lib/Target/PTX/PTXAsmPrinter.cpp

   1 //===-- PTXAsmPrinter.cpp - PTX LLVM assembly writer ----------------------===//
   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 contains a printer that converts from our internal representation
  11 // of machine-dependent LLVM code to PTX assembly language.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #define DEBUG_TYPE "ptx-asm-printer"
  16
  17 #include "PTX.h"
  18 #include "PTXMachineFunctionInfo.h"
  19 #include "PTXTargetMachine.h"
  20 #include "llvm/DerivedTypes.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/ADT/SmallString.h"
  23 #include "llvm/ADT/StringExtras.h"
  24 #include "llvm/ADT/Twine.h"
  25 #include "llvm/Analysis/DebugInfo.h"
  26 #include "llvm/CodeGen/AsmPrinter.h"
  27 #include "llvm/CodeGen/MachineFrameInfo.h"
  28 #include "llvm/CodeGen/MachineInstr.h"
  29 #include "llvm/CodeGen/MachineRegisterInfo.h"
  30 #include "llvm/MC/MCContext.h"
  31 #include "llvm/MC/MCStreamer.h"
  32 #include "llvm/MC/MCSymbol.h"
  33 #include "llvm/Target/Mangler.h"
  34 #include "llvm/Target/TargetLoweringObjectFile.h"
  35 #include "llvm/Target/TargetRegistry.h"
  36 #include "llvm/Support/CommandLine.h"
  37 #include "llvm/Support/Debug.h"
  38 #include "llvm/Support/ErrorHandling.h"
  39 #include "llvm/Support/MathExtras.h"
  40 #include "llvm/Support/Path.h"
  41 #include "llvm/Support/raw_ostream.h"
  42
  43 using namespace llvm;
  44
  45 namespace {
  46 class PTXAsmPrinter : public AsmPrinter {
  47 public:
  48   explicit PTXAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
  49     : AsmPrinter(TM, Streamer) {}
  50
  51   const char *getPassName() const { return "PTX Assembly Printer"; }
  52
  53   bool doFinalization(Module &M);
  54
  55   virtual void EmitStartOfAsmFile(Module &M);
  56
  57   virtual bool runOnMachineFunction(MachineFunction &MF);
  58
  59   virtual void EmitFunctionBodyStart();
  60   virtual void EmitFunctionBodyEnd() { OutStreamer.EmitRawText(Twine("}")); }
  61
  62   virtual void EmitInstruction(const MachineInstr *MI);
  63
  64   void printOperand(const MachineInstr *MI, int opNum, raw_ostream &OS);
  65   void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &OS,
  66                        const char *Modifier = 0);
  67   void printParamOperand(const MachineInstr *MI, int opNum, raw_ostream &OS,
  68                          const char *Modifier = 0);
  69   void printReturnOperand(const MachineInstr *MI, int opNum, raw_ostream &OS,
  70                           const char *Modifier = 0);
  71   void printPredicateOperand(const MachineInstr *MI, raw_ostream &O);
  72
  73   unsigned GetOrCreateSourceID(StringRef FileName,
  74                                StringRef DirName);
  75
  76   // autogen'd.
  77   void printInstruction(const MachineInstr *MI, raw_ostream &OS);
  78   static const char *getRegisterName(unsigned RegNo);
  79
  80 private:
  81   void EmitVariableDeclaration(const GlobalVariable *gv);
  82   void EmitFunctionDeclaration();
  83
  84   StringMap<unsigned> SourceIdMap;
  85 }; // class PTXAsmPrinter
  86 } // namespace
  87
  88 static const char PARAM_PREFIX[] = "__param_";
  89 static const char RETURN_PREFIX[] = "__ret_";
  90
  91 static const char *getRegisterTypeName(unsigned RegNo) {
  92 #define TEST_REGCLS(cls, clsstr)                \
  93   if (PTX::cls ## RegisterClass->contains(RegNo)) return # clsstr;
  94   TEST_REGCLS(RegPred, pred);
  95   TEST_REGCLS(RegI16, b16);
  96   TEST_REGCLS(RegI32, b32);
  97   TEST_REGCLS(RegI64, b64);
  98   TEST_REGCLS(RegF32, b32);
  99   TEST_REGCLS(RegF64, b64);
 100 #undef TEST_REGCLS
 101
 102   llvm_unreachable("Not in any register class!");
 103   return NULL;
 104 }
 105
 106 static const char *getStateSpaceName(unsigned addressSpace) {
 107   switch (addressSpace) {
 108   default: llvm_unreachable("Unknown state space");
 109   case PTX::GLOBAL:    return "global";
 110   case PTX::CONSTANT:  return "const";
 111   case PTX::LOCAL:     return "local";
 112   case PTX::PARAMETER: return "param";
 113   case PTX::SHARED:    return "shared";
 114   }
 115   return NULL;
 116 }
 117
 118 static const char *getTypeName(const Type* type) {
 119   while (true) {
 120     switch (type->getTypeID()) {
 121       default: llvm_unreachable("Unknown type");
 122       case Type::FloatTyID: return ".f32";
 123       case Type::DoubleTyID: return ".f64";
 124       case Type::IntegerTyID:
 125         switch (type->getPrimitiveSizeInBits()) {
 126           default: llvm_unreachable("Unknown integer bit-width");
 127           case 16: return ".u16";
 128           case 32: return ".u32";
 129           case 64: return ".u64";
 130         }
 131       case Type::ArrayTyID:
 132       case Type::PointerTyID:
 133         type = dyn_cast<const SequentialType>(type)->getElementType();
 134         break;
 135     }
 136   }
 137   return NULL;
 138 }
 139
 140 bool PTXAsmPrinter::doFinalization(Module &M) {
 141   // XXX Temproarily remove global variables so that doFinalization() will not
 142   // emit them again (global variables are emitted at beginning).
 143
 144   Module::GlobalListType &global_list = M.getGlobalList();
 145   int i, n = global_list.size();
 146   GlobalVariable **gv_array = new GlobalVariable* [n];
 147
 148   // first, back-up GlobalVariable in gv_array
 149   i = 0;
 150   for (Module::global_iterator I = global_list.begin(), E = global_list.end();
 151        I != E; ++I)
 152     gv_array[i++] = &*I;
 153
 154   // second, empty global_list
 155   while (!global_list.empty())
 156     global_list.remove(global_list.begin());
 157
 158   // call doFinalization
 159   bool ret = AsmPrinter::doFinalization(M);
 160
 161   // now we restore global variables
 162   for (i = 0; i < n; i ++)
 163     global_list.insert(global_list.end(), gv_array[i]);
 164
 165   delete[] gv_array;
 166   return ret;
 167 }
 168
 169 void PTXAsmPrinter::EmitStartOfAsmFile(Module &M)
 170 {
 171   const PTXSubtarget& ST = TM.getSubtarget<PTXSubtarget>();
 172
 173   OutStreamer.EmitRawText(Twine("\t.version " + ST.getPTXVersionString()));
 174   OutStreamer.EmitRawText(Twine("\t.target " + ST.getTargetString() +
 175                                 (ST.supportsDouble() ? ""
 176                                                      : ", map_f64_to_f32")));
 177   // .address_size directive is optional, but it must immediately follow
 178   // the .target directive if present within a module
 179   if (ST.supportsPTX23()) {
 180     std::string addrSize = ST.is64Bit() ? "64" : "32";
 181     OutStreamer.EmitRawText(Twine("\t.address_size " + addrSize));
 182   }
 183
 184   OutStreamer.AddBlankLine();
 185
 186   // Define any .file directives
 187   DebugInfoFinder DbgFinder;
 188   DbgFinder.processModule(M);
 189
 190   for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
 191        E = DbgFinder.compile_unit_end(); I != E; ++I) {
 192     DICompileUnit DIUnit(*I);
 193     StringRef FN = DIUnit.getFilename();
 194     StringRef Dir = DIUnit.getDirectory();
 195     GetOrCreateSourceID(FN, Dir);
 196   }
 197
 198   OutStreamer.AddBlankLine();
 199
 200   // declare global variables
 201   for (Module::const_global_iterator i = M.global_begin(), e = M.global_end();
 202        i != e; ++i)
 203     EmitVariableDeclaration(i);
 204 }
 205
 206 bool PTXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 207   SetupMachineFunction(MF);
 208   EmitFunctionDeclaration();
 209   EmitFunctionBody();
 210   return false;
 211 }
 212
 213 void PTXAsmPrinter::EmitFunctionBodyStart() {
 214   OutStreamer.EmitRawText(Twine("{"));
 215
 216   const PTXMachineFunctionInfo *MFI = MF->getInfo<PTXMachineFunctionInfo>();
 217
 218   // Print local variable definition
 219   for (PTXMachineFunctionInfo::reg_iterator
 220        i = MFI->localVarRegBegin(), e = MFI->localVarRegEnd(); i != e; ++ i) {
 221     unsigned reg = *i;
 222
 223     std::string def = "\t.reg .";
 224     def += getRegisterTypeName(reg);
 225     def += ' ';
 226     def += getRegisterName(reg);
 227     def += ';';
 228     OutStreamer.EmitRawText(Twine(def));
 229   }
 230
 231   const MachineFrameInfo* FrameInfo = MF->getFrameInfo();
 232   DEBUG(dbgs() << "Have " << FrameInfo->getNumObjects()
 233                << " frame object(s)\n");
 234   for (unsigned i = 0, e = FrameInfo->getNumObjects(); i != e; ++i) {
 235     DEBUG(dbgs() << "Size of object: " << FrameInfo->getObjectSize(i) << "\n");
 236     if (FrameInfo->getObjectSize(i) > 0) {
 237       std::string def = "\t.reg .b";
 238       def += utostr(FrameInfo->getObjectSize(i)*8); // Convert to bits
 239       def += " s";
 240       def += utostr(i);
 241       def += ";";
 242       OutStreamer.EmitRawText(Twine(def));
 243     }
 244   }
 245 }
 246
 247 void PTXAsmPrinter::EmitInstruction(const MachineInstr *MI) {
 248   std::string str;
 249   str.reserve(64);
 250
 251   raw_string_ostream OS(str);
 252
 253   DebugLoc DL = MI->getDebugLoc();
 254   if (!DL.isUnknown()) {
 255
 256     const MDNode *S = DL.getScope(MF->getFunction()->getContext());
 257
 258     // This is taken from DwarfDebug.cpp, which is conveniently not a public
 259     // LLVM class.
 260     StringRef Fn;
 261     StringRef Dir;
 262     unsigned Src = 1;
 263     if (S) {
 264       DIDescriptor Scope(S);
 265       if (Scope.isCompileUnit()) {
 266         DICompileUnit CU(S);
 267         Fn = CU.getFilename();
 268         Dir = CU.getDirectory();
 269       } else if (Scope.isFile()) {
 270         DIFile F(S);
 271         Fn = F.getFilename();
 272         Dir = F.getDirectory();
 273       } else if (Scope.isSubprogram()) {
 274         DISubprogram SP(S);
 275         Fn = SP.getFilename();
 276         Dir = SP.getDirectory();
 277       } else if (Scope.isLexicalBlock()) {
 278         DILexicalBlock DB(S);
 279         Fn = DB.getFilename();
 280         Dir = DB.getDirectory();
 281       } else
 282         assert(0 && "Unexpected scope info");
 283
 284       Src = GetOrCreateSourceID(Fn, Dir);
 285     }
 286     OutStreamer.EmitDwarfLocDirective(Src, DL.getLine(), DL.getCol(),
 287                                      0, 0, 0, Fn);
 288
 289     const MCDwarfLoc& MDL = OutContext.getCurrentDwarfLoc();
 290
 291     OS << "\t.loc ";
 292     OS << utostr(MDL.getFileNum());
 293     OS << " ";
 294     OS << utostr(MDL.getLine());
 295     OS << " ";
 296     OS << utostr(MDL.getColumn());
 297     OS << "\n";
 298   }
 299
 300
 301   // Emit predicate
 302   printPredicateOperand(MI, OS);
 303
 304   // Write instruction to str
 305   printInstruction(MI, OS);
 306   OS << ';';
 307   OS.flush();
 308
 309   StringRef strref = StringRef(str);
 310   OutStreamer.EmitRawText(strref);
 311 }
 312
 313 void PTXAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
 314                                  raw_ostream &OS) {
 315   const MachineOperand &MO = MI->getOperand(opNum);
 316
 317   switch (MO.getType()) {
 318     default:
 319       llvm_unreachable("<unknown operand type>");
 320       break;
 321     case MachineOperand::MO_GlobalAddress:
 322       OS << *Mang->getSymbol(MO.getGlobal());
 323       break;
 324     case MachineOperand::MO_Immediate:
 325       OS << (long) MO.getImm();
 326       break;
 327     case MachineOperand::MO_MachineBasicBlock:
 328       OS << *MO.getMBB()->getSymbol();
 329       break;
 330     case MachineOperand::MO_Register:
 331       OS << getRegisterName(MO.getReg());
 332       break;
 333     case MachineOperand::MO_FPImmediate:
 334       APInt constFP = MO.getFPImm()->getValueAPF().bitcastToAPInt();
 335       bool  isFloat = MO.getFPImm()->getType()->getTypeID() == Type::FloatTyID;
 336       // Emit 0F for 32-bit floats and 0D for 64-bit doubles.
 337       if (isFloat) {
 338         OS << "0F";
 339       }
 340       else {
 341         OS << "0D";
 342       }
 343       // Emit the encoded floating-point value.
 344       if (constFP.getZExtValue() > 0) {
 345         OS << constFP.toString(16, false);
 346       }
 347       else {
 348         OS << "00000000";
 349         // If We have a double-precision zero, pad to 8-bytes.
 350         if (!isFloat) {
 351           OS << "00000000";
 352         }
 353       }
 354       break;
 355   }
 356 }
 357
 358 void PTXAsmPrinter::printMemOperand(const MachineInstr *MI, int opNum,
 359                                     raw_ostream &OS, const char *Modifier) {
 360   printOperand(MI, opNum, OS);
 361
 362   if (MI->getOperand(opNum+1).isImm() && MI->getOperand(opNum+1).getImm() == 0)
 363     return; // don't print "+0"
 364
 365   OS << "+";
 366   printOperand(MI, opNum+1, OS);
 367 }
 368
 369 void PTXAsmPrinter::printParamOperand(const MachineInstr *MI, int opNum,
 370                                       raw_ostream &OS, const char *Modifier) {
 371   OS << PARAM_PREFIX << (int) MI->getOperand(opNum).getImm() + 1;
 372 }
 373
 374 void PTXAsmPrinter::printReturnOperand(const MachineInstr *MI, int opNum,
 375                                        raw_ostream &OS, const char *Modifier) {
 376   OS << RETURN_PREFIX << (int) MI->getOperand(opNum).getImm() + 1;
 377 }
 378
 379 void PTXAsmPrinter::EmitVariableDeclaration(const GlobalVariable *gv) {
 380   // Check to see if this is a special global used by LLVM, if so, emit it.
 381   if (EmitSpecialLLVMGlobal(gv))
 382     return;
 383
 384   MCSymbol *gvsym = Mang->getSymbol(gv);
 385
 386   assert(gvsym->isUndefined() && "Cannot define a symbol twice!");
 387
 388   std::string decl;
 389
 390   // check if it is defined in some other translation unit
 391   if (gv->isDeclaration())
 392     decl += ".extern ";
 393
 394   // state space: e.g., .global
 395   decl += ".";
 396   decl += getStateSpaceName(gv->getType()->getAddressSpace());
 397   decl += " ";
 398
 399   // alignment (optional)
 400   unsigned alignment = gv->getAlignment();
 401   if (alignment != 0) {
 402     decl += ".align ";
 403     decl += utostr(Log2_32(gv->getAlignment()));
 404     decl += " ";
 405   }
 406
 407
 408   if (PointerType::classof(gv->getType())) {
 409     const PointerType* pointerTy = dyn_cast<const PointerType>(gv->getType());
 410     const Type* elementTy = pointerTy->getElementType();
 411
 412     decl += ".b8 ";
 413     decl += gvsym->getName();
 414     decl += "[";
 415
 416     if (elementTy->isArrayTy())
 417     {
 418       assert(elementTy->isArrayTy() && "Only pointers to arrays are supported");
 419
 420       const ArrayType* arrayTy = dyn_cast<const ArrayType>(elementTy);
 421       elementTy = arrayTy->getElementType();
 422
 423       unsigned numElements = arrayTy->getNumElements();
 424
 425       while (elementTy->isArrayTy()) {
 426
 427         arrayTy = dyn_cast<const ArrayType>(elementTy);
 428         elementTy = arrayTy->getElementType();
 429
 430         numElements *= arrayTy->getNumElements();
 431       }
 432
 433       // FIXME: isPrimitiveType() == false for i16?
 434       assert(elementTy->isSingleValueType() &&
 435               "Non-primitive types are not handled");
 436
 437       // Compute the size of the array, in bytes.
 438       uint64_t arraySize = (elementTy->getPrimitiveSizeInBits() >> 3)
 439                         * numElements;
 440
 441       decl += utostr(arraySize);
 442     }
 443
 444     decl += "]";
 445
 446     // handle string constants (assume ConstantArray means string)
 447
 448     if (gv->hasInitializer())
 449     {
 450       const Constant *C = gv->getInitializer();
 451       if (const ConstantArray *CA = dyn_cast<ConstantArray>(C))
 452       {
 453         decl += " = {";
 454
 455         for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 456         {
 457           if (i > 0)   decl += ",";
 458
 459           decl += "0x" +
 460                 utohexstr(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
 461         }
 462
 463         decl += "}";
 464       }
 465     }
 466   }
 467   else {
 468     // Note: this is currently the fall-through case and most likely generates
 469     //       incorrect code.
 470     decl += getTypeName(gv->getType());
 471     decl += " ";
 472
 473     decl += gvsym->getName();
 474
 475     if (ArrayType::classof(gv->getType()) ||
 476         PointerType::classof(gv->getType()))
 477       decl += "[]";
 478   }
 479
 480   decl += ";";
 481
 482   OutStreamer.EmitRawText(Twine(decl));
 483
 484   OutStreamer.AddBlankLine();
 485 }
 486
 487 void PTXAsmPrinter::EmitFunctionDeclaration() {
 488   // The function label could have already been emitted if two symbols end up
 489   // conflicting due to asm renaming.  Detect this and emit an error.
 490   if (!CurrentFnSym->isUndefined()) {
 491     report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
 492                        "' label emitted multiple times to assembly file");
 493     return;
 494   }
 495
 496   const PTXMachineFunctionInfo *MFI = MF->getInfo<PTXMachineFunctionInfo>();
 497   const bool isKernel = MFI->isKernel();
 498   const PTXSubtarget& ST = TM.getSubtarget<PTXSubtarget>();
 499
 500   std::string decl = isKernel ? ".entry" : ".func";
 501
 502   unsigned cnt = 0;
 503
 504   if (!isKernel) {
 505     decl += " (";
 506     for (PTXMachineFunctionInfo::ret_iterator
 507          i = MFI->retRegBegin(), e = MFI->retRegEnd(), b = i;
 508          i != e; ++i) {
 509       if (i != b) {
 510         decl += ", ";
 511       }
 512       decl += ".reg .";
 513       decl += getRegisterTypeName(*i);
 514       decl += " ";
 515       decl += getRegisterName(*i);
 516     }
 517     decl += ")";
 518   }
 519
 520   // Print function name
 521   decl += " ";
 522   decl += CurrentFnSym->getName().str();
 523
 524   decl += " (";
 525
 526   cnt = 0;
 527
 528   // Print parameters
 529   for (PTXMachineFunctionInfo::reg_iterator
 530        i = MFI->argRegBegin(), e = MFI->argRegEnd(), b = i;
 531        i != e; ++i) {
 532     if (i != b) {
 533       decl += ", ";
 534     }
 535     if (isKernel || ST.useParamSpaceForDeviceArgs()) {
 536       decl += ".param .b";
 537       decl += utostr(*i);
 538       decl += " ";
 539       decl += PARAM_PREFIX;
 540       decl += utostr(++cnt);
 541     } else {
 542       decl += ".reg .";
 543       decl += getRegisterTypeName(*i);
 544       decl += " ";
 545       decl += getRegisterName(*i);
 546     }
 547   }
 548   decl += ")";
 549
 550   OutStreamer.EmitRawText(Twine(decl));
 551 }
 552
 553 void PTXAsmPrinter::
 554 printPredicateOperand(const MachineInstr *MI, raw_ostream &O) {
 555   int i = MI->findFirstPredOperandIdx();
 556   if (i == -1)
 557     llvm_unreachable("missing predicate operand");
 558
 559   unsigned reg = MI->getOperand(i).getReg();
 560   int predOp = MI->getOperand(i+1).getImm();
 561
 562   DEBUG(dbgs() << "predicate: (" << reg << ", " << predOp << ")\n");
 563
 564   if (reg != PTX::NoRegister) {
 565     O << '@';
 566     if (predOp == PTX::PRED_NEGATE)
 567       O << '!';
 568     O << getRegisterName(reg);
 569   }
 570 }
 571
 572 unsigned PTXAsmPrinter::GetOrCreateSourceID(StringRef FileName,
 573                                             StringRef DirName) {
 574   // If FE did not provide a file name, then assume stdin.
 575   if (FileName.empty())
 576     return GetOrCreateSourceID("<stdin>", StringRef());
 577
 578   // MCStream expects full path name as filename.
 579   if (!DirName.empty() && !sys::path::is_absolute(FileName)) {
 580     SmallString<128> FullPathName = DirName;
 581     sys::path::append(FullPathName, FileName);
 582     // Here FullPathName will be copied into StringMap by GetOrCreateSourceID.
 583     return GetOrCreateSourceID(StringRef(FullPathName), StringRef());
 584   }
 585
 586   StringMapEntry<unsigned> &Entry = SourceIdMap.GetOrCreateValue(FileName);
 587   if (Entry.getValue())
 588     return Entry.getValue();
 589
 590   unsigned SrcId = SourceIdMap.size();
 591   Entry.setValue(SrcId);
 592
 593   // Print out a .file directive to specify files for .loc directives.
 594   OutStreamer.EmitDwarfFileDirective(SrcId, Entry.getKey());
 595
 596   return SrcId;
 597 }
 598
 599 #include "PTXGenAsmWriter.inc"
 600
 601 // Force static initialization.
 602 extern "C" void LLVMInitializePTXAsmPrinter() {
 603   RegisterAsmPrinter<PTXAsmPrinter> X(ThePTX32Target);
 604   RegisterAsmPrinter<PTXAsmPrinter> Y(ThePTX64Target);
 605 }