AsmPrinter.cpp revision c143f0a7ff75e13d1878480965f68dd1aa1256cb
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the AsmPrinter class. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "asm-printer" 15#include "llvm/CodeGen/AsmPrinter.h" 16#include "llvm/Module.h" 17#include "llvm/CodeGen/DwarfWriter.h" 18#include "llvm/CodeGen/GCMetadataPrinter.h" 19#include "llvm/CodeGen/MachineConstantPool.h" 20#include "llvm/CodeGen/MachineFrameInfo.h" 21#include "llvm/CodeGen/MachineFunction.h" 22#include "llvm/CodeGen/MachineJumpTableInfo.h" 23#include "llvm/CodeGen/MachineLoopInfo.h" 24#include "llvm/CodeGen/MachineModuleInfo.h" 25#include "llvm/Analysis/ConstantFolding.h" 26#include "llvm/Analysis/DebugInfo.h" 27#include "llvm/MC/MCAsmInfo.h" 28#include "llvm/MC/MCContext.h" 29#include "llvm/MC/MCExpr.h" 30#include "llvm/MC/MCInst.h" 31#include "llvm/MC/MCSection.h" 32#include "llvm/MC/MCStreamer.h" 33#include "llvm/MC/MCSymbol.h" 34#include "llvm/Target/Mangler.h" 35#include "llvm/Target/TargetData.h" 36#include "llvm/Target/TargetInstrInfo.h" 37#include "llvm/Target/TargetLowering.h" 38#include "llvm/Target/TargetLoweringObjectFile.h" 39#include "llvm/Target/TargetOptions.h" 40#include "llvm/Target/TargetRegisterInfo.h" 41#include "llvm/ADT/SmallString.h" 42#include "llvm/ADT/Statistic.h" 43#include "llvm/Support/ErrorHandling.h" 44#include "llvm/Support/Format.h" 45using namespace llvm; 46 47STATISTIC(EmittedInsts, "Number of machine instrs printed"); 48 49char AsmPrinter::ID = 0; 50 51typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 52static gcp_map_type &getGCMap(void *&P) { 53 if (P == 0) 54 P = new gcp_map_type(); 55 return *(gcp_map_type*)P; 56} 57 58 59AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 60 : MachineFunctionPass(&ID), 61 TM(tm), MAI(tm.getMCAsmInfo()), 62 OutContext(Streamer.getContext()), 63 OutStreamer(Streamer), 64 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 65 DW = 0; MMI = 0; LI = 0; 66 GCMetadataPrinters = 0; 67 VerboseAsm = Streamer.isVerboseAsm(); 68} 69 70AsmPrinter::~AsmPrinter() { 71 if (GCMetadataPrinters != 0) { 72 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 73 74 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 75 delete I->second; 76 delete &GCMap; 77 GCMetadataPrinters = 0; 78 } 79 80 delete &OutStreamer; 81} 82 83/// getFunctionNumber - Return a unique ID for the current function. 84/// 85unsigned AsmPrinter::getFunctionNumber() const { 86 return MF->getFunctionNumber(); 87} 88 89TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 90 return TM.getTargetLowering()->getObjFileLowering(); 91} 92 93/// getCurrentSection() - Return the current section we are emitting to. 94const MCSection *AsmPrinter::getCurrentSection() const { 95 return OutStreamer.getCurrentSection(); 96} 97 98 99void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 100 AU.setPreservesAll(); 101 MachineFunctionPass::getAnalysisUsage(AU); 102 AU.addRequired<MachineModuleInfo>(); 103 AU.addRequired<GCModuleInfo>(); 104 if (isVerbose()) 105 AU.addRequired<MachineLoopInfo>(); 106} 107 108bool AsmPrinter::doInitialization(Module &M) { 109 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 110 MMI->AnalyzeModule(M); 111 112 // Initialize TargetLoweringObjectFile. 113 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 114 .Initialize(OutContext, TM); 115 116 Mang = new Mangler(OutContext, *TM.getTargetData()); 117 118 // Allow the target to emit any magic that it wants at the start of the file. 119 EmitStartOfAsmFile(M); 120 121 // Very minimal debug info. It is ignored if we emit actual debug info. If we 122 // don't, this at least helps the user find where a global came from. 123 if (MAI->hasSingleParameterDotFile()) { 124 // .file "foo.c" 125 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 126 } 127 128 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 129 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 130 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 131 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 132 MP->beginAssembly(*this); 133 134 // Emit module-level inline asm if it exists. 135 if (!M.getModuleInlineAsm().empty()) { 136 OutStreamer.AddComment("Start of file scope inline assembly"); 137 OutStreamer.AddBlankLine(); 138 EmitInlineAsm(M.getModuleInlineAsm()); 139 OutStreamer.AddComment("End of file scope inline assembly"); 140 OutStreamer.AddBlankLine(); 141 } 142 143 DW = getAnalysisIfAvailable<DwarfWriter>(); 144 if (DW) 145 DW->BeginModule(&M, this); 146 147 return false; 148} 149 150void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 151 switch ((GlobalValue::LinkageTypes)Linkage) { 152 case GlobalValue::CommonLinkage: 153 case GlobalValue::LinkOnceAnyLinkage: 154 case GlobalValue::LinkOnceODRLinkage: 155 case GlobalValue::WeakAnyLinkage: 156 case GlobalValue::WeakODRLinkage: 157 case GlobalValue::LinkerPrivateLinkage: 158 if (MAI->getWeakDefDirective() != 0) { 159 // .globl _foo 160 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 161 // .weak_definition _foo 162 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 163 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) { 164 // .globl _foo 165 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 166 // FIXME: linkonce should be a section attribute, handled by COFF Section 167 // assignment. 168 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce 169 // .linkonce discard 170 // FIXME: It would be nice to use .linkonce samesize for non-common 171 // globals. 172 OutStreamer.EmitRawText(StringRef(LinkOnce)); 173 } else { 174 // .weak _foo 175 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 176 } 177 break; 178 case GlobalValue::DLLExportLinkage: 179 case GlobalValue::AppendingLinkage: 180 // FIXME: appending linkage variables should go into a section of 181 // their name or something. For now, just emit them as external. 182 case GlobalValue::ExternalLinkage: 183 // If external or appending, declare as a global symbol. 184 // .globl _foo 185 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 186 break; 187 case GlobalValue::PrivateLinkage: 188 case GlobalValue::InternalLinkage: 189 break; 190 default: 191 llvm_unreachable("Unknown linkage type!"); 192 } 193} 194 195 196/// EmitGlobalVariable - Emit the specified global variable to the .s file. 197void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 198 if (!GV->hasInitializer()) // External globals require no code. 199 return; 200 201 // Check to see if this is a special global used by LLVM, if so, emit it. 202 if (EmitSpecialLLVMGlobal(GV)) 203 return; 204 205 MCSymbol *GVSym = Mang->getSymbol(GV); 206 EmitVisibility(GVSym, GV->getVisibility()); 207 208 if (MAI->hasDotTypeDotSizeDirective()) 209 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 210 211 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 212 213 const TargetData *TD = TM.getTargetData(); 214 unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 215 unsigned AlignLog = TD->getPreferredAlignmentLog(GV); 216 217 // Handle common and BSS local symbols (.lcomm). 218 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 219 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 220 221 if (isVerbose()) { 222 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 223 /*PrintType=*/false, GV->getParent()); 224 OutStreamer.GetCommentOS() << '\n'; 225 } 226 227 // Handle common symbols. 228 if (GVKind.isCommon()) { 229 // .comm _foo, 42, 4 230 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 231 return; 232 } 233 234 // Handle local BSS symbols. 235 if (MAI->hasMachoZeroFillDirective()) { 236 const MCSection *TheSection = 237 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 238 // .zerofill __DATA, __bss, _foo, 400, 5 239 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 240 return; 241 } 242 243 if (MAI->hasLCOMMDirective()) { 244 // .lcomm _foo, 42 245 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 246 return; 247 } 248 249 // .local _foo 250 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 251 // .comm _foo, 42, 4 252 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 253 return; 254 } 255 256 const MCSection *TheSection = 257 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 258 259 // Handle the zerofill directive on darwin, which is a special form of BSS 260 // emission. 261 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 262 // .globl _foo 263 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 264 // .zerofill __DATA, __common, _foo, 400, 5 265 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 266 return; 267 } 268 269 OutStreamer.SwitchSection(TheSection); 270 271 EmitLinkage(GV->getLinkage(), GVSym); 272 EmitAlignment(AlignLog, GV); 273 274 if (isVerbose()) { 275 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 276 /*PrintType=*/false, GV->getParent()); 277 OutStreamer.GetCommentOS() << '\n'; 278 } 279 OutStreamer.EmitLabel(GVSym); 280 281 EmitGlobalConstant(GV->getInitializer()); 282 283 if (MAI->hasDotTypeDotSizeDirective()) 284 // .size foo, 42 285 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 286 287 OutStreamer.AddBlankLine(); 288} 289 290/// EmitFunctionHeader - This method emits the header for the current 291/// function. 292void AsmPrinter::EmitFunctionHeader() { 293 // Print out constants referenced by the function 294 EmitConstantPool(); 295 296 // Print the 'header' of function. 297 const Function *F = MF->getFunction(); 298 299 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 300 EmitVisibility(CurrentFnSym, F->getVisibility()); 301 302 EmitLinkage(F->getLinkage(), CurrentFnSym); 303 EmitAlignment(MF->getAlignment(), F); 304 305 if (MAI->hasDotTypeDotSizeDirective()) 306 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 307 308 if (isVerbose()) { 309 WriteAsOperand(OutStreamer.GetCommentOS(), F, 310 /*PrintType=*/false, F->getParent()); 311 OutStreamer.GetCommentOS() << '\n'; 312 } 313 314 // Emit the CurrentFnSym. This is a virtual function to allow targets to 315 // do their wild and crazy things as required. 316 EmitFunctionEntryLabel(); 317 318 // If the function had address-taken blocks that got deleted, then we have 319 // references to the dangling symbols. Emit them at the start of the function 320 // so that we don't get references to undefined symbols. 321 std::vector<MCSymbol*> DeadBlockSyms; 322 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 323 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 324 OutStreamer.AddComment("Address taken block that was later removed"); 325 OutStreamer.EmitLabel(DeadBlockSyms[i]); 326 } 327 328 // Add some workaround for linkonce linkage on Cygwin\MinGW. 329 if (MAI->getLinkOnceDirective() != 0 && 330 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 331 // FIXME: What is this? 332 MCSymbol *FakeStub = 333 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 334 CurrentFnSym->getName()); 335 OutStreamer.EmitLabel(FakeStub); 336 } 337 338 // Emit pre-function debug and/or EH information. 339 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 340 DW->BeginFunction(MF); 341} 342 343/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 344/// function. This can be overridden by targets as required to do custom stuff. 345void AsmPrinter::EmitFunctionEntryLabel() { 346 OutStreamer.EmitLabel(CurrentFnSym); 347} 348 349 350/// EmitComments - Pretty-print comments for instructions. 351static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 352 const MachineFunction *MF = MI.getParent()->getParent(); 353 const TargetMachine &TM = MF->getTarget(); 354 355 DebugLoc DL = MI.getDebugLoc(); 356 if (!DL.isUnknown()) { // Print source line info. 357 DIScope Scope(DL.getScope(MF->getFunction()->getContext())); 358 // Omit the directory, because it's likely to be long and uninteresting. 359 if (Scope.Verify()) 360 CommentOS << Scope.getFilename(); 361 else 362 CommentOS << "<unknown>"; 363 CommentOS << ':' << DL.getLine(); 364 if (DL.getCol() != 0) 365 CommentOS << ':' << DL.getCol(); 366 CommentOS << '\n'; 367 } 368 369 // Check for spills and reloads 370 int FI; 371 372 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 373 374 // We assume a single instruction only has a spill or reload, not 375 // both. 376 const MachineMemOperand *MMO; 377 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 378 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 379 MMO = *MI.memoperands_begin(); 380 CommentOS << MMO->getSize() << "-byte Reload\n"; 381 } 382 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 383 if (FrameInfo->isSpillSlotObjectIndex(FI)) 384 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 385 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 386 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 387 MMO = *MI.memoperands_begin(); 388 CommentOS << MMO->getSize() << "-byte Spill\n"; 389 } 390 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 391 if (FrameInfo->isSpillSlotObjectIndex(FI)) 392 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 393 } 394 395 // Check for spill-induced copies 396 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; 397 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg, 398 SrcSubIdx, DstSubIdx)) { 399 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 400 CommentOS << " Reload Reuse\n"; 401 } 402} 403 404/// EmitImplicitDef - This method emits the specified machine instruction 405/// that is an implicit def. 406static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 407 unsigned RegNo = MI->getOperand(0).getReg(); 408 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 409 AP.TM.getRegisterInfo()->getName(RegNo)); 410 AP.OutStreamer.AddBlankLine(); 411} 412 413static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 414 std::string Str = "kill:"; 415 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 416 const MachineOperand &Op = MI->getOperand(i); 417 assert(Op.isReg() && "KILL instruction must have only register operands"); 418 Str += ' '; 419 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 420 Str += (Op.isDef() ? "<def>" : "<kill>"); 421 } 422 AP.OutStreamer.AddComment(Str); 423 AP.OutStreamer.AddBlankLine(); 424} 425 426 427 428/// EmitFunctionBody - This method emits the body and trailer for a 429/// function. 430void AsmPrinter::EmitFunctionBody() { 431 // Emit target-specific gunk before the function body. 432 EmitFunctionBodyStart(); 433 434 bool ShouldPrintDebugScopes = 435 DW && MAI->doesSupportDebugInformation() &&DW->ShouldEmitDwarfDebug(); 436 437 // Print out code for the function. 438 bool HasAnyRealCode = false; 439 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 440 I != E; ++I) { 441 // Print a label for the basic block. 442 EmitBasicBlockStart(I); 443 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 444 II != IE; ++II) { 445 // Print the assembly for the instruction. 446 if (!II->isLabel()) 447 HasAnyRealCode = true; 448 449 ++EmittedInsts; 450 451 if (ShouldPrintDebugScopes) 452 DW->BeginScope(II); 453 454 if (isVerbose()) 455 EmitComments(*II, OutStreamer.GetCommentOS()); 456 457 switch (II->getOpcode()) { 458 case TargetOpcode::DBG_LABEL: 459 case TargetOpcode::EH_LABEL: 460 case TargetOpcode::GC_LABEL: 461 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 462 break; 463 case TargetOpcode::INLINEASM: 464 EmitInlineAsm(II); 465 break; 466 case TargetOpcode::IMPLICIT_DEF: 467 if (isVerbose()) EmitImplicitDef(II, *this); 468 break; 469 case TargetOpcode::KILL: 470 if (isVerbose()) EmitKill(II, *this); 471 break; 472 default: 473 EmitInstruction(II); 474 break; 475 } 476 477 if (ShouldPrintDebugScopes) 478 DW->EndScope(II); 479 } 480 } 481 482 // If the function is empty and the object file uses .subsections_via_symbols, 483 // then we need to emit *something* to the function body to prevent the 484 // labels from collapsing together. Just emit a 0 byte. 485 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) 486 OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/); 487 488 // Emit target-specific gunk after the function body. 489 EmitFunctionBodyEnd(); 490 491 // If the target wants a .size directive for the size of the function, emit 492 // it. 493 if (MAI->hasDotTypeDotSizeDirective()) { 494 // Create a symbol for the end of function, so we can get the size as 495 // difference between the function label and the temp label. 496 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 497 OutStreamer.EmitLabel(FnEndLabel); 498 499 const MCExpr *SizeExp = 500 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 501 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 502 OutContext); 503 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 504 } 505 506 // Emit post-function debug information. 507 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 508 DW->EndFunction(MF); 509 510 // Print out jump tables referenced by the function. 511 EmitJumpTableInfo(); 512 513 OutStreamer.AddBlankLine(); 514} 515 516 517bool AsmPrinter::doFinalization(Module &M) { 518 // Emit global variables. 519 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 520 I != E; ++I) 521 EmitGlobalVariable(I); 522 523 // Emit final debug information. 524 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 525 DW->EndModule(); 526 527 // If the target wants to know about weak references, print them all. 528 if (MAI->getWeakRefDirective()) { 529 // FIXME: This is not lazy, it would be nice to only print weak references 530 // to stuff that is actually used. Note that doing so would require targets 531 // to notice uses in operands (due to constant exprs etc). This should 532 // happen with the MC stuff eventually. 533 534 // Print out module-level global variables here. 535 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 536 I != E; ++I) { 537 if (!I->hasExternalWeakLinkage()) continue; 538 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 539 } 540 541 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 542 if (!I->hasExternalWeakLinkage()) continue; 543 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 544 } 545 } 546 547 if (MAI->hasSetDirective()) { 548 OutStreamer.AddBlankLine(); 549 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 550 I != E; ++I) { 551 MCSymbol *Name = Mang->getSymbol(I); 552 553 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 554 MCSymbol *Target = Mang->getSymbol(GV); 555 556 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 557 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 558 else if (I->hasWeakLinkage()) 559 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 560 else 561 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 562 563 EmitVisibility(Name, I->getVisibility()); 564 565 // Emit the directives as assignments aka .set: 566 OutStreamer.EmitAssignment(Name, 567 MCSymbolRefExpr::Create(Target, OutContext)); 568 } 569 } 570 571 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 572 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 573 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 574 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 575 MP->finishAssembly(*this); 576 577 // If we don't have any trampolines, then we don't require stack memory 578 // to be executable. Some targets have a directive to declare this. 579 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 580 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 581 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 582 OutStreamer.SwitchSection(S); 583 584 // Allow the target to emit any magic that it wants at the end of the file, 585 // after everything else has gone out. 586 EmitEndOfAsmFile(M); 587 588 delete Mang; Mang = 0; 589 DW = 0; MMI = 0; 590 591 OutStreamer.Finish(); 592 return false; 593} 594 595void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 596 this->MF = &MF; 597 // Get the function symbol. 598 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 599 600 if (isVerbose()) 601 LI = &getAnalysis<MachineLoopInfo>(); 602} 603 604namespace { 605 // SectionCPs - Keep track the alignment, constpool entries per Section. 606 struct SectionCPs { 607 const MCSection *S; 608 unsigned Alignment; 609 SmallVector<unsigned, 4> CPEs; 610 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 611 }; 612} 613 614/// EmitConstantPool - Print to the current output stream assembly 615/// representations of the constants in the constant pool MCP. This is 616/// used to print out constants which have been "spilled to memory" by 617/// the code generator. 618/// 619void AsmPrinter::EmitConstantPool() { 620 const MachineConstantPool *MCP = MF->getConstantPool(); 621 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 622 if (CP.empty()) return; 623 624 // Calculate sections for constant pool entries. We collect entries to go into 625 // the same section together to reduce amount of section switch statements. 626 SmallVector<SectionCPs, 4> CPSections; 627 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 628 const MachineConstantPoolEntry &CPE = CP[i]; 629 unsigned Align = CPE.getAlignment(); 630 631 SectionKind Kind; 632 switch (CPE.getRelocationInfo()) { 633 default: llvm_unreachable("Unknown section kind"); 634 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 635 case 1: 636 Kind = SectionKind::getReadOnlyWithRelLocal(); 637 break; 638 case 0: 639 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 640 case 4: Kind = SectionKind::getMergeableConst4(); break; 641 case 8: Kind = SectionKind::getMergeableConst8(); break; 642 case 16: Kind = SectionKind::getMergeableConst16();break; 643 default: Kind = SectionKind::getMergeableConst(); break; 644 } 645 } 646 647 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 648 649 // The number of sections are small, just do a linear search from the 650 // last section to the first. 651 bool Found = false; 652 unsigned SecIdx = CPSections.size(); 653 while (SecIdx != 0) { 654 if (CPSections[--SecIdx].S == S) { 655 Found = true; 656 break; 657 } 658 } 659 if (!Found) { 660 SecIdx = CPSections.size(); 661 CPSections.push_back(SectionCPs(S, Align)); 662 } 663 664 if (Align > CPSections[SecIdx].Alignment) 665 CPSections[SecIdx].Alignment = Align; 666 CPSections[SecIdx].CPEs.push_back(i); 667 } 668 669 // Now print stuff into the calculated sections. 670 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 671 OutStreamer.SwitchSection(CPSections[i].S); 672 EmitAlignment(Log2_32(CPSections[i].Alignment)); 673 674 unsigned Offset = 0; 675 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 676 unsigned CPI = CPSections[i].CPEs[j]; 677 MachineConstantPoolEntry CPE = CP[CPI]; 678 679 // Emit inter-object padding for alignment. 680 unsigned AlignMask = CPE.getAlignment() - 1; 681 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 682 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 683 684 const Type *Ty = CPE.getType(); 685 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 686 687 // Emit the label with a comment on it. 688 if (isVerbose()) { 689 OutStreamer.GetCommentOS() << "constant pool "; 690 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(), 691 MF->getFunction()->getParent()); 692 OutStreamer.GetCommentOS() << '\n'; 693 } 694 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 695 696 if (CPE.isMachineConstantPoolEntry()) 697 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 698 else 699 EmitGlobalConstant(CPE.Val.ConstVal); 700 } 701 } 702} 703 704/// EmitJumpTableInfo - Print assembly representations of the jump tables used 705/// by the current function to the current output stream. 706/// 707void AsmPrinter::EmitJumpTableInfo() { 708 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 709 if (MJTI == 0) return; 710 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 711 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 712 if (JT.empty()) return; 713 714 // Pick the directive to use to print the jump table entries, and switch to 715 // the appropriate section. 716 const Function *F = MF->getFunction(); 717 bool JTInDiffSection = false; 718 if (// In PIC mode, we need to emit the jump table to the same section as the 719 // function body itself, otherwise the label differences won't make sense. 720 // FIXME: Need a better predicate for this: what about custom entries? 721 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 722 // We should also do if the section name is NULL or function is declared 723 // in discardable section 724 // FIXME: this isn't the right predicate, should be based on the MCSection 725 // for the function. 726 F->isWeakForLinker()) { 727 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 728 } else { 729 // Otherwise, drop it in the readonly section. 730 const MCSection *ReadOnlySection = 731 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 732 OutStreamer.SwitchSection(ReadOnlySection); 733 JTInDiffSection = true; 734 } 735 736 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 737 738 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 739 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 740 741 // If this jump table was deleted, ignore it. 742 if (JTBBs.empty()) continue; 743 744 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 745 // .set directive for each unique entry. This reduces the number of 746 // relocations the assembler will generate for the jump table. 747 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 748 MAI->hasSetDirective()) { 749 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 750 const TargetLowering *TLI = TM.getTargetLowering(); 751 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 752 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 753 const MachineBasicBlock *MBB = JTBBs[ii]; 754 if (!EmittedSets.insert(MBB)) continue; 755 756 // .set LJTSet, LBB32-base 757 const MCExpr *LHS = 758 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 759 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 760 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 761 } 762 } 763 764 // On some targets (e.g. Darwin) we want to emit two consequtive labels 765 // before each jump table. The first label is never referenced, but tells 766 // the assembler and linker the extents of the jump table object. The 767 // second label is actually referenced by the code. 768 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 769 // FIXME: This doesn't have to have any specific name, just any randomly 770 // named and numbered 'l' label would work. Simplify GetJTISymbol. 771 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 772 773 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 774 775 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 776 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 777 } 778} 779 780/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 781/// current stream. 782void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 783 const MachineBasicBlock *MBB, 784 unsigned UID) const { 785 const MCExpr *Value = 0; 786 switch (MJTI->getEntryKind()) { 787 case MachineJumpTableInfo::EK_Inline: 788 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 789 case MachineJumpTableInfo::EK_Custom32: 790 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 791 OutContext); 792 break; 793 case MachineJumpTableInfo::EK_BlockAddress: 794 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 795 // .word LBB123 796 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 797 break; 798 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 799 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 800 // with a relocation as gp-relative, e.g.: 801 // .gprel32 LBB123 802 MCSymbol *MBBSym = MBB->getSymbol(); 803 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 804 return; 805 } 806 807 case MachineJumpTableInfo::EK_LabelDifference32: { 808 // EK_LabelDifference32 - Each entry is the address of the block minus 809 // the address of the jump table. This is used for PIC jump tables where 810 // gprel32 is not supported. e.g.: 811 // .word LBB123 - LJTI1_2 812 // If the .set directive is supported, this is emitted as: 813 // .set L4_5_set_123, LBB123 - LJTI1_2 814 // .word L4_5_set_123 815 816 // If we have emitted set directives for the jump table entries, print 817 // them rather than the entries themselves. If we're emitting PIC, then 818 // emit the table entries as differences between two text section labels. 819 if (MAI->hasSetDirective()) { 820 // If we used .set, reference the .set's symbol. 821 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 822 OutContext); 823 break; 824 } 825 // Otherwise, use the difference as the jump table entry. 826 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 827 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 828 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 829 break; 830 } 831 } 832 833 assert(Value && "Unknown entry kind!"); 834 835 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 836 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 837} 838 839 840/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 841/// special global used by LLVM. If so, emit it and return true, otherwise 842/// do nothing and return false. 843bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 844 if (GV->getName() == "llvm.used") { 845 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 846 EmitLLVMUsedList(GV->getInitializer()); 847 return true; 848 } 849 850 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 851 if (GV->getSection() == "llvm.metadata" || 852 GV->hasAvailableExternallyLinkage()) 853 return true; 854 855 if (!GV->hasAppendingLinkage()) return false; 856 857 assert(GV->hasInitializer() && "Not a special LLVM global!"); 858 859 const TargetData *TD = TM.getTargetData(); 860 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 861 if (GV->getName() == "llvm.global_ctors") { 862 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 863 EmitAlignment(Align, 0); 864 EmitXXStructorList(GV->getInitializer()); 865 866 if (TM.getRelocationModel() == Reloc::Static && 867 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 868 StringRef Sym(".constructors_used"); 869 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 870 MCSA_Reference); 871 } 872 return true; 873 } 874 875 if (GV->getName() == "llvm.global_dtors") { 876 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 877 EmitAlignment(Align, 0); 878 EmitXXStructorList(GV->getInitializer()); 879 880 if (TM.getRelocationModel() == Reloc::Static && 881 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 882 StringRef Sym(".destructors_used"); 883 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 884 MCSA_Reference); 885 } 886 return true; 887 } 888 889 return false; 890} 891 892/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 893/// global in the specified llvm.used list for which emitUsedDirectiveFor 894/// is true, as being used with this directive. 895void AsmPrinter::EmitLLVMUsedList(Constant *List) { 896 // Should be an array of 'i8*'. 897 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 898 if (InitList == 0) return; 899 900 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 901 const GlobalValue *GV = 902 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 903 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 904 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 905 } 906} 907 908/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 909/// function pointers, ignoring the init priority. 910void AsmPrinter::EmitXXStructorList(Constant *List) { 911 // Should be an array of '{ int, void ()* }' structs. The first value is the 912 // init priority, which we ignore. 913 if (!isa<ConstantArray>(List)) return; 914 ConstantArray *InitList = cast<ConstantArray>(List); 915 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 916 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 917 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 918 919 if (CS->getOperand(1)->isNullValue()) 920 return; // Found a null terminator, exit printing. 921 // Emit the function pointer. 922 EmitGlobalConstant(CS->getOperand(1)); 923 } 924} 925 926//===--------------------------------------------------------------------===// 927// Emission and print routines 928// 929 930/// EmitInt8 - Emit a byte directive and value. 931/// 932void AsmPrinter::EmitInt8(int Value) const { 933 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 934} 935 936/// EmitInt16 - Emit a short directive and value. 937/// 938void AsmPrinter::EmitInt16(int Value) const { 939 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 940} 941 942/// EmitInt32 - Emit a long directive and value. 943/// 944void AsmPrinter::EmitInt32(int Value) const { 945 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 946} 947 948/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 949/// in bytes of the directive is specified by Size and Hi/Lo specify the 950/// labels. This implicitly uses .set if it is available. 951void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 952 unsigned Size) const { 953 // Get the Hi-Lo expression. 954 const MCExpr *Diff = 955 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 956 MCSymbolRefExpr::Create(Lo, OutContext), 957 OutContext); 958 959 if (!MAI->hasSetDirective()) { 960 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 961 return; 962 } 963 964 // Otherwise, emit with .set (aka assignment). 965 MCSymbol *SetLabel = 966 OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 967 "set" + Twine(SetCounter++)); 968 OutStreamer.EmitAssignment(SetLabel, Diff); 969 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 970} 971 972 973//===----------------------------------------------------------------------===// 974 975// EmitAlignment - Emit an alignment directive to the specified power of 976// two boundary. For example, if you pass in 3 here, you will get an 8 977// byte alignment. If a global value is specified, and if that global has 978// an explicit alignment requested, it will unconditionally override the 979// alignment request. However, if ForcedAlignBits is specified, this value 980// has final say: the ultimate alignment will be the max of ForcedAlignBits 981// and the alignment computed with NumBits and the global. 982// 983// The algorithm is: 984// Align = NumBits; 985// if (GV && GV->hasalignment) Align = GV->getalignment(); 986// Align = std::max(Align, ForcedAlignBits); 987// 988void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV, 989 unsigned ForcedAlignBits, 990 bool UseFillExpr) const { 991 if (GV && GV->getAlignment()) 992 NumBits = Log2_32(GV->getAlignment()); 993 NumBits = std::max(NumBits, ForcedAlignBits); 994 995 if (NumBits == 0) return; // No need to emit alignment. 996 997 if (getCurrentSection()->getKind().isText()) 998 OutStreamer.EmitCodeAlignment(1 << NumBits); 999 else 1000 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1001} 1002 1003/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1004/// 1005static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1006 MCContext &Ctx = AP.OutContext; 1007 1008 if (CV->isNullValue() || isa<UndefValue>(CV)) 1009 return MCConstantExpr::Create(0, Ctx); 1010 1011 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1012 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1013 1014 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1015 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1016 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1017 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1018 1019 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1020 if (CE == 0) { 1021 llvm_unreachable("Unknown constant value to lower!"); 1022 return MCConstantExpr::Create(0, Ctx); 1023 } 1024 1025 switch (CE->getOpcode()) { 1026 default: 1027 // If the code isn't optimized, there may be outstanding folding 1028 // opportunities. Attempt to fold the expression using TargetData as a 1029 // last resort before giving up. 1030 if (Constant *C = 1031 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1032 if (C != CE) 1033 return LowerConstant(C, AP); 1034#ifndef NDEBUG 1035 CE->dump(); 1036#endif 1037 llvm_unreachable("FIXME: Don't support this constant expr"); 1038 case Instruction::GetElementPtr: { 1039 const TargetData &TD = *AP.TM.getTargetData(); 1040 // Generate a symbolic expression for the byte address 1041 const Constant *PtrVal = CE->getOperand(0); 1042 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1043 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1044 IdxVec.size()); 1045 1046 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1047 if (Offset == 0) 1048 return Base; 1049 1050 // Truncate/sext the offset to the pointer size. 1051 if (TD.getPointerSizeInBits() != 64) { 1052 int SExtAmount = 64-TD.getPointerSizeInBits(); 1053 Offset = (Offset << SExtAmount) >> SExtAmount; 1054 } 1055 1056 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1057 Ctx); 1058 } 1059 1060 case Instruction::Trunc: 1061 // We emit the value and depend on the assembler to truncate the generated 1062 // expression properly. This is important for differences between 1063 // blockaddress labels. Since the two labels are in the same function, it 1064 // is reasonable to treat their delta as a 32-bit value. 1065 // FALL THROUGH. 1066 case Instruction::BitCast: 1067 return LowerConstant(CE->getOperand(0), AP); 1068 1069 case Instruction::IntToPtr: { 1070 const TargetData &TD = *AP.TM.getTargetData(); 1071 // Handle casts to pointers by changing them into casts to the appropriate 1072 // integer type. This promotes constant folding and simplifies this code. 1073 Constant *Op = CE->getOperand(0); 1074 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1075 false/*ZExt*/); 1076 return LowerConstant(Op, AP); 1077 } 1078 1079 case Instruction::PtrToInt: { 1080 const TargetData &TD = *AP.TM.getTargetData(); 1081 // Support only foldable casts to/from pointers that can be eliminated by 1082 // changing the pointer to the appropriately sized integer type. 1083 Constant *Op = CE->getOperand(0); 1084 const Type *Ty = CE->getType(); 1085 1086 const MCExpr *OpExpr = LowerConstant(Op, AP); 1087 1088 // We can emit the pointer value into this slot if the slot is an 1089 // integer slot equal to the size of the pointer. 1090 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1091 return OpExpr; 1092 1093 // Otherwise the pointer is smaller than the resultant integer, mask off 1094 // the high bits so we are sure to get a proper truncation if the input is 1095 // a constant expr. 1096 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1097 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1098 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1099 } 1100 1101 // The MC library also has a right-shift operator, but it isn't consistently 1102 // signed or unsigned between different targets. 1103 case Instruction::Add: 1104 case Instruction::Sub: 1105 case Instruction::Mul: 1106 case Instruction::SDiv: 1107 case Instruction::SRem: 1108 case Instruction::Shl: 1109 case Instruction::And: 1110 case Instruction::Or: 1111 case Instruction::Xor: { 1112 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1113 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1114 switch (CE->getOpcode()) { 1115 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1116 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1117 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1118 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1119 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1120 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1121 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1122 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1123 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1124 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1125 } 1126 } 1127 } 1128} 1129 1130static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1131 AsmPrinter &AP) { 1132 if (AddrSpace != 0 || !CA->isString()) { 1133 // Not a string. Print the values in successive locations 1134 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1135 AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace); 1136 return; 1137 } 1138 1139 // Otherwise, it can be emitted as .ascii. 1140 SmallVector<char, 128> TmpVec; 1141 TmpVec.reserve(CA->getNumOperands()); 1142 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1143 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1144 1145 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1146} 1147 1148static void EmitGlobalConstantVector(const ConstantVector *CV, 1149 unsigned AddrSpace, AsmPrinter &AP) { 1150 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1151 AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace); 1152} 1153 1154static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1155 unsigned AddrSpace, AsmPrinter &AP) { 1156 // Print the fields in successive locations. Pad to align if needed! 1157 const TargetData *TD = AP.TM.getTargetData(); 1158 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1159 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1160 uint64_t SizeSoFar = 0; 1161 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1162 const Constant *Field = CS->getOperand(i); 1163 1164 // Check if padding is needed and insert one or more 0s. 1165 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1166 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1167 - Layout->getElementOffset(i)) - FieldSize; 1168 SizeSoFar += FieldSize + PadSize; 1169 1170 // Now print the actual field value. 1171 AP.EmitGlobalConstant(Field, AddrSpace); 1172 1173 // Insert padding - this may include padding to increase the size of the 1174 // current field up to the ABI size (if the struct is not packed) as well 1175 // as padding to ensure that the next field starts at the right offset. 1176 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1177 } 1178 assert(SizeSoFar == Layout->getSizeInBytes() && 1179 "Layout of constant struct may be incorrect!"); 1180} 1181 1182static void EmitGlobalConstantUnion(const ConstantUnion *CU, 1183 unsigned AddrSpace, AsmPrinter &AP) { 1184 const TargetData *TD = AP.TM.getTargetData(); 1185 unsigned Size = TD->getTypeAllocSize(CU->getType()); 1186 1187 const Constant *Contents = CU->getOperand(0); 1188 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType()); 1189 1190 // Print the actually filled part 1191 AP.EmitGlobalConstant(Contents, AddrSpace); 1192 1193 // And pad with enough zeroes 1194 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace); 1195} 1196 1197static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1198 AsmPrinter &AP) { 1199 // FP Constants are printed as integer constants to avoid losing 1200 // precision. 1201 if (CFP->getType()->isDoubleTy()) { 1202 if (AP.isVerbose()) { 1203 double Val = CFP->getValueAPF().convertToDouble(); 1204 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1205 } 1206 1207 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1208 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1209 return; 1210 } 1211 1212 if (CFP->getType()->isFloatTy()) { 1213 if (AP.isVerbose()) { 1214 float Val = CFP->getValueAPF().convertToFloat(); 1215 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1216 } 1217 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1218 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1219 return; 1220 } 1221 1222 if (CFP->getType()->isX86_FP80Ty()) { 1223 // all long double variants are printed as hex 1224 // api needed to prevent premature destruction 1225 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1226 const uint64_t *p = API.getRawData(); 1227 if (AP.isVerbose()) { 1228 // Convert to double so we can print the approximate val as a comment. 1229 APFloat DoubleVal = CFP->getValueAPF(); 1230 bool ignored; 1231 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1232 &ignored); 1233 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1234 << DoubleVal.convertToDouble() << '\n'; 1235 } 1236 1237 if (AP.TM.getTargetData()->isBigEndian()) { 1238 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1239 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1240 } else { 1241 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1242 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1243 } 1244 1245 // Emit the tail padding for the long double. 1246 const TargetData &TD = *AP.TM.getTargetData(); 1247 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1248 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1249 return; 1250 } 1251 1252 assert(CFP->getType()->isPPC_FP128Ty() && 1253 "Floating point constant type not handled"); 1254 // All long double variants are printed as hex api needed to prevent 1255 // premature destruction. 1256 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1257 const uint64_t *p = API.getRawData(); 1258 if (AP.TM.getTargetData()->isBigEndian()) { 1259 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1260 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1261 } else { 1262 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1263 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1264 } 1265} 1266 1267static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1268 unsigned AddrSpace, AsmPrinter &AP) { 1269 const TargetData *TD = AP.TM.getTargetData(); 1270 unsigned BitWidth = CI->getBitWidth(); 1271 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1272 1273 // We don't expect assemblers to support integer data directives 1274 // for more than 64 bits, so we emit the data in at most 64-bit 1275 // quantities at a time. 1276 const uint64_t *RawData = CI->getValue().getRawData(); 1277 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1278 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1279 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1280 } 1281} 1282 1283/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1284void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1285 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1286 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1287 if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef. 1288 return OutStreamer.EmitZeros(Size, AddrSpace); 1289 } 1290 1291 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1292 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1293 switch (Size) { 1294 case 1: 1295 case 2: 1296 case 4: 1297 case 8: 1298 if (isVerbose()) 1299 OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1300 OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1301 return; 1302 default: 1303 EmitGlobalConstantLargeInt(CI, AddrSpace, *this); 1304 return; 1305 } 1306 } 1307 1308 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1309 return EmitGlobalConstantArray(CVA, AddrSpace, *this); 1310 1311 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1312 return EmitGlobalConstantStruct(CVS, AddrSpace, *this); 1313 1314 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1315 return EmitGlobalConstantFP(CFP, AddrSpace, *this); 1316 1317 if (isa<ConstantPointerNull>(CV)) { 1318 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1319 OutStreamer.EmitIntValue(0, Size, AddrSpace); 1320 return; 1321 } 1322 1323 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV)) 1324 return EmitGlobalConstantUnion(CVU, AddrSpace, *this); 1325 1326 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1327 return EmitGlobalConstantVector(V, AddrSpace, *this); 1328 1329 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1330 // thread the streamer with EmitValue. 1331 OutStreamer.EmitValue(LowerConstant(CV, *this), 1332 TM.getTargetData()->getTypeAllocSize(CV->getType()), 1333 AddrSpace); 1334} 1335 1336void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1337 // Target doesn't support this yet! 1338 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1339} 1340 1341void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1342 if (Offset > 0) 1343 OS << '+' << Offset; 1344 else if (Offset < 0) 1345 OS << Offset; 1346} 1347 1348 1349MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1350 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1351} 1352 1353MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1354 return MMI->getAddrLabelSymbol(BB); 1355} 1356 1357/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1358MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1359 return OutContext.GetOrCreateSymbol 1360 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1361 + "_" + Twine(CPID)); 1362} 1363 1364/// GetJTISymbol - Return the symbol for the specified jump table entry. 1365MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1366 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1367} 1368 1369/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1370/// FIXME: privatize to AsmPrinter. 1371MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1372 return OutContext.GetOrCreateSymbol 1373 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1374 Twine(UID) + "_set_" + Twine(MBBID)); 1375} 1376 1377/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1378/// global value name as its base, with the specified suffix, and where the 1379/// symbol is forced to have private linkage if ForcePrivate is true. 1380MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1381 StringRef Suffix, 1382 bool ForcePrivate) const { 1383 SmallString<60> NameStr; 1384 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1385 NameStr.append(Suffix.begin(), Suffix.end()); 1386 return OutContext.GetOrCreateSymbol(NameStr.str()); 1387} 1388 1389/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1390/// ExternalSymbol. 1391MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1392 SmallString<60> NameStr; 1393 Mang->getNameWithPrefix(NameStr, Sym); 1394 return OutContext.GetOrCreateSymbol(NameStr.str()); 1395} 1396 1397 1398 1399/// PrintParentLoopComment - Print comments about parent loops of this one. 1400static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1401 unsigned FunctionNumber) { 1402 if (Loop == 0) return; 1403 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1404 OS.indent(Loop->getLoopDepth()*2) 1405 << "Parent Loop BB" << FunctionNumber << "_" 1406 << Loop->getHeader()->getNumber() 1407 << " Depth=" << Loop->getLoopDepth() << '\n'; 1408} 1409 1410 1411/// PrintChildLoopComment - Print comments about child loops within 1412/// the loop for this basic block, with nesting. 1413static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1414 unsigned FunctionNumber) { 1415 // Add child loop information 1416 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1417 OS.indent((*CL)->getLoopDepth()*2) 1418 << "Child Loop BB" << FunctionNumber << "_" 1419 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1420 << '\n'; 1421 PrintChildLoopComment(OS, *CL, FunctionNumber); 1422 } 1423} 1424 1425/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1426static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1427 const MachineLoopInfo *LI, 1428 const AsmPrinter &AP) { 1429 // Add loop depth information 1430 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1431 if (Loop == 0) return; 1432 1433 MachineBasicBlock *Header = Loop->getHeader(); 1434 assert(Header && "No header for loop"); 1435 1436 // If this block is not a loop header, just print out what is the loop header 1437 // and return. 1438 if (Header != &MBB) { 1439 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1440 Twine(AP.getFunctionNumber())+"_" + 1441 Twine(Loop->getHeader()->getNumber())+ 1442 " Depth="+Twine(Loop->getLoopDepth())); 1443 return; 1444 } 1445 1446 // Otherwise, it is a loop header. Print out information about child and 1447 // parent loops. 1448 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1449 1450 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1451 1452 OS << "=>"; 1453 OS.indent(Loop->getLoopDepth()*2-2); 1454 1455 OS << "This "; 1456 if (Loop->empty()) 1457 OS << "Inner "; 1458 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1459 1460 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1461} 1462 1463 1464/// EmitBasicBlockStart - This method prints the label for the specified 1465/// MachineBasicBlock, an alignment (if present) and a comment describing 1466/// it if appropriate. 1467void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1468 // Emit an alignment directive for this block, if needed. 1469 if (unsigned Align = MBB->getAlignment()) 1470 EmitAlignment(Log2_32(Align)); 1471 1472 // If the block has its address taken, emit any labels that were used to 1473 // reference the block. It is possible that there is more than one label 1474 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1475 // the references were generated. 1476 if (MBB->hasAddressTaken()) { 1477 const BasicBlock *BB = MBB->getBasicBlock(); 1478 if (isVerbose()) 1479 OutStreamer.AddComment("Block address taken"); 1480 1481 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1482 1483 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1484 OutStreamer.EmitLabel(Syms[i]); 1485 } 1486 1487 // Print the main label for the block. 1488 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1489 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1490 if (const BasicBlock *BB = MBB->getBasicBlock()) 1491 if (BB->hasName()) 1492 OutStreamer.AddComment("%" + BB->getName()); 1493 1494 EmitBasicBlockLoopComments(*MBB, LI, *this); 1495 1496 // NOTE: Want this comment at start of line, don't emit with AddComment. 1497 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1498 Twine(MBB->getNumber()) + ":"); 1499 } 1500 } else { 1501 if (isVerbose()) { 1502 if (const BasicBlock *BB = MBB->getBasicBlock()) 1503 if (BB->hasName()) 1504 OutStreamer.AddComment("%" + BB->getName()); 1505 EmitBasicBlockLoopComments(*MBB, LI, *this); 1506 } 1507 1508 OutStreamer.EmitLabel(MBB->getSymbol()); 1509 } 1510} 1511 1512void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1513 MCSymbolAttr Attr = MCSA_Invalid; 1514 1515 switch (Visibility) { 1516 default: break; 1517 case GlobalValue::HiddenVisibility: 1518 Attr = MAI->getHiddenVisibilityAttr(); 1519 break; 1520 case GlobalValue::ProtectedVisibility: 1521 Attr = MAI->getProtectedVisibilityAttr(); 1522 break; 1523 } 1524 1525 if (Attr != MCSA_Invalid) 1526 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1527} 1528 1529/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1530/// exactly one predecessor and the control transfer mechanism between 1531/// the predecessor and this block is a fall-through. 1532bool AsmPrinter:: 1533isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1534 // If this is a landing pad, it isn't a fall through. If it has no preds, 1535 // then nothing falls through to it. 1536 if (MBB->isLandingPad() || MBB->pred_empty()) 1537 return false; 1538 1539 // If there isn't exactly one predecessor, it can't be a fall through. 1540 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1541 ++PI2; 1542 if (PI2 != MBB->pred_end()) 1543 return false; 1544 1545 // The predecessor has to be immediately before this block. 1546 const MachineBasicBlock *Pred = *PI; 1547 1548 if (!Pred->isLayoutSuccessor(MBB)) 1549 return false; 1550 1551 // If the block is completely empty, then it definitely does fall through. 1552 if (Pred->empty()) 1553 return true; 1554 1555 // Otherwise, check the last instruction. 1556 const MachineInstr &LastInst = Pred->back(); 1557 return !LastInst.getDesc().isBarrier(); 1558} 1559 1560 1561 1562GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1563 if (!S->usesMetadata()) 1564 return 0; 1565 1566 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1567 gcp_map_type::iterator GCPI = GCMap.find(S); 1568 if (GCPI != GCMap.end()) 1569 return GCPI->second; 1570 1571 const char *Name = S->getName().c_str(); 1572 1573 for (GCMetadataPrinterRegistry::iterator 1574 I = GCMetadataPrinterRegistry::begin(), 1575 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1576 if (strcmp(Name, I->getName()) == 0) { 1577 GCMetadataPrinter *GMP = I->instantiate(); 1578 GMP->S = S; 1579 GCMap.insert(std::make_pair(S, GMP)); 1580 return GMP; 1581 } 1582 1583 llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1584 return 0; 1585} 1586 1587