentFnSym = Mang->getSymbol(MF.getFunction());
959 CurrentFnSymForSize = CurrentFnSym;
961 if (isVerbose())
962 LI = &getAnalysis<MachineLoopInfo>();
963 }
965 namespace {
966 // SectionCPs - Keep track the alignment, constpool entries per Section.
967 struct SectionCPs {
968 const MCSection *S;
969 unsigned Alignment;
970 SmallVector<unsigned, 4> CPEs;
971 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
972 };
973 }
975 /// EmitConstantPool - Print to the current output stream assembly
976 /// representations of the constants in the constant pool MCP. This is
977 /// used to print out constants which have been "spilled to memory" by
978 /// the code generator.
979 ///
980 void AsmPrinter::EmitConstantPool() {
981 const MachineConstantPool *MCP = MF->getConstantPool();
982 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
983 if (CP.empty()) return;
985 // Calculate sections for constant pool entries. We collect entries to go into
986 // the same section together to reduce amount of section switch statements.
987 SmallVector<SectionCPs, 4> CPSections;
988 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
989 const MachineConstantPoolEntry &CPE = CP[i];
990 unsigned Align = CPE.getAlignment();
992 SectionKind Kind;
993 switch (CPE.getRelocationInfo()) {
994 default: llvm_unreachable("Unknown section kind");
995 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
996 case 1:
997 Kind = SectionKind::getReadOnlyWithRelLocal();
998 break;
999 case 0:
1000 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1001 case 4: Kind = SectionKind::getMergeableConst4(); break;
1002 case 8: Kind = SectionKind::getMergeableConst8(); break;
1003 case 16: Kind = SectionKind::getMergeableConst16();break;
1004 default: Kind = SectionKind::getMergeableConst(); break;
1005 }
1006 }
1008 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1010 // The number of sections are small, just do a linear search from the
1011 // last section to the first.
1012 bool Found = false;
1013 unsigned SecIdx = CPSections.size();
1014 while (SecIdx != 0) {
1015 if (CPSections[--SecIdx].S == S) {
1016 Found = true;
1017 break;
1018 }
1019 }
1020 if (!Found) {
1021 SecIdx = CPSections.size();
1022 CPSections.push_back(SectionCPs(S, Align));
1023 }
1025 if (Align > CPSections[SecIdx].Alignment)
1026 CPSections[SecIdx].Alignment = Align;
1027 CPSections[SecIdx].CPEs.push_back(i);
1028 }
1030 // Now print stuff into the calculated sections.
1031 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1032 OutStreamer.SwitchSection(CPSections[i].S);
1033 EmitAlignment(Log2_32(CPSections[i].Alignment));
1035 unsigned Offset = 0;
1036 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1037 unsigned CPI = CPSections[i].CPEs[j];
1038 MachineConstantPoolEntry CPE = CP[CPI];
1040 // Emit inter-object padding for alignment.
1041 unsigned AlignMask = CPE.getAlignment() - 1;
1042 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1043 OutStreamer.EmitZeros(NewOffset - Offset);
1045 Type *Ty = CPE.getType();
1046 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1047 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1049 if (CPE.isMachineConstantPoolEntry())
1050 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1051 else
1052 EmitGlobalConstant(CPE.Val.ConstVal);
1053 }
1054 }
1055 }
1057 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1058 /// by the current function to the current output stream.
1059 ///
1060 void AsmPrinter::EmitJumpTableInfo() {
1061 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1062 if (MJTI == 0) return;
1063 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1064 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1065 if (JT.empty()) return;
1067 // Pick the directive to use to print the jump table entries, and switch to
1068 // the appropriate section.
1069 const Function *F = MF->getFunction();
1070 bool JTInDiffSection = false;
1071 if (// In PIC mode, we need to emit the jump table to the same section as the
1072 // function body itself, otherwise the label differences won't make sense.
1073 // FIXME: Need a better predicate for this: what about custom entries?
1074 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1075 // We should also do if the section name is NULL or function is declared
1076 // in discardable section
1077 // FIXME: this isn't the right predicate, should be based on the MCSection
1078 // for the function.
1079 F->isWeakForLinker()) {
1080 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1081 } else {
1082 // Otherwise, drop it in the readonly section.
1083 const MCSection *ReadOnlySection =
1084 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1085 OutStreamer.SwitchSection(ReadOnlySection);
1086 JTInDiffSection = true;
1087 }
1089 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1091 // Jump tables in code sections are marked with a data_region directive
1092 // where that's supported.
1093 if (!JTInDiffSection)
1094 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1096 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1097 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1099 // If this jump table was deleted, ignore it.
1100 if (JTBBs.empty()) continue;
1102 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1103 // .set directive for each unique entry. This reduces the number of
1104 // relocations the assembler will generate for the jump table.
1105 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1106 MAI->hasSetDirective()) {
1107 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1108 const TargetLowering *TLI = TM.getTargetLowering();
1109 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1110 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1111 const MachineBasicBlock *MBB = JTBBs[ii];
1112 if (!EmittedSets.insert(MBB)) continue;
1114 // .set LJTSet, LBB32-base
1115 const MCExpr *LHS =
1116 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1117 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1118 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1119 }
1120 }
1122 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1123 // before each jump table. The first label is never referenced, but tells
1124 // the assembler and linker the extents of the jump table object. The
1125 // second label is actually referenced by the code.
1126 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1127 // FIXME: This doesn't have to have any specific name, just any randomly
1128 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1129 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1131 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1133 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1134 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1135 }
1136 if (!JTInDiffSection)
1137 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1138 }
1140 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1141 /// current stream.
1142 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1143 const MachineBasicBlock *MBB,
1144 unsigned UID) const {
1145 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1146 const MCExpr *Value = 0;
1147 switch (MJTI->getEntryKind()) {
1148 case MachineJumpTableInfo::EK_Inline:
1149 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1150 case MachineJumpTableInfo::EK_Custom32:
1151 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1152 OutContext);
1153 break;
1154 case MachineJumpTableInfo::EK_BlockAddress:
1155 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1156 // .word LBB123
1157 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1158 break;
1159 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1160 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1161 // with a relocation as gp-relative, e.g.:
1162 // .gprel32 LBB123
1163 MCSymbol *MBBSym = MBB->getSymbol();
1164 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1165 return;
1166 }
1168 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1169 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1170 // with a relocation as gp-relative, e.g.:
1171 // .gpdword LBB123
1172 MCSymbol *MBBSym = MBB->getSymbol();
1173 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1174 return;
1175 }
1177 case MachineJumpTableInfo::EK_LabelDifference32: {
1178 // EK_LabelDifference32 - Each entry is the address of the block minus
1179 // the address of the jump table. This is used for PIC jump tables where
1180 // gprel32 is not supported. e.g.:
1181 // .word LBB123 - LJTI1_2
1182 // If the .set directive is supported, this is emitted as:
1183 // .set L4_5_set_123, LBB123 - LJTI1_2
1184 // .word L4_5_set_123
1186 // If we have emitted set directives for the jump table entries, print
1187 // them rather than the entries themselves. If we're emitting PIC, then
1188 // emit the table entries as differences between two text section labels.
1189 if (MAI->hasSetDirective()) {
1190 // If we used .set, reference the .set's symbol.
1191 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1192 OutContext);
1193 break;
1194 }
1195 // Otherwise, use the difference as the jump table entry.
1196 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1197 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1198 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1199 break;
1200 }
1201 }
1203 assert(Value && "Unknown entry kind!");
1205 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1206 OutStreamer.EmitValue(Value, EntrySize);
1207 }
1210 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1211 /// special global used by LLVM. If so, emit it and return true, otherwise
1212 /// do nothing and return false.
1213 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1214 if (GV->getName() == "llvm.used") {
1215 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1216 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1217 return true;
1218 }
1220 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1221 if (GV->getSection() == "llvm.metadata" ||
1222 GV->hasAvailableExternallyLinkage())
1223 return true;
1225 if (!GV->hasAppendingLinkage()) return false;
1227 assert(GV->hasInitializer() && "Not a special LLVM global!");
1229 if (GV->getName() == "llvm.global_ctors") {
1230 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1232 if (TM.getRelocationModel() == Reloc::Static &&
1233 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1234 StringRef Sym(".constructors_used");
1235 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1236 MCSA_Reference);
1237 }
1238 return true;
1239 }
1241 if (GV->getName() == "llvm.global_dtors") {
1242 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1244 if (TM.getRelocationModel() == Reloc::Static &&
1245 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1246 StringRef Sym(".destructors_used");
1247 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1248 MCSA_Reference);
1249 }
1250 return true;
1251 }
1253 return false;
1254 }
1256 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1257 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1258 /// is true, as being used with this directive.
1259 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1260 // Should be an array of 'i8*'.
1261 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1262 const GlobalValue *GV =
1263 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1264 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1265 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1266 }
1267 }
1269 typedef std::pair<unsigned, Constant*> Structor;
1271 static bool priority_order(const Structor& lhs, const Structor& rhs) {
1272 return lhs.first < rhs.first;
1273 }
1275 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1276 /// priority.
1277 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1278 // Should be an array of '{ int, void ()* }' structs. The first value is the
1279 // init priority.
1280 if (!isa<ConstantArray>(List)) return;
1282 // Sanity check the structors list.
1283 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1284 if (!InitList) return; // Not an array!
1285 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1286 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1287 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1288 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1290 // Gather the structors in a form that's convenient for sorting by priority.
1291 SmallVector<Structor, 8> Structors;
1292 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1293 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1294 if (!CS) continue; // Malformed.
1295 if (CS->getOperand(1)->isNullValue())
1296 break; // Found a null terminator, skip the rest.
1297 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1298 if (!Priority) continue; // Malformed.
1299 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1300 CS->getOperand(1)));
1301 }
1303 // Emit the function pointers in the target-specific order
1304 const DataLayout *TD = TM.getDataLayout();
1305 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1306 std::stable_sort(Structors.begin(), Structors.end(), priority_order);
1307 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1308 const MCSection *OutputSection =
1309 (isCtor ?
1310 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1311 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1312 OutStreamer.SwitchSection(OutputSection);
1313 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1314 EmitAlignment(Align);
1315 EmitXXStructor(Structors[i].second);
1316 }
1317 }
1319 //===--------------------------------------------------------------------===//
1320 // Emission and print routines
1321 //
1323 /// EmitInt8 - Emit a byte directive and value.
1324 ///
1325 void AsmPrinter::EmitInt8(int Value) const {
1326 OutStreamer.EmitIntValue(Value, 1);
1327 }
1329 /// EmitInt16 - Emit a short directive and value.
1330 ///
1331 void AsmPrinter::EmitInt16(int Value) const {
1332 OutStreamer.EmitIntValue(Value, 2);
1333 }
1335 /// EmitInt32 - Emit a long directive and value.
1336 ///
1337 void AsmPrinter::EmitInt32(int Value) const {
1338 OutStreamer.EmitIntValue(Value, 4);
1339 }
1341 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1342 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1343 /// labels. This implicitly uses .set if it is available.
1344 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1345 unsigned Size) const {
1346 // Get the Hi-Lo expression.
1347 const MCExpr *Diff =
1348 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1349 MCSymbolRefExpr::Create(Lo, OutContext),
1350 OutContext);
1352 if (!MAI->hasSetDirective()) {
1353 OutStreamer.EmitValue(Diff, Size);
1354 return;
1355 }
1357 // Otherwise, emit with .set (aka assignment).
1358 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1359 OutStreamer.EmitAssignment(SetLabel, Diff);
1360 OutStreamer.EmitSymbolValue(SetLabel, Size);
1361 }
1363 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1364 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1365 /// specify the labels. This implicitly uses .set if it is available.
1366 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1367 const MCSymbol *Lo, unsigned Size)
1368 const {
1370 // Emit Hi+Offset - Lo
1371 // Get the Hi+Offset expression.
1372 const MCExpr *Plus =
1373 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1374 MCConstantExpr::Create(Offset, OutContext),
1375 OutContext);
1377 // Get the Hi+Offset-Lo expression.
1378 const MCExpr *Diff =
1379 MCBinaryExpr::CreateSub(Plus,
1380 MCSymbolRefExpr::Create(Lo, OutContext),
1381 OutContext);
1383 if (!MAI->hasSetDirective())
1384 OutStreamer.EmitValue(Diff, 4);
1385 else {
1386 // Otherwise, emit with .set (aka assignment).
1387 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1388 OutStreamer.EmitAssignment(SetLabel, Diff);
1389 OutStreamer.EmitSymbolValue(SetLabel, 4);
1390 }
1391 }
1393 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1394 /// where the size in bytes of the directive is specified by Size and Label
1395 /// specifies the label. This implicitly uses .set if it is available.
1396 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1397 unsigned Size)
1398 const {
1400 // Emit Label+Offset (or just Label if Offset is zero)
1401 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1402 if (Offset)
1403 Expr = MCBinaryExpr::CreateAdd(Expr,
1404 MCConstantExpr::Create(Offset, OutContext),
1405 OutContext);
1407 OutStreamer.EmitValue(Expr, Size);
1408 }
1411 //===----------------------------------------------------------------------===//
1413 // EmitAlignment - Emit an alignment directive to the specified power of
1414 // two boundary. For example, if you pass in 3 here, you will get an 8
1415 // byte alignment. If a global value is specified, and if that global has
1416 // an explicit alignment requested, it will override the alignment request
1417 // if required for correctness.
1418 //
1419 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1420 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1422 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1424 if (getCurrentSection()->getKind().isText())
1425 OutStreamer.EmitCodeAlignment(1 << NumBits);
1426 else
1427 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1428 }
1430 //===----------------------------------------------------------------------===//
1431 // Constant emission.
1432 //===----------------------------------------------------------------------===//
1434 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1435 ///
1436 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1437 MCContext &Ctx = AP.OutContext;
1439 if (CV->isNullValue() || isa<UndefValue>(CV))
1440 return MCConstantExpr::Create(0, Ctx);
1442 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1443 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1445 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1446 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1448 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1449 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1451 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1452 if (CE == 0) {
1453 llvm_unreachable("Unknown constant value to lower!");
1454 }
1456 switch (CE->getOpcode()) {
1457 default:
1458 // If the code isn't optimized, there may be outstanding folding
1459 // opportunities. Attempt to fold the expression using DataLayout as a
1460 // last resort before giving up.
1461 if (Constant *C =
1462 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1463 if (C != CE)
1464 return lowerConstant(C, AP);
1466 // Otherwise report the problem to the user.
1467 {
1468 std::string S;
1469 raw_string_ostream OS(S);
1470 OS << "Unsupported expression in static initializer: ";
1471 WriteAsOperand(OS, CE, /*PrintType=*/false,
1472 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1473 report_fatal_error(OS.str());
1474 }
1475 case Instruction::GetElementPtr: {
1476 const DataLayout &TD = *AP.TM.getDataLayout();
1477 // Generate a symbolic expression for the byte address
1478 APInt OffsetAI(TD.getPointerSizeInBits(), 0);
1479 cast<GEPOperator>(CE)->accumulateConstantOffset(TD, OffsetAI);
1481 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1482 if (!OffsetAI)
1483 return Base;
1485 int64_t Offset = OffsetAI.getSExtValue();
1486 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1487 Ctx);
1488 }
1490 case Instruction::Trunc:
1491 // We emit the value and depend on the assembler to truncate the generated
1492 // expression properly. This is important for differences between
1493 // blockaddress labels. Since the two labels are in the same function, it
1494 // is reasonable to treat their delta as a 32-bit value.
1495 // FALL THROUGH.
1496 case Instruction::BitCast:
1497 return lowerConstant(CE->getOperand(0), AP);
1499 case Instruction::IntToPtr: {
1500 const DataLayout &TD = *AP.TM.getDataLayout();
1501 // Handle casts to pointers by changing them into casts to the appropriate
1502 // integer type. This promotes constant folding and simplifies this code.
1503 Constant *Op = CE->getOperand(0);
1504 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1505 false/*ZExt*/);
1506 return lowerConstant(Op, AP);
1507 }
1509 case Instruction::PtrToInt: {
1510 const DataLayout &TD = *AP.TM.getDataLayout();
1511 // Support only foldable casts to/from pointers that can be eliminated by
1512 // changing the pointer to the appropriately sized integer type.
1513 Constant *Op = CE->getOperand(0);
1514 Type *Ty = CE->getType();
1516 const MCExpr *OpExpr = lowerConstant(Op, AP);
1518 // We can emit the pointer value into this slot if the slot is an
1519 // integer slot equal to the size of the pointer.
1520 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1521 return OpExpr;
1523 // Otherwise the pointer is smaller than the resultant integer, mask off
1524 // the high bits so we are sure to get a proper truncation if the input is
1525 // a constant expr.
1526 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1527 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1528 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1529 }
1531 // The MC library also has a right-shift operator, but it isn't consistently
1532 // signed or unsigned between different targets.
1533 case Instruction::Add:
1534 case Instruction::Sub:
1535 case Instruction::Mul:
1536 case Instruction::SDiv:
1537 case Instruction::SRem:
1538 case Instruction::Shl:
1539 case Instruction::And:
1540 case Instruction::Or:
1541 case Instruction::Xor: {
1542 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1543 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1544 switch (CE->getOpcode()) {
1545 default: llvm_unreachable("Unknown binary operator constant cast expr");
1546 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1547 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1548 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1549 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1550 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1551 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1552 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1553 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1554 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1555 }
1556 }
1557 }
1558 }
1560 static void emitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1561 AsmPrinter &AP);
1563 /// isRepeatedByteSequence - Determine whether the given value is
1564 /// composed of a repeated sequence of identical bytes and return the
1565 /// byte value. If it is not a repeated sequence, return -1.
1566 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1567 StringRef Data = V->getRawDataValues();
1568 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1569 char C = Data[0];
1570 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1571 if (Data[i] != C) return -1;
1572 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1573 }
1576 /// isRepeatedByteSequence - Determine whether the given value is
1577 /// composed of a repeated sequence of identical bytes and return the
1578 /// byte value. If it is not a repeated sequence, return -1.
1579 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1581 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1582 if (CI->getBitWidth() > 64) return -1;
1584 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1585 uint64_t Value = CI->getZExtValue();
1587 // Make sure the constant is at least 8 bits long and has a power
1588 // of 2 bit width. This guarantees the constant bit width is
1589 // always a multiple of 8 bits, avoiding issues with padding out
1590 // to Size and other such corner cases.
1591 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1593 uint8_t Byte = static_cast<uint8_t>(Value);
1595 for (unsigned i = 1; i < Size; ++i) {
1596 Value >>= 8;
1597 if (static_cast<uint8_t>(Value) != Byte) return -1;
1598 }
1599 return Byte;
1600 }
1601 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1602 // Make sure all array elements are sequences of the same repeated
1603 // byte.
1604 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1605 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1606 if (Byte == -1) return -1;
1608 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1609 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1610 if (ThisByte == -1) return -1;
1611 if (Byte != ThisByte) return -1;
1612 }
1613 return Byte;
1614 }
1616 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1617 return isRepeatedByteSequence(CDS);
1619 return -1;
1620 }
1622 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1623 unsigned AddrSpace,AsmPrinter &AP){
1625 // See if we can aggregate this into a .fill, if so, emit it as such.
1626 int Value = isRepeatedByteSequence(CDS, AP.TM);
1627 if (Value != -1) {
1628 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1629 // Don't emit a 1-byte object as a .fill.
1630 if (Bytes > 1)
1631 return AP.OutStreamer.EmitFill(Bytes, Value, AddrSpace);
1632 }
1634 // If this can be emitted with .ascii/.asciz, emit it as such.
1635 if (CDS->isString())
1636 return AP.OutStreamer.EmitBytes(CDS->getAsString(), AddrSpace);
1638 // Otherwise, emit the values in successive locations.
1639 unsigned ElementByteSize = CDS->getElementByteSize();
1640 if (isa<IntegerType>(CDS->getElementType())) {
1641 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1642 if (AP.isVerbose())
1643 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1644 CDS->getElementAsInteger(i));
1645 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1646 ElementByteSize, AddrSpace);
1647 }
1648 } else if (ElementByteSize == 4) {
1649 // FP Constants are printed as integer constants to avoid losing
1650 // precision.
1651 assert(CDS->getElementType()->isFloatTy());
1652 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1653 union {
1654 float F;
1655 uint32_t I;
1656 };
1658 F = CDS->getElementAsFloat(i);
1659 if (AP.isVerbose())
1660 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1661 AP.OutStreamer.EmitIntValue(I, 4, AddrSpace);
1662 }
1663 } else {
1664 assert(CDS->getElementType()->isDoubleTy());
1665 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1666 union {
1667 double F;
1668 uint64_t I;
1669 };
1671 F = CDS->getElementAsDouble(i);
1672 if (AP.isVerbose())
1673 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1674 AP.OutStreamer.EmitIntValue(I, 8, AddrSpace);
1675 }
1676 }
1678 const DataLayout &TD = *AP.TM.getDataLayout();
1679 unsigned Size = TD.getTypeAllocSize(CDS->getType());
1680 unsigned EmittedSize = TD.getTypeAllocSize(CDS->getType()->getElementType()) *
1681 CDS->getNumElements();
1682 if (unsigned Padding = Size - EmittedSize)
1683 AP.OutStreamer.EmitZeros(Padding, AddrSpace);
1685 }
1687 static void emitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1688 AsmPrinter &AP) {
1689 // See if we can aggregate some values. Make sure it can be
1690 // represented as a series of bytes of the constant value.
1691 int Value = isRepeatedByteSequence(CA, AP.TM);
1693 if (Value != -1) {
1694 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1695 AP.OutStreamer.EmitFill(Bytes, Value, AddrSpace);
1696 }
1697 else {
1698 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1699 emitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1700 }
1701 }
1703 static void emitGlobalConstantVector(const ConstantVector *CV,
1704 unsigned AddrSpace, AsmPrinter &AP) {
1705 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1706 emitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1708 const DataLayout &TD = *AP.TM.getDataLayout();
1709 unsigned Size = TD.getTypeAllocSize(CV->getType());
1710 unsigned EmittedSize = TD.getTypeAllocSize(CV->getType()->getElementType()) *
1711 CV->getType()->getNumElements();
1712 if (unsigned Padding = Size - EmittedSize)
1713 AP.OutStreamer.EmitZeros(Padding, AddrSpace);
1714 }
1716 static void emitGlobalConstantStruct(const ConstantStruct *CS,
1717 unsigned AddrSpace, AsmPrinter &AP) {
1718 // Print the fields in successive locations. Pad to align if needed!
1719 const DataLayout *TD = AP.TM.getDataLayout();
1720 unsigned Size = TD->getTypeAllocSize(CS->getType());
1721 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1722 uint64_t SizeSoFar = 0;
1723 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1724 const Constant *Field = CS->getOperand(i);
1726 // Check if padding is needed and insert one or more 0s.
1727 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1728 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1729 - Layout->getElementOffset(i)) - FieldSize;
1730 SizeSoFar += FieldSize + PadSize;
1732 // Now print the actual field value.
1733 emitGlobalConstantImpl(Field, AddrSpace, AP);
1735 // Insert padding - this may include padding to increase the size of the
1736 // current field up to the ABI size (if the struct is not packed) as well
1737 // as padding to ensure that the next field starts at the right offset.
1738 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1739 }
1740 assert(SizeSoFar == Layout->getSizeInBytes() &&
1741 "Layout of constant struct may be incorrect!");
1742 }
1744 static void emitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1745 AsmPrinter &AP) {
1746 APInt API = CFP->getValueAPF().bitcastToAPInt();
1748 // First print a comment with what we think the original floating-point value
1749 // should have been.
1750 if (AP.isVerbose()) {
1751 SmallString<8> StrVal;
1752 CFP->getValueAPF().toString(StrVal);
1754 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1755 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1756 }
1758 // Now iterate through the APInt chunks, emitting them in endian-correct
1759 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1760 // floats).
1761 unsigned NumBytes = API.getBitWidth() / 8;
1762 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1763 const uint64_t *p = API.getRawData();
1765 // PPC's long double has odd notions of endianness compared to how LLVM
1766 // handles it: p[0] goes first for *big* endian on PPC.
1767 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1768 int Chunk = API.getNumWords() - 1;
1770 if (TrailingBytes)
1771 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes, AddrSpace);
1773 for (; Chunk >= 0; --Chunk)
1774 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t), AddrSpace);
1775 } else {
1776 unsigned Chunk;
1777 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1778 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t), AddrSpace);
1780 if (TrailingBytes)
1781 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes, AddrSpace);
1782 }
1784 // Emit the tail padding for the long double.
1785 const DataLayout &TD = *AP.TM.getDataLayout();
1786 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1787 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1788 }
1790 static void emitGlobalConstantLargeInt(const ConstantInt *CI,
1791 unsigned AddrSpace, AsmPrinter &AP) {
1792 const DataLayout *TD = AP.TM.getDataLayout();
1793 unsigned BitWidth = CI->getBitWidth();
1794 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1796 // We don't expect assemblers to support integer data directives
1797 // for more than 64 bits, so we emit the data in at most 64-bit
1798 // quantities at a time.
1799 const uint64_t *RawData = CI->getValue().getRawData();
1800 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1801 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1802 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1803 }
1804 }
1806 static void emitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1807 AsmPrinter &AP) {
1808 const DataLayout *TD = AP.TM.getDataLayout();
1809 uint64_t Size = TD->getTypeAllocSize(CV->getType());
1810 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1811 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1813 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1814 switch (Size) {
1815 case 1:
1816 case 2:
1817 case 4:
1818 case 8:
1819 if (AP.isVerbose())
1820 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1821 CI->getZExtValue());
1822 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1823 return;
1824 default:
1825 emitGlobalConstantLargeInt(CI, AddrSpace, AP);
1826 return;
1827 }
1828 }
1830 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1831 return emitGlobalConstantFP(CFP, AddrSpace, AP);
1833 if (isa<ConstantPointerNull>(CV)) {
1834 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1835 return;
1836 }
1838 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1839 return emitGlobalConstantDataSequential(CDS, AddrSpace, AP);
1841 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1842 return emitGlobalConstantArray(CVA, AddrSpace, AP);
1844 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1845 return emitGlobalConstantStruct(CVS, AddrSpace, AP);
1847 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1848 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1849 // vectors).
1850 if (CE->getOpcode() == Instruction::BitCast)
1851 return emitGlobalConstantImpl(CE->getOperand(0), AddrSpace, AP);
1853 if (Size > 8) {
1854 // If the constant expression's size is greater than 64-bits, then we have
1855 // to emit the value in chunks. Try to constant fold the value and emit it
1856 // that way.
1857 Constant *New = ConstantFoldConstantExpression(CE, TD);
1858 if (New && New != CE)
1859 return emitGlobalConstantImpl(New, AddrSpace, AP);
1860 }
1861 }
1863 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1864 return emitGlobalConstantVector(V, AddrSpace, AP);
1866 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1867 // thread the streamer with EmitValue.
1868 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size, AddrSpace);
1869 }
1871 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1872 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1873 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1874 if (Size)
1875 emitGlobalConstantImpl(CV, AddrSpace, *this);
1876 else if (MAI->hasSubsectionsViaSymbols()) {
1877 // If the global has zero size, emit a single byte so that two labels don't
1878 // look like they are at the same location.
1879 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1880 }
1881 }
1883 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1884 // Target doesn't support this yet!
1885 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1886 }
1888 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1889 if (Offset > 0)
1890 OS << '+' << Offset;
1891 else if (Offset < 0)
1892 OS << Offset;
1893 }
1895 //===----------------------------------------------------------------------===//
1896 // Symbol Lowering Routines.
1897 //===----------------------------------------------------------------------===//
1899 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1900 /// temporary label with the specified stem and unique ID.
1901 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1902 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1903 Name + Twine(ID));
1904 }
1906 /// GetTempSymbol - Return an assembler temporary label with the specified
1907 /// stem.
1908 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1909 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1910 Name);
1911 }
1914 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1915 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1916 }
1918 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1919 return MMI->getAddrLabelSymbol(BB);
1920 }
1922 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1923 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1924 return OutContext.GetOrCreateSymbol
1925 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1926 + "_" + Twine(CPID));
1927 }
1929 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1930 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1931 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1932 }
1934 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1935 /// FIXME: privatize to AsmPrinter.
1936 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1937 return OutContext.GetOrCreateSymbol
1938 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1939 Twine(UID) + "_set_" + Twine(MBBID));
1940 }
1942 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1943 /// global value name as its base, with the specified suffix, and where the
1944 /// symbol is forced to have private linkage if ForcePrivate is true.
1945 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1946 StringRef Suffix,
1947 bool ForcePrivate) const {
1948 SmallString<60> NameStr;
1949 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1950 NameStr.append(Suffix.begin(), Suffix.end());
1951 return OutContext.GetOrCreateSymbol(NameStr.str());
1952 }
1954 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1955 /// ExternalSymbol.
1956 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1957 SmallString<60> NameStr;
1958 Mang->getNameWithPrefix(NameStr, Sym);
1959 return OutContext.GetOrCreateSymbol(NameStr.str());
1960 }
1964 /// PrintParentLoopComment - Print comments about parent loops of this one.
1965 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1966 unsigned FunctionNumber) {
1967 if (Loop == 0) return;
1968 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1969 OS.indent(Loop->getLoopDepth()*2)
1970 << "Parent Loop BB" << FunctionNumber << "_"
1971 << Loop->getHeader()->getNumber()
1972 << " Depth=" << Loop->getLoopDepth() << '\n';
1973 }
1976 /// PrintChildLoopComment - Print comments about child loops within
1977 /// the loop for this basic block, with nesting.
1978 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1979 unsigned FunctionNumber) {
1980 // Add child loop information
1981 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1982 OS.indent((*CL)->getLoopDepth()*2)
1983 << "Child Loop BB" << FunctionNumber << "_"
1984 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1985 << '\n';
1986 PrintChildLoopComment(OS, *CL, FunctionNumber);
1987 }
1988 }
1990 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1991 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1992 const MachineLoopInfo *LI,
1993 const AsmPrinter &AP) {
1994 // Add loop depth information
1995 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1996 if (Loop == 0) return;
1998 MachineBasicBlock *Header = Loop->getHeader();
1999 assert(Header && "No header for loop");
2001 // If this block is not a loop header, just print out what is the loop header
2002 // and return.
2003 if (Header != &MBB) {
2004 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2005 Twine(AP.getFunctionNumber())+"_" +
2006 Twine(Loop->getHeader()->getNumber())+
2007 " Depth="+Twine(Loop->getLoopDepth()));
2008 return;
2009 }
2011 // Otherwise, it is a loop header. Print out information about child and
2012 // parent loops.
2013 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2015 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2017 OS << "=>";
2018 OS.indent(Loop->getLoopDepth()*2-2);
2020 OS << "This ";
2021 if (Loop->empty())
2022 OS << "Inner ";
2023 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2025 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2026 }
2029 /// EmitBasicBlockStart - This method prints the label for the specified
2030 /// MachineBasicBlock, an alignment (if present) and a comment describing
2031 /// it if appropriate.
2032 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2033 // Emit an alignment directive for this block, if needed.
2034 if (unsigned Align = MBB->getAlignment())
2035 EmitAlignment(Align);
2037 // If the block has its address taken, emit any labels that were used to
2038 // reference the block. It is possible that there is more than one label
2039 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2040 // the references were generated.
2041 if (MBB->hasAddressTaken()) {
2042 const BasicBlock *BB = MBB->getBasicBlock();
2043 if (isVerbose())
2044 OutStreamer.AddComment("Block address taken");
2046 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2048 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2049 OutStreamer.EmitLabel(Syms[i]);
2050 }
2052 // Print some verbose block comments.
2053 if (isVerbose()) {
2054 if (const BasicBlock *BB = MBB->getBasicBlock())
2055 if (BB->hasName())
2056 OutStreamer.AddComment("%" + BB->getName());
2057 emitBasicBlockLoopComments(*MBB, LI, *this);
2058 }
2060 // Print the main label for the block.
2061 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2062 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
2063 // NOTE: Want this comment at start of line, don't emit with AddComment.
2064 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
2065 Twine(MBB->getNumber()) + ":");
2066 }
2067 } else {
2068 OutStreamer.EmitLabel(MBB->getSymbol());
2069 }
2070 }
2072 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2073 bool IsDefinition) const {
2074 MCSymbolAttr Attr = MCSA_Invalid;
2076 switch (Visibility) {
2077 default: break;
2078 case GlobalValue::HiddenVisibility:
2079 if (IsDefinition)
2080 Attr = MAI->getHiddenVisibilityAttr();
2081 else
2082 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2083 break;
2084 case GlobalValue::ProtectedVisibility:
2085 Attr = MAI->getProtectedVisibilityAttr();
2086 break;
2087 }
2089 if (Attr != MCSA_Invalid)
2090 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2091 }
2093 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2094 /// exactly one predecessor and the control transfer mechanism between
2095 /// the predecessor and this block is a fall-through.
2096 bool AsmPrinter::
2097 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2098 // If this is a landing pad, it isn't a fall through. If it has no preds,
2099 // then nothing falls through to it.
2100 if (MBB->isLandingPad() || MBB->pred_empty())
2101 return false;
2103 // If there isn't exactly one predecessor, it can't be a fall through.
2104 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2105 ++PI2;
2106 if (PI2 != MBB->pred_end())
2107 return false;
2109 // The predecessor has to be immediately before this block.
2110 MachineBasicBlock *Pred = *PI;
2112 if (!Pred->isLayoutSuccessor(MBB))
2113 return false;
2115 // If the block is completely empty, then it definitely does fall through.
2116 if (Pred->empty())
2117 return true;
2119 // Check the terminators in the previous blocks
2120 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2121 IE = Pred->end(); II != IE; ++II) {
2122 MachineInstr &MI = *II;
2124 // If it is not a simple branch, we are in a table somewhere.
2125 if (!MI.isBranch() || MI.isIndirectBranch())
2126 return false;
2128 // If we are the operands of one of the branches, this is not
2129 // a fall through.
2130 for (MachineInstr::mop_iterator OI = MI.operands_begin(),
2131 OE = MI.operands_end(); OI != OE; ++OI) {
2132 const MachineOperand& OP = *OI;
2133 if (OP.isJTI())
2134 return false;
2135 if (OP.isMBB() && OP.getMBB() == MBB)
2136 return false;
2137 }
2138 }
2140 return true;
2141 }
2145 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2146 if (!S->usesMetadata())
2147 return 0;
2149 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2150 gcp_map_type::iterator GCPI = GCMap.find(S);
2151 if (GCPI != GCMap.end())
2152 return GCPI->second;
2154 const char *Name = S->getName().c_str();
2156 for (GCMetadataPrinterRegistry::iterator
2157 I = GCMetadataPrinterRegistry::begin(),
2158 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2159 if (strcmp(Name, I->getName()) == 0) {
2160 GCMetadataPrinter *GMP = I->instantiate();
2161 GMP->S = S;
2162 GCMap.insert(std::make_pair(S, GMP));
2163 return GMP;
2164 }
2166 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2167 }