AsmPrinter.cpp revision 3b197832bf569e331ee057aece06ecd99b13ba2f
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/Assembly/Writer.h" 17#include "llvm/DerivedTypes.h" 18#include "llvm/Constants.h" 19#include "llvm/Module.h" 20#include "llvm/CodeGen/DwarfWriter.h" 21#include "llvm/CodeGen/GCMetadataPrinter.h" 22#include "llvm/CodeGen/MachineConstantPool.h" 23#include "llvm/CodeGen/MachineFrameInfo.h" 24#include "llvm/CodeGen/MachineFunction.h" 25#include "llvm/CodeGen/MachineJumpTableInfo.h" 26#include "llvm/CodeGen/MachineLoopInfo.h" 27#include "llvm/CodeGen/MachineModuleInfo.h" 28#include "llvm/Analysis/ConstantFolding.h" 29#include "llvm/Analysis/DebugInfo.h" 30#include "llvm/MC/MCContext.h" 31#include "llvm/MC/MCExpr.h" 32#include "llvm/MC/MCInst.h" 33#include "llvm/MC/MCSection.h" 34#include "llvm/MC/MCStreamer.h" 35#include "llvm/MC/MCSymbol.h" 36#include "llvm/MC/MCAsmInfo.h" 37#include "llvm/Target/Mangler.h" 38#include "llvm/Target/TargetData.h" 39#include "llvm/Target/TargetInstrInfo.h" 40#include "llvm/Target/TargetLowering.h" 41#include "llvm/Target/TargetLoweringObjectFile.h" 42#include "llvm/Target/TargetOptions.h" 43#include "llvm/Target/TargetRegisterInfo.h" 44#include "llvm/ADT/SmallPtrSet.h" 45#include "llvm/ADT/SmallString.h" 46#include "llvm/ADT/Statistic.h" 47#include "llvm/Support/CommandLine.h" 48#include "llvm/Support/Debug.h" 49#include "llvm/Support/ErrorHandling.h" 50#include "llvm/Support/Format.h" 51#include "llvm/Support/FormattedStream.h" 52#include <cerrno> 53using namespace llvm; 54 55STATISTIC(EmittedInsts, "Number of machine instrs printed"); 56 57char AsmPrinter::ID = 0; 58 59AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm, 60 MCStreamer &Streamer) 61 : MachineFunctionPass(&ID), O(o), 62 TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()), 63 OutContext(Streamer.getContext()), 64 OutStreamer(Streamer), 65 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 66 DW = 0; MMI = 0; 67 VerboseAsm = Streamer.isVerboseAsm(); 68} 69 70AsmPrinter::~AsmPrinter() { 71 for (gcp_iterator I = GCMetadataPrinters.begin(), 72 E = GCMetadataPrinters.end(); I != E; ++I) 73 delete I->second; 74 75 delete &OutStreamer; 76} 77 78/// getFunctionNumber - Return a unique ID for the current function. 79/// 80unsigned AsmPrinter::getFunctionNumber() const { 81 return MF->getFunctionNumber(); 82} 83 84TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 85 return TM.getTargetLowering()->getObjFileLowering(); 86} 87 88/// getCurrentSection() - Return the current section we are emitting to. 89const MCSection *AsmPrinter::getCurrentSection() const { 90 return OutStreamer.getCurrentSection(); 91} 92 93 94void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 95 AU.setPreservesAll(); 96 MachineFunctionPass::getAnalysisUsage(AU); 97 AU.addRequired<MachineModuleInfo>(); 98 AU.addRequired<GCModuleInfo>(); 99 if (VerboseAsm) 100 AU.addRequired<MachineLoopInfo>(); 101} 102 103bool AsmPrinter::doInitialization(Module &M) { 104 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 105 MMI->AnalyzeModule(M); 106 107 // Initialize TargetLoweringObjectFile. 108 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 109 .Initialize(OutContext, TM); 110 111 Mang = new Mangler(OutContext, *TM.getTargetData()); 112 113 // Allow the target to emit any magic that it wants at the start of the file. 114 EmitStartOfAsmFile(M); 115 116 // Very minimal debug info. It is ignored if we emit actual debug info. If we 117 // don't, this at least helps the user find where a global came from. 118 if (MAI->hasSingleParameterDotFile()) { 119 // .file "foo.c" 120 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 121 } 122 123 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 124 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 125 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 126 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 127 MP->beginAssembly(O, *this, *MAI); 128 129 if (!M.getModuleInlineAsm().empty()) 130 O << MAI->getCommentString() << " Start of file scope inline assembly\n" 131 << M.getModuleInlineAsm() 132 << '\n' << MAI->getCommentString() 133 << " End of file scope inline assembly\n"; 134 135 DW = getAnalysisIfAvailable<DwarfWriter>(); 136 if (DW) 137 DW->BeginModule(&M, MMI, O, this, MAI); 138 139 return false; 140} 141 142void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 143 switch ((GlobalValue::LinkageTypes)Linkage) { 144 case GlobalValue::CommonLinkage: 145 case GlobalValue::LinkOnceAnyLinkage: 146 case GlobalValue::LinkOnceODRLinkage: 147 case GlobalValue::WeakAnyLinkage: 148 case GlobalValue::WeakODRLinkage: 149 case GlobalValue::LinkerPrivateLinkage: 150 if (MAI->getWeakDefDirective() != 0) { 151 // .globl _foo 152 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 153 // .weak_definition _foo 154 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 155 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) { 156 // .globl _foo 157 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 158 // FIXME: linkonce should be a section attribute, handled by COFF Section 159 // assignment. 160 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce 161 // .linkonce discard 162 // FIXME: It would be nice to use .linkonce samesize for non-common 163 // globals. 164 O << LinkOnce; 165 } else { 166 // .weak _foo 167 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 168 } 169 break; 170 case GlobalValue::DLLExportLinkage: 171 case GlobalValue::AppendingLinkage: 172 // FIXME: appending linkage variables should go into a section of 173 // their name or something. For now, just emit them as external. 174 case GlobalValue::ExternalLinkage: 175 // If external or appending, declare as a global symbol. 176 // .globl _foo 177 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 178 break; 179 case GlobalValue::PrivateLinkage: 180 case GlobalValue::InternalLinkage: 181 break; 182 default: 183 llvm_unreachable("Unknown linkage type!"); 184 } 185} 186 187 188/// EmitGlobalVariable - Emit the specified global variable to the .s file. 189void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 190 if (!GV->hasInitializer()) // External globals require no code. 191 return; 192 193 // Check to see if this is a special global used by LLVM, if so, emit it. 194 if (EmitSpecialLLVMGlobal(GV)) 195 return; 196 197 MCSymbol *GVSym = Mang->getSymbol(GV); 198 EmitVisibility(GVSym, GV->getVisibility()); 199 200 if (MAI->hasDotTypeDotSizeDirective()) 201 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 202 203 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 204 205 const TargetData *TD = TM.getTargetData(); 206 unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 207 unsigned AlignLog = TD->getPreferredAlignmentLog(GV); 208 209 // Handle common and BSS local symbols (.lcomm). 210 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 211 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 212 213 if (VerboseAsm) { 214 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 215 /*PrintType=*/false, GV->getParent()); 216 OutStreamer.GetCommentOS() << '\n'; 217 } 218 219 // Handle common symbols. 220 if (GVKind.isCommon()) { 221 // .comm _foo, 42, 4 222 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 223 return; 224 } 225 226 // Handle local BSS symbols. 227 if (MAI->hasMachoZeroFillDirective()) { 228 const MCSection *TheSection = 229 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 230 // .zerofill __DATA, __bss, _foo, 400, 5 231 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 232 return; 233 } 234 235 if (MAI->hasLCOMMDirective()) { 236 // .lcomm _foo, 42 237 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 238 return; 239 } 240 241 // .local _foo 242 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 243 // .comm _foo, 42, 4 244 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 245 return; 246 } 247 248 const MCSection *TheSection = 249 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 250 251 // Handle the zerofill directive on darwin, which is a special form of BSS 252 // emission. 253 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 254 // .globl _foo 255 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 256 // .zerofill __DATA, __common, _foo, 400, 5 257 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 258 return; 259 } 260 261 OutStreamer.SwitchSection(TheSection); 262 263 EmitLinkage(GV->getLinkage(), GVSym); 264 EmitAlignment(AlignLog, GV); 265 266 if (VerboseAsm) { 267 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 268 /*PrintType=*/false, GV->getParent()); 269 OutStreamer.GetCommentOS() << '\n'; 270 } 271 OutStreamer.EmitLabel(GVSym); 272 273 EmitGlobalConstant(GV->getInitializer()); 274 275 if (MAI->hasDotTypeDotSizeDirective()) 276 // .size foo, 42 277 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 278 279 OutStreamer.AddBlankLine(); 280} 281 282/// EmitFunctionHeader - This method emits the header for the current 283/// function. 284void AsmPrinter::EmitFunctionHeader() { 285 // Print out constants referenced by the function 286 EmitConstantPool(); 287 288 // Print the 'header' of function. 289 const Function *F = MF->getFunction(); 290 291 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 292 EmitVisibility(CurrentFnSym, F->getVisibility()); 293 294 EmitLinkage(F->getLinkage(), CurrentFnSym); 295 EmitAlignment(MF->getAlignment(), F); 296 297 if (MAI->hasDotTypeDotSizeDirective()) 298 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 299 300 if (VerboseAsm) { 301 WriteAsOperand(OutStreamer.GetCommentOS(), F, 302 /*PrintType=*/false, F->getParent()); 303 OutStreamer.GetCommentOS() << '\n'; 304 } 305 306 // Emit the CurrentFnSym. This is a virtual function to allow targets to 307 // do their wild and crazy things as required. 308 EmitFunctionEntryLabel(); 309 310 // If the function had address-taken blocks that got deleted, then we have 311 // references to the dangling symbols. Emit them at the start of the function 312 // so that we don't get references to undefined symbols. 313 std::vector<MCSymbol*> DeadBlockSyms; 314 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 315 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 316 OutStreamer.AddComment("Address taken block that was later removed"); 317 OutStreamer.EmitLabel(DeadBlockSyms[i]); 318 } 319 320 // Add some workaround for linkonce linkage on Cygwin\MinGW. 321 if (MAI->getLinkOnceDirective() != 0 && 322 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) 323 // FIXME: What is this? 324 O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n"; 325 326 // Emit pre-function debug and/or EH information. 327 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 328 DW->BeginFunction(MF); 329} 330 331/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 332/// function. This can be overridden by targets as required to do custom stuff. 333void AsmPrinter::EmitFunctionEntryLabel() { 334 OutStreamer.EmitLabel(CurrentFnSym); 335} 336 337 338/// EmitComments - Pretty-print comments for instructions. 339static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 340 const MachineFunction *MF = MI.getParent()->getParent(); 341 const TargetMachine &TM = MF->getTarget(); 342 343 if (!MI.getDebugLoc().isUnknown()) { 344 DILocation DLT = MF->getDILocation(MI.getDebugLoc()); 345 346 // Print source line info. 347 DIScope Scope = DLT.getScope(); 348 // Omit the directory, because it's likely to be long and uninteresting. 349 if (Scope.Verify()) 350 CommentOS << Scope.getFilename(); 351 else 352 CommentOS << "<unknown>"; 353 CommentOS << ':' << DLT.getLineNumber(); 354 if (DLT.getColumnNumber() != 0) 355 CommentOS << ':' << DLT.getColumnNumber(); 356 CommentOS << '\n'; 357 } 358 359 // Check for spills and reloads 360 int FI; 361 362 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 363 364 // We assume a single instruction only has a spill or reload, not 365 // both. 366 const MachineMemOperand *MMO; 367 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 368 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 369 MMO = *MI.memoperands_begin(); 370 CommentOS << MMO->getSize() << "-byte Reload\n"; 371 } 372 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 373 if (FrameInfo->isSpillSlotObjectIndex(FI)) 374 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 375 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 376 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 377 MMO = *MI.memoperands_begin(); 378 CommentOS << MMO->getSize() << "-byte Spill\n"; 379 } 380 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 381 if (FrameInfo->isSpillSlotObjectIndex(FI)) 382 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 383 } 384 385 // Check for spill-induced copies 386 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; 387 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg, 388 SrcSubIdx, DstSubIdx)) { 389 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 390 CommentOS << " Reload Reuse\n"; 391 } 392} 393 394 395 396/// EmitFunctionBody - This method emits the body and trailer for a 397/// function. 398void AsmPrinter::EmitFunctionBody() { 399 // Emit target-specific gunk before the function body. 400 EmitFunctionBodyStart(); 401 402 // Print out code for the function. 403 bool HasAnyRealCode = false; 404 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 405 I != E; ++I) { 406 // Print a label for the basic block. 407 EmitBasicBlockStart(I); 408 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 409 II != IE; ++II) { 410 // Print the assembly for the instruction. 411 if (!II->isLabel()) 412 HasAnyRealCode = true; 413 414 ++EmittedInsts; 415 416 // FIXME: Clean up processDebugLoc. 417 processDebugLoc(II, true); 418 419 if (VerboseAsm) 420 EmitComments(*II, OutStreamer.GetCommentOS()); 421 422 switch (II->getOpcode()) { 423 case TargetOpcode::DBG_LABEL: 424 case TargetOpcode::EH_LABEL: 425 case TargetOpcode::GC_LABEL: 426 printLabelInst(II); 427 break; 428 case TargetOpcode::INLINEASM: 429 printInlineAsm(II); 430 break; 431 case TargetOpcode::IMPLICIT_DEF: 432 printImplicitDef(II); 433 break; 434 case TargetOpcode::KILL: 435 printKill(II); 436 break; 437 default: 438 EmitInstruction(II); 439 break; 440 } 441 442 // FIXME: Clean up processDebugLoc. 443 processDebugLoc(II, false); 444 } 445 } 446 447 // If the function is empty and the object file uses .subsections_via_symbols, 448 // then we need to emit *something* to the function body to prevent the 449 // labels from collapsing together. Just emit a 0 byte. 450 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) 451 OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/); 452 453 // Emit target-specific gunk after the function body. 454 EmitFunctionBodyEnd(); 455 456 if (MAI->hasDotTypeDotSizeDirective()) 457 O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n'; 458 459 // Emit post-function debug information. 460 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 461 DW->EndFunction(MF); 462 463 // Print out jump tables referenced by the function. 464 EmitJumpTableInfo(); 465 466 OutStreamer.AddBlankLine(); 467} 468 469 470bool AsmPrinter::doFinalization(Module &M) { 471 // Emit global variables. 472 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 473 I != E; ++I) 474 EmitGlobalVariable(I); 475 476 // Emit final debug information. 477 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling()) 478 DW->EndModule(); 479 480 // If the target wants to know about weak references, print them all. 481 if (MAI->getWeakRefDirective()) { 482 // FIXME: This is not lazy, it would be nice to only print weak references 483 // to stuff that is actually used. Note that doing so would require targets 484 // to notice uses in operands (due to constant exprs etc). This should 485 // happen with the MC stuff eventually. 486 487 // Print out module-level global variables here. 488 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 489 I != E; ++I) { 490 if (!I->hasExternalWeakLinkage()) continue; 491 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 492 } 493 494 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 495 if (!I->hasExternalWeakLinkage()) continue; 496 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 497 } 498 } 499 500 if (MAI->hasSetDirective()) { 501 OutStreamer.AddBlankLine(); 502 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 503 I != E; ++I) { 504 MCSymbol *Name = Mang->getSymbol(I); 505 506 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 507 MCSymbol *Target = Mang->getSymbol(GV); 508 509 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 510 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 511 else if (I->hasWeakLinkage()) 512 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 513 else 514 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 515 516 EmitVisibility(Name, I->getVisibility()); 517 518 // Emit the directives as assignments aka .set: 519 OutStreamer.EmitAssignment(Name, 520 MCSymbolRefExpr::Create(Target, OutContext)); 521 } 522 } 523 524 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 525 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 526 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 527 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 528 MP->finishAssembly(O, *this, *MAI); 529 530 // If we don't have any trampolines, then we don't require stack memory 531 // to be executable. Some targets have a directive to declare this. 532 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 533 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 534 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 535 OutStreamer.SwitchSection(S); 536 537 // Allow the target to emit any magic that it wants at the end of the file, 538 // after everything else has gone out. 539 EmitEndOfAsmFile(M); 540 541 delete Mang; Mang = 0; 542 DW = 0; MMI = 0; 543 544 OutStreamer.Finish(); 545 return false; 546} 547 548void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 549 this->MF = &MF; 550 // Get the function symbol. 551 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 552 553 if (VerboseAsm) 554 LI = &getAnalysis<MachineLoopInfo>(); 555} 556 557namespace { 558 // SectionCPs - Keep track the alignment, constpool entries per Section. 559 struct SectionCPs { 560 const MCSection *S; 561 unsigned Alignment; 562 SmallVector<unsigned, 4> CPEs; 563 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 564 }; 565} 566 567/// EmitConstantPool - Print to the current output stream assembly 568/// representations of the constants in the constant pool MCP. This is 569/// used to print out constants which have been "spilled to memory" by 570/// the code generator. 571/// 572void AsmPrinter::EmitConstantPool() { 573 const MachineConstantPool *MCP = MF->getConstantPool(); 574 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 575 if (CP.empty()) return; 576 577 // Calculate sections for constant pool entries. We collect entries to go into 578 // the same section together to reduce amount of section switch statements. 579 SmallVector<SectionCPs, 4> CPSections; 580 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 581 const MachineConstantPoolEntry &CPE = CP[i]; 582 unsigned Align = CPE.getAlignment(); 583 584 SectionKind Kind; 585 switch (CPE.getRelocationInfo()) { 586 default: llvm_unreachable("Unknown section kind"); 587 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 588 case 1: 589 Kind = SectionKind::getReadOnlyWithRelLocal(); 590 break; 591 case 0: 592 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 593 case 4: Kind = SectionKind::getMergeableConst4(); break; 594 case 8: Kind = SectionKind::getMergeableConst8(); break; 595 case 16: Kind = SectionKind::getMergeableConst16();break; 596 default: Kind = SectionKind::getMergeableConst(); break; 597 } 598 } 599 600 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 601 602 // The number of sections are small, just do a linear search from the 603 // last section to the first. 604 bool Found = false; 605 unsigned SecIdx = CPSections.size(); 606 while (SecIdx != 0) { 607 if (CPSections[--SecIdx].S == S) { 608 Found = true; 609 break; 610 } 611 } 612 if (!Found) { 613 SecIdx = CPSections.size(); 614 CPSections.push_back(SectionCPs(S, Align)); 615 } 616 617 if (Align > CPSections[SecIdx].Alignment) 618 CPSections[SecIdx].Alignment = Align; 619 CPSections[SecIdx].CPEs.push_back(i); 620 } 621 622 // Now print stuff into the calculated sections. 623 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 624 OutStreamer.SwitchSection(CPSections[i].S); 625 EmitAlignment(Log2_32(CPSections[i].Alignment)); 626 627 unsigned Offset = 0; 628 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 629 unsigned CPI = CPSections[i].CPEs[j]; 630 MachineConstantPoolEntry CPE = CP[CPI]; 631 632 // Emit inter-object padding for alignment. 633 unsigned AlignMask = CPE.getAlignment() - 1; 634 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 635 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 636 637 const Type *Ty = CPE.getType(); 638 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 639 640 // Emit the label with a comment on it. 641 if (VerboseAsm) { 642 OutStreamer.GetCommentOS() << "constant pool "; 643 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(), 644 MF->getFunction()->getParent()); 645 OutStreamer.GetCommentOS() << '\n'; 646 } 647 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 648 649 if (CPE.isMachineConstantPoolEntry()) 650 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 651 else 652 EmitGlobalConstant(CPE.Val.ConstVal); 653 } 654 } 655} 656 657/// EmitJumpTableInfo - Print assembly representations of the jump tables used 658/// by the current function to the current output stream. 659/// 660void AsmPrinter::EmitJumpTableInfo() { 661 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 662 if (MJTI == 0) return; 663 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 664 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 665 if (JT.empty()) return; 666 667 // Pick the directive to use to print the jump table entries, and switch to 668 // the appropriate section. 669 const Function *F = MF->getFunction(); 670 bool JTInDiffSection = false; 671 if (// In PIC mode, we need to emit the jump table to the same section as the 672 // function body itself, otherwise the label differences won't make sense. 673 // FIXME: Need a better predicate for this: what about custom entries? 674 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 675 // We should also do if the section name is NULL or function is declared 676 // in discardable section 677 // FIXME: this isn't the right predicate, should be based on the MCSection 678 // for the function. 679 F->isWeakForLinker()) { 680 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 681 } else { 682 // Otherwise, drop it in the readonly section. 683 const MCSection *ReadOnlySection = 684 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 685 OutStreamer.SwitchSection(ReadOnlySection); 686 JTInDiffSection = true; 687 } 688 689 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 690 691 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 692 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 693 694 // If this jump table was deleted, ignore it. 695 if (JTBBs.empty()) continue; 696 697 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 698 // .set directive for each unique entry. This reduces the number of 699 // relocations the assembler will generate for the jump table. 700 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 701 MAI->hasSetDirective()) { 702 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 703 const TargetLowering *TLI = TM.getTargetLowering(); 704 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 705 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 706 const MachineBasicBlock *MBB = JTBBs[ii]; 707 if (!EmittedSets.insert(MBB)) continue; 708 709 // .set LJTSet, LBB32-base 710 const MCExpr *LHS = 711 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 712 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 713 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 714 } 715 } 716 717 // On some targets (e.g. Darwin) we want to emit two consequtive labels 718 // before each jump table. The first label is never referenced, but tells 719 // the assembler and linker the extents of the jump table object. The 720 // second label is actually referenced by the code. 721 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 722 // FIXME: This doesn't have to have any specific name, just any randomly 723 // named and numbered 'l' label would work. Simplify GetJTISymbol. 724 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 725 726 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 727 728 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 729 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 730 } 731} 732 733/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 734/// current stream. 735void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 736 const MachineBasicBlock *MBB, 737 unsigned UID) const { 738 const MCExpr *Value = 0; 739 switch (MJTI->getEntryKind()) { 740 case MachineJumpTableInfo::EK_Inline: 741 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 742 case MachineJumpTableInfo::EK_Custom32: 743 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 744 OutContext); 745 break; 746 case MachineJumpTableInfo::EK_BlockAddress: 747 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 748 // .word LBB123 749 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 750 break; 751 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 752 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 753 // with a relocation as gp-relative, e.g.: 754 // .gprel32 LBB123 755 MCSymbol *MBBSym = MBB->getSymbol(); 756 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 757 return; 758 } 759 760 case MachineJumpTableInfo::EK_LabelDifference32: { 761 // EK_LabelDifference32 - Each entry is the address of the block minus 762 // the address of the jump table. This is used for PIC jump tables where 763 // gprel32 is not supported. e.g.: 764 // .word LBB123 - LJTI1_2 765 // If the .set directive is supported, this is emitted as: 766 // .set L4_5_set_123, LBB123 - LJTI1_2 767 // .word L4_5_set_123 768 769 // If we have emitted set directives for the jump table entries, print 770 // them rather than the entries themselves. If we're emitting PIC, then 771 // emit the table entries as differences between two text section labels. 772 if (MAI->hasSetDirective()) { 773 // If we used .set, reference the .set's symbol. 774 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 775 OutContext); 776 break; 777 } 778 // Otherwise, use the difference as the jump table entry. 779 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 780 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 781 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 782 break; 783 } 784 } 785 786 assert(Value && "Unknown entry kind!"); 787 788 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 789 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 790} 791 792 793/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 794/// special global used by LLVM. If so, emit it and return true, otherwise 795/// do nothing and return false. 796bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 797 if (GV->getName() == "llvm.used") { 798 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 799 EmitLLVMUsedList(GV->getInitializer()); 800 return true; 801 } 802 803 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 804 if (GV->getSection() == "llvm.metadata" || 805 GV->hasAvailableExternallyLinkage()) 806 return true; 807 808 if (!GV->hasAppendingLinkage()) return false; 809 810 assert(GV->hasInitializer() && "Not a special LLVM global!"); 811 812 const TargetData *TD = TM.getTargetData(); 813 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 814 if (GV->getName() == "llvm.global_ctors") { 815 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 816 EmitAlignment(Align, 0); 817 EmitXXStructorList(GV->getInitializer()); 818 819 if (TM.getRelocationModel() == Reloc::Static && 820 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 821 StringRef Sym(".constructors_used"); 822 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 823 MCSA_Reference); 824 } 825 return true; 826 } 827 828 if (GV->getName() == "llvm.global_dtors") { 829 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 830 EmitAlignment(Align, 0); 831 EmitXXStructorList(GV->getInitializer()); 832 833 if (TM.getRelocationModel() == Reloc::Static && 834 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 835 StringRef Sym(".destructors_used"); 836 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 837 MCSA_Reference); 838 } 839 return true; 840 } 841 842 return false; 843} 844 845/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 846/// global in the specified llvm.used list for which emitUsedDirectiveFor 847/// is true, as being used with this directive. 848void AsmPrinter::EmitLLVMUsedList(Constant *List) { 849 // Should be an array of 'i8*'. 850 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 851 if (InitList == 0) return; 852 853 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 854 const GlobalValue *GV = 855 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 856 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 857 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 858 } 859} 860 861/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 862/// function pointers, ignoring the init priority. 863void AsmPrinter::EmitXXStructorList(Constant *List) { 864 // Should be an array of '{ int, void ()* }' structs. The first value is the 865 // init priority, which we ignore. 866 if (!isa<ConstantArray>(List)) return; 867 ConstantArray *InitList = cast<ConstantArray>(List); 868 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 869 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 870 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 871 872 if (CS->getOperand(1)->isNullValue()) 873 return; // Found a null terminator, exit printing. 874 // Emit the function pointer. 875 EmitGlobalConstant(CS->getOperand(1)); 876 } 877} 878 879//===--------------------------------------------------------------------===// 880// Emission and print routines 881// 882 883/// EmitInt8 - Emit a byte directive and value. 884/// 885void AsmPrinter::EmitInt8(int Value) const { 886 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 887} 888 889/// EmitInt16 - Emit a short directive and value. 890/// 891void AsmPrinter::EmitInt16(int Value) const { 892 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 893} 894 895/// EmitInt32 - Emit a long directive and value. 896/// 897void AsmPrinter::EmitInt32(int Value) const { 898 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 899} 900 901/// EmitInt64 - Emit a long long directive and value. 902/// 903void AsmPrinter::EmitInt64(uint64_t Value) const { 904 OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/); 905} 906 907/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 908/// in bytes of the directive is specified by Size and Hi/Lo specify the 909/// labels. This implicitly uses .set if it is available. 910void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 911 unsigned Size) const { 912 // Get the Hi-Lo expression. 913 const MCExpr *Diff = 914 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 915 MCSymbolRefExpr::Create(Lo, OutContext), 916 OutContext); 917 918 if (!MAI->hasSetDirective()) { 919 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 920 return; 921 } 922 923 // Otherwise, emit with .set (aka assignment). 924 MCSymbol *SetLabel = 925 OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 926 "set" + Twine(SetCounter++)); 927 OutStreamer.EmitAssignment(SetLabel, Diff); 928 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 929} 930 931 932//===----------------------------------------------------------------------===// 933 934// EmitAlignment - Emit an alignment directive to the specified power of 935// two boundary. For example, if you pass in 3 here, you will get an 8 936// byte alignment. If a global value is specified, and if that global has 937// an explicit alignment requested, it will unconditionally override the 938// alignment request. However, if ForcedAlignBits is specified, this value 939// has final say: the ultimate alignment will be the max of ForcedAlignBits 940// and the alignment computed with NumBits and the global. 941// 942// The algorithm is: 943// Align = NumBits; 944// if (GV && GV->hasalignment) Align = GV->getalignment(); 945// Align = std::max(Align, ForcedAlignBits); 946// 947void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV, 948 unsigned ForcedAlignBits, 949 bool UseFillExpr) const { 950 if (GV && GV->getAlignment()) 951 NumBits = Log2_32(GV->getAlignment()); 952 NumBits = std::max(NumBits, ForcedAlignBits); 953 954 if (NumBits == 0) return; // No need to emit alignment. 955 956 if (getCurrentSection()->getKind().isText()) 957 OutStreamer.EmitCodeAlignment(1 << NumBits); 958 else 959 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 960} 961 962/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 963/// 964static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 965 MCContext &Ctx = AP.OutContext; 966 967 if (CV->isNullValue() || isa<UndefValue>(CV)) 968 return MCConstantExpr::Create(0, Ctx); 969 970 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 971 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 972 973 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 974 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 975 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 976 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 977 978 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 979 if (CE == 0) { 980 llvm_unreachable("Unknown constant value to lower!"); 981 return MCConstantExpr::Create(0, Ctx); 982 } 983 984 switch (CE->getOpcode()) { 985 default: 986 // If the code isn't optimized, there may be outstanding folding 987 // opportunities. Attempt to fold the expression using TargetData as a 988 // last resort before giving up. 989 if (Constant *C = 990 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 991 if (C != CE) 992 return LowerConstant(C, AP); 993#ifndef NDEBUG 994 CE->dump(); 995#endif 996 llvm_unreachable("FIXME: Don't support this constant expr"); 997 case Instruction::GetElementPtr: { 998 const TargetData &TD = *AP.TM.getTargetData(); 999 // Generate a symbolic expression for the byte address 1000 const Constant *PtrVal = CE->getOperand(0); 1001 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1002 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1003 IdxVec.size()); 1004 1005 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1006 if (Offset == 0) 1007 return Base; 1008 1009 // Truncate/sext the offset to the pointer size. 1010 if (TD.getPointerSizeInBits() != 64) { 1011 int SExtAmount = 64-TD.getPointerSizeInBits(); 1012 Offset = (Offset << SExtAmount) >> SExtAmount; 1013 } 1014 1015 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1016 Ctx); 1017 } 1018 1019 case Instruction::Trunc: 1020 // We emit the value and depend on the assembler to truncate the generated 1021 // expression properly. This is important for differences between 1022 // blockaddress labels. Since the two labels are in the same function, it 1023 // is reasonable to treat their delta as a 32-bit value. 1024 // FALL THROUGH. 1025 case Instruction::BitCast: 1026 return LowerConstant(CE->getOperand(0), AP); 1027 1028 case Instruction::IntToPtr: { 1029 const TargetData &TD = *AP.TM.getTargetData(); 1030 // Handle casts to pointers by changing them into casts to the appropriate 1031 // integer type. This promotes constant folding and simplifies this code. 1032 Constant *Op = CE->getOperand(0); 1033 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1034 false/*ZExt*/); 1035 return LowerConstant(Op, AP); 1036 } 1037 1038 case Instruction::PtrToInt: { 1039 const TargetData &TD = *AP.TM.getTargetData(); 1040 // Support only foldable casts to/from pointers that can be eliminated by 1041 // changing the pointer to the appropriately sized integer type. 1042 Constant *Op = CE->getOperand(0); 1043 const Type *Ty = CE->getType(); 1044 1045 const MCExpr *OpExpr = LowerConstant(Op, AP); 1046 1047 // We can emit the pointer value into this slot if the slot is an 1048 // integer slot equal to the size of the pointer. 1049 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1050 return OpExpr; 1051 1052 // Otherwise the pointer is smaller than the resultant integer, mask off 1053 // the high bits so we are sure to get a proper truncation if the input is 1054 // a constant expr. 1055 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1056 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1057 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1058 } 1059 1060 // The MC library also has a right-shift operator, but it isn't consistently 1061 // signed or unsigned between different targets. 1062 case Instruction::Add: 1063 case Instruction::Sub: 1064 case Instruction::Mul: 1065 case Instruction::SDiv: 1066 case Instruction::SRem: 1067 case Instruction::Shl: 1068 case Instruction::And: 1069 case Instruction::Or: 1070 case Instruction::Xor: { 1071 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1072 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1073 switch (CE->getOpcode()) { 1074 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1075 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1076 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1077 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1078 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1079 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1080 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1081 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1082 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1083 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1084 } 1085 } 1086 } 1087} 1088 1089static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1090 AsmPrinter &AP) { 1091 if (AddrSpace != 0 || !CA->isString()) { 1092 // Not a string. Print the values in successive locations 1093 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1094 AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace); 1095 return; 1096 } 1097 1098 // Otherwise, it can be emitted as .ascii. 1099 SmallVector<char, 128> TmpVec; 1100 TmpVec.reserve(CA->getNumOperands()); 1101 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1102 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1103 1104 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1105} 1106 1107static void EmitGlobalConstantVector(const ConstantVector *CV, 1108 unsigned AddrSpace, AsmPrinter &AP) { 1109 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1110 AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace); 1111} 1112 1113static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1114 unsigned AddrSpace, AsmPrinter &AP) { 1115 // Print the fields in successive locations. Pad to align if needed! 1116 const TargetData *TD = AP.TM.getTargetData(); 1117 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1118 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1119 uint64_t SizeSoFar = 0; 1120 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1121 const Constant *Field = CS->getOperand(i); 1122 1123 // Check if padding is needed and insert one or more 0s. 1124 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1125 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1126 - Layout->getElementOffset(i)) - FieldSize; 1127 SizeSoFar += FieldSize + PadSize; 1128 1129 // Now print the actual field value. 1130 AP.EmitGlobalConstant(Field, AddrSpace); 1131 1132 // Insert padding - this may include padding to increase the size of the 1133 // current field up to the ABI size (if the struct is not packed) as well 1134 // as padding to ensure that the next field starts at the right offset. 1135 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1136 } 1137 assert(SizeSoFar == Layout->getSizeInBytes() && 1138 "Layout of constant struct may be incorrect!"); 1139} 1140 1141static void EmitGlobalConstantUnion(const ConstantUnion *CU, 1142 unsigned AddrSpace, AsmPrinter &AP) { 1143 const TargetData *TD = AP.TM.getTargetData(); 1144 unsigned Size = TD->getTypeAllocSize(CU->getType()); 1145 1146 const Constant *Contents = CU->getOperand(0); 1147 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType()); 1148 1149 // Print the actually filled part 1150 AP.EmitGlobalConstant(Contents, AddrSpace); 1151 1152 // And pad with enough zeroes 1153 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace); 1154} 1155 1156static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1157 AsmPrinter &AP) { 1158 // FP Constants are printed as integer constants to avoid losing 1159 // precision. 1160 if (CFP->getType()->isDoubleTy()) { 1161 if (AP.VerboseAsm) { 1162 double Val = CFP->getValueAPF().convertToDouble(); 1163 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1164 } 1165 1166 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1167 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1168 return; 1169 } 1170 1171 if (CFP->getType()->isFloatTy()) { 1172 if (AP.VerboseAsm) { 1173 float Val = CFP->getValueAPF().convertToFloat(); 1174 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1175 } 1176 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1177 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1178 return; 1179 } 1180 1181 if (CFP->getType()->isX86_FP80Ty()) { 1182 // all long double variants are printed as hex 1183 // api needed to prevent premature destruction 1184 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1185 const uint64_t *p = API.getRawData(); 1186 if (AP.VerboseAsm) { 1187 // Convert to double so we can print the approximate val as a comment. 1188 APFloat DoubleVal = CFP->getValueAPF(); 1189 bool ignored; 1190 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1191 &ignored); 1192 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1193 << DoubleVal.convertToDouble() << '\n'; 1194 } 1195 1196 if (AP.TM.getTargetData()->isBigEndian()) { 1197 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1198 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1199 } else { 1200 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1201 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1202 } 1203 1204 // Emit the tail padding for the long double. 1205 const TargetData &TD = *AP.TM.getTargetData(); 1206 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1207 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1208 return; 1209 } 1210 1211 assert(CFP->getType()->isPPC_FP128Ty() && 1212 "Floating point constant type not handled"); 1213 // All long double variants are printed as hex api needed to prevent 1214 // premature destruction. 1215 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1216 const uint64_t *p = API.getRawData(); 1217 if (AP.TM.getTargetData()->isBigEndian()) { 1218 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1219 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1220 } else { 1221 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1222 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1223 } 1224} 1225 1226static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1227 unsigned AddrSpace, AsmPrinter &AP) { 1228 const TargetData *TD = AP.TM.getTargetData(); 1229 unsigned BitWidth = CI->getBitWidth(); 1230 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1231 1232 // We don't expect assemblers to support integer data directives 1233 // for more than 64 bits, so we emit the data in at most 64-bit 1234 // quantities at a time. 1235 const uint64_t *RawData = CI->getValue().getRawData(); 1236 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1237 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1238 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1239 } 1240} 1241 1242/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1243void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1244 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1245 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1246 if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef. 1247 return OutStreamer.EmitZeros(Size, AddrSpace); 1248 } 1249 1250 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1251 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1252 switch (Size) { 1253 case 1: 1254 case 2: 1255 case 4: 1256 case 8: 1257 if (VerboseAsm) 1258 OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1259 OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1260 return; 1261 default: 1262 EmitGlobalConstantLargeInt(CI, AddrSpace, *this); 1263 return; 1264 } 1265 } 1266 1267 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1268 return EmitGlobalConstantArray(CVA, AddrSpace, *this); 1269 1270 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1271 return EmitGlobalConstantStruct(CVS, AddrSpace, *this); 1272 1273 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1274 return EmitGlobalConstantFP(CFP, AddrSpace, *this); 1275 1276 if (isa<ConstantPointerNull>(CV)) { 1277 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1278 OutStreamer.EmitIntValue(0, Size, AddrSpace); 1279 return; 1280 } 1281 1282 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV)) 1283 return EmitGlobalConstantUnion(CVU, AddrSpace, *this); 1284 1285 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1286 return EmitGlobalConstantVector(V, AddrSpace, *this); 1287 1288 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1289 // thread the streamer with EmitValue. 1290 OutStreamer.EmitValue(LowerConstant(CV, *this), 1291 TM.getTargetData()->getTypeAllocSize(CV->getType()), 1292 AddrSpace); 1293} 1294 1295void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1296 // Target doesn't support this yet! 1297 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1298} 1299 1300/// PrintSpecial - Print information related to the specified machine instr 1301/// that is independent of the operand, and may be independent of the instr 1302/// itself. This can be useful for portably encoding the comment character 1303/// or other bits of target-specific knowledge into the asmstrings. The 1304/// syntax used is ${:comment}. Targets can override this to add support 1305/// for their own strange codes. 1306void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const { 1307 if (!strcmp(Code, "private")) { 1308 O << MAI->getPrivateGlobalPrefix(); 1309 } else if (!strcmp(Code, "comment")) { 1310 if (VerboseAsm) 1311 O << MAI->getCommentString(); 1312 } else if (!strcmp(Code, "uid")) { 1313 // Comparing the address of MI isn't sufficient, because machineinstrs may 1314 // be allocated to the same address across functions. 1315 const Function *ThisF = MI->getParent()->getParent()->getFunction(); 1316 1317 // If this is a new LastFn instruction, bump the counter. 1318 if (LastMI != MI || LastFn != ThisF) { 1319 ++Counter; 1320 LastMI = MI; 1321 LastFn = ThisF; 1322 } 1323 O << Counter; 1324 } else { 1325 std::string msg; 1326 raw_string_ostream Msg(msg); 1327 Msg << "Unknown special formatter '" << Code 1328 << "' for machine instr: " << *MI; 1329 llvm_report_error(Msg.str()); 1330 } 1331} 1332 1333/// processDebugLoc - Processes the debug information of each machine 1334/// instruction's DebugLoc. 1335void AsmPrinter::processDebugLoc(const MachineInstr *MI, 1336 bool BeforePrintingInsn) { 1337 if (!MAI || !DW || !MAI->doesSupportDebugInformation() 1338 || !DW->ShouldEmitDwarfDebug()) 1339 return; 1340 1341 if (!BeforePrintingInsn) 1342 // After printing instruction 1343 DW->EndScope(MI); 1344 else 1345 DW->BeginScope(MI); 1346} 1347 1348 1349/// printInlineAsm - This method formats and prints the specified machine 1350/// instruction that is an inline asm. 1351void AsmPrinter::printInlineAsm(const MachineInstr *MI) const { 1352 unsigned NumOperands = MI->getNumOperands(); 1353 1354 // Count the number of register definitions. 1355 unsigned NumDefs = 0; 1356 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef(); 1357 ++NumDefs) 1358 assert(NumDefs != NumOperands-1 && "No asm string?"); 1359 1360 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?"); 1361 1362 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc. 1363 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName(); 1364 1365 O << '\t'; 1366 1367 // If this asmstr is empty, just print the #APP/#NOAPP markers. 1368 // These are useful to see where empty asm's wound up. 1369 if (AsmStr[0] == 0) { 1370 O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t"; 1371 O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n'; 1372 return; 1373 } 1374 1375 O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t"; 1376 1377 // The variant of the current asmprinter. 1378 int AsmPrinterVariant = MAI->getAssemblerDialect(); 1379 1380 int CurVariant = -1; // The number of the {.|.|.} region we are in. 1381 const char *LastEmitted = AsmStr; // One past the last character emitted. 1382 1383 while (*LastEmitted) { 1384 switch (*LastEmitted) { 1385 default: { 1386 // Not a special case, emit the string section literally. 1387 const char *LiteralEnd = LastEmitted+1; 1388 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' && 1389 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n') 1390 ++LiteralEnd; 1391 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) 1392 O.write(LastEmitted, LiteralEnd-LastEmitted); 1393 LastEmitted = LiteralEnd; 1394 break; 1395 } 1396 case '\n': 1397 ++LastEmitted; // Consume newline character. 1398 O << '\n'; // Indent code with newline. 1399 break; 1400 case '$': { 1401 ++LastEmitted; // Consume '$' character. 1402 bool Done = true; 1403 1404 // Handle escapes. 1405 switch (*LastEmitted) { 1406 default: Done = false; break; 1407 case '$': // $$ -> $ 1408 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) 1409 O << '$'; 1410 ++LastEmitted; // Consume second '$' character. 1411 break; 1412 case '(': // $( -> same as GCC's { character. 1413 ++LastEmitted; // Consume '(' character. 1414 if (CurVariant != -1) { 1415 llvm_report_error("Nested variants found in inline asm string: '" 1416 + std::string(AsmStr) + "'"); 1417 } 1418 CurVariant = 0; // We're in the first variant now. 1419 break; 1420 case '|': 1421 ++LastEmitted; // consume '|' character. 1422 if (CurVariant == -1) 1423 O << '|'; // this is gcc's behavior for | outside a variant 1424 else 1425 ++CurVariant; // We're in the next variant. 1426 break; 1427 case ')': // $) -> same as GCC's } char. 1428 ++LastEmitted; // consume ')' character. 1429 if (CurVariant == -1) 1430 O << '}'; // this is gcc's behavior for } outside a variant 1431 else 1432 CurVariant = -1; 1433 break; 1434 } 1435 if (Done) break; 1436 1437 bool HasCurlyBraces = false; 1438 if (*LastEmitted == '{') { // ${variable} 1439 ++LastEmitted; // Consume '{' character. 1440 HasCurlyBraces = true; 1441 } 1442 1443 // If we have ${:foo}, then this is not a real operand reference, it is a 1444 // "magic" string reference, just like in .td files. Arrange to call 1445 // PrintSpecial. 1446 if (HasCurlyBraces && *LastEmitted == ':') { 1447 ++LastEmitted; 1448 const char *StrStart = LastEmitted; 1449 const char *StrEnd = strchr(StrStart, '}'); 1450 if (StrEnd == 0) { 1451 llvm_report_error("Unterminated ${:foo} operand in inline asm string: '" 1452 + std::string(AsmStr) + "'"); 1453 } 1454 1455 std::string Val(StrStart, StrEnd); 1456 PrintSpecial(MI, Val.c_str()); 1457 LastEmitted = StrEnd+1; 1458 break; 1459 } 1460 1461 const char *IDStart = LastEmitted; 1462 char *IDEnd; 1463 errno = 0; 1464 long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs. 1465 if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) { 1466 llvm_report_error("Bad $ operand number in inline asm string: '" 1467 + std::string(AsmStr) + "'"); 1468 } 1469 LastEmitted = IDEnd; 1470 1471 char Modifier[2] = { 0, 0 }; 1472 1473 if (HasCurlyBraces) { 1474 // If we have curly braces, check for a modifier character. This 1475 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm. 1476 if (*LastEmitted == ':') { 1477 ++LastEmitted; // Consume ':' character. 1478 if (*LastEmitted == 0) { 1479 llvm_report_error("Bad ${:} expression in inline asm string: '" 1480 + std::string(AsmStr) + "'"); 1481 } 1482 1483 Modifier[0] = *LastEmitted; 1484 ++LastEmitted; // Consume modifier character. 1485 } 1486 1487 if (*LastEmitted != '}') { 1488 llvm_report_error("Bad ${} expression in inline asm string: '" 1489 + std::string(AsmStr) + "'"); 1490 } 1491 ++LastEmitted; // Consume '}' character. 1492 } 1493 1494 if ((unsigned)Val >= NumOperands-1) { 1495 llvm_report_error("Invalid $ operand number in inline asm string: '" 1496 + std::string(AsmStr) + "'"); 1497 } 1498 1499 // Okay, we finally have a value number. Ask the target to print this 1500 // operand! 1501 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) { 1502 unsigned OpNo = 1; 1503 1504 bool Error = false; 1505 1506 // Scan to find the machine operand number for the operand. 1507 for (; Val; --Val) { 1508 if (OpNo >= MI->getNumOperands()) break; 1509 unsigned OpFlags = MI->getOperand(OpNo).getImm(); 1510 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1; 1511 } 1512 1513 if (OpNo >= MI->getNumOperands()) { 1514 Error = true; 1515 } else { 1516 unsigned OpFlags = MI->getOperand(OpNo).getImm(); 1517 ++OpNo; // Skip over the ID number. 1518 1519 if (Modifier[0] == 'l') // labels are target independent 1520 O << *MI->getOperand(OpNo).getMBB()->getSymbol(); 1521 else { 1522 AsmPrinter *AP = const_cast<AsmPrinter*>(this); 1523 if ((OpFlags & 7) == 4) { 1524 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant, 1525 Modifier[0] ? Modifier : 0); 1526 } else { 1527 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant, 1528 Modifier[0] ? Modifier : 0); 1529 } 1530 } 1531 } 1532 if (Error) { 1533 std::string msg; 1534 raw_string_ostream Msg(msg); 1535 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n"; 1536 MI->print(Msg); 1537 llvm_report_error(Msg.str()); 1538 } 1539 } 1540 break; 1541 } 1542 } 1543 } 1544 O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd(); 1545 OutStreamer.AddBlankLine(); 1546} 1547 1548/// printImplicitDef - This method prints the specified machine instruction 1549/// that is an implicit def. 1550void AsmPrinter::printImplicitDef(const MachineInstr *MI) const { 1551 if (!VerboseAsm) return; 1552 O.PadToColumn(MAI->getCommentColumn()); 1553 O << MAI->getCommentString() << " implicit-def: " 1554 << TRI->getName(MI->getOperand(0).getReg()); 1555 OutStreamer.AddBlankLine(); 1556} 1557 1558void AsmPrinter::printKill(const MachineInstr *MI) const { 1559 if (!VerboseAsm) return; 1560 O.PadToColumn(MAI->getCommentColumn()); 1561 O << MAI->getCommentString() << " kill:"; 1562 for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) { 1563 const MachineOperand &op = MI->getOperand(n); 1564 assert(op.isReg() && "KILL instruction must have only register operands"); 1565 O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>"); 1566 } 1567 OutStreamer.AddBlankLine(); 1568} 1569 1570/// printLabel - This method prints a local label used by debug and 1571/// exception handling tables. 1572void AsmPrinter::printLabelInst(const MachineInstr *MI) const { 1573 OutStreamer.EmitLabel(MI->getOperand(0).getMCSymbol()); 1574} 1575 1576/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM 1577/// instruction, using the specified assembler variant. Targets should 1578/// override this to format as appropriate. 1579bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 1580 unsigned AsmVariant, const char *ExtraCode) { 1581 // Target doesn't support this yet! 1582 return true; 1583} 1584 1585bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, 1586 unsigned AsmVariant, 1587 const char *ExtraCode) { 1588 // Target doesn't support this yet! 1589 return true; 1590} 1591 1592MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1593 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1594} 1595 1596MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1597 return MMI->getAddrLabelSymbol(BB); 1598} 1599 1600/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1601MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1602 return OutContext.GetOrCreateSymbol 1603 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1604 + "_" + Twine(CPID)); 1605} 1606 1607/// GetJTISymbol - Return the symbol for the specified jump table entry. 1608MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1609 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1610} 1611 1612/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1613/// FIXME: privatize to AsmPrinter. 1614MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1615 return OutContext.GetOrCreateSymbol 1616 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1617 Twine(UID) + "_set_" + Twine(MBBID)); 1618} 1619 1620/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1621/// global value name as its base, with the specified suffix, and where the 1622/// symbol is forced to have private linkage if ForcePrivate is true. 1623MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1624 StringRef Suffix, 1625 bool ForcePrivate) const { 1626 SmallString<60> NameStr; 1627 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1628 NameStr.append(Suffix.begin(), Suffix.end()); 1629 return OutContext.GetOrCreateSymbol(NameStr.str()); 1630} 1631 1632/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1633/// ExternalSymbol. 1634MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1635 SmallString<60> NameStr; 1636 Mang->getNameWithPrefix(NameStr, Sym); 1637 return OutContext.GetOrCreateSymbol(NameStr.str()); 1638} 1639 1640 1641 1642/// PrintParentLoopComment - Print comments about parent loops of this one. 1643static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1644 unsigned FunctionNumber) { 1645 if (Loop == 0) return; 1646 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1647 OS.indent(Loop->getLoopDepth()*2) 1648 << "Parent Loop BB" << FunctionNumber << "_" 1649 << Loop->getHeader()->getNumber() 1650 << " Depth=" << Loop->getLoopDepth() << '\n'; 1651} 1652 1653 1654/// PrintChildLoopComment - Print comments about child loops within 1655/// the loop for this basic block, with nesting. 1656static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1657 unsigned FunctionNumber) { 1658 // Add child loop information 1659 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1660 OS.indent((*CL)->getLoopDepth()*2) 1661 << "Child Loop BB" << FunctionNumber << "_" 1662 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1663 << '\n'; 1664 PrintChildLoopComment(OS, *CL, FunctionNumber); 1665 } 1666} 1667 1668/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks. 1669static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB, 1670 const MachineLoopInfo *LI, 1671 const AsmPrinter &AP) { 1672 // Add loop depth information 1673 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1674 if (Loop == 0) return; 1675 1676 MachineBasicBlock *Header = Loop->getHeader(); 1677 assert(Header && "No header for loop"); 1678 1679 // If this block is not a loop header, just print out what is the loop header 1680 // and return. 1681 if (Header != &MBB) { 1682 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1683 Twine(AP.getFunctionNumber())+"_" + 1684 Twine(Loop->getHeader()->getNumber())+ 1685 " Depth="+Twine(Loop->getLoopDepth())); 1686 return; 1687 } 1688 1689 // Otherwise, it is a loop header. Print out information about child and 1690 // parent loops. 1691 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1692 1693 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1694 1695 OS << "=>"; 1696 OS.indent(Loop->getLoopDepth()*2-2); 1697 1698 OS << "This "; 1699 if (Loop->empty()) 1700 OS << "Inner "; 1701 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1702 1703 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1704} 1705 1706 1707/// EmitBasicBlockStart - This method prints the label for the specified 1708/// MachineBasicBlock, an alignment (if present) and a comment describing 1709/// it if appropriate. 1710void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1711 // Emit an alignment directive for this block, if needed. 1712 if (unsigned Align = MBB->getAlignment()) 1713 EmitAlignment(Log2_32(Align)); 1714 1715 // If the block has its address taken, emit any labels that were used to 1716 // reference the block. It is possible that there is more than one label 1717 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1718 // the references were generated. 1719 if (MBB->hasAddressTaken()) { 1720 const BasicBlock *BB = MBB->getBasicBlock(); 1721 if (VerboseAsm) 1722 OutStreamer.AddComment("Block address taken"); 1723 1724 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1725 1726 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1727 OutStreamer.EmitLabel(Syms[i]); 1728 } 1729 1730 // Print the main label for the block. 1731 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1732 if (VerboseAsm) { 1733 // NOTE: Want this comment at start of line. 1734 O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':'; 1735 if (const BasicBlock *BB = MBB->getBasicBlock()) 1736 if (BB->hasName()) 1737 OutStreamer.AddComment("%" + BB->getName()); 1738 1739 PrintBasicBlockLoopComments(*MBB, LI, *this); 1740 OutStreamer.AddBlankLine(); 1741 } 1742 } else { 1743 if (VerboseAsm) { 1744 if (const BasicBlock *BB = MBB->getBasicBlock()) 1745 if (BB->hasName()) 1746 OutStreamer.AddComment("%" + BB->getName()); 1747 PrintBasicBlockLoopComments(*MBB, LI, *this); 1748 } 1749 1750 OutStreamer.EmitLabel(MBB->getSymbol()); 1751 } 1752} 1753 1754void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1755 MCSymbolAttr Attr = MCSA_Invalid; 1756 1757 switch (Visibility) { 1758 default: break; 1759 case GlobalValue::HiddenVisibility: 1760 Attr = MAI->getHiddenVisibilityAttr(); 1761 break; 1762 case GlobalValue::ProtectedVisibility: 1763 Attr = MAI->getProtectedVisibilityAttr(); 1764 break; 1765 } 1766 1767 if (Attr != MCSA_Invalid) 1768 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1769} 1770 1771void AsmPrinter::printOffset(int64_t Offset) const { 1772 if (Offset > 0) 1773 O << '+' << Offset; 1774 else if (Offset < 0) 1775 O << Offset; 1776} 1777 1778/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1779/// exactly one predecessor and the control transfer mechanism between 1780/// the predecessor and this block is a fall-through. 1781bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) 1782 const { 1783 // If this is a landing pad, it isn't a fall through. If it has no preds, 1784 // then nothing falls through to it. 1785 if (MBB->isLandingPad() || MBB->pred_empty()) 1786 return false; 1787 1788 // If there isn't exactly one predecessor, it can't be a fall through. 1789 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1790 ++PI2; 1791 if (PI2 != MBB->pred_end()) 1792 return false; 1793 1794 // The predecessor has to be immediately before this block. 1795 const MachineBasicBlock *Pred = *PI; 1796 1797 if (!Pred->isLayoutSuccessor(MBB)) 1798 return false; 1799 1800 // If the block is completely empty, then it definitely does fall through. 1801 if (Pred->empty()) 1802 return true; 1803 1804 // Otherwise, check the last instruction. 1805 const MachineInstr &LastInst = Pred->back(); 1806 return !LastInst.getDesc().isBarrier(); 1807} 1808 1809 1810 1811GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1812 if (!S->usesMetadata()) 1813 return 0; 1814 1815 gcp_iterator GCPI = GCMetadataPrinters.find(S); 1816 if (GCPI != GCMetadataPrinters.end()) 1817 return GCPI->second; 1818 1819 const char *Name = S->getName().c_str(); 1820 1821 for (GCMetadataPrinterRegistry::iterator 1822 I = GCMetadataPrinterRegistry::begin(), 1823 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1824 if (strcmp(Name, I->getName()) == 0) { 1825 GCMetadataPrinter *GMP = I->instantiate(); 1826 GMP->S = S; 1827 GCMetadataPrinters.insert(std::make_pair(S, GMP)); 1828 return GMP; 1829 } 1830 1831 llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1832 return 0; 1833} 1834 1835