LLVM 19.0.0git
AsmPrinter.cpp
Go to the documentation of this file.
1//===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the AsmPrinter class.
10//
11//===----------------------------------------------------------------------===//
12
14#include "CodeViewDebug.h"
15#include "DwarfDebug.h"
16#include "DwarfException.h"
17#include "PseudoProbePrinter.h"
18#include "WasmException.h"
19#include "WinCFGuard.h"
20#include "WinException.h"
21#include "llvm/ADT/APFloat.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
28#include "llvm/ADT/Statistic.h"
30#include "llvm/ADT/StringRef.h"
32#include "llvm/ADT/Twine.h"
64#include "llvm/Config/config.h"
65#include "llvm/IR/BasicBlock.h"
66#include "llvm/IR/Comdat.h"
67#include "llvm/IR/Constant.h"
68#include "llvm/IR/Constants.h"
69#include "llvm/IR/DataLayout.h"
73#include "llvm/IR/Function.h"
74#include "llvm/IR/GCStrategy.h"
75#include "llvm/IR/GlobalAlias.h"
76#include "llvm/IR/GlobalIFunc.h"
78#include "llvm/IR/GlobalValue.h"
80#include "llvm/IR/Instruction.h"
81#include "llvm/IR/Mangler.h"
82#include "llvm/IR/Metadata.h"
83#include "llvm/IR/Module.h"
84#include "llvm/IR/Operator.h"
85#include "llvm/IR/PseudoProbe.h"
86#include "llvm/IR/Type.h"
87#include "llvm/IR/Value.h"
88#include "llvm/IR/ValueHandle.h"
89#include "llvm/MC/MCAsmInfo.h"
90#include "llvm/MC/MCContext.h"
92#include "llvm/MC/MCExpr.h"
93#include "llvm/MC/MCInst.h"
94#include "llvm/MC/MCSection.h"
99#include "llvm/MC/MCStreamer.h"
101#include "llvm/MC/MCSymbol.h"
102#include "llvm/MC/MCSymbolELF.h"
104#include "llvm/MC/MCValue.h"
105#include "llvm/MC/SectionKind.h"
106#include "llvm/Object/ELFTypes.h"
107#include "llvm/Pass.h"
109#include "llvm/Support/Casting.h"
113#include "llvm/Support/Format.h"
115#include "llvm/Support/Path.h"
116#include "llvm/Support/VCSRevision.h"
122#include <algorithm>
123#include <cassert>
124#include <cinttypes>
125#include <cstdint>
126#include <iterator>
127#include <memory>
128#include <optional>
129#include <string>
130#include <utility>
131#include <vector>
132
133using namespace llvm;
134
135#define DEBUG_TYPE "asm-printer"
136
137// This is a replication of fields of object::PGOAnalysisMap::Features. It
138// should match the order of the fields so that
139// `object::PGOAnalysisMap::Features::decode(PgoAnalysisMapFeatures.getBits())`
140// succeeds.
143 BBFreq,
144 BrProb,
145};
147 "pgo-analysis-map", cl::Hidden, cl::CommaSeparated,
149 "func-entry-count", "Function Entry Count"),
151 "Basic Block Frequency"),
153 "Branch Probability")),
154 cl::desc(
155 "Enable extended information within the SHT_LLVM_BB_ADDR_MAP that is "
156 "extracted from PGO related analysis."));
157
158STATISTIC(EmittedInsts, "Number of machine instrs printed");
159
160char AsmPrinter::ID = 0;
161
162namespace {
163class AddrLabelMapCallbackPtr final : CallbackVH {
164 AddrLabelMap *Map = nullptr;
165
166public:
167 AddrLabelMapCallbackPtr() = default;
168 AddrLabelMapCallbackPtr(Value *V) : CallbackVH(V) {}
169
170 void setPtr(BasicBlock *BB) {
172 }
173
174 void setMap(AddrLabelMap *map) { Map = map; }
175
176 void deleted() override;
177 void allUsesReplacedWith(Value *V2) override;
178};
179} // namespace
180
182 MCContext &Context;
183 struct AddrLabelSymEntry {
184 /// The symbols for the label.
186
187 Function *Fn; // The containing function of the BasicBlock.
188 unsigned Index; // The index in BBCallbacks for the BasicBlock.
189 };
190
191 DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
192
193 /// Callbacks for the BasicBlock's that we have entries for. We use this so
194 /// we get notified if a block is deleted or RAUWd.
195 std::vector<AddrLabelMapCallbackPtr> BBCallbacks;
196
197 /// This is a per-function list of symbols whose corresponding BasicBlock got
198 /// deleted. These symbols need to be emitted at some point in the file, so
199 /// AsmPrinter emits them after the function body.
200 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>
201 DeletedAddrLabelsNeedingEmission;
202
203public:
204 AddrLabelMap(MCContext &context) : Context(context) {}
205
207 assert(DeletedAddrLabelsNeedingEmission.empty() &&
208 "Some labels for deleted blocks never got emitted");
209 }
210
212
214 std::vector<MCSymbol *> &Result);
215
218};
219
221 assert(BB->hasAddressTaken() &&
222 "Shouldn't get label for block without address taken");
223 AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
224
225 // If we already had an entry for this block, just return it.
226 if (!Entry.Symbols.empty()) {
227 assert(BB->getParent() == Entry.Fn && "Parent changed");
228 return Entry.Symbols;
229 }
230
231 // Otherwise, this is a new entry, create a new symbol for it and add an
232 // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
233 BBCallbacks.emplace_back(BB);
234 BBCallbacks.back().setMap(this);
235 Entry.Index = BBCallbacks.size() - 1;
236 Entry.Fn = BB->getParent();
238 : Context.createTempSymbol();
239 Entry.Symbols.push_back(Sym);
240 return Entry.Symbols;
241}
242
243/// If we have any deleted symbols for F, return them.
245 Function *F, std::vector<MCSymbol *> &Result) {
246 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>::iterator I =
247 DeletedAddrLabelsNeedingEmission.find(F);
248
249 // If there are no entries for the function, just return.
250 if (I == DeletedAddrLabelsNeedingEmission.end())
251 return;
252
253 // Otherwise, take the list.
254 std::swap(Result, I->second);
255 DeletedAddrLabelsNeedingEmission.erase(I);
256}
257
258//===- Address of Block Management ----------------------------------------===//
259
262 // Lazily create AddrLabelSymbols.
263 if (!AddrLabelSymbols)
264 AddrLabelSymbols = std::make_unique<AddrLabelMap>(OutContext);
265 return AddrLabelSymbols->getAddrLabelSymbolToEmit(
266 const_cast<BasicBlock *>(BB));
267}
268
270 const Function *F, std::vector<MCSymbol *> &Result) {
271 // If no blocks have had their addresses taken, we're done.
272 if (!AddrLabelSymbols)
273 return;
274 return AddrLabelSymbols->takeDeletedSymbolsForFunction(
275 const_cast<Function *>(F), Result);
276}
277
279 // If the block got deleted, there is no need for the symbol. If the symbol
280 // was already emitted, we can just forget about it, otherwise we need to
281 // queue it up for later emission when the function is output.
282 AddrLabelSymEntry Entry = std::move(AddrLabelSymbols[BB]);
283 AddrLabelSymbols.erase(BB);
284 assert(!Entry.Symbols.empty() && "Didn't have a symbol, why a callback?");
285 BBCallbacks[Entry.Index] = nullptr; // Clear the callback.
286
287#if !LLVM_MEMORY_SANITIZER_BUILD
288 // BasicBlock is destroyed already, so this access is UB detectable by msan.
289 assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
290 "Block/parent mismatch");
291#endif
292
293 for (MCSymbol *Sym : Entry.Symbols) {
294 if (Sym->isDefined())
295 return;
296
297 // If the block is not yet defined, we need to emit it at the end of the
298 // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
299 // for the containing Function. Since the block is being deleted, its
300 // parent may already be removed, we have to get the function from 'Entry'.
301 DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
302 }
303}
304
306 // Get the entry for the RAUW'd block and remove it from our map.
307 AddrLabelSymEntry OldEntry = std::move(AddrLabelSymbols[Old]);
308 AddrLabelSymbols.erase(Old);
309 assert(!OldEntry.Symbols.empty() && "Didn't have a symbol, why a callback?");
310
311 AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
312
313 // If New is not address taken, just move our symbol over to it.
314 if (NewEntry.Symbols.empty()) {
315 BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
316 NewEntry = std::move(OldEntry); // Set New's entry.
317 return;
318 }
319
320 BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
321
322 // Otherwise, we need to add the old symbols to the new block's set.
323 llvm::append_range(NewEntry.Symbols, OldEntry.Symbols);
324}
325
326void AddrLabelMapCallbackPtr::deleted() {
327 Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr()));
328}
329
330void AddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
331 Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
332}
333
334/// getGVAlignment - Return the alignment to use for the specified global
335/// value. This rounds up to the preferred alignment if possible and legal.
337 Align InAlign) {
338 Align Alignment;
339 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
340 Alignment = DL.getPreferredAlign(GVar);
341
342 // If InAlign is specified, round it to it.
343 if (InAlign > Alignment)
344 Alignment = InAlign;
345
346 // If the GV has a specified alignment, take it into account.
347 const MaybeAlign GVAlign(GV->getAlign());
348 if (!GVAlign)
349 return Alignment;
350
351 assert(GVAlign && "GVAlign must be set");
352
353 // If the GVAlign is larger than NumBits, or if we are required to obey
354 // NumBits because the GV has an assigned section, obey it.
355 if (*GVAlign > Alignment || GV->hasSection())
356 Alignment = *GVAlign;
357 return Alignment;
358}
359
360AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
361 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
362 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
363 SM(*this) {
364 VerboseAsm = OutStreamer->isVerboseAsm();
365 DwarfUsesRelocationsAcrossSections =
367}
368
370 assert(!DD && Handlers.size() == NumUserHandlers &&
371 "Debug/EH info didn't get finalized");
372}
373
375 return TM.isPositionIndependent();
376}
377
378/// getFunctionNumber - Return a unique ID for the current function.
380 return MF->getFunctionNumber();
381}
382
384 return *TM.getObjFileLowering();
385}
386
388 assert(MMI && "MMI could not be nullptr!");
389 return MMI->getModule()->getDataLayout();
390}
391
392// Do not use the cached DataLayout because some client use it without a Module
393// (dsymutil, llvm-dwarfdump).
395 return TM.getPointerSize(0); // FIXME: Default address space
396}
397
399 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
401}
402
405}
406
408 if (DD) {
409 assert(OutStreamer->hasRawTextSupport() &&
410 "Expected assembly output mode.");
411 // This is NVPTX specific and it's unclear why.
412 // PR51079: If we have code without debug information we need to give up.
414 if (!MFSP)
415 return;
416 (void)DD->emitInitialLocDirective(MF, /*CUID=*/0);
417 }
418}
419
420/// getCurrentSection() - Return the current section we are emitting to.
422 return OutStreamer->getCurrentSectionOnly();
423}
424
426 AU.setPreservesAll();
432}
433
435 auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>();
436 MMI = MMIWP ? &MMIWP->getMMI() : nullptr;
437 HasSplitStack = false;
438 HasNoSplitStack = false;
439
440 AddrLabelSymbols = nullptr;
441
442 // Initialize TargetLoweringObjectFile.
444 .Initialize(OutContext, TM);
445
447 .getModuleMetadata(M);
448
449 // On AIX, we delay emitting any section information until
450 // after emitting the .file pseudo-op. This allows additional
451 // information (such as the embedded command line) to be associated
452 // with all sections in the object file rather than a single section.
454 OutStreamer->initSections(false, *TM.getMCSubtargetInfo());
455
456 // Emit the version-min deployment target directive if needed.
457 //
458 // FIXME: If we end up with a collection of these sorts of Darwin-specific
459 // or ELF-specific things, it may make sense to have a platform helper class
460 // that will work with the target helper class. For now keep it here, as the
461 // alternative is duplicated code in each of the target asm printers that
462 // use the directive, where it would need the same conditionalization
463 // anyway.
464 const Triple &Target = TM.getTargetTriple();
465 if (Target.isOSBinFormatMachO() && Target.isOSDarwin()) {
466 Triple TVT(M.getDarwinTargetVariantTriple());
467 OutStreamer->emitVersionForTarget(
468 Target, M.getSDKVersion(),
469 M.getDarwinTargetVariantTriple().empty() ? nullptr : &TVT,
470 M.getDarwinTargetVariantSDKVersion());
471 }
472
473 // Allow the target to emit any magic that it wants at the start of the file.
475
476 // Very minimal debug info. It is ignored if we emit actual debug info. If we
477 // don't, this at least helps the user find where a global came from.
479 // .file "foo.c"
480
481 SmallString<128> FileName;
483 FileName = llvm::sys::path::filename(M.getSourceFileName());
484 else
485 FileName = M.getSourceFileName();
486 if (MAI->hasFourStringsDotFile()) {
487 const char VerStr[] =
488#ifdef PACKAGE_VENDOR
489 PACKAGE_VENDOR " "
490#endif
491 PACKAGE_NAME " version " PACKAGE_VERSION
492#ifdef LLVM_REVISION
493 " (" LLVM_REVISION ")"
494#endif
495 ;
496 // TODO: Add timestamp and description.
497 OutStreamer->emitFileDirective(FileName, VerStr, "", "");
498 } else {
499 OutStreamer->emitFileDirective(FileName);
500 }
501 }
502
503 // On AIX, emit bytes for llvm.commandline metadata after .file so that the
504 // C_INFO symbol is preserved if any csect is kept by the linker.
506 emitModuleCommandLines(M);
507 // Now we can generate section information.
508 OutStreamer->initSections(false, *TM.getMCSubtargetInfo());
509
510 // To work around an AIX assembler and/or linker bug, generate
511 // a rename for the default text-section symbol name. This call has
512 // no effect when generating object code directly.
513 MCSection *TextSection =
514 OutStreamer->getContext().getObjectFileInfo()->getTextSection();
515 MCSymbolXCOFF *XSym =
516 static_cast<MCSectionXCOFF *>(TextSection)->getQualNameSymbol();
517 if (XSym->hasRename())
518 OutStreamer->emitXCOFFRenameDirective(XSym, XSym->getSymbolTableName());
519 }
520
521 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
522 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
523 for (const auto &I : *MI)
524 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(*I))
525 MP->beginAssembly(M, *MI, *this);
526
527 // Emit module-level inline asm if it exists.
528 if (!M.getModuleInlineAsm().empty()) {
529 OutStreamer->AddComment("Start of file scope inline assembly");
530 OutStreamer->addBlankLine();
531 emitInlineAsm(
532 M.getModuleInlineAsm() + "\n", *TM.getMCSubtargetInfo(),
533 TM.Options.MCOptions, nullptr,
535 OutStreamer->AddComment("End of file scope inline assembly");
536 OutStreamer->addBlankLine();
537 }
538
540 bool EmitCodeView = M.getCodeViewFlag();
541 if (EmitCodeView && TM.getTargetTriple().isOSWindows())
542 DebugHandlers.push_back(std::make_unique<CodeViewDebug>(this));
543 if (!EmitCodeView || M.getDwarfVersion()) {
544 assert(MMI && "MMI could not be nullptr here!");
545 if (MMI->hasDebugInfo()) {
546 DD = new DwarfDebug(this);
547 DebugHandlers.push_back(std::unique_ptr<DwarfDebug>(DD));
548 }
549 }
550 }
551
552 if (M.getNamedMetadata(PseudoProbeDescMetadataName))
553 PP = std::make_unique<PseudoProbeHandler>(this);
554
555 switch (MAI->getExceptionHandlingType()) {
557 // We may want to emit CFI for debug.
558 [[fallthrough]];
562 for (auto &F : M.getFunctionList()) {
564 ModuleCFISection = getFunctionCFISectionType(F);
565 // If any function needsUnwindTableEntry(), it needs .eh_frame and hence
566 // the module needs .eh_frame. If we have found that case, we are done.
567 if (ModuleCFISection == CFISection::EH)
568 break;
569 }
571 usesCFIWithoutEH() || ModuleCFISection != CFISection::EH);
572 break;
573 default:
574 break;
575 }
576
577 EHStreamer *ES = nullptr;
578 switch (MAI->getExceptionHandlingType()) {
580 if (!usesCFIWithoutEH())
581 break;
582 [[fallthrough]];
586 ES = new DwarfCFIException(this);
587 break;
589 ES = new ARMException(this);
590 break;
592 switch (MAI->getWinEHEncodingType()) {
593 default: llvm_unreachable("unsupported unwinding information encoding");
595 break;
598 ES = new WinException(this);
599 break;
600 }
601 break;
603 ES = new WasmException(this);
604 break;
606 ES = new AIXException(this);
607 break;
608 }
609 if (ES)
610 Handlers.push_back(std::unique_ptr<EHStreamer>(ES));
611
612 // Emit tables for any value of cfguard flag (i.e. cfguard=1 or cfguard=2).
613 if (mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("cfguard")))
614 Handlers.push_back(std::make_unique<WinCFGuard>(this));
615
616 for (auto &Handler : DebugHandlers)
617 Handler->beginModule(&M);
618 for (auto &Handler : Handlers)
619 Handler->beginModule(&M);
620
621 return false;
622}
623
624static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
626 return false;
627
628 return GV->canBeOmittedFromSymbolTable();
629}
630
631void AsmPrinter::emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
633 switch (Linkage) {
639 if (MAI->hasWeakDefDirective()) {
640 // .globl _foo
641 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
642
643 if (!canBeHidden(GV, *MAI))
644 // .weak_definition _foo
645 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefinition);
646 else
647 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
648 } else if (MAI->avoidWeakIfComdat() && GV->hasComdat()) {
649 // .globl _foo
650 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
651 //NOTE: linkonce is handled by the section the symbol was assigned to.
652 } else {
653 // .weak _foo
654 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Weak);
655 }
656 return;
658 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
659 return;
662 return;
666 llvm_unreachable("Should never emit this");
667 }
668 llvm_unreachable("Unknown linkage type!");
669}
670
672 const GlobalValue *GV) const {
673 TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
674}
675
677 return TM.getSymbol(GV);
678}
679
681 // On ELF, use .Lfoo$local if GV is a non-interposable GlobalObject with an
682 // exact definion (intersection of GlobalValue::hasExactDefinition() and
683 // !isInterposable()). These linkages include: external, appending, internal,
684 // private. It may be profitable to use a local alias for external. The
685 // assembler would otherwise be conservative and assume a global default
686 // visibility symbol can be interposable, even if the code generator already
687 // assumed it.
689 const Module &M = *GV.getParent();
691 M.getPIELevel() == PIELevel::Default && GV.isDSOLocal())
692 return getSymbolWithGlobalValueBase(&GV, "$local");
693 }
694 return TM.getSymbol(&GV);
695}
696
697/// EmitGlobalVariable - Emit the specified global variable to the .s file.
699 bool IsEmuTLSVar = TM.useEmulatedTLS() && GV->isThreadLocal();
700 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
701 "No emulated TLS variables in the common section");
702
703 // Never emit TLS variable xyz in emulated TLS model.
704 // The initialization value is in __emutls_t.xyz instead of xyz.
705 if (IsEmuTLSVar)
706 return;
707
708 if (GV->hasInitializer()) {
709 // Check to see if this is a special global used by LLVM, if so, emit it.
710 if (emitSpecialLLVMGlobal(GV))
711 return;
712
713 // Skip the emission of global equivalents. The symbol can be emitted later
714 // on by emitGlobalGOTEquivs in case it turns out to be needed.
715 if (GlobalGOTEquivs.count(getSymbol(GV)))
716 return;
717
718 if (isVerbose()) {
719 // When printing the control variable __emutls_v.*,
720 // we don't need to print the original TLS variable name.
721 GV->printAsOperand(OutStreamer->getCommentOS(),
722 /*PrintType=*/false, GV->getParent());
723 OutStreamer->getCommentOS() << '\n';
724 }
725 }
726
727 MCSymbol *GVSym = getSymbol(GV);
728 MCSymbol *EmittedSym = GVSym;
729
730 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
731 // attributes.
732 // GV's or GVSym's attributes will be used for the EmittedSym.
733 emitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
734
735 if (GV->isTagged()) {
737
738 if (T.getArch() != Triple::aarch64 || !T.isAndroid())
740 "tagged symbols (-fsanitize=memtag-globals) are "
741 "only supported on AArch64 Android");
742 OutStreamer->emitSymbolAttribute(EmittedSym, MAI->getMemtagAttr());
743 }
744
745 if (!GV->hasInitializer()) // External globals require no extra code.
746 return;
747
748 GVSym->redefineIfPossible();
749 if (GVSym->isDefined() || GVSym->isVariable())
750 OutContext.reportError(SMLoc(), "symbol '" + Twine(GVSym->getName()) +
751 "' is already defined");
752
754 OutStreamer->emitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
755
757
758 const DataLayout &DL = GV->getDataLayout();
759 uint64_t Size = DL.getTypeAllocSize(GV->getValueType());
760
761 // If the alignment is specified, we *must* obey it. Overaligning a global
762 // with a specified alignment is a prompt way to break globals emitted to
763 // sections and expected to be contiguous (e.g. ObjC metadata).
764 const Align Alignment = getGVAlignment(GV, DL);
765
766 for (auto &Handler : DebugHandlers)
767 Handler->setSymbolSize(GVSym, Size);
768
769 // Handle common symbols
770 if (GVKind.isCommon()) {
771 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
772 // .comm _foo, 42, 4
773 OutStreamer->emitCommonSymbol(GVSym, Size, Alignment);
774 return;
775 }
776
777 // Determine to which section this global should be emitted.
778 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
779
780 // If we have a bss global going to a section that supports the
781 // zerofill directive, do so here.
782 if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
783 TheSection->isVirtualSection()) {
784 if (Size == 0)
785 Size = 1; // zerofill of 0 bytes is undefined.
786 emitLinkage(GV, GVSym);
787 // .zerofill __DATA, __bss, _foo, 400, 5
788 OutStreamer->emitZerofill(TheSection, GVSym, Size, Alignment);
789 return;
790 }
791
792 // If this is a BSS local symbol and we are emitting in the BSS
793 // section use .lcomm/.comm directive.
794 if (GVKind.isBSSLocal() &&
795 getObjFileLowering().getBSSSection() == TheSection) {
796 if (Size == 0)
797 Size = 1; // .comm Foo, 0 is undefined, avoid it.
798
799 // Use .lcomm only if it supports user-specified alignment.
800 // Otherwise, while it would still be correct to use .lcomm in some
801 // cases (e.g. when Align == 1), the external assembler might enfore
802 // some -unknown- default alignment behavior, which could cause
803 // spurious differences between external and integrated assembler.
804 // Prefer to simply fall back to .local / .comm in this case.
806 // .lcomm _foo, 42
807 OutStreamer->emitLocalCommonSymbol(GVSym, Size, Alignment);
808 return;
809 }
810
811 // .local _foo
812 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Local);
813 // .comm _foo, 42, 4
814 OutStreamer->emitCommonSymbol(GVSym, Size, Alignment);
815 return;
816 }
817
818 // Handle thread local data for mach-o which requires us to output an
819 // additional structure of data and mangle the original symbol so that we
820 // can reference it later.
821 //
822 // TODO: This should become an "emit thread local global" method on TLOF.
823 // All of this macho specific stuff should be sunk down into TLOFMachO and
824 // stuff like "TLSExtraDataSection" should no longer be part of the parent
825 // TLOF class. This will also make it more obvious that stuff like
826 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
827 // specific code.
828 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
829 // Emit the .tbss symbol
830 MCSymbol *MangSym =
831 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
832
833 if (GVKind.isThreadBSS()) {
834 TheSection = getObjFileLowering().getTLSBSSSection();
835 OutStreamer->emitTBSSSymbol(TheSection, MangSym, Size, Alignment);
836 } else if (GVKind.isThreadData()) {
837 OutStreamer->switchSection(TheSection);
838
839 emitAlignment(Alignment, GV);
840 OutStreamer->emitLabel(MangSym);
841
843 GV->getInitializer());
844 }
845
846 OutStreamer->addBlankLine();
847
848 // Emit the variable struct for the runtime.
850
851 OutStreamer->switchSection(TLVSect);
852 // Emit the linkage here.
853 emitLinkage(GV, GVSym);
854 OutStreamer->emitLabel(GVSym);
855
856 // Three pointers in size:
857 // - __tlv_bootstrap - used to make sure support exists
858 // - spare pointer, used when mapped by the runtime
859 // - pointer to mangled symbol above with initializer
860 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
861 OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
862 PtrSize);
863 OutStreamer->emitIntValue(0, PtrSize);
864 OutStreamer->emitSymbolValue(MangSym, PtrSize);
865
866 OutStreamer->addBlankLine();
867 return;
868 }
869
870 MCSymbol *EmittedInitSym = GVSym;
871
872 OutStreamer->switchSection(TheSection);
873
874 emitLinkage(GV, EmittedInitSym);
875 emitAlignment(Alignment, GV);
876
877 OutStreamer->emitLabel(EmittedInitSym);
878 MCSymbol *LocalAlias = getSymbolPreferLocal(*GV);
879 if (LocalAlias != EmittedInitSym)
880 OutStreamer->emitLabel(LocalAlias);
881
883
885 // .size foo, 42
886 OutStreamer->emitELFSize(EmittedInitSym,
888
889 OutStreamer->addBlankLine();
890}
891
892/// Emit the directive and value for debug thread local expression
893///
894/// \p Value - The value to emit.
895/// \p Size - The size of the integer (in bytes) to emit.
896void AsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const {
897 OutStreamer->emitValue(Value, Size);
898}
899
900void AsmPrinter::emitFunctionHeaderComment() {}
901
902void AsmPrinter::emitFunctionPrefix(ArrayRef<const Constant *> Prefix) {
903 const Function &F = MF->getFunction();
905 for (auto &C : Prefix)
906 emitGlobalConstant(F.getDataLayout(), C);
907 return;
908 }
909 // Preserving prefix-like data on platforms which use subsections-via-symbols
910 // is a bit tricky. Here we introduce a symbol for the prefix-like data
911 // and use the .alt_entry attribute to mark the function's real entry point
912 // as an alternative entry point to the symbol that precedes the function..
914
915 for (auto &C : Prefix) {
916 emitGlobalConstant(F.getDataLayout(), C);
917 }
918
919 // Emit an .alt_entry directive for the actual function symbol.
920 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_AltEntry);
921}
922
923/// EmitFunctionHeader - This method emits the header for the current
924/// function.
925void AsmPrinter::emitFunctionHeader() {
926 const Function &F = MF->getFunction();
927
928 if (isVerbose())
929 OutStreamer->getCommentOS()
930 << "-- Begin function "
931 << GlobalValue::dropLLVMManglingEscape(F.getName()) << '\n';
932
933 // Print out constants referenced by the function
935
936 // Print the 'header' of function.
937 // If basic block sections are desired, explicitly request a unique section
938 // for this function's entry block.
939 if (MF->front().isBeginSection())
940 MF->setSection(getObjFileLowering().getUniqueSectionForFunction(F, TM));
941 else
942 MF->setSection(getObjFileLowering().SectionForGlobal(&F, TM));
943 OutStreamer->switchSection(MF->getSection());
944
946 emitVisibility(CurrentFnSym, F.getVisibility());
947
950
954
956 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
957
958 if (F.hasFnAttribute(Attribute::Cold))
959 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_Cold);
960
961 // Emit the prefix data.
962 if (F.hasPrefixData())
963 emitFunctionPrefix({F.getPrefixData()});
964
965 // Emit KCFI type information before patchable-function-prefix nops.
967
968 // Emit M NOPs for -fpatchable-function-entry=N,M where M>0. We arbitrarily
969 // place prefix data before NOPs.
970 unsigned PatchableFunctionPrefix = 0;
971 unsigned PatchableFunctionEntry = 0;
972 (void)F.getFnAttribute("patchable-function-prefix")
973 .getValueAsString()
974 .getAsInteger(10, PatchableFunctionPrefix);
975 (void)F.getFnAttribute("patchable-function-entry")
976 .getValueAsString()
977 .getAsInteger(10, PatchableFunctionEntry);
978 if (PatchableFunctionPrefix) {
982 emitNops(PatchableFunctionPrefix);
983 } else if (PatchableFunctionEntry) {
984 // May be reassigned when emitting the body, to reference the label after
985 // the initial BTI (AArch64) or endbr32/endbr64 (x86).
987 }
988
989 // Emit the function prologue data for the indirect call sanitizer.
990 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_func_sanitize)) {
991 assert(MD->getNumOperands() == 2);
992
993 auto *PrologueSig = mdconst::extract<Constant>(MD->getOperand(0));
994 auto *TypeHash = mdconst::extract<Constant>(MD->getOperand(1));
995 emitFunctionPrefix({PrologueSig, TypeHash});
996 }
997
998 if (isVerbose()) {
999 F.printAsOperand(OutStreamer->getCommentOS(),
1000 /*PrintType=*/false, F.getParent());
1001 emitFunctionHeaderComment();
1002 OutStreamer->getCommentOS() << '\n';
1003 }
1004
1005 // Emit the function descriptor. This is a virtual function to allow targets
1006 // to emit their specific function descriptor. Right now it is only used by
1007 // the AIX target. The PowerPC 64-bit V1 ELF target also uses function
1008 // descriptors and should be converted to use this hook as well.
1011
1012 // Emit the CurrentFnSym. This is a virtual function to allow targets to do
1013 // their wild and crazy things as required.
1015
1016 // If the function had address-taken blocks that got deleted, then we have
1017 // references to the dangling symbols. Emit them at the start of the function
1018 // so that we don't get references to undefined symbols.
1019 std::vector<MCSymbol*> DeadBlockSyms;
1020 takeDeletedSymbolsForFunction(&F, DeadBlockSyms);
1021 for (MCSymbol *DeadBlockSym : DeadBlockSyms) {
1022 OutStreamer->AddComment("Address taken block that was later removed");
1023 OutStreamer->emitLabel(DeadBlockSym);
1024 }
1025
1026 if (CurrentFnBegin) {
1029 OutStreamer->emitLabel(CurPos);
1030 OutStreamer->emitAssignment(CurrentFnBegin,
1032 } else {
1033 OutStreamer->emitLabel(CurrentFnBegin);
1034 }
1035 }
1036
1037 // Emit pre-function debug and/or EH information.
1038 for (auto &Handler : DebugHandlers) {
1039 Handler->beginFunction(MF);
1040 Handler->beginBasicBlockSection(MF->front());
1041 }
1042 for (auto &Handler : Handlers)
1043 Handler->beginFunction(MF);
1044 for (auto &Handler : Handlers)
1045 Handler->beginBasicBlockSection(MF->front());
1046
1047 // Emit the prologue data.
1048 if (F.hasPrologueData())
1049 emitGlobalConstant(F.getDataLayout(), F.getPrologueData());
1050}
1051
1052/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
1053/// function. This can be overridden by targets as required to do custom stuff.
1056
1057 // The function label could have already been emitted if two symbols end up
1058 // conflicting due to asm renaming. Detect this and emit an error.
1059 if (CurrentFnSym->isVariable())
1061 "' is a protected alias");
1062
1063 OutStreamer->emitLabel(CurrentFnSym);
1064
1067 if (Sym != CurrentFnSym) {
1068 cast<MCSymbolELF>(Sym)->setType(ELF::STT_FUNC);
1070 OutStreamer->emitLabel(Sym);
1072 OutStreamer->emitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
1073 }
1074 }
1075}
1076
1077/// emitComments - Pretty-print comments for instructions.
1078static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
1079 const MachineFunction *MF = MI.getMF();
1081
1082 // Check for spills and reloads
1083
1084 // We assume a single instruction only has a spill or reload, not
1085 // both.
1086 std::optional<LocationSize> Size;
1087 if ((Size = MI.getRestoreSize(TII))) {
1088 CommentOS << Size->getValue() << "-byte Reload\n";
1089 } else if ((Size = MI.getFoldedRestoreSize(TII))) {
1090 if (!Size->hasValue())
1091 CommentOS << "Unknown-size Folded Reload\n";
1092 else if (Size->getValue())
1093 CommentOS << Size->getValue() << "-byte Folded Reload\n";
1094 } else if ((Size = MI.getSpillSize(TII))) {
1095 CommentOS << Size->getValue() << "-byte Spill\n";
1096 } else if ((Size = MI.getFoldedSpillSize(TII))) {
1097 if (!Size->hasValue())
1098 CommentOS << "Unknown-size Folded Spill\n";
1099 else if (Size->getValue())
1100 CommentOS << Size->getValue() << "-byte Folded Spill\n";
1101 }
1102
1103 // Check for spill-induced copies
1104 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
1105 CommentOS << " Reload Reuse\n";
1106}
1107
1108/// emitImplicitDef - This method emits the specified machine instruction
1109/// that is an implicit def.
1111 Register RegNo = MI->getOperand(0).getReg();
1112
1113 SmallString<128> Str;
1115 OS << "implicit-def: "
1116 << printReg(RegNo, MF->getSubtarget().getRegisterInfo());
1117
1118 OutStreamer->AddComment(OS.str());
1119 OutStreamer->addBlankLine();
1120}
1121
1122static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
1123 std::string Str;
1125 OS << "kill:";
1126 for (const MachineOperand &Op : MI->operands()) {
1127 assert(Op.isReg() && "KILL instruction must have only register operands");
1128 OS << ' ' << (Op.isDef() ? "def " : "killed ")
1129 << printReg(Op.getReg(), AP.MF->getSubtarget().getRegisterInfo());
1130 }
1131 AP.OutStreamer->AddComment(Str);
1132 AP.OutStreamer->addBlankLine();
1133}
1134
1135/// emitDebugValueComment - This method handles the target-independent form
1136/// of DBG_VALUE, returning true if it was able to do so. A false return
1137/// means the target will need to handle MI in EmitInstruction.
1139 // This code handles only the 4-operand target-independent form.
1140 if (MI->isNonListDebugValue() && MI->getNumOperands() != 4)
1141 return false;
1142
1143 SmallString<128> Str;
1145 OS << "DEBUG_VALUE: ";
1146
1147 const DILocalVariable *V = MI->getDebugVariable();
1148 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
1149 StringRef Name = SP->getName();
1150 if (!Name.empty())
1151 OS << Name << ":";
1152 }
1153 OS << V->getName();
1154 OS << " <- ";
1155
1156 const DIExpression *Expr = MI->getDebugExpression();
1157 // First convert this to a non-variadic expression if possible, to simplify
1158 // the output.
1159 if (auto NonVariadicExpr = DIExpression::convertToNonVariadicExpression(Expr))
1160 Expr = *NonVariadicExpr;
1161 // Then, output the possibly-simplified expression.
1162 if (Expr->getNumElements()) {
1163 OS << '[';
1164 ListSeparator LS;
1165 for (auto &Op : Expr->expr_ops()) {
1166 OS << LS << dwarf::OperationEncodingString(Op.getOp());
1167 for (unsigned I = 0; I < Op.getNumArgs(); ++I)
1168 OS << ' ' << Op.getArg(I);
1169 }
1170 OS << "] ";
1171 }
1172
1173 // Register or immediate value. Register 0 means undef.
1174 for (const MachineOperand &Op : MI->debug_operands()) {
1175 if (&Op != MI->debug_operands().begin())
1176 OS << ", ";
1177 switch (Op.getType()) {
1179 APFloat APF = APFloat(Op.getFPImm()->getValueAPF());
1180 Type *ImmTy = Op.getFPImm()->getType();
1181 if (ImmTy->isBFloatTy() || ImmTy->isHalfTy() || ImmTy->isFloatTy() ||
1182 ImmTy->isDoubleTy()) {
1183 OS << APF.convertToDouble();
1184 } else {
1185 // There is no good way to print long double. Convert a copy to
1186 // double. Ah well, it's only a comment.
1187 bool ignored;
1189 &ignored);
1190 OS << "(long double) " << APF.convertToDouble();
1191 }
1192 break;
1193 }
1195 OS << Op.getImm();
1196 break;
1197 }
1199 Op.getCImm()->getValue().print(OS, false /*isSigned*/);
1200 break;
1201 }
1203 OS << "!target-index(" << Op.getIndex() << "," << Op.getOffset() << ")";
1204 break;
1205 }
1208 Register Reg;
1209 std::optional<StackOffset> Offset;
1210 if (Op.isReg()) {
1211 Reg = Op.getReg();
1212 } else {
1213 const TargetFrameLowering *TFI =
1215 Offset = TFI->getFrameIndexReference(*AP.MF, Op.getIndex(), Reg);
1216 }
1217 if (!Reg) {
1218 // Suppress offset, it is not meaningful here.
1219 OS << "undef";
1220 break;
1221 }
1222 // The second operand is only an offset if it's an immediate.
1223 if (MI->isIndirectDebugValue())
1224 Offset = StackOffset::getFixed(MI->getDebugOffset().getImm());
1225 if (Offset)
1226 OS << '[';
1227 OS << printReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
1228 if (Offset)
1229 OS << '+' << Offset->getFixed() << ']';
1230 break;
1231 }
1232 default:
1233 llvm_unreachable("Unknown operand type");
1234 }
1235 }
1236
1237 // NOTE: Want this comment at start of line, don't emit with AddComment.
1238 AP.OutStreamer->emitRawComment(Str);
1239 return true;
1240}
1241
1242/// This method handles the target-independent form of DBG_LABEL, returning
1243/// true if it was able to do so. A false return means the target will need
1244/// to handle MI in EmitInstruction.
1246 if (MI->getNumOperands() != 1)
1247 return false;
1248
1249 SmallString<128> Str;
1251 OS << "DEBUG_LABEL: ";
1252
1253 const DILabel *V = MI->getDebugLabel();
1254 if (auto *SP = dyn_cast<DISubprogram>(
1255 V->getScope()->getNonLexicalBlockFileScope())) {
1256 StringRef Name = SP->getName();
1257 if (!Name.empty())
1258 OS << Name << ":";
1259 }
1260 OS << V->getName();
1261
1262 // NOTE: Want this comment at start of line, don't emit with AddComment.
1263 AP.OutStreamer->emitRawComment(OS.str());
1264 return true;
1265}
1266
1269 // Ignore functions that won't get emitted.
1270 if (F.isDeclarationForLinker())
1271 return CFISection::None;
1272
1274 F.needsUnwindTableEntry())
1275 return CFISection::EH;
1276
1277 if (MAI->usesCFIWithoutEH() && F.hasUWTable())
1278 return CFISection::EH;
1279
1280 assert(MMI != nullptr && "Invalid machine module info");
1282 return CFISection::Debug;
1283
1284 return CFISection::None;
1285}
1286
1290}
1291
1294}
1295
1297 return MAI->usesCFIWithoutEH() && ModuleCFISection != CFISection::None;
1298}
1299
1301 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
1302 if (!usesCFIWithoutEH() &&
1303 ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
1304 ExceptionHandlingType != ExceptionHandling::ARM)
1305 return;
1306
1308 return;
1309
1310 // If there is no "real" instruction following this CFI instruction, skip
1311 // emitting it; it would be beyond the end of the function's FDE range.
1312 auto *MBB = MI.getParent();
1313 auto I = std::next(MI.getIterator());
1314 while (I != MBB->end() && I->isTransient())
1315 ++I;
1316 if (I == MBB->instr_end() &&
1318 return;
1319
1320 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
1321 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
1322 const MCCFIInstruction &CFI = Instrs[CFIIndex];
1323 emitCFIInstruction(CFI);
1324}
1325
1327 // The operands are the MCSymbol and the frame offset of the allocation.
1328 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
1329 int FrameOffset = MI.getOperand(1).getImm();
1330
1331 // Emit a symbol assignment.
1332 OutStreamer->emitAssignment(FrameAllocSym,
1333 MCConstantExpr::create(FrameOffset, OutContext));
1334}
1335
1336/// Returns the BB metadata to be emitted in the SHT_LLVM_BB_ADDR_MAP section
1337/// for a given basic block. This can be used to capture more precise profile
1338/// information.
1343 MBB.isEHPad(), const_cast<MachineBasicBlock &>(MBB).canFallThrough(),
1344 !MBB.empty() && MBB.rbegin()->isIndirectBranch()}
1345 .encode();
1346}
1347
1349getBBAddrMapFeature(const MachineFunction &MF, int NumMBBSectionRanges) {
1350 return {PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::FuncEntryCount),
1351 PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::BBFreq),
1352 PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::BrProb),
1353 MF.hasBBSections() && NumMBBSectionRanges > 1};
1354}
1355
1357 MCSection *BBAddrMapSection =
1359 assert(BBAddrMapSection && ".llvm_bb_addr_map section is not initialized.");
1360
1361 const MCSymbol *FunctionSymbol = getFunctionBegin();
1362
1363 OutStreamer->pushSection();
1364 OutStreamer->switchSection(BBAddrMapSection);
1365 OutStreamer->AddComment("version");
1366 uint8_t BBAddrMapVersion = OutStreamer->getContext().getBBAddrMapVersion();
1367 OutStreamer->emitInt8(BBAddrMapVersion);
1368 OutStreamer->AddComment("feature");
1369 auto Features = getBBAddrMapFeature(MF, MBBSectionRanges.size());
1370 OutStreamer->emitInt8(Features.encode());
1371 // Emit BB Information for each basic block in the function.
1372 if (Features.MultiBBRange) {
1373 OutStreamer->AddComment("number of basic block ranges");
1374 OutStreamer->emitULEB128IntValue(MBBSectionRanges.size());
1375 }
1376 // Number of blocks in each MBB section.
1377 MapVector<MBBSectionID, unsigned> MBBSectionNumBlocks;
1378 const MCSymbol *PrevMBBEndSymbol = nullptr;
1379 if (!Features.MultiBBRange) {
1380 OutStreamer->AddComment("function address");
1381 OutStreamer->emitSymbolValue(FunctionSymbol, getPointerSize());
1382 OutStreamer->AddComment("number of basic blocks");
1383 OutStreamer->emitULEB128IntValue(MF.size());
1384 PrevMBBEndSymbol = FunctionSymbol;
1385 } else {
1386 unsigned BBCount = 0;
1387 for (const MachineBasicBlock &MBB : MF) {
1388 BBCount++;
1389 if (MBB.isEndSection()) {
1390 // Store each section's basic block count when it ends.
1391 MBBSectionNumBlocks[MBB.getSectionID()] = BBCount;
1392 // Reset the count for the next section.
1393 BBCount = 0;
1394 }
1395 }
1396 }
1397 // Emit the BB entry for each basic block in the function.
1398 for (const MachineBasicBlock &MBB : MF) {
1399 const MCSymbol *MBBSymbol =
1400 MBB.isEntryBlock() ? FunctionSymbol : MBB.getSymbol();
1401 bool IsBeginSection =
1402 Features.MultiBBRange && (MBB.isBeginSection() || MBB.isEntryBlock());
1403 if (IsBeginSection) {
1404 OutStreamer->AddComment("base address");
1405 OutStreamer->emitSymbolValue(MBBSymbol, getPointerSize());
1406 OutStreamer->AddComment("number of basic blocks");
1407 OutStreamer->emitULEB128IntValue(MBBSectionNumBlocks[MBB.getSectionID()]);
1408 PrevMBBEndSymbol = MBBSymbol;
1409 }
1410 // TODO: Remove this check when version 1 is deprecated.
1411 if (BBAddrMapVersion > 1) {
1412 OutStreamer->AddComment("BB id");
1413 // Emit the BB ID for this basic block.
1414 // We only emit BaseID since CloneID is unset for
1415 // basic-block-sections=labels.
1416 // TODO: Emit the full BBID when labels and sections can be mixed
1417 // together.
1418 OutStreamer->emitULEB128IntValue(MBB.getBBID()->BaseID);
1419 }
1420 // Emit the basic block offset relative to the end of the previous block.
1421 // This is zero unless the block is padded due to alignment.
1422 emitLabelDifferenceAsULEB128(MBBSymbol, PrevMBBEndSymbol);
1423 // Emit the basic block size. When BBs have alignments, their size cannot
1424 // always be computed from their offsets.
1426 // Emit the Metadata.
1427 OutStreamer->emitULEB128IntValue(getBBAddrMapMetadata(MBB));
1428 PrevMBBEndSymbol = MBB.getEndSymbol();
1429 }
1430
1431 if (Features.hasPGOAnalysis()) {
1432 assert(BBAddrMapVersion >= 2 &&
1433 "PGOAnalysisMap only supports version 2 or later");
1434
1435 if (Features.FuncEntryCount) {
1436 OutStreamer->AddComment("function entry count");
1437 auto MaybeEntryCount = MF.getFunction().getEntryCount();
1438 OutStreamer->emitULEB128IntValue(
1439 MaybeEntryCount ? MaybeEntryCount->getCount() : 0);
1440 }
1441 const MachineBlockFrequencyInfo *MBFI =
1442 Features.BBFreq
1443 ? &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI()
1444 : nullptr;
1445 const MachineBranchProbabilityInfo *MBPI =
1446 Features.BrProb
1447 ? &getAnalysis<MachineBranchProbabilityInfoWrapperPass>().getMBPI()
1448 : nullptr;
1449
1450 if (Features.BBFreq || Features.BrProb) {
1451 for (const MachineBasicBlock &MBB : MF) {
1452 if (Features.BBFreq) {
1453 OutStreamer->AddComment("basic block frequency");
1454 OutStreamer->emitULEB128IntValue(
1455 MBFI->getBlockFreq(&MBB).getFrequency());
1456 }
1457 if (Features.BrProb) {
1458 unsigned SuccCount = MBB.succ_size();
1459 OutStreamer->AddComment("basic block successor count");
1460 OutStreamer->emitULEB128IntValue(SuccCount);
1461 for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
1462 OutStreamer->AddComment("successor BB ID");
1463 OutStreamer->emitULEB128IntValue(SuccMBB->getBBID()->BaseID);
1464 OutStreamer->AddComment("successor branch probability");
1465 OutStreamer->emitULEB128IntValue(
1466 MBPI->getEdgeProbability(&MBB, SuccMBB).getNumerator());
1467 }
1468 }
1469 }
1470 }
1471 }
1472
1473 OutStreamer->popSection();
1474}
1475
1477 const MCSymbol *Symbol) {
1478 MCSection *Section =
1480 if (!Section)
1481 return;
1482
1483 OutStreamer->pushSection();
1484 OutStreamer->switchSection(Section);
1485
1487 OutStreamer->emitLabel(Loc);
1488 OutStreamer->emitAbsoluteSymbolDiff(Symbol, Loc, 4);
1489
1490 OutStreamer->popSection();
1491}
1492
1494 const Function &F = MF.getFunction();
1495 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_kcfi_type))
1496 emitGlobalConstant(F.getDataLayout(),
1497 mdconst::extract<ConstantInt>(MD->getOperand(0)));
1498}
1499
1501 if (PP) {
1502 auto GUID = MI.getOperand(0).getImm();
1503 auto Index = MI.getOperand(1).getImm();
1504 auto Type = MI.getOperand(2).getImm();
1505 auto Attr = MI.getOperand(3).getImm();
1506 DILocation *DebugLoc = MI.getDebugLoc();
1507 PP->emitPseudoProbe(GUID, Index, Type, Attr, DebugLoc);
1508 }
1509}
1510
1513 return;
1514
1515 MCSection *StackSizeSection =
1517 if (!StackSizeSection)
1518 return;
1519
1520 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1521 // Don't emit functions with dynamic stack allocations.
1522 if (FrameInfo.hasVarSizedObjects())
1523 return;
1524
1525 OutStreamer->pushSection();
1526 OutStreamer->switchSection(StackSizeSection);
1527
1528 const MCSymbol *FunctionSymbol = getFunctionBegin();
1529 uint64_t StackSize =
1530 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1531 OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
1532 OutStreamer->emitULEB128IntValue(StackSize);
1533
1534 OutStreamer->popSection();
1535}
1536
1538 const std::string &OutputFilename = MF.getTarget().Options.StackUsageOutput;
1539
1540 // OutputFilename empty implies -fstack-usage is not passed.
1541 if (OutputFilename.empty())
1542 return;
1543
1544 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1545 uint64_t StackSize =
1546 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1547
1548 if (StackUsageStream == nullptr) {
1549 std::error_code EC;
1550 StackUsageStream =
1551 std::make_unique<raw_fd_ostream>(OutputFilename, EC, sys::fs::OF_Text);
1552 if (EC) {
1553 errs() << "Could not open file: " << EC.message();
1554 return;
1555 }
1556 }
1557
1558 if (const DISubprogram *DSP = MF.getFunction().getSubprogram())
1559 *StackUsageStream << DSP->getFilename() << ':' << DSP->getLine();
1560 else
1561 *StackUsageStream << MF.getFunction().getParent()->getName();
1562
1563 *StackUsageStream << ':' << MF.getName() << '\t' << StackSize << '\t';
1564 if (FrameInfo.hasVarSizedObjects())
1565 *StackUsageStream << "dynamic\n";
1566 else
1567 *StackUsageStream << "static\n";
1568}
1569
1571 const MDNode &MD) {
1572 MCSymbol *S = MF.getContext().createTempSymbol("pcsection");
1573 OutStreamer->emitLabel(S);
1574 PCSectionsSymbols[&MD].emplace_back(S);
1575}
1576
1578 const Function &F = MF.getFunction();
1579 if (PCSectionsSymbols.empty() && !F.hasMetadata(LLVMContext::MD_pcsections))
1580 return;
1581
1583 const unsigned RelativeRelocSize =
1585 : 4;
1586
1587 // Switch to PCSection, short-circuiting the common case where the current
1588 // section is still valid (assume most MD_pcsections contain just 1 section).
1589 auto SwitchSection = [&, Prev = StringRef()](const StringRef &Sec) mutable {
1590 if (Sec == Prev)
1591 return;
1593 assert(S && "PC section is not initialized");
1594 OutStreamer->switchSection(S);
1595 Prev = Sec;
1596 };
1597 // Emit symbols into sections and data as specified in the pcsections MDNode.
1598 auto EmitForMD = [&](const MDNode &MD, ArrayRef<const MCSymbol *> Syms,
1599 bool Deltas) {
1600 // Expect the first operand to be a section name. After that, a tuple of
1601 // constants may appear, which will simply be emitted into the current
1602 // section (the user of MD_pcsections decides the format of encoded data).
1603 assert(isa<MDString>(MD.getOperand(0)) && "first operand not a string");
1604 bool ConstULEB128 = false;
1605 for (const MDOperand &MDO : MD.operands()) {
1606 if (auto *S = dyn_cast<MDString>(MDO)) {
1607 // Found string, start of new section!
1608 // Find options for this section "<section>!<opts>" - supported options:
1609 // C = Compress constant integers of size 2-8 bytes as ULEB128.
1610 const StringRef SecWithOpt = S->getString();
1611 const size_t OptStart = SecWithOpt.find('!'); // likely npos
1612 const StringRef Sec = SecWithOpt.substr(0, OptStart);
1613 const StringRef Opts = SecWithOpt.substr(OptStart); // likely empty
1614 ConstULEB128 = Opts.contains('C');
1615#ifndef NDEBUG
1616 for (char O : Opts)
1617 assert((O == '!' || O == 'C') && "Invalid !pcsections options");
1618#endif
1619 SwitchSection(Sec);
1620 const MCSymbol *Prev = Syms.front();
1621 for (const MCSymbol *Sym : Syms) {
1622 if (Sym == Prev || !Deltas) {
1623 // Use the entry itself as the base of the relative offset.
1624 MCSymbol *Base = MF.getContext().createTempSymbol("pcsection_base");
1625 OutStreamer->emitLabel(Base);
1626 // Emit relative relocation `addr - base`, which avoids a dynamic
1627 // relocation in the final binary. User will get the address with
1628 // `base + addr`.
1629 emitLabelDifference(Sym, Base, RelativeRelocSize);
1630 } else {
1631 // Emit delta between symbol and previous symbol.
1632 if (ConstULEB128)
1634 else
1635 emitLabelDifference(Sym, Prev, 4);
1636 }
1637 Prev = Sym;
1638 }
1639 } else {
1640 // Emit auxiliary data after PC.
1641 assert(isa<MDNode>(MDO) && "expecting either string or tuple");
1642 const auto *AuxMDs = cast<MDNode>(MDO);
1643 for (const MDOperand &AuxMDO : AuxMDs->operands()) {
1644 assert(isa<ConstantAsMetadata>(AuxMDO) && "expecting a constant");
1645 const Constant *C = cast<ConstantAsMetadata>(AuxMDO)->getValue();
1646 const DataLayout &DL = F.getDataLayout();
1647 const uint64_t Size = DL.getTypeStoreSize(C->getType());
1648
1649 if (auto *CI = dyn_cast<ConstantInt>(C);
1650 CI && ConstULEB128 && Size > 1 && Size <= 8) {
1651 emitULEB128(CI->getZExtValue());
1652 } else {
1654 }
1655 }
1656 }
1657 }
1658 };
1659
1660 OutStreamer->pushSection();
1661 // Emit PCs for function start and function size.
1662 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_pcsections))
1663 EmitForMD(*MD, {getFunctionBegin(), getFunctionEnd()}, true);
1664 // Emit PCs for instructions collected.
1665 for (const auto &MS : PCSectionsSymbols)
1666 EmitForMD(*MS.first, MS.second, false);
1667 OutStreamer->popSection();
1668 PCSectionsSymbols.clear();
1669}
1670
1671/// Returns true if function begin and end labels should be emitted.
1672static bool needFuncLabels(const MachineFunction &MF,
1673 const MachineModuleInfo &MMI) {
1674 if (!MF.getLandingPads().empty() || MF.hasEHFunclets() ||
1675 MMI.hasDebugInfo() ||
1676 MF.getFunction().hasMetadata(LLVMContext::MD_pcsections))
1677 return true;
1678
1679 // We might emit an EH table that uses function begin and end labels even if
1680 // we don't have any landingpads.
1681 if (!MF.getFunction().hasPersonalityFn())
1682 return false;
1683 return !isNoOpWithoutInvoke(
1685}
1686
1687/// EmitFunctionBody - This method emits the body and trailer for a
1688/// function.
1690 emitFunctionHeader();
1691
1692 // Emit target-specific gunk before the function body.
1694
1695 if (isVerbose()) {
1696 // Get MachineDominatorTree or compute it on the fly if it's unavailable
1697 auto MDTWrapper = getAnalysisIfAvailable<MachineDominatorTreeWrapperPass>();
1698 MDT = MDTWrapper ? &MDTWrapper->getDomTree() : nullptr;
1699 if (!MDT) {
1700 OwnedMDT = std::make_unique<MachineDominatorTree>();
1701 OwnedMDT->getBase().recalculate(*MF);
1702 MDT = OwnedMDT.get();
1703 }
1704
1705 // Get MachineLoopInfo or compute it on the fly if it's unavailable
1706 auto *MLIWrapper = getAnalysisIfAvailable<MachineLoopInfoWrapperPass>();
1707 MLI = MLIWrapper ? &MLIWrapper->getLI() : nullptr;
1708 if (!MLI) {
1709 OwnedMLI = std::make_unique<MachineLoopInfo>();
1710 OwnedMLI->analyze(MDT->getBase());
1711 MLI = OwnedMLI.get();
1712 }
1713 }
1714
1715 // Print out code for the function.
1716 bool HasAnyRealCode = false;
1717 int NumInstsInFunction = 0;
1718 bool IsEHa = MMI->getModule()->getModuleFlag("eh-asynch");
1719
1720 bool CanDoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
1721 for (auto &MBB : *MF) {
1722 // Print a label for the basic block.
1724 DenseMap<StringRef, unsigned> MnemonicCounts;
1725 for (auto &MI : MBB) {
1726 // Print the assembly for the instruction.
1727 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
1728 !MI.isDebugInstr()) {
1729 HasAnyRealCode = true;
1730 ++NumInstsInFunction;
1731 }
1732
1733 // If there is a pre-instruction symbol, emit a label for it here.
1734 if (MCSymbol *S = MI.getPreInstrSymbol())
1735 OutStreamer->emitLabel(S);
1736
1737 if (MDNode *MD = MI.getPCSections())
1738 emitPCSectionsLabel(*MF, *MD);
1739
1740 for (auto &Handler : DebugHandlers)
1741 Handler->beginInstruction(&MI);
1742
1743 if (isVerbose())
1744 emitComments(MI, OutStreamer->getCommentOS());
1745
1746 switch (MI.getOpcode()) {
1747 case TargetOpcode::CFI_INSTRUCTION:
1749 break;
1750 case TargetOpcode::LOCAL_ESCAPE:
1752 break;
1753 case TargetOpcode::ANNOTATION_LABEL:
1754 case TargetOpcode::GC_LABEL:
1755 OutStreamer->emitLabel(MI.getOperand(0).getMCSymbol());
1756 break;
1757 case TargetOpcode::EH_LABEL:
1758 OutStreamer->emitLabel(MI.getOperand(0).getMCSymbol());
1759 // For AsynchEH, insert a Nop if followed by a trap inst
1760 // Or the exception won't be caught.
1761 // (see MCConstantExpr::create(1,..) in WinException.cpp)
1762 // Ignore SDiv/UDiv because a DIV with Const-0 divisor
1763 // must have being turned into an UndefValue.
1764 // Div with variable opnds won't be the first instruction in
1765 // an EH region as it must be led by at least a Load
1766 {
1767 auto MI2 = std::next(MI.getIterator());
1768 if (IsEHa && MI2 != MBB.end() &&
1769 (MI2->mayLoadOrStore() || MI2->mayRaiseFPException()))
1770 emitNops(1);
1771 }
1772 break;
1773 case TargetOpcode::INLINEASM:
1774 case TargetOpcode::INLINEASM_BR:
1775 emitInlineAsm(&MI);
1776 break;
1777 case TargetOpcode::DBG_VALUE:
1778 case TargetOpcode::DBG_VALUE_LIST:
1779 if (isVerbose()) {
1780 if (!emitDebugValueComment(&MI, *this))
1782 }
1783 break;
1784 case TargetOpcode::DBG_INSTR_REF:
1785 // This instruction reference will have been resolved to a machine
1786 // location, and a nearby DBG_VALUE created. We can safely ignore
1787 // the instruction reference.
1788 break;
1789 case TargetOpcode::DBG_PHI:
1790 // This instruction is only used to label a program point, it's purely
1791 // meta information.
1792 break;
1793 case TargetOpcode::DBG_LABEL:
1794 if (isVerbose()) {
1795 if (!emitDebugLabelComment(&MI, *this))
1797 }
1798 break;
1799 case TargetOpcode::IMPLICIT_DEF:
1800 if (isVerbose()) emitImplicitDef(&MI);
1801 break;
1802 case TargetOpcode::KILL:
1803 if (isVerbose()) emitKill(&MI, *this);
1804 break;
1805 case TargetOpcode::PSEUDO_PROBE:
1807 break;
1808 case TargetOpcode::ARITH_FENCE:
1809 if (isVerbose())
1810 OutStreamer->emitRawComment("ARITH_FENCE");
1811 break;
1812 case TargetOpcode::MEMBARRIER:
1813 OutStreamer->emitRawComment("MEMBARRIER");
1814 break;
1815 case TargetOpcode::JUMP_TABLE_DEBUG_INFO:
1816 // This instruction is only used to note jump table debug info, it's
1817 // purely meta information.
1818 break;
1819 default:
1821 if (CanDoExtraAnalysis) {
1822 MCInst MCI;
1823 MCI.setOpcode(MI.getOpcode());
1824 auto Name = OutStreamer->getMnemonic(MCI);
1825 auto I = MnemonicCounts.insert({Name, 0u});
1826 I.first->second++;
1827 }
1828 break;
1829 }
1830
1831 // If there is a post-instruction symbol, emit a label for it here.
1832 if (MCSymbol *S = MI.getPostInstrSymbol())
1833 OutStreamer->emitLabel(S);
1834
1835 for (auto &Handler : DebugHandlers)
1836 Handler->endInstruction();
1837 }
1838
1839 // We must emit temporary symbol for the end of this basic block, if either
1840 // we have BBLabels enabled or if this basic blocks marks the end of a
1841 // section.
1842 if (MF->hasBBLabels() || MF->getTarget().Options.BBAddrMap ||
1844 OutStreamer->emitLabel(MBB.getEndSymbol());
1845
1846 if (MBB.isEndSection()) {
1847 // The size directive for the section containing the entry block is
1848 // handled separately by the function section.
1849 if (!MBB.sameSection(&MF->front())) {
1851 // Emit the size directive for the basic block section.
1852 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1854 MCSymbolRefExpr::create(CurrentSectionBeginSym, OutContext),
1855 OutContext);
1856 OutStreamer->emitELFSize(CurrentSectionBeginSym, SizeExp);
1857 }
1858 assert(!MBBSectionRanges.contains(MBB.getSectionID()) &&
1859 "Overwrite section range");
1861 MBBSectionRange{CurrentSectionBeginSym, MBB.getEndSymbol()};
1862 }
1863 }
1865
1866 if (CanDoExtraAnalysis) {
1867 // Skip empty blocks.
1868 if (MBB.empty())
1869 continue;
1870
1872 MBB.begin()->getDebugLoc(), &MBB);
1873
1874 // Generate instruction mix remark. First, sort counts in descending order
1875 // by count and name.
1877 for (auto &KV : MnemonicCounts)
1878 MnemonicVec.emplace_back(KV.first, KV.second);
1879
1880 sort(MnemonicVec, [](const std::pair<StringRef, unsigned> &A,
1881 const std::pair<StringRef, unsigned> &B) {
1882 if (A.second > B.second)
1883 return true;
1884 if (A.second == B.second)
1885 return StringRef(A.first) < StringRef(B.first);
1886 return false;
1887 });
1888 R << "BasicBlock: " << ore::NV("BasicBlock", MBB.getName()) << "\n";
1889 for (auto &KV : MnemonicVec) {
1890 auto Name = (Twine("INST_") + getToken(KV.first.trim()).first).str();
1891 R << KV.first << ": " << ore::NV(Name, KV.second) << "\n";
1892 }
1893 ORE->emit(R);
1894 }
1895 }
1896
1897 EmittedInsts += NumInstsInFunction;
1898 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE, "InstructionCount",
1900 &MF->front());
1901 R << ore::NV("NumInstructions", NumInstsInFunction)
1902 << " instructions in function";
1903 ORE->emit(R);
1904
1905 // If the function is empty and the object file uses .subsections_via_symbols,
1906 // then we need to emit *something* to the function body to prevent the
1907 // labels from collapsing together. Just emit a noop.
1908 // Similarly, don't emit empty functions on Windows either. It can lead to
1909 // duplicate entries (two functions with the same RVA) in the Guard CF Table
1910 // after linking, causing the kernel not to load the binary:
1911 // https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
1912 // FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
1913 const Triple &TT = TM.getTargetTriple();
1914 if (!HasAnyRealCode && (MAI->hasSubsectionsViaSymbols() ||
1915 (TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
1916 MCInst Noop = MF->getSubtarget().getInstrInfo()->getNop();
1917
1918 // Targets can opt-out of emitting the noop here by leaving the opcode
1919 // unspecified.
1920 if (Noop.getOpcode()) {
1921 OutStreamer->AddComment("avoids zero-length function");
1922 emitNops(1);
1923 }
1924 }
1925
1926 // Switch to the original section in case basic block sections was used.
1927 OutStreamer->switchSection(MF->getSection());
1928
1929 const Function &F = MF->getFunction();
1930 for (const auto &BB : F) {
1931 if (!BB.hasAddressTaken())
1932 continue;
1934 if (Sym->isDefined())
1935 continue;
1936 OutStreamer->AddComment("Address of block that was removed by CodeGen");
1937 OutStreamer->emitLabel(Sym);
1938 }
1939
1940 // Emit target-specific gunk after the function body.
1942
1943 // Even though wasm supports .type and .size in general, function symbols
1944 // are automatically sized.
1945 bool EmitFunctionSize = MAI->hasDotTypeDotSizeDirective() && !TT.isWasm();
1946
1947 if (needFuncLabels(*MF, *MMI) || EmitFunctionSize) {
1948 // Create a symbol for the end of function.
1949 CurrentFnEnd = createTempSymbol("func_end");
1950 OutStreamer->emitLabel(CurrentFnEnd);
1951 }
1952
1953 // If the target wants a .size directive for the size of the function, emit
1954 // it.
1955 if (EmitFunctionSize) {
1956 // We can get the size as difference between the function label and the
1957 // temp label.
1958 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1959 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
1961 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
1963 OutStreamer->emitELFSize(CurrentFnBeginLocal, SizeExp);
1964 }
1965
1966 // Call endBasicBlockSection on the last block now, if it wasn't already
1967 // called.
1968 if (!MF->back().isEndSection()) {
1969 for (auto &Handler : DebugHandlers)
1970 Handler->endBasicBlockSection(MF->back());
1971 for (auto &Handler : Handlers)
1972 Handler->endBasicBlockSection(MF->back());
1973 }
1974 for (auto &Handler : Handlers)
1975 Handler->markFunctionEnd();
1976
1977 assert(!MBBSectionRanges.contains(MF->front().getSectionID()) &&
1978 "Overwrite section range");
1980 MBBSectionRange{CurrentFnBegin, CurrentFnEnd};
1981
1982 // Print out jump tables referenced by the function.
1984
1985 // Emit post-function debug and/or EH information.
1986 for (auto &Handler : DebugHandlers)
1987 Handler->endFunction(MF);
1988 for (auto &Handler : Handlers)
1989 Handler->endFunction(MF);
1990
1991 // Emit section containing BB address offsets and their metadata, when
1992 // BB labels are requested for this function. Skip empty functions.
1993 if (HasAnyRealCode) {
1996 else if (PgoAnalysisMapFeatures.getBits() != 0)
1998 SMLoc(), "pgo-analysis-map is enabled for function " + MF->getName() +
1999 " but it does not have labels");
2000 }
2001
2002 // Emit sections containing instruction and function PCs.
2004
2005 // Emit section containing stack size metadata.
2007
2008 // Emit .su file containing function stack size information.
2010
2012
2013 if (isVerbose())
2014 OutStreamer->getCommentOS() << "-- End function\n";
2015
2016 OutStreamer->addBlankLine();
2017}
2018
2019/// Compute the number of Global Variables that uses a Constant.
2020static unsigned getNumGlobalVariableUses(const Constant *C) {
2021 if (!C)
2022 return 0;
2023
2024 if (isa<GlobalVariable>(C))
2025 return 1;
2026
2027 unsigned NumUses = 0;
2028 for (const auto *CU : C->users())
2029 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
2030
2031 return NumUses;
2032}
2033
2034/// Only consider global GOT equivalents if at least one user is a
2035/// cstexpr inside an initializer of another global variables. Also, don't
2036/// handle cstexpr inside instructions. During global variable emission,
2037/// candidates are skipped and are emitted later in case at least one cstexpr
2038/// isn't replaced by a PC relative GOT entry access.
2040 unsigned &NumGOTEquivUsers) {
2041 // Global GOT equivalents are unnamed private globals with a constant
2042 // pointer initializer to another global symbol. They must point to a
2043 // GlobalVariable or Function, i.e., as GlobalValue.
2044 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
2045 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
2046 !isa<GlobalValue>(GV->getOperand(0)))
2047 return false;
2048
2049 // To be a got equivalent, at least one of its users need to be a constant
2050 // expression used by another global variable.
2051 for (const auto *U : GV->users())
2052 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
2053
2054 return NumGOTEquivUsers > 0;
2055}
2056
2057/// Unnamed constant global variables solely contaning a pointer to
2058/// another globals variable is equivalent to a GOT table entry; it contains the
2059/// the address of another symbol. Optimize it and replace accesses to these
2060/// "GOT equivalents" by using the GOT entry for the final global instead.
2061/// Compute GOT equivalent candidates among all global variables to avoid
2062/// emitting them if possible later on, after it use is replaced by a GOT entry
2063/// access.
2065 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2066 return;
2067
2068 for (const auto &G : M.globals()) {
2069 unsigned NumGOTEquivUsers = 0;
2070 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
2071 continue;
2072
2073 const MCSymbol *GOTEquivSym = getSymbol(&G);
2074 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
2075 }
2076}
2077
2078/// Constant expressions using GOT equivalent globals may not be eligible
2079/// for PC relative GOT entry conversion, in such cases we need to emit such
2080/// globals we previously omitted in EmitGlobalVariable.
2082 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2083 return;
2084
2086 for (auto &I : GlobalGOTEquivs) {
2087 const GlobalVariable *GV = I.second.first;
2088 unsigned Cnt = I.second.second;
2089 if (Cnt)
2090 FailedCandidates.push_back(GV);
2091 }
2092 GlobalGOTEquivs.clear();
2093
2094 for (const auto *GV : FailedCandidates)
2096}
2097
2099 MCSymbol *Name = getSymbol(&GA);
2100 bool IsFunction = GA.getValueType()->isFunctionTy();
2101 // Treat bitcasts of functions as functions also. This is important at least
2102 // on WebAssembly where object and function addresses can't alias each other.
2103 if (!IsFunction)
2104 IsFunction = isa<Function>(GA.getAliasee()->stripPointerCasts());
2105
2106 // AIX's assembly directive `.set` is not usable for aliasing purpose,
2107 // so AIX has to use the extra-label-at-definition strategy. At this
2108 // point, all the extra label is emitted, we just have to emit linkage for
2109 // those labels.
2112 "Visibility should be handled with emitLinkage() on AIX.");
2113
2114 // Linkage for alias of global variable has been emitted.
2115 if (isa<GlobalVariable>(GA.getAliaseeObject()))
2116 return;
2117
2118 emitLinkage(&GA, Name);
2119 // If it's a function, also emit linkage for aliases of function entry
2120 // point.
2121 if (IsFunction)
2122 emitLinkage(&GA,
2123 getObjFileLowering().getFunctionEntryPointSymbol(&GA, TM));
2124 return;
2125 }
2126
2128 OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
2129 else if (GA.hasWeakLinkage() || GA.hasLinkOnceLinkage())
2130 OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
2131 else
2132 assert(GA.hasLocalLinkage() && "Invalid alias linkage");
2133
2134 // Set the symbol type to function if the alias has a function type.
2135 // This affects codegen when the aliasee is not a function.
2136 if (IsFunction) {
2137 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
2139 OutStreamer->beginCOFFSymbolDef(Name);
2140 OutStreamer->emitCOFFSymbolStorageClass(
2145 OutStreamer->endCOFFSymbolDef();
2146 }
2147 }
2148
2150
2151 const MCExpr *Expr = lowerConstant(GA.getAliasee());
2152
2153 if (MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
2154 OutStreamer->emitSymbolAttribute(Name, MCSA_AltEntry);
2155
2156 // Emit the directives as assignments aka .set:
2157 OutStreamer->emitAssignment(Name, Expr);
2158 MCSymbol *LocalAlias = getSymbolPreferLocal(GA);
2159 if (LocalAlias != Name)
2160 OutStreamer->emitAssignment(LocalAlias, Expr);
2161
2162 // If the aliasee does not correspond to a symbol in the output, i.e. the
2163 // alias is not of an object or the aliased object is private, then set the
2164 // size of the alias symbol from the type of the alias. We don't do this in
2165 // other situations as the alias and aliasee having differing types but same
2166 // size may be intentional.
2167 const GlobalObject *BaseObject = GA.getAliaseeObject();
2169 (!BaseObject || BaseObject->hasPrivateLinkage())) {
2170 const DataLayout &DL = M.getDataLayout();
2171 uint64_t Size = DL.getTypeAllocSize(GA.getValueType());
2173 }
2174}
2175
2176void AsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
2178 "IFunc is not supported on AIX.");
2179
2180 auto EmitLinkage = [&](MCSymbol *Sym) {
2182 OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
2183 else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
2184 OutStreamer->emitSymbolAttribute(Sym, MCSA_WeakReference);
2185 else
2186 assert(GI.hasLocalLinkage() && "Invalid ifunc linkage");
2187 };
2188
2190 MCSymbol *Name = getSymbol(&GI);
2191 EmitLinkage(Name);
2192 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
2194
2195 // Emit the directives as assignments aka .set:
2196 const MCExpr *Expr = lowerConstant(GI.getResolver());
2197 OutStreamer->emitAssignment(Name, Expr);
2198 MCSymbol *LocalAlias = getSymbolPreferLocal(GI);
2199 if (LocalAlias != Name)
2200 OutStreamer->emitAssignment(LocalAlias, Expr);
2201
2202 return;
2203 }
2204
2206 llvm::report_fatal_error("IFuncs are not supported on this platform");
2207
2208 // On Darwin platforms, emit a manually-constructed .symbol_resolver that
2209 // implements the symbol resolution duties of the IFunc.
2210 //
2211 // Normally, this would be handled by linker magic, but unfortunately there
2212 // are a few limitations in ld64 and ld-prime's implementation of
2213 // .symbol_resolver that mean we can't always use them:
2214 //
2215 // * resolvers cannot be the target of an alias
2216 // * resolvers cannot have private linkage
2217 // * resolvers cannot have linkonce linkage
2218 // * resolvers cannot appear in executables
2219 // * resolvers cannot appear in bundles
2220 //
2221 // This works around that by emitting a close approximation of what the
2222 // linker would have done.
2223
2224 MCSymbol *LazyPointer =
2225 GetExternalSymbolSymbol(GI.getName() + ".lazy_pointer");
2226 MCSymbol *StubHelper = GetExternalSymbolSymbol(GI.getName() + ".stub_helper");
2227
2229
2230 const DataLayout &DL = M.getDataLayout();
2231 emitAlignment(Align(DL.getPointerSize()));
2232 OutStreamer->emitLabel(LazyPointer);
2233 emitVisibility(LazyPointer, GI.getVisibility());
2234 OutStreamer->emitValue(MCSymbolRefExpr::create(StubHelper, OutContext), 8);
2235
2237
2238 const TargetSubtargetInfo *STI =
2240 const TargetLowering *TLI = STI->getTargetLowering();
2241 Align TextAlign(TLI->getMinFunctionAlignment());
2242
2243 MCSymbol *Stub = getSymbol(&GI);
2244 EmitLinkage(Stub);
2245 OutStreamer->emitCodeAlignment(TextAlign, getIFuncMCSubtargetInfo());
2246 OutStreamer->emitLabel(Stub);
2247 emitVisibility(Stub, GI.getVisibility());
2248 emitMachOIFuncStubBody(M, GI, LazyPointer);
2249
2250 OutStreamer->emitCodeAlignment(TextAlign, getIFuncMCSubtargetInfo());
2251 OutStreamer->emitLabel(StubHelper);
2252 emitVisibility(StubHelper, GI.getVisibility());
2253 emitMachOIFuncStubHelperBody(M, GI, LazyPointer);
2254}
2255
2257 if (!RS.needsSection())
2258 return;
2259
2260 remarks::RemarkSerializer &RemarkSerializer = RS.getSerializer();
2261
2262 std::optional<SmallString<128>> Filename;
2263 if (std::optional<StringRef> FilenameRef = RS.getFilename()) {
2264 Filename = *FilenameRef;
2265 sys::fs::make_absolute(*Filename);
2266 assert(!Filename->empty() && "The filename can't be empty.");
2267 }
2268
2269 std::string Buf;
2271 std::unique_ptr<remarks::MetaSerializer> MetaSerializer =
2272 Filename ? RemarkSerializer.metaSerializer(OS, Filename->str())
2273 : RemarkSerializer.metaSerializer(OS);
2274 MetaSerializer->emit();
2275
2276 // Switch to the remarks section.
2277 MCSection *RemarksSection =
2279 OutStreamer->switchSection(RemarksSection);
2280
2281 OutStreamer->emitBinaryData(Buf);
2282}
2283
2285 // Set the MachineFunction to nullptr so that we can catch attempted
2286 // accesses to MF specific features at the module level and so that
2287 // we can conditionalize accesses based on whether or not it is nullptr.
2288 MF = nullptr;
2289
2290 // Gather all GOT equivalent globals in the module. We really need two
2291 // passes over the globals: one to compute and another to avoid its emission
2292 // in EmitGlobalVariable, otherwise we would not be able to handle cases
2293 // where the got equivalent shows up before its use.
2295
2296 // Emit global variables.
2297 for (const auto &G : M.globals())
2299
2300 // Emit remaining GOT equivalent globals.
2302
2304
2305 // Emit linkage(XCOFF) and visibility info for declarations
2306 for (const Function &F : M) {
2307 if (!F.isDeclarationForLinker())
2308 continue;
2309
2310 MCSymbol *Name = getSymbol(&F);
2311 // Function getSymbol gives us the function descriptor symbol for XCOFF.
2312
2314 GlobalValue::VisibilityTypes V = F.getVisibility();
2316 continue;
2317
2318 emitVisibility(Name, V, false);
2319 continue;
2320 }
2321
2322 if (F.isIntrinsic())
2323 continue;
2324
2325 // Handle the XCOFF case.
2326 // Variable `Name` is the function descriptor symbol (see above). Get the
2327 // function entry point symbol.
2328 MCSymbol *FnEntryPointSym = TLOF.getFunctionEntryPointSymbol(&F, TM);
2329 // Emit linkage for the function entry point.
2330 emitLinkage(&F, FnEntryPointSym);
2331
2332 // If a function's address is taken, which means it may be called via a
2333 // function pointer, we need the function descriptor for it.
2334 if (F.hasAddressTaken())
2335 emitLinkage(&F, Name);
2336 }
2337
2338 // Emit the remarks section contents.
2339 // FIXME: Figure out when is the safest time to emit this section. It should
2340 // not come after debug info.
2341 if (remarks::RemarkStreamer *RS = M.getContext().getMainRemarkStreamer())
2342 emitRemarksSection(*RS);
2343
2345
2348
2349 // Output stubs for external and common global variables.
2351 if (!Stubs.empty()) {
2352 OutStreamer->switchSection(TLOF.getDataSection());
2353 const DataLayout &DL = M.getDataLayout();
2354
2355 emitAlignment(Align(DL.getPointerSize()));
2356 for (const auto &Stub : Stubs) {
2357 OutStreamer->emitLabel(Stub.first);
2358 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
2359 DL.getPointerSize());
2360 }
2361 }
2362 }
2363
2365 MachineModuleInfoCOFF &MMICOFF =
2367
2368 // Output stubs for external and common global variables.
2370 if (!Stubs.empty()) {
2371 const DataLayout &DL = M.getDataLayout();
2372
2373 for (const auto &Stub : Stubs) {
2375 SectionName += Stub.first->getName();
2376 OutStreamer->switchSection(OutContext.getCOFFSection(
2380 Stub.first->getName(), COFF::IMAGE_COMDAT_SELECT_ANY));
2381 emitAlignment(Align(DL.getPointerSize()));
2382 OutStreamer->emitSymbolAttribute(Stub.first, MCSA_Global);
2383 OutStreamer->emitLabel(Stub.first);
2384 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
2385 DL.getPointerSize());
2386 }
2387 }
2388 }
2389
2390 // This needs to happen before emitting debug information since that can end
2391 // arbitrary sections.
2392 if (auto *TS = OutStreamer->getTargetStreamer())
2393 TS->emitConstantPools();
2394
2395 // Emit Stack maps before any debug info. Mach-O requires that no data or
2396 // text sections come after debug info has been emitted. This matters for
2397 // stack maps as they are arbitrary data, and may even have a custom format
2398 // through user plugins.
2399 emitStackMaps();
2400
2401 // Print aliases in topological order, that is, for each alias a = b,
2402 // b must be printed before a.
2403 // This is because on some targets (e.g. PowerPC) linker expects aliases in
2404 // such an order to generate correct TOC information.
2407 for (const auto &Alias : M.aliases()) {
2408 if (Alias.hasAvailableExternallyLinkage())
2409 continue;
2410 for (const GlobalAlias *Cur = &Alias; Cur;
2411 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
2412 if (!AliasVisited.insert(Cur).second)
2413 break;
2414 AliasStack.push_back(Cur);
2415 }
2416 for (const GlobalAlias *AncestorAlias : llvm::reverse(AliasStack))
2417 emitGlobalAlias(M, *AncestorAlias);
2418 AliasStack.clear();
2419 }
2420
2421 // IFuncs must come before deubginfo in case the backend decides to emit them
2422 // as actual functions, since on Mach-O targets, we cannot create regular
2423 // sections after DWARF.
2424 for (const auto &IFunc : M.ifuncs())
2425 emitGlobalIFunc(M, IFunc);
2426
2427 // Finalize debug and EH information.
2428 for (auto &Handler : DebugHandlers)
2429 Handler->endModule();
2430 for (auto &Handler : Handlers)
2431 Handler->endModule();
2432
2433 // This deletes all the ephemeral handlers that AsmPrinter added, while
2434 // keeping all the user-added handlers alive until the AsmPrinter is
2435 // destroyed.
2436 Handlers.erase(Handlers.begin() + NumUserHandlers, Handlers.end());
2438 DebugHandlers.end());
2439 DD = nullptr;
2440
2441 // If the target wants to know about weak references, print them all.
2442 if (MAI->getWeakRefDirective()) {
2443 // FIXME: This is not lazy, it would be nice to only print weak references
2444 // to stuff that is actually used. Note that doing so would require targets
2445 // to notice uses in operands (due to constant exprs etc). This should
2446 // happen with the MC stuff eventually.
2447
2448 // Print out module-level global objects here.
2449 for (const auto &GO : M.global_objects()) {
2450 if (!GO.hasExternalWeakLinkage())
2451 continue;
2452 OutStreamer->emitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
2453 }
2455 auto SymbolName = "swift_async_extendedFramePointerFlags";
2456 auto Global = M.getGlobalVariable(SymbolName);
2457 if (!Global) {
2458 auto Int8PtrTy = PointerType::getUnqual(M.getContext());
2459 Global = new GlobalVariable(M, Int8PtrTy, false,
2461 SymbolName);
2462 OutStreamer->emitSymbolAttribute(getSymbol(Global), MCSA_WeakReference);
2463 }
2464 }
2465 }
2466
2467 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
2468 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
2469 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
2470 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(**--I))
2471 MP->finishAssembly(M, *MI, *this);
2472
2473 // Emit llvm.ident metadata in an '.ident' directive.
2474 emitModuleIdents(M);
2475
2476 // Emit bytes for llvm.commandline metadata.
2477 // The command line metadata is emitted earlier on XCOFF.
2479 emitModuleCommandLines(M);
2480
2481 // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
2482 // split-stack is used.
2483 if (TM.getTargetTriple().isOSBinFormatELF() && HasSplitStack) {
2484 OutStreamer->switchSection(OutContext.getELFSection(".note.GNU-split-stack",
2485 ELF::SHT_PROGBITS, 0));
2486 if (HasNoSplitStack)
2487 OutStreamer->switchSection(OutContext.getELFSection(
2488 ".note.GNU-no-split-stack", ELF::SHT_PROGBITS, 0));
2489 }
2490
2491 // If we don't have any trampolines, then we don't require stack memory
2492 // to be executable. Some targets have a directive to declare this.
2493 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
2494 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
2496 OutStreamer->switchSection(S);
2497
2498 if (TM.Options.EmitAddrsig) {
2499 // Emit address-significance attributes for all globals.
2500 OutStreamer->emitAddrsig();
2501 for (const GlobalValue &GV : M.global_values()) {
2502 if (!GV.use_empty() && !GV.isThreadLocal() &&
2503 !GV.hasDLLImportStorageClass() &&
2504 !GV.getName().starts_with("llvm.") &&
2505 !GV.hasAtLeastLocalUnnamedAddr())
2506 OutStreamer->emitAddrsigSym(getSymbol(&GV));
2507 }
2508 }
2509
2510 // Emit symbol partition specifications (ELF only).
2512 unsigned UniqueID = 0;
2513 for (const GlobalValue &GV : M.global_values()) {
2514 if (!GV.hasPartition() || GV.isDeclarationForLinker() ||
2515 GV.getVisibility() != GlobalValue::DefaultVisibility)
2516 continue;
2517
2518 OutStreamer->switchSection(
2519 OutContext.getELFSection(".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0,
2520 "", false, ++UniqueID, nullptr));
2521 OutStreamer->emitBytes(GV.getPartition());
2522 OutStreamer->emitZeros(1);
2523 OutStreamer->emitValue(
2526 }
2527 }
2528
2529 // Allow the target to emit any magic that it wants at the end of the file,
2530 // after everything else has gone out.
2532
2533 MMI = nullptr;
2534 AddrLabelSymbols = nullptr;
2535
2536 OutStreamer->finish();
2537 OutStreamer->reset();
2538 OwnedMLI.reset();
2539 OwnedMDT.reset();
2540
2541 return false;
2542}
2543
2545 auto Res = MBBSectionExceptionSyms.try_emplace(MBB.getSectionID());
2546 if (Res.second)
2547 Res.first->second = createTempSymbol("exception");
2548 return Res.first->second;
2549}
2550
2552 this->MF = &MF;
2553 const Function &F = MF.getFunction();
2554
2555 // Record that there are split-stack functions, so we will emit a special
2556 // section to tell the linker.
2557 if (MF.shouldSplitStack()) {
2558 HasSplitStack = true;
2559
2561 HasNoSplitStack = true;
2562 } else
2563 HasNoSplitStack = true;
2564
2565 // Get the function symbol.
2566 if (!MAI->needsFunctionDescriptors()) {
2568 } else {
2570 "Only AIX uses the function descriptor hooks.");
2571 // AIX is unique here in that the name of the symbol emitted for the
2572 // function body does not have the same name as the source function's
2573 // C-linkage name.
2574 assert(CurrentFnDescSym && "The function descriptor symbol needs to be"
2575 " initalized first.");
2576
2577 // Get the function entry point symbol.
2579 }
2580
2582 CurrentFnBegin = nullptr;
2583 CurrentFnBeginLocal = nullptr;
2584 CurrentSectionBeginSym = nullptr;
2585 MBBSectionRanges.clear();
2586 MBBSectionExceptionSyms.clear();
2587 bool NeedsLocalForSize = MAI->needsLocalForSize();
2588 if (F.hasFnAttribute("patchable-function-entry") ||
2589 F.hasFnAttribute("function-instrument") ||
2590 F.hasFnAttribute("xray-instruction-threshold") ||
2591 needFuncLabels(MF, *MMI) || NeedsLocalForSize ||
2594 CurrentFnBegin = createTempSymbol("func_begin");
2595 if (NeedsLocalForSize)
2597 }
2598
2599 ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
2600}
2601
2602namespace {
2603
2604// Keep track the alignment, constpool entries per Section.
2605 struct SectionCPs {
2606 MCSection *S;
2607 Align Alignment;
2609
2610 SectionCPs(MCSection *s, Align a) : S(s), Alignment(a) {}
2611 };
2612
2613} // end anonymous namespace
2614
2615/// EmitConstantPool - Print to the current output stream assembly
2616/// representations of the constants in the constant pool MCP. This is
2617/// used to print out constants which have been "spilled to memory" by
2618/// the code generator.
2620 const MachineConstantPool *MCP = MF->getConstantPool();
2621 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
2622 if (CP.empty()) return;
2623
2624 // Calculate sections for constant pool entries. We collect entries to go into
2625 // the same section together to reduce amount of section switch statements.
2626 SmallVector<SectionCPs, 4> CPSections;
2627 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
2628 const MachineConstantPoolEntry &CPE = CP[i];
2629 Align Alignment = CPE.getAlign();
2630
2632
2633 const Constant *C = nullptr;
2634 if (!CPE.isMachineConstantPoolEntry())
2635 C = CPE.Val.ConstVal;
2636
2638 getDataLayout(), Kind, C, Alignment);
2639
2640 // The number of sections are small, just do a linear search from the
2641 // last section to the first.
2642 bool Found = false;
2643 unsigned SecIdx = CPSections.size();
2644 while (SecIdx != 0) {
2645 if (CPSections[--SecIdx].S == S) {
2646 Found = true;
2647 break;
2648 }
2649 }
2650 if (!Found) {
2651 SecIdx = CPSections.size();
2652 CPSections.push_back(SectionCPs(S, Alignment));
2653 }
2654
2655 if (Alignment > CPSections[SecIdx].Alignment)
2656 CPSections[SecIdx].Alignment = Alignment;
2657 CPSections[SecIdx].CPEs.push_back(i);
2658 }
2659
2660 // Now print stuff into the calculated sections.
2661 const MCSection *CurSection = nullptr;
2662 unsigned Offset = 0;
2663 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
2664 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
2665 unsigned CPI = CPSections[i].CPEs[j];
2666 MCSymbol *Sym = GetCPISymbol(CPI);
2667 if (!Sym->isUndefined())
2668 continue;
2669
2670 if (CurSection != CPSections[i].S) {
2671 OutStreamer->switchSection(CPSections[i].S);
2672 emitAlignment(Align(CPSections[i].Alignment));
2673 CurSection = CPSections[i].S;
2674 Offset = 0;
2675 }
2676
2677 MachineConstantPoolEntry CPE = CP[CPI];
2678
2679 // Emit inter-object padding for alignment.
2680 unsigned NewOffset = alignTo(Offset, CPE.getAlign());
2681 OutStreamer->emitZeros(NewOffset - Offset);
2682
2683 Offset = NewOffset + CPE.getSizeInBytes(getDataLayout());
2684
2685 OutStreamer->emitLabel(Sym);
2688 else
2690 }
2691 }
2692}
2693
2694// Print assembly representations of the jump tables used by the current
2695// function.
2697 const DataLayout &DL = MF->getDataLayout();
2698 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
2699 if (!MJTI) return;
2700 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
2701 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
2702 if (JT.empty()) return;
2703
2704 // Pick the directive to use to print the jump table entries, and switch to
2705 // the appropriate section.
2706 const Function &F = MF->getFunction();
2708 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
2711 F);
2712 if (JTInDiffSection) {
2713 // Drop it in the readonly section.
2714 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(F, TM);
2715 OutStreamer->switchSection(ReadOnlySection);
2716 }
2717
2719
2720 // Jump tables in code sections are marked with a data_region directive
2721 // where that's supported.
2722 if (!JTInDiffSection)
2723 OutStreamer->emitDataRegion(MCDR_DataRegionJT32);
2724
2725 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
2726 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
2727
2728 // If this jump table was deleted, ignore it.
2729 if (JTBBs.empty()) continue;
2730
2731 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
2732 /// emit a .set directive for each unique entry.
2738 for (const MachineBasicBlock *MBB : JTBBs) {
2739 if (!EmittedSets.insert(MBB).second)
2740 continue;
2741
2742 // .set LJTSet, LBB32-base
2743 const MCExpr *LHS =
2745 OutStreamer->emitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
2747 OutContext));
2748 }
2749 }
2750
2751 // On some targets (e.g. Darwin) we want to emit two consecutive labels
2752 // before each jump table. The first label is never referenced, but tells
2753 // the assembler and linker the extents of the jump table object. The
2754 // second label is actually referenced by the code.
2755 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
2756 // FIXME: This doesn't have to have any specific name, just any randomly
2757 // named and numbered local label started with 'l' would work. Simplify
2758 // GetJTISymbol.
2759 OutStreamer->emitLabel(GetJTISymbol(JTI, true));
2760
2761 MCSymbol* JTISymbol = GetJTISymbol(JTI);
2762 OutStreamer->emitLabel(JTISymbol);
2763
2764 // Defer MCAssembler based constant folding due to a performance issue. The
2765 // label differences will be evaluated at write time.
2766 for (const MachineBasicBlock *MBB : JTBBs)
2767 emitJumpTableEntry(MJTI, MBB, JTI);
2768 }
2769 if (!JTInDiffSection)
2770 OutStreamer->emitDataRegion(MCDR_DataRegionEnd);
2771}
2772
2773/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
2774/// current stream.
2775void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
2776 const MachineBasicBlock *MBB,
2777 unsigned UID) const {
2778 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
2779 const MCExpr *Value = nullptr;
2780 switch (MJTI->getEntryKind()) {
2782 llvm_unreachable("Cannot emit EK_Inline jump table entry");
2785 MJTI, MBB, UID, OutContext);
2786 break;
2788 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
2789 // .word LBB123
2791 break;
2793 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
2794 // with a relocation as gp-relative, e.g.:
2795 // .gprel32 LBB123
2796 MCSymbol *MBBSym = MBB->getSymbol();
2797 OutStreamer->emitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2798 return;
2799 }
2800
2802 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
2803 // with a relocation as gp-relative, e.g.:
2804 // .gpdword LBB123
2805 MCSymbol *MBBSym = MBB->getSymbol();
2806 OutStreamer->emitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2807 return;
2808 }
2809
2812 // Each entry is the address of the block minus the address of the jump
2813 // table. This is used for PIC jump tables where gprel32 is not supported.
2814 // e.g.:
2815 // .word LBB123 - LJTI1_2
2816 // If the .set directive avoids relocations, this is emitted as:
2817 // .set L4_5_set_123, LBB123 - LJTI1_2
2818 // .word L4_5_set_123
2822 OutContext);
2823 break;
2824 }
2829 break;
2830 }
2831 }
2832
2833 assert(Value && "Unknown entry kind!");
2834
2835 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
2836 OutStreamer->emitValue(Value, EntrySize);
2837}
2838
2839/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
2840/// special global used by LLVM. If so, emit it and return true, otherwise
2841/// do nothing and return false.
2843 if (GV->getName() == "llvm.used") {
2844 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
2845 emitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
2846 return true;
2847 }
2848
2849 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
2850 if (GV->getSection() == "llvm.metadata" ||
2852 return true;
2853
2854 if (GV->getName() == "llvm.arm64ec.symbolmap") {
2855 // For ARM64EC, print the table that maps between symbols and the
2856 // corresponding thunks to translate between x64 and AArch64 code.
2857 // This table is generated by AArch64Arm64ECCallLowering.
2858 OutStreamer->switchSection(
2860 auto *Arr = cast<ConstantArray>(GV->getInitializer());
2861 for (auto &U : Arr->operands()) {
2862 auto *C = cast<Constant>(U);
2863 auto *Src = cast<GlobalValue>(C->getOperand(0)->stripPointerCasts());
2864 auto *Dst = cast<GlobalValue>(C->getOperand(1)->stripPointerCasts());
2865 int Kind = cast<ConstantInt>(C->getOperand(2))->getZExtValue();
2866
2867 if (Src->hasDLLImportStorageClass()) {
2868 // For now, we assume dllimport functions aren't directly called.
2869 // (We might change this later to match MSVC.)
2870 OutStreamer->emitCOFFSymbolIndex(
2871 OutContext.getOrCreateSymbol("__imp_" + Src->getName()));
2872 OutStreamer->emitCOFFSymbolIndex(getSymbol(Dst));
2873 OutStreamer->emitInt32(Kind);
2874 } else {
2875 // FIXME: For non-dllimport functions, MSVC emits the same entry
2876 // twice, for reasons I don't understand. I have to assume the linker
2877 // ignores the redundant entry; there aren't any reasonable semantics
2878 // to attach to it.
2879 OutStreamer->emitCOFFSymbolIndex(getSymbol(Src));
2880 OutStreamer->emitCOFFSymbolIndex(getSymbol(Dst));
2881 OutStreamer->emitInt32(Kind);
2882 }
2883 }
2884 return true;
2885 }
2886
2887 if (!GV->hasAppendingLinkage()) return false;
2888
2889 assert(GV->hasInitializer() && "Not a special LLVM global!");
2890
2891 if (GV->getName() == "llvm.global_ctors") {
2893 /* isCtor */ true);
2894
2895 return true;
2896 }
2897
2898 if (GV->getName() == "llvm.global_dtors") {
2900 /* isCtor */ false);
2901
2902 return true;
2903 }
2904
2905 report_fatal_error("unknown special variable with appending linkage");
2906}
2907
2908/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
2909/// global in the specified llvm.used list.
2910void AsmPrinter::emitLLVMUsedList(const ConstantArray *InitList) {
2911 // Should be an array of 'i8*'.
2912 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
2913 const GlobalValue *GV =
2914 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
2915 if (GV)
2916 OutStreamer->emitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
2917 }
2918}
2919
2921 const Constant *List,
2922 SmallVector<Structor, 8> &Structors) {
2923 // Should be an array of '{ i32, void ()*, i8* }' structs. The first value is
2924 // the init priority.
2925 if (!isa<ConstantArray>(List))
2926 return;
2927
2928 // Gather the structors in a form that's convenient for sorting by priority.
2929 for (Value *O : cast<ConstantArray>(List)->operands()) {
2930 auto *CS = cast<ConstantStruct>(O);
2931 if (CS->getOperand(1)->isNullValue())
2932 break; // Found a null terminator, skip the rest.
2933 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
2934 if (!Priority)
2935 continue; // Malformed.
2936 Structors.push_back(Structor());
2937 Structor &S = Structors.back();
2938 S.Priority = Priority->getLimitedValue(65535);
2939 S.Func = CS->getOperand(1);
2940 if (!CS->getOperand(2)->isNullValue()) {
2941 if (TM.getTargetTriple().isOSAIX())
2943 "associated data of XXStructor list is not yet supported on AIX");
2944 S.ComdatKey =
2945 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
2946 }
2947 }
2948
2949 // Emit the function pointers in the target-specific order
2950 llvm::stable_sort(Structors, [](const Structor &L, const Structor &R) {
2951 return L.Priority < R.Priority;
2952 });
2953}
2954
2955/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
2956/// priority.
2958 bool IsCtor) {
2959 SmallVector<Structor, 8> Structors;
2960 preprocessXXStructorList(DL, List, Structors);
2961 if (Structors.empty())
2962 return;
2963
2964 // Emit the structors in reverse order if we are using the .ctor/.dtor
2965 // initialization scheme.
2966 if (!TM.Options.UseInitArray)
2967 std::reverse(Structors.begin(), Structors.end());
2968
2969 const Align Align = DL.getPointerPrefAlignment();
2970 for (Structor &S : Structors) {
2972 const MCSymbol *KeySym = nullptr;
2973 if (GlobalValue *GV = S.ComdatKey) {
2974 if (GV->isDeclarationForLinker())
2975 // If the associated variable is not defined in this module
2976 // (it might be available_externally, or have been an
2977 // available_externally definition that was dropped by the
2978 // EliminateAvailableExternally pass), some other TU
2979 // will provide its dynamic initializer.
2980 continue;
2981
2982 KeySym = getSymbol(GV);
2983 }
2984
2985 MCSection *OutputSection =
2986 (IsCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
2987 : Obj.getStaticDtorSection(S.Priority, KeySym));
2988 OutStreamer->switchSection(OutputSection);
2989 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
2991 emitXXStructor(DL, S.Func);
2992 }
2993}
2994
2995void AsmPrinter::emitModuleIdents(Module &M) {
2996 if (!MAI->hasIdentDirective())
2997 return;
2998
2999 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
3000 for (const MDNode *N : NMD->operands()) {
3001 assert(N->getNumOperands() == 1 &&
3002 "llvm.ident metadata entry can have only one operand");
3003 const MDString *S = cast<MDString>(N->getOperand(0));
3004 OutStreamer->emitIdent(S->getString());
3005 }
3006 }
3007}
3008
3009void AsmPrinter::emitModuleCommandLines(Module &M) {
3011 if (!CommandLine)
3012 return;
3013
3014 const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
3015 if (!NMD || !NMD->getNumOperands())
3016 return;
3017
3018 OutStreamer->pushSection();
3019 OutStreamer->switchSection(CommandLine);
3020 OutStreamer->emitZeros(1);
3021 for (const MDNode *N : NMD->operands()) {
3022 assert(N->getNumOperands() == 1 &&
3023 "llvm.commandline metadata entry can have only one operand");
3024 const MDString *S = cast<MDString>(N->getOperand(0));
3025 OutStreamer->emitBytes(S->getString());
3026 OutStreamer->emitZeros(1);
3027 }
3028 OutStreamer->popSection();
3029}
3030
3031//===--------------------------------------------------------------------===//
3032// Emission and print routines
3033//
3034
3035/// Emit a byte directive and value.
3036///
3037void AsmPrinter::emitInt8(int Value) const { OutStreamer->emitInt8(Value); }
3038
3039/// Emit a short directive and value.
3040void AsmPrinter::emitInt16(int Value) const { OutStreamer->emitInt16(Value); }
3041
3042/// Emit a long directive and value.
3043void AsmPrinter::emitInt32(int Value) const { OutStreamer->emitInt32(Value); }
3044
3045/// EmitSLEB128 - emit the specified signed leb128 value.
3046void AsmPrinter::emitSLEB128(int64_t Value, const char *Desc) const {
3047 if (isVerbose() && Desc)
3048 OutStreamer->AddComment(Desc);
3049
3050 OutStreamer->emitSLEB128IntValue(Value);
3051}
3052
3054 unsigned PadTo) const {
3055 if (isVerbose() && Desc)
3056 OutStreamer->AddComment(Desc);
3057
3058 OutStreamer->emitULEB128IntValue(Value, PadTo);
3059}
3060
3061/// Emit a long long directive and value.
3063 OutStreamer->emitInt64(Value);
3064}
3065
3066/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
3067/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
3068/// .set if it avoids relocations.
3070 unsigned Size) const {
3071 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
3072}
3073
3074/// Emit something like ".uleb128 Hi-Lo".
3076 const MCSymbol *Lo) const {
3077 OutStreamer->emitAbsoluteSymbolDiffAsULEB128(Hi, Lo);
3078}
3079
3080/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
3081/// where the size in bytes of the directive is specified by Size and Label
3082/// specifies the label. This implicitly uses .set if it is available.
3084 unsigned Size,
3085 bool IsSectionRelative) const {
3086 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
3087 OutStreamer->emitCOFFSecRel32(Label, Offset);
3088 if (Size > 4)
3089 OutStreamer->emitZeros(Size - 4);
3090 return;
3091 }
3092
3093 // Emit Label+Offset (or just Label if Offset is zero)
3094 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
3095 if (Offset)
3098
3099 OutStreamer->emitValue(Expr, Size);
3100}
3101
3102//===----------------------------------------------------------------------===//
3103
3104// EmitAlignment - Emit an alignment directive to the specified power of
3105// two boundary. If a global value is specified, and if that global has
3106// an explicit alignment requested, it will override the alignment request
3107// if required for correctness.
3109 unsigned MaxBytesToEmit) const {
3110 if (GV)
3111 Alignment = getGVAlignment(GV, GV->getDataLayout(), Alignment);
3112
3113 if (Alignment == Align(1))
3114 return; // 1-byte aligned: no need to emit alignment.
3115
3116 if (getCurrentSection()->isText()) {
3117 const MCSubtargetInfo *STI = nullptr;
3118 if (this->MF)
3119 STI = &getSubtargetInfo();
3120 else
3121 STI = TM.getMCSubtargetInfo();
3122 OutStreamer->emitCodeAlignment(Alignment, STI, MaxBytesToEmit);
3123 } else
3124 OutStreamer->emitValueToAlignment(Alignment, 0, 1, MaxBytesToEmit);
3125}
3126
3127//===----------------------------------------------------------------------===//
3128// Constant emission.
3129//===----------------------------------------------------------------------===//
3130
3132 MCContext &Ctx = OutContext;
3133
3134 if (CV->isNullValue() || isa<UndefValue>(CV))
3135 return MCConstantExpr::create(0, Ctx);
3136
3137 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
3138 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
3139
3140 if (const ConstantPtrAuth *CPA = dyn_cast<ConstantPtrAuth>(CV))
3141 return lowerConstantPtrAuth(*CPA);
3142
3143 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
3144 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
3145
3146 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
3148
3149 if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(CV))
3151
3152 if (const NoCFIValue *NC = dyn_cast<NoCFIValue>(CV))
3153 return MCSymbolRefExpr::create(getSymbol(NC->getGlobalValue()), Ctx);
3154
3155 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
3156 if (!CE) {
3157 llvm_unreachable("Unknown constant value to lower!");
3158 }
3159
3160 // The constant expression opcodes are limited to those that are necessary
3161 // to represent relocations on supported targets. Expressions involving only
3162 // constant addresses are constant folded instead.
3163 switch (CE->getOpcode()) {
3164 default:
3165 break; // Error
3166 case Instruction::AddrSpaceCast: {
3167 const Constant *Op = CE->getOperand(0);
3168 unsigned DstAS = CE->getType()->getPointerAddressSpace();
3169 unsigned SrcAS = Op->getType()->getPointerAddressSpace();
3170 if (TM.isNoopAddrSpaceCast(SrcAS, DstAS))
3171 return lowerConstant(Op);
3172
3173 break; // Error
3174 }
3175 case Instruction::GetElementPtr: {
3176 // Generate a symbolic expression for the byte address
3177 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
3178 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
3179
3180 const MCExpr *Base = lowerConstant(CE->getOperand(0));
3181 if (!OffsetAI)
3182 return Base;
3183
3184 int64_t Offset = OffsetAI.getSExtValue();
3186 Ctx);
3187 }
3188
3189 case Instruction::Trunc:
3190 // We emit the value and depend on the assembler to truncate the generated
3191 // expression properly. This is important for differences between
3192 // blockaddress labels. Since the two labels are in the same function, it
3193 // is reasonable to treat their delta as a 32-bit value.
3194 [[fallthrough]];
3195 case Instruction::BitCast:
3196 return lowerConstant(CE->getOperand(0));
3197
3198 case Instruction::IntToPtr: {
3199 const DataLayout &DL = getDataLayout();
3200
3201 // Handle casts to pointers by changing them into casts to the appropriate
3202 // integer type. This promotes constant folding and simplifies this code.
3203 Constant *Op = CE->getOperand(0);
3204 Op = ConstantFoldIntegerCast(Op, DL.getIntPtrType(CV->getType()),
3205 /*IsSigned*/ false, DL);
3206 if (Op)
3207 return lowerConstant(Op);
3208
3209 break; // Error
3210 }
3211
3212 case Instruction::PtrToInt: {
3213 const DataLayout &DL = getDataLayout();
3214
3215 // Support only foldable casts to/from pointers that can be eliminated by
3216 // changing the pointer to the appropriately sized integer type.
3217 Constant *Op = CE->getOperand(0);
3218 Type *Ty = CE->getType();
3219
3220 const MCExpr *OpExpr = lowerConstant(Op);
3221
3222 // We can emit the pointer value into this slot if the slot is an
3223 // integer slot equal to the size of the pointer.
3224 //
3225 // If the pointer is larger than the resultant integer, then
3226 // as with Trunc just depend on the assembler to truncate it.
3227 if (DL.getTypeAllocSize(Ty).getFixedValue() <=
3228 DL.getTypeAllocSize(Op->getType()).getFixedValue())
3229 return OpExpr;
3230
3231 break; // Error
3232 }
3233
3234 case Instruction::Sub: {
3235 GlobalValue *LHSGV;
3236 APInt LHSOffset;
3237 DSOLocalEquivalent *DSOEquiv;
3238 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
3239 getDataLayout(), &DSOEquiv)) {
3240 GlobalValue *RHSGV;
3241 APInt RHSOffset;
3242 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
3243 getDataLayout())) {
3244 const MCExpr *RelocExpr =
3246 if (!RelocExpr) {
3247 const MCExpr *LHSExpr =
3249 if (DSOEquiv &&
3250 getObjFileLowering().supportDSOLocalEquivalentLowering())
3251 LHSExpr =
3253 RelocExpr = MCBinaryExpr::createSub(
3254 LHSExpr, MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
3255 }
3256 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
3257 if (Addend != 0)
3258 RelocExpr = MCBinaryExpr::createAdd(
3259 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
3260 return RelocExpr;
3261 }
3262 }
3263
3264 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
3265 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
3266 return MCBinaryExpr::createSub(LHS, RHS, Ctx);
3267 break;
3268 }
3269
3270 case Instruction::Add: {
3271 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
3272 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
3273 return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
3274 }
3275 }
3276
3277 // If the code isn't optimized, there may be outstanding folding
3278 // opportunities. Attempt to fold the expression using DataLayout as a
3279 // last resort before giving up.
3281 if (C != CE)
3282 return lowerConstant(C);
3283
3284 // Otherwise report the problem to the user.
3285 std::string S;
3287 OS << "Unsupported expression in static initializer: ";
3288 CE->printAsOperand(OS, /*PrintType=*/false,
3289 !MF ? nullptr : MF->getFunction().getParent());
3291}
3292
3293static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
3294 AsmPrinter &AP,
3295 const Constant *BaseCV = nullptr,
3296 uint64_t Offset = 0,
3297 AsmPrinter::AliasMapTy *AliasList = nullptr);
3298
3299static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
3300static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP);
3301
3302/// isRepeatedByteSequence - Determine whether the given value is
3303/// composed of a repeated sequence of identical bytes and return the
3304/// byte value. If it is not a repeated sequence, return -1.
3306 StringRef Data = V->getRawDataValues();
3307 assert(!Data.empty() && "Empty aggregates should be CAZ node");
3308 char C = Data[0];
3309 for (unsigned i = 1, e = Data.size(); i != e; ++i)
3310 if (Data[i] != C) return -1;
3311 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
3312}
3313
3314/// isRepeatedByteSequence - Determine whether the given value is
3315/// composed of a repeated sequence of identical bytes and return the
3316/// byte value. If it is not a repeated sequence, return -1.
3317static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
3318 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
3319 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
3320 assert(Size % 8 == 0);
3321
3322 // Extend the element to take zero padding into account.
3323 APInt Value = CI->getValue().zext(Size);
3324 if (!Value.isSplat(8))
3325 return -1;
3326
3327 return Value.zextOrTrunc(8).getZExtValue();
3328 }
3329 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
3330 // Make sure all array elements are sequences of the same repeated
3331 // byte.
3332 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
3333 Constant *Op0 = CA->getOperand(0);
3334 int Byte = isRepeatedByteSequence(Op0, DL);
3335 if (Byte == -1)
3336 return -1;
3337
3338 // All array elements must be equal.
3339 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
3340 if (CA->getOperand(i) != Op0)
3341 return -1;
3342 return Byte;
3343 }
3344
3345 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
3346 return isRepeatedByteSequence(CDS);
3347
3348 return -1;
3349}
3350
3352 AsmPrinter::AliasMapTy *AliasList) {
3353 if (AliasList) {
3354 auto AliasIt = AliasList->find(Offset);
3355 if (AliasIt != AliasList->end()) {
3356 for (const GlobalAlias *GA : AliasIt->second)
3357 AP.OutStreamer->emitLabel(AP.getSymbol(GA));
3358 AliasList->erase(Offset);
3359 }
3360 }
3361}
3362
3364 const DataLayout &DL, const ConstantDataSequential *CDS, AsmPrinter &AP,
3365 AsmPrinter::AliasMapTy *AliasList) {
3366 // See if we can aggregate this into a .fill, if so, emit it as such.
3367 int Value = isRepeatedByteSequence(CDS, DL);
3368 if (Value != -1) {
3369 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
3370 // Don't emit a 1-byte object as a .fill.
3371 if (Bytes > 1)
3372 return AP.OutStreamer->emitFill(Bytes, Value);
3373 }
3374
3375 // If this can be emitted with .ascii/.asciz, emit it as such.
3376 if (CDS->isString())
3377 return AP.OutStreamer->emitBytes(CDS->getAsString());
3378
3379 // Otherwise, emit the values in successive locations.
3380 unsigned ElementByteSize = CDS->getElementByteSize();
3381 if (isa<IntegerType>(CDS->getElementType())) {
3382 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
3383 emitGlobalAliasInline(AP, ElementByteSize * I, AliasList);
3384 if (AP.isVerbose())
3385 AP.OutStreamer->getCommentOS()
3386 << format("0x%" PRIx64 "\n", CDS->getElementAsInteger(I));
3387 AP.OutStreamer->emitIntValue(CDS->getElementAsInteger(I),
3388 ElementByteSize);
3389 }
3390 } else {
3391 Type *ET = CDS->getElementType();
3392 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
3393 emitGlobalAliasInline(AP, ElementByteSize * I, AliasList);
3395 }
3396 }
3397
3398 unsigned Size = DL.getTypeAllocSize(CDS->getType());
3399 unsigned EmittedSize =
3400 DL.getTypeAllocSize(CDS->getElementType()) * CDS->getNumElements();
3401 assert(EmittedSize <= Size && "Size cannot be less than EmittedSize!");
3402 if (unsigned Padding = Size - EmittedSize)
3403 AP.OutStreamer->emitZeros(Padding);
3404}
3405
3407 const ConstantArray *CA, AsmPrinter &AP,
3408 const Constant *BaseCV, uint64_t Offset,
3409 AsmPrinter::AliasMapTy *AliasList) {
3410 // See if we can aggregate some values. Make sure it can be
3411 // represented as a series of bytes of the constant value.
3412 int Value = isRepeatedByteSequence(CA, DL);
3413
3414 if (Value != -1) {
3415 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
3416 AP.OutStreamer->emitFill(Bytes, Value);
3417 } else {
3418 for (unsigned I = 0, E = CA->getNumOperands(); I != E; ++I) {
3419 emitGlobalConstantImpl(DL, CA->getOperand(I), AP, BaseCV, Offset,
3420 AliasList);
3421 Offset += DL.getTypeAllocSize(CA->getOperand(I)->getType());
3422 }
3423 }
3424}
3425
3426static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP);
3427
3429 const ConstantVector *CV, AsmPrinter &AP,
3430 AsmPrinter::AliasMapTy *AliasList) {
3431 Type *ElementType = CV->getType()->getElementType();
3432 uint64_t ElementSizeInBits = DL.getTypeSizeInBits(ElementType);
3433 uint64_t ElementAllocSizeInBits = DL.getTypeAllocSizeInBits(ElementType);
3434 uint64_t EmittedSize;
3435 if (ElementSizeInBits != ElementAllocSizeInBits) {
3436 // If the allocation size of an element is different from the size in bits,
3437 // printing each element separately will insert incorrect padding.
3438 //
3439 // The general algorithm here is complicated; instead of writing it out
3440 // here, just use the existing code in ConstantFolding.
3441 Type *IntT =
3442 IntegerType::get(CV->getContext(), DL.getTypeSizeInBits(CV->getType()));
3443 ConstantInt *CI = dyn_cast_or_null<ConstantInt>(ConstantFoldConstant(
3444 ConstantExpr::getBitCast(const_cast<ConstantVector *>(CV), IntT), DL));
3445 if (!CI) {
3447 "Cannot lower vector global with unusual element type");
3448 }
3449 emitGlobalAliasInline(AP, 0, AliasList);
3451 EmittedSize = DL.getTypeStoreSize(CV->getType());
3452 } else {
3453 for (unsigned I = 0, E = CV->getType()->getNumElements(); I != E; ++I) {
3454 emitGlobalAliasInline(AP, DL.getTypeAllocSize(CV->getType()) * I, AliasList);
3456 }
3457 EmittedSize =
3458 DL.getTypeAllocSize(ElementType) * CV->getType()->getNumElements();
3459 }
3460
3461 unsigned Size = DL.getTypeAllocSize(CV->getType());
3462 if (unsigned Padding = Size - EmittedSize)
3463 AP.OutStreamer->emitZeros(Padding);
3464}
3465
3467 const ConstantStruct *CS, AsmPrinter &AP,
3468 const Constant *BaseCV, uint64_t Offset,
3469 AsmPrinter::AliasMapTy *AliasList) {
3470 // Print the fields in successive locations. Pad to align if needed!
3471 uint64_t Size = DL.getTypeAllocSize(CS->getType());
3472 const StructLayout *Layout = DL.getStructLayout(CS->getType());
3473 uint64_t SizeSoFar = 0;
3474 for (unsigned I = 0, E = CS->getNumOperands(); I != E; ++I) {
3475 const Constant *Field = CS->getOperand(I);
3476
3477 // Print the actual field value.
3478 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar,
3479 AliasList);
3480
3481 // Check if padding is needed and insert one or more 0s.
3482 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
3483 uint64_t PadSize = ((I == E - 1 ? Size : Layout->getElementOffset(I + 1)) -
3484 Layout->getElementOffset(I)) -
3485 FieldSize;
3486 SizeSoFar += FieldSize + PadSize;
3487
3488 // Insert padding - this may include padding to increase the size of the
3489 // current field up to the ABI size (if the struct is not packed) as well
3490 // as padding to ensure that the next field starts at the right offset.
3491 AP.OutStreamer->emitZeros(PadSize);
3492 }
3493 assert(SizeSoFar == Layout->getSizeInBytes() &&
3494 "Layout of constant struct may be incorrect!");
3495}
3496
3497static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP) {
3498 assert(ET && "Unknown float type");
3499 APInt API = APF.bitcastToAPInt();
3500
3501 // First print a comment with what we think the original floating-point value
3502 // should have been.
3503 if (AP.isVerbose()) {
3504 SmallString<8> StrVal;
3505 APF.toString(StrVal);
3506 ET->print(AP.OutStreamer->getCommentOS());
3507 AP.OutStreamer->getCommentOS() << ' ' << StrVal << '\n';
3508 }
3509
3510 // Now iterate through the APInt chunks, emitting them in endian-correct
3511 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
3512 // floats).
3513 unsigned NumBytes = API.getBitWidth() / 8;
3514 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
3515 const uint64_t *p = API.getRawData();
3516
3517 // PPC's long double has odd notions of endianness compared to how LLVM
3518 // handles it: p[0] goes first for *big* endian on PPC.
3519 if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
3520 int Chunk = API.getNumWords() - 1;
3521
3522 if (TrailingBytes)
3523 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk--], TrailingBytes);
3524
3525 for (; Chunk >= 0; --Chunk)
3526 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
3527 } else {
3528 unsigned Chunk;
3529 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
3530 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
3531
3532 if (TrailingBytes)
3533 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], TrailingBytes);
3534 }
3535
3536 // Emit the tail padding for the long double.
3537 const DataLayout &DL = AP.getDataLayout();
3538 AP.OutStreamer->emitZeros(DL.getTypeAllocSize(ET) - DL.getTypeStoreSize(ET));
3539}
3540
3541static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
3542 emitGlobalConstantFP(CFP->getValueAPF(), CFP->getType(), AP);
3543}
3544
3546 const DataLayout &DL = AP.getDataLayout();
3547 unsigned BitWidth = CI->getBitWidth();
3548
3549 // Copy the value as we may massage the layout for constants whose bit width
3550 // is not a multiple of 64-bits.
3551 APInt Realigned(CI->getValue());
3552 uint64_t ExtraBits = 0;
3553 unsigned ExtraBitsSize = BitWidth & 63;
3554
3555 if (ExtraBitsSize) {
3556 // The bit width of the data is not a multiple of 64-bits.
3557 // The extra bits are expected to be at the end of the chunk of the memory.
3558 // Little endian:
3559 // * Nothing to be done, just record the extra bits to emit.
3560 // Big endian:
3561 // * Record the extra bits to emit.
3562 // * Realign the raw data to emit the chunks of 64-bits.
3563 if (DL.isBigEndian()) {
3564 // Basically the structure of the raw data is a chunk of 64-bits cells:
3565 // 0 1 BitWidth / 64
3566 // [chunk1][chunk2] ... [chunkN].
3567 // The most significant chunk is chunkN and it should be emitted first.
3568 // However, due to the alignment issue chunkN contains useless bits.
3569 // Realign the chunks so that they contain only useful information:
3570 // ExtraBits 0 1 (BitWidth / 64) - 1
3571 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
3572 ExtraBitsSize = alignTo(ExtraBitsSize, 8);
3573 ExtraBits = Realigned.getRawData()[0] &
3574 (((uint64_t)-1) >> (64 - ExtraBitsSize));
3575 if (BitWidth >= 64)
3576 Realigned.lshrInPlace(ExtraBitsSize);
3577 } else
3578 ExtraBits = Realigned.getRawData()[BitWidth / 64];
3579 }
3580
3581 // We don't expect assemblers to support integer data directives
3582 // for more than 64 bits, so we emit the data in at most 64-bit
3583 // quantities at a time.
3584 const uint64_t *RawData = Realigned.getRawData();
3585 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
3586 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
3587 AP.OutStreamer->emitIntValue(Val, 8);
3588 }
3589
3590 if (ExtraBitsSize) {
3591 // Emit the extra bits after the 64-bits chunks.
3592
3593 // Emit a directive that fills the expected size.
3595 Size -= (BitWidth / 64) * 8;
3596 assert(Size && Size * 8 >= ExtraBitsSize &&
3597 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
3598 == ExtraBits && "Directive too small for extra bits.");
3599 AP.OutStreamer->emitIntValue(ExtraBits, Size);
3600 }
3601}
3602
3603/// Transform a not absolute MCExpr containing a reference to a GOT
3604/// equivalent global, by a target specific GOT pc relative access to the
3605/// final symbol.
3607 const Constant *BaseCst,
3608 uint64_t Offset) {
3609 // The global @foo below illustrates a global that uses a got equivalent.
3610 //
3611 // @bar = global i32 42
3612 // @gotequiv = private unnamed_addr constant i32* @bar
3613 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
3614 // i64 ptrtoint (i32* @foo to i64))
3615 // to i32)
3616 //
3617 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
3618 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
3619 // form:
3620 //
3621 // foo = cstexpr, where
3622 // cstexpr := <gotequiv> - "." + <cst>
3623 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
3624 //
3625 // After canonicalization by evaluateAsRelocatable `ME` turns into:
3626 //
3627 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
3628 // gotpcrelcst := <offset from @foo base> + <cst>
3629 MCValue MV;
3630 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
3631 return;
3632 const MCSymbolRefExpr *SymA = MV.getSymA();
3633 if (!SymA)
3634 return;
3635
3636 // Check that GOT equivalent symbol is cached.
3637 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
3638 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
3639 return;
3640
3641 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
3642 if (!BaseGV)
3643 return;
3644
3645 // Check for a valid base symbol
3646 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
3647 const MCSymbolRefExpr *SymB = MV.getSymB();
3648
3649 if (!SymB || BaseSym != &SymB->getSymbol())
3650 return;
3651
3652 // Make sure to match:
3653 //
3654 // gotpcrelcst := <offset from @foo base> + <cst>
3655 //
3656 int64_t GOTPCRelCst = Offset + MV.getConstant();
3657 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
3658 return;
3659
3660 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
3661 //
3662 // bar:
3663 // .long 42
3664 // gotequiv:
3665 // .quad bar
3666 // foo:
3667 // .long gotequiv - "." + <cst>
3668 //
3669 // is replaced by the target specific equivalent to:
3670 //
3671 // bar:
3672 // .long 42
3673 // foo:
3674 // .long bar@GOTPCREL+<gotpcrelcst>
3675 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
3676 const GlobalVariable *GV = Result.first;
3677 int NumUses = (int)Result.second;
3678 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
3679 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
3681 FinalGV, FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
3682
3683 // Update GOT equivalent usage information
3684 --NumUses;
3685 if (NumUses >= 0)
3686 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
3687}
3688
3689static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
3690 AsmPrinter &AP, const Constant *BaseCV,
3692 AsmPrinter::AliasMapTy *AliasList) {
3693 emitGlobalAliasInline(AP, Offset, AliasList);
3694 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3695
3696 // Globals with sub-elements such as combinations of arrays and structs
3697 // are handled recursively by emitGlobalConstantImpl. Keep track of the
3698 // constant symbol base and the current position with BaseCV and Offset.
3699 if (!BaseCV && CV->hasOneUse())
3700 BaseCV = dyn_cast<Constant>(CV->user_back());
3701
3702 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
3703 return AP.OutStreamer->emitZeros(Size);
3704
3705 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
3706 const uint64_t StoreSize = DL.getTypeStoreSize(CV->getType());
3707
3708 if (StoreSize <= 8) {
3709 if (AP.isVerbose())
3710 AP.OutStreamer->getCommentOS()
3711 << format("0x%" PRIx64 "\n", CI->getZExtValue());
3712 AP.OutStreamer->emitIntValue(CI->getZExtValue(), StoreSize);
3713 } else {
3715 }
3716
3717 // Emit tail padding if needed
3718 if (Size != StoreSize)
3719 AP.OutStreamer->emitZeros(Size - StoreSize);
3720
3721 return;
3722 }
3723
3724 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
3725 return emitGlobalConstantFP(CFP, AP);
3726
3727 if (isa<ConstantPointerNull>(CV)) {
3728 AP.OutStreamer->emitIntValue(0, Size);
3729 return;
3730 }
3731
3732 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
3733 return emitGlobalConstantDataSequential(DL, CDS, AP, AliasList);
3734
3735 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
3736 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset, AliasList);
3737
3738 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
3739 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset, AliasList);
3740
3741 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
3742 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
3743 // vectors).
3744 if (CE->getOpcode() == Instruction::BitCast)
3745 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
3746
3747 if (Size > 8) {
3748 // If the constant expression's size is greater than 64-bits, then we have
3749 // to emit the value in chunks. Try to constant fold the value and emit it
3750 // that way.
3751 Constant *New = ConstantFoldConstant(CE, DL);
3752 if (New != CE)
3753 return emitGlobalConstantImpl(DL, New, AP);
3754 }
3755 }
3756
3757 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
3758 return emitGlobalConstantVector(DL, V, AP, AliasList);
3759
3760 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
3761 // thread the streamer with EmitValue.
3762 const MCExpr *ME = AP.lowerConstant(CV);
3763
3764 // Since lowerConstant already folded and got rid of all IR pointer and
3765 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
3766 // directly.
3768 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
3769
3770 AP.OutStreamer->emitValue(ME, Size);
3771}
3772
3773/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
3775 AliasMapTy *AliasList) {
3776 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3777 if (Size)
3778 emitGlobalConstantImpl(DL, CV, *this, nullptr, 0, AliasList);
3779 else if (MAI->hasSubsectionsViaSymbols()) {
3780 // If the global has zero size, emit a single byte so that two labels don't
3781 // look like they are at the same location.
3782 OutStreamer->emitIntValue(0, 1);
3783 }
3784 if (!AliasList)
3785 return;
3786 // TODO: These remaining aliases are not emitted in the correct location. Need
3787 // to handle the case where the alias offset doesn't refer to any sub-element.
3788 for (auto &AliasPair : *AliasList) {
3789 for (const GlobalAlias *GA : AliasPair.second)
3790 OutStreamer->emitLabel(getSymbol(GA));
3791 }
3792}
3793
3795 // Target doesn't support this yet!
3796 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
3797}
3798
3800 if (Offset > 0)
3801 OS << '+' << Offset;
3802 else if (Offset < 0)
3803 OS << Offset;
3804}
3805
3806void AsmPrinter::emitNops(unsigned N) {
3808 for (; N; --N)
3810}
3811
3812//===----------------------------------------------------------------------===//
3813// Symbol Lowering Routines.
3814//===----------------------------------------------------------------------===//
3815
3817 return OutContext.createTempSymbol(Name, true);
3818}
3819
3821 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(
3822 BA->getBasicBlock());
3823}
3824
3826 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(BB);
3827}
3828
3829/// GetCPISymbol - Return the symbol for the specified constant pool entry.
3830MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
3831 if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment()) {
3832 const MachineConstantPoolEntry &CPE =
3833 MF->getConstantPool()->getConstants()[CPID];
3834 if (!CPE.isMachineConstantPoolEntry()) {
3835 const DataLayout &DL = MF->getDataLayout();
3836 SectionKind Kind = CPE.getSectionKind(&DL);
3837 const Constant *C = CPE.Val.ConstVal;
3838 Align Alignment = CPE.Alignment;
3839 if (const MCSectionCOFF *S = dyn_cast<MCSectionCOFF>(
3840 getObjFileLowering().getSectionForConstant(DL, Kind, C,
3841 Alignment))) {
3842 if (MCSymbol *Sym = S->getCOMDATSymbol()) {
3843 if (Sym->isUndefined())
3844 OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
3845 return Sym;
3846 }
3847 }
3848 }
3849 }
3850
3851 const DataLayout &DL = getDataLayout();
3852 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3853 "CPI" + Twine(getFunctionNumber()) + "_" +
3854 Twine(CPID));
3855}
3856
3857/// GetJTISymbol - Return the symbol for the specified jump table entry.
3858MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
3859 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
3860}
3861
3862/// GetJTSetSymbol - Return the symbol for the specified jump table .set
3863/// FIXME: privatize to AsmPrinter.
3864MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
3865 const DataLayout &DL = getDataLayout();
3866 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3867 Twine(getFunctionNumber()) + "_" +
3868 Twine(UID) + "_set_" + Twine(MBBID));
3869}
3870
3872 StringRef Suffix) const {
3874}
3875
3876/// Return the MCSymbol for the specified ExternalSymbol.
3878 SmallString<60> NameStr;
3880 return OutContext.getOrCreateSymbol(NameStr);
3881}
3882
3883/// PrintParentLoopComment - Print comments about parent loops of this one.
3885 unsigned FunctionNumber) {
3886 if (!Loop) return;
3887 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
3889 << "Parent Loop BB" << FunctionNumber << "_"
3890 << Loop->getHeader()->getNumber()
3891 << " Depth=" << Loop->getLoopDepth() << '\n';
3892}
3893
3894/// PrintChildLoopComment - Print comments about child loops within
3895/// the loop for this basic block, with nesting.
3897 unsigned FunctionNumber) {
3898 // Add child loop information
3899 for (const MachineLoop *CL : *Loop) {
3900 OS.indent(CL->getLoopDepth()*2)
3901 << "Child Loop BB" << FunctionNumber << "_"
3902 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
3903 << '\n';
3904 PrintChildLoopComment(OS, CL, FunctionNumber);
3905 }
3906}
3907
3908/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
3910 const MachineLoopInfo *LI,
3911 const AsmPrinter &AP) {
3912 // Add loop depth information
3913 const MachineLoop *Loop = LI->getLoopFor(&MBB);
3914 if (!Loop) return;
3915
3916 MachineBasicBlock *Header = Loop->getHeader();
3917 assert(Header && "No header for loop");
3918
3919 // If this block is not a loop header, just print out what is the loop header
3920 // and return.
3921 if (Header != &MBB) {
3922 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
3923 Twine(AP.getFunctionNumber())+"_" +
3924 Twine(Loop->getHeader()->getNumber())+
3925 " Depth="+Twine(Loop->getLoopDepth()));
3926 return;
3927 }
3928
3929 // Otherwise, it is a loop header. Print out information about child and
3930 // parent loops.
3931 raw_ostream &OS = AP.OutStreamer->getCommentOS();
3932
3934
3935 OS << "=>";
3936 OS.indent(Loop->getLoopDepth()*2-2);
3937
3938 OS << "This ";
3939 if (Loop->isInnermost())
3940 OS << "Inner ";
3941 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
3942
3944}
3945
3946/// emitBasicBlockStart - This method prints the label for the specified
3947/// MachineBasicBlock, an alignment (if present) and a comment describing
3948/// it if appropriate.
3950 // End the previous funclet and start a new one.
3951 if (MBB.isEHFuncletEntry()) {
3952 for (auto &Handler : Handlers) {
3953 Handler->endFunclet();
3954 Handler->beginFunclet(MBB);
3955 }
3956 }
3957
3958 // Switch to a new section if this basic block must begin a section. The
3959 // entry block is always placed in the function section and is handled
3960 // separately.
3961 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
3962 OutStreamer->switchSection(
3963 getObjFileLowering().getSectionForMachineBasicBlock(MF->getFunction(),
3964 MBB, TM));
3965 CurrentSectionBeginSym = MBB.getSymbol();
3966 }
3967
3968 // Emit an alignment directive for this block, if needed.
3969 const Align Alignment = MBB.getAlignment();
3970 if (Alignment != Align(1))
3971 emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
3972
3973 // If the block has its address taken, emit any labels that were used to
3974 // reference the block. It is possible that there is more than one label
3975 // here, because multiple LLVM BB's may have been RAUW'd to this block after
3976 // the references were generated.
3977 if (MBB.isIRBlockAddressTaken()) {
3978 if (isVerbose())
3979 OutStreamer->AddComment("Block address taken");
3980
3982 assert(BB && BB->hasAddressTaken() && "Missing BB");
3984 OutStreamer->emitLabel(Sym);
3985 } else if (isVerbose() && MBB.isMachineBlockAddressTaken()) {
3986 OutStreamer->AddComment("Block address taken");
3987 }
3988
3989 // Print some verbose block comments.
3990 if (isVerbose()) {
3991 if (const BasicBlock *BB = MBB.getBasicBlock()) {
3992 if (BB->hasName()) {
3993 BB->printAsOperand(OutStreamer->getCommentOS(),
3994 /*PrintType=*/false, BB->getModule());
3995 OutStreamer->getCommentOS() << '\n';
3996 }
3997 }
3998
3999 assert(MLI != nullptr && "MachineLoopInfo should has been computed");
4001 }
4002
4003 // Print the main label for the block.
4004 if (shouldEmitLabelForBasicBlock(MBB)) {
4006 OutStreamer->AddComment("Label of block must be emitted");
4007 OutStreamer->emitLabel(MBB.getSymbol());
4008 } else {
4009 if (isVerbose()) {
4010 // NOTE: Want this comment at start of line, don't emit with AddComment.
4011 OutStreamer->emitRawComment(" %bb." + Twine(MBB.getNumber()) + ":",
4012 false);
4013 }
4014 }
4015
4016 if (MBB.isEHCatchretTarget() &&
4018 OutStreamer->emitLabel(MBB.getEHCatchretSymbol());
4019 }
4020
4021 // With BB sections, each basic block must handle CFI information on its own
4022 // if it begins a section (Entry block call is handled separately, next to
4023 // beginFunction).
4024 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
4025 for (auto &Handler : DebugHandlers)
4026 Handler->beginBasicBlockSection(MBB);
4027 for (auto &Handler : Handlers)
4028 Handler->beginBasicBlockSection(MBB);
4029 }
4030}
4031
4033 // Check if CFI information needs to be updated for this MBB with basic block
4034 // sections.
4035 if (MBB.isEndSection()) {
4036 for (auto &Handler : DebugHandlers)
4037 Handler->endBasicBlockSection(MBB);
4038 for (auto &Handler : Handlers)
4039 Handler->endBasicBlockSection(MBB);
4040 }
4041}
4042
4043void AsmPrinter::emitVisibility(MCSymbol *Sym, unsigned Visibility,
4044 bool IsDefinition) const {
4046
4047 switch (Visibility) {
4048 default: break;
4050 if (IsDefinition)
4051 Attr = MAI->getHiddenVisibilityAttr();
4052 else
4054 break;
4057 break;
4058 }
4059
4060 if (Attr != MCSA_Invalid)
4061 OutStreamer->emitSymbolAttribute(Sym, Attr);
4062}
4063
4064bool AsmPrinter::shouldEmitLabelForBasicBlock(
4065 const MachineBasicBlock &MBB) const {
4066 // With `-fbasic-block-sections=`, a label is needed for every non-entry block
4067 // in the labels mode (option `=labels`) and every section beginning in the
4068 // sections mode (`=all` and `=list=`).
4069 if ((MF->hasBBLabels() || MF->getTarget().Options.BBAddrMap ||
4070 MBB.isBeginSection()) &&
4071 !MBB.isEntryBlock())
4072 return true;
4073 // A label is needed for any block with at least one predecessor (when that
4074 // predecessor is not the fallthrough predecessor, or if it is an EH funclet
4075 // entry, or if a label is forced).
4076 return !MBB.pred_empty() &&
4079}
4080
4081/// isBlockOnlyReachableByFallthough - Return true if the basic block has
4082/// exactly one predecessor and the control transfer mechanism between
4083/// the predecessor and this block is a fall-through.
4086 // If this is a landing pad, it isn't a fall through. If it has no preds,
4087 // then nothing falls through to it.
4088 if (MBB->isEHPad() || MBB->pred_empty())
4089 return false;
4090
4091 // If there isn't exactly one predecessor, it can't be a fall through.
4092 if (MBB->pred_size() > 1)
4093 return false;
4094
4095 // The predecessor has to be immediately before this block.
4096 MachineBasicBlock *Pred = *MBB->pred_begin();
4097 if (!Pred->isLayoutSuccessor(MBB))
4098 return false;
4099
4100 // If the block is completely empty, then it definitely does fall through.
4101 if (Pred->empty())
4102 return true;
4103
4104 // Check the terminators in the previous blocks
4105 for (const auto &MI : Pred->terminators()) {
4106 // If it is not a simple branch, we are in a table somewhere.
4107 if (!MI.isBranch() || MI.isIndirectBranch())
4108 return false;
4109
4110 // If we are the operands of one of the branches, this is not a fall
4111 // through. Note that targets with delay slots will usually bundle
4112 // terminators with the delay slot instruction.
4113 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
4114 if (OP->isJTI())
4115 return false;
4116 if (OP->isMBB() && OP->getMBB() == MBB)
4117 return false;
4118 }
4119 }
4120
4121 return true;
4122}
4123
4124GCMetadataPrinter *AsmPrinter::getOrCreateGCPrinter(GCStrategy &S) {
4125 if (!S.usesMetadata())
4126 return nullptr;
4127
4128 auto [GCPI, Inserted] = GCMetadataPrinters.insert({&S, nullptr});
4129 if (!Inserted)
4130 return GCPI->second.get();
4131
4132 auto Name = S.getName();
4133
4134 for (const GCMetadataPrinterRegistry::entry &GCMetaPrinter :
4136 if (Name == GCMetaPrinter.getName()) {
4137 std::unique_ptr<GCMetadataPrinter> GMP = GCMetaPrinter.instantiate();
4138 GMP->S = &S;
4139 GCPI->second = std::move(GMP);
4140 return GCPI->second.get();
4141 }
4142
4143 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
4144}
4145
4147 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
4148 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
4149 bool NeedsDefault = false;
4150 if (MI->begin() == MI->end())
4151 // No GC strategy, use the default format.
4152 NeedsDefault = true;
4153 else
4154 for (const auto &I : *MI) {
4155 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(*I))
4156 if (MP->emitStackMaps(SM, *this))
4157 continue;
4158 // The strategy doesn't have printer or doesn't emit custom stack maps.
4159 // Use the default format.
4160 NeedsDefault = true;
4161 }
4162
4163 if (NeedsDefault)
4165}
4166
4168 std::unique_ptr<AsmPrinterHandler> Handler) {
4169 Handlers.insert(Handlers.begin(), std::move(Handler));
4171}
4172
4173void AsmPrinter::addDebugHandler(std::unique_ptr<DebugHandlerBase> Handler) {
4174 DebugHandlers.insert(DebugHandlers.begin(), std::move(Handler));
4176}
4177
4178/// Pin vtable to this file.
4180
4182
4183// In the binary's "xray_instr_map" section, an array of these function entries
4184// describes each instrumentation point. When XRay patches your code, the index
4185// into this table will be given to your handler as a patch point identifier.
4187 auto Kind8 = static_cast<uint8_t>(Kind);
4188 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
4189 Out->emitBinaryData(
4190 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
4191 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Version), 1));
4192 auto Padding = (4 * Bytes) - ((2 * Bytes) + 3);
4193 assert(Padding >= 0 && "Instrumentation map entry > 4 * Word Size");
4194 Out->emitZeros(Padding);
4195}
4196
4198 if (Sleds.empty())
4199 return;
4200
4201 auto PrevSection = OutStreamer->getCurrentSectionOnly();
4202 const Function &F = MF->getFunction();
4203 MCSection *InstMap = nullptr;
4204 MCSection *FnSledIndex = nullptr;
4205 const Triple &TT = TM.getTargetTriple();
4206 // Use PC-relative addresses on all targets.
4207 if (TT.isOSBinFormatELF()) {
4208 auto LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
4209 auto Flags = ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
4210 StringRef GroupName;
4211 if (F.hasComdat()) {
4212 Flags |= ELF::SHF_GROUP;
4213 GroupName = F.getComdat()->getName();
4214 }
4215 InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
4216 Flags, 0, GroupName, F.hasComdat(),
4217 MCSection::NonUniqueID, LinkedToSym);
4218
4220 FnSledIndex = OutContext.getELFSection(
4221 "xray_fn_idx", ELF::SHT_PROGBITS, Flags, 0, GroupName, F.hasComdat(),
4222 MCSection::NonUniqueID, LinkedToSym);
4224 InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map",
4228 FnSledIndex = OutContext.getMachOSection("__DATA", "xray_fn_idx",
4231 } else {
4232 llvm_unreachable("Unsupported target");
4233 }
4234
4235 auto WordSizeBytes = MAI->getCodePointerSize();
4236
4237 // Now we switch to the instrumentation map section. Because this is done
4238 // per-function, we are able to create an index entry that will represent the
4239 // range of sleds associated with a function.
4240 auto &Ctx = OutContext;
4241 MCSymbol *SledsStart =
4242 OutContext.createLinkerPrivateSymbol("xray_sleds_start");
4243 OutStreamer->switchSection(InstMap);
4244 OutStreamer->emitLabel(SledsStart);
4245 for (const auto &Sled : Sleds) {
4246 MCSymbol *Dot = Ctx.createTempSymbol();
4247 OutStreamer->emitLabel(Dot);
4248 OutStreamer->emitValueImpl(
4250 MCSymbolRefExpr::create(Dot, Ctx), Ctx),
4251 WordSizeBytes);
4252 OutStreamer->emitValueImpl(
4256 MCConstantExpr::create(WordSizeBytes, Ctx),
4257 Ctx),
4258 Ctx),
4259 WordSizeBytes);
4260 Sled.emit(WordSizeBytes, OutStreamer.get());
4261 }
4262 MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_sleds_end", true);
4263 OutStreamer->emitLabel(SledsEnd);
4264
4265 // We then emit a single entry in the index per function. We use the symbols
4266 // that bound the instrumentation map as the range for a specific function.
4267 // Each entry here will be 2 * word size aligned, as we're writing down two
4268 // pointers. This should work for both 32-bit and 64-bit platforms.
4269 if (FnSledIndex) {
4270 OutStreamer->switchSection(FnSledIndex);
4271 OutStreamer->emitCodeAlignment(Align(2 * WordSizeBytes),
4272 &getSubtargetInfo());
4273 // For Mach-O, use an "l" symbol as the atom of this subsection. The label
4274 // difference uses a SUBTRACTOR external relocation which references the
4275 // symbol.
4276 MCSymbol *Dot = Ctx.createLinkerPrivateSymbol("xray_fn_idx");
4277 OutStreamer->emitLabel(Dot);
4278 OutStreamer->emitValueImpl(
4280 MCSymbolRefExpr::create(Dot, Ctx), Ctx),
4281 WordSizeBytes);
4282 OutStreamer->emitValueImpl(MCConstantExpr::create(Sleds.size(), Ctx),
4283 WordSizeBytes);
4284 OutStreamer->switchSection(PrevSection);
4285 }
4286 Sleds.clear();
4287}
4288
4290 SledKind Kind, uint8_t Version) {
4291 const Function &F = MI.getMF()->getFunction();
4292 auto Attr = F.getFnAttribute("function-instrument");
4293 bool LogArgs = F.hasFnAttribute("xray-log-args");
4294 bool AlwaysInstrument =
4295 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
4296 if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
4298 Sleds.emplace_back(XRayFunctionEntry{Sled, CurrentFnSym, Kind,
4299 AlwaysInstrument, &F, Version});
4300}
4301
4303 const Function &F = MF->getFunction();
4304 unsigned PatchableFunctionPrefix = 0, PatchableFunctionEntry = 0;
4305 (void)F.getFnAttribute("patchable-function-prefix")
4306 .getValueAsString()
4307 .getAsInteger(10, PatchableFunctionPrefix);
4308 (void)F.getFnAttribute("patchable-function-entry")
4309 .getValueAsString()
4310 .getAsInteger(10, PatchableFunctionEntry);
4311 if (!PatchableFunctionPrefix && !PatchableFunctionEntry)
4312 return;
4313 const unsigned PointerSize = getPointerSize();
4315 auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC;
4316 const MCSymbolELF *LinkedToSym = nullptr;
4317 StringRef GroupName;
4318
4319 // GNU as < 2.35 did not support section flag 'o'. GNU ld < 2.36 did not
4320 // support mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER sections.
4321 if (MAI->useIntegratedAssembler() || MAI->binutilsIsAtLeast(2, 36)) {
4322 Flags |= ELF::SHF_LINK_ORDER;
4323 if (F.hasComdat()) {
4324 Flags |= ELF::SHF_GROUP;
4325 GroupName = F.getComdat()->getName();
4326 }
4327 LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
4328 }
4329 OutStreamer->switchSection(OutContext.getELFSection(
4330 "__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0, GroupName,
4331 F.hasComdat(), MCSection::NonUniqueID, LinkedToSym));
4332 emitAlignment(Align(PointerSize));
4333 OutStreamer->emitSymbolValue(CurrentPatchableFunctionEntrySym, PointerSize);
4334 }
4335}
4336
4338 return OutStreamer->getContext().getDwarfVersion();
4339}
4340
4342 OutStreamer->getContext().setDwarfVersion(Version);
4343}
4344
4346 return OutStreamer->getContext().getDwarfFormat() == dwarf::DWARF64;
4347}
4348
4351 OutStreamer->getContext().getDwarfFormat());
4352}
4353
4355 return {getDwarfVersion(), uint8_t(MAI->getCodePointerSize()),
4356 OutStreamer->getContext().getDwarfFormat(),
4358}
4359
4362 OutStreamer->getContext().getDwarfFormat());
4363}
4364
4365std::tuple<const MCSymbol *, uint64_t, const MCSymbol *,
4368 const MCSymbol *BranchLabel) const {
4369 const auto TLI = MF->getSubtarget().getTargetLowering();
4370 const auto BaseExpr =
4372 const auto Base = &cast<MCSymbolRefExpr>(BaseExpr)->getSymbol();
4373
4374 // By default, for the architectures that support CodeView,
4375 // EK_LabelDifference32 is implemented as an Int32 from the base address.
4376 return std::make_tuple(Base, 0, BranchLabel,
4378}
This file declares a class to represent arbitrary precision floating point values and provide a varie...
This file implements a class to represent arbitrary precision integral constant values and operations...
MachineBasicBlock & MBB
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP)
emitDebugValueComment - This method handles the target-independent form of DBG_VALUE,...
static llvm::object::BBAddrMap::Features getBBAddrMapFeature(const MachineFunction &MF, int NumMBBSectionRanges)
static void emitGlobalConstantVector(const DataLayout &DL, const ConstantVector *CV, AsmPrinter &AP, AsmPrinter::AliasMapTy *AliasList)
static cl::bits< PGOMapFeaturesEnum > PgoAnalysisMapFeatures("pgo-analysis-map", cl::Hidden, cl::CommaSeparated, cl::values(clEnumValN(PGOMapFeaturesEnum::FuncEntryCount, "func-entry-count", "Function Entry Count"), clEnumValN(PGOMapFeaturesEnum::BBFreq, "bb-freq", "Basic Block Frequency"), clEnumValN(PGOMapFeaturesEnum::BrProb, "br-prob", "Branch Probability")), cl::desc("Enable extended information within the SHT_LLVM_BB_ADDR_MAP that is " "extracted from PGO related analysis."))
static uint32_t getBBAddrMapMetadata(const MachineBasicBlock &MBB)
Returns the BB metadata to be emitted in the SHT_LLVM_BB_ADDR_MAP section for a given basic block.
static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP)
static bool isGOTEquivalentCandidate(const GlobalVariable *GV, unsigned &NumGOTEquivUsers)
Only consider global GOT equivalents if at least one user is a cstexpr inside an initializer of anoth...
static unsigned getNumGlobalVariableUses(const Constant *C)
Compute the number of Global Variables that uses a Constant.
static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB, const MachineLoopInfo *LI, const AsmPrinter &AP)
emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME, const Constant *BaseCst, uint64_t Offset)
Transform a not absolute MCExpr containing a reference to a GOT equivalent global,...
static int isRepeatedByteSequence(const ConstantDataSequential *V)
isRepeatedByteSequence - Determine whether the given value is composed of a repeated sequence of iden...
static void emitGlobalAliasInline(AsmPrinter &AP, uint64_t Offset, AsmPrinter::AliasMapTy *AliasList)
static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, unsigned FunctionNumber)
PrintChildLoopComment - Print comments about child loops within the loop for this basic block,...
PGOMapFeaturesEnum
Definition: AsmPrinter.cpp:141