lib/Target/X86/X86ATTAsmPrinter.cpp

   1 //===-- X86ATTAsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly -----===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source 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 AT&T format assembly
  12 // language. This printer is the output mechanism used by `llc'.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #define DEBUG_TYPE "asm-printer"
  17 #include "X86ATTAsmPrinter.h"
  18 #include "X86.h"
  19 #include "X86COFF.h"
  20 #include "X86MachineFunctionInfo.h"
  21 #include "X86TargetMachine.h"
  22 #include "X86TargetAsmInfo.h"
  23 #include "llvm/ADT/StringExtras.h"
  24 #include "llvm/CallingConv.h"
  25 #include "llvm/Module.h"
  26 #include "llvm/Support/Mangler.h"
  27 #include "llvm/Target/TargetAsmInfo.h"
  28 #include "llvm/Target/TargetOptions.h"
  29 #include "llvm/ADT/Statistic.h"
  30 using namespace llvm;
  31
  32 STATISTIC(EmittedInsts, "Number of machine instrs printed");
  33
  34 static std::string computePICLabel(unsigned FnNum,
  35                                    const TargetAsmInfo *TAI,
  36                                    const X86Subtarget* Subtarget)  {
  37   std::string label;
  38   if (Subtarget->isTargetDarwin())
  39     label =  "\"L" + utostr_32(FnNum) + "$pb\"";
  40   else if (Subtarget->isTargetELF())
  41     label = ".Lllvm$" + utostr_32(FnNum) + "$piclabel";
  42   else
  43     assert(0 && "Don't know how to print PIC label!\n");
  44
  45   return label;
  46 }
  47
  48 /// getSectionForFunction - Return the section that we should emit the
  49 /// specified function body into.
  50 std::string X86ATTAsmPrinter::getSectionForFunction(const Function &F) const {
  51   switch (F.getLinkage()) {
  52   default: assert(0 && "Unknown linkage type!");
  53   case Function::InternalLinkage:
  54   case Function::DLLExportLinkage:
  55   case Function::ExternalLinkage:
  56     return TAI->getTextSection();
  57   case Function::WeakLinkage:
  58   case Function::LinkOnceLinkage:
  59     if (Subtarget->isTargetDarwin()) {
  60       return ".section __TEXT,__textcoal_nt,coalesced,pure_instructions";
  61     } else if (Subtarget->isTargetCygMing()) {
  62       return "\t.section\t.text$linkonce." + CurrentFnName + ",\"ax\"";
  63     } else {
  64       return "\t.section\t.llvm.linkonce.t." + CurrentFnName +
  65              ",\"ax\",@progbits";
  66     }
  67   }
  68 }
  69
  70 /// runOnMachineFunction - This uses the printMachineInstruction()
  71 /// method to print assembly for each instruction.
  72 ///
  73 bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
  74   if (TAI->doesSupportDebugInformation()) {
  75     // Let PassManager know we need debug information and relay
  76     // the MachineModuleInfo address on to DwarfWriter.
  77     MMI = &getAnalysis<MachineModuleInfo>();
  78     DW.SetModuleInfo(MMI);
  79   }
  80
  81   SetupMachineFunction(MF);
  82   O << "\n\n";
  83
  84   // Print out constants referenced by the function
  85   EmitConstantPool(MF.getConstantPool());
  86
  87   // Print out labels for the function.
  88   const Function *F = MF.getFunction();
  89   unsigned CC = F->getCallingConv();
  90
  91   // Populate function information map.  Actually, We don't want to populate
  92   // non-stdcall or non-fastcall functions' information right now.
  93   if (CC == CallingConv::X86_StdCall || CC == CallingConv::X86_FastCall)
  94     FunctionInfoMap[F] = *MF.getInfo<X86MachineFunctionInfo>();
  95
  96   X86SharedAsmPrinter::decorateName(CurrentFnName, F);
  97
  98   SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
  99
 100   switch (F->getLinkage()) {
 101   default: assert(0 && "Unknown linkage type!");
 102   case Function::InternalLinkage:  // Symbols default to internal.
 103     if (Subtarget->isTargetDarwin())
 104       // FIXME: This should be parameterized somewhere.
 105       EmitAlignment(4, F, 0, true, 0x90);
 106     else
 107       EmitAlignment(4, F);     // FIXME: This should be parameterized somewhere.
 108     break;
 109   case Function::DLLExportLinkage:
 110     DLLExportedFns.insert(Mang->makeNameProper(F->getName(), ""));
 111     //FALLS THROUGH
 112   case Function::ExternalLinkage:
 113     if (Subtarget->isTargetDarwin())
 114       // FIXME: This should be parameterized somewhere.
 115       EmitAlignment(4, F, 0, true, 0x90);
 116     else
 117       EmitAlignment(4, F);     // FIXME: This should be parameterized somewhere.
 118     O << "\t.globl\t" << CurrentFnName << "\n";
 119     break;
 120   case Function::LinkOnceLinkage:
 121   case Function::WeakLinkage:
 122     if (Subtarget->isTargetDarwin()) {
 123       // FIXME: This should be parameterized somewhere.
 124       EmitAlignment(4, F, 0, true, 0x90);
 125       O << "\t.globl\t" << CurrentFnName << "\n";
 126       O << "\t.weak_definition\t" << CurrentFnName << "\n";
 127     } else if (Subtarget->isTargetCygMing()) {
 128       EmitAlignment(4, F);     // FIXME: This should be parameterized somewhere.
 129       O << "\t.globl " << CurrentFnName << "\n";
 130       O << "\t.linkonce discard\n";
 131     } else {
 132       EmitAlignment(4, F);     // FIXME: This should be parameterized somewhere.
 133       O << "\t.weak\t" << CurrentFnName << "\n";
 134     }
 135     break;
 136   }
 137   if (F->hasHiddenVisibility()) {
 138     if (const char *Directive = TAI->getHiddenDirective())
 139       O << Directive << CurrentFnName << "\n";
 140   } else if (F->hasProtectedVisibility()) {
 141     if (const char *Directive = TAI->getProtectedDirective())
 142       O << Directive << CurrentFnName << "\n";
 143   }
 144
 145   if (Subtarget->isTargetELF())
 146     O << "\t.type\t" << CurrentFnName << ",@function\n";
 147   else if (Subtarget->isTargetCygMing()) {
 148     O << "\t.def\t " << CurrentFnName
 149       << ";\t.scl\t" <<
 150       (F->getLinkage() == Function::InternalLinkage ? COFF::C_STAT : COFF::C_EXT)
 151       << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
 152       << ";\t.endef\n";
 153   }
 154
 155   O << CurrentFnName << ":\n";
 156   // Add some workaround for linkonce linkage on Cygwin\MinGW
 157   if (Subtarget->isTargetCygMing() &&
 158       (F->getLinkage() == Function::LinkOnceLinkage ||
 159        F->getLinkage() == Function::WeakLinkage))
 160     O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
 161
 162   if (TAI->doesSupportDebugInformation()) {
 163     // Emit pre-function debug information.
 164     DW.BeginFunction(&MF);
 165   }
 166
 167   // Print out code for the function.
 168   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 169        I != E; ++I) {
 170     // Print a label for the basic block.
 171     if (I->pred_begin() != I->pred_end()) {
 172       printBasicBlockLabel(I, true);
 173       O << '\n';
 174     }
 175     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 176          II != E; ++II) {
 177       // Print the assembly for the instruction.
 178       O << "\t";
 179       printMachineInstruction(II);
 180     }
 181   }
 182
 183   if (TAI->hasDotTypeDotSizeDirective())
 184     O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << "\n";
 185
 186   if (TAI->doesSupportDebugInformation()) {
 187     // Emit post-function debug information.
 188     DW.EndFunction();
 189   }
 190
 191   // Print out jump tables referenced by the function.
 192   EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
 193
 194   // We didn't modify anything.
 195   return false;
 196 }
 197
 198 static inline bool printGOT(TargetMachine &TM, const X86Subtarget* ST) {
 199   return ST->isPICStyleGOT() && TM.getRelocationModel() == Reloc::PIC_;
 200 }
 201
 202 static inline bool printStub(TargetMachine &TM, const X86Subtarget* ST) {
 203   return ST->isPICStyleStub() && TM.getRelocationModel() != Reloc::Static;
 204 }
 205
 206 void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
 207                                     const char *Modifier, bool NotRIPRel) {
 208   const MachineOperand &MO = MI->getOperand(OpNo);
 209   const MRegisterInfo &RI = *TM.getRegisterInfo();
 210   switch (MO.getType()) {
 211   case MachineOperand::MO_Register: {
 212     assert(MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
 213            "Virtual registers should not make it this far!");
 214     O << '%';
 215     unsigned Reg = MO.getReg();
 216     if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
 217       MVT::ValueType VT = (strcmp(Modifier+6,"64") == 0) ?
 218         MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
 219                     ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
 220       Reg = getX86SubSuperRegister(Reg, VT);
 221     }
 222     for (const char *Name = RI.get(Reg).Name; *Name; ++Name)
 223       O << (char)tolower(*Name);
 224     return;
 225   }
 226
 227   case MachineOperand::MO_Immediate:
 228     if (!Modifier ||
 229         (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
 230       O << '$';
 231     O << MO.getImmedValue();
 232     return;
 233   case MachineOperand::MO_MachineBasicBlock:
 234     printBasicBlockLabel(MO.getMachineBasicBlock());
 235     return;
 236   case MachineOperand::MO_JumpTableIndex: {
 237     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 238     if (!isMemOp) O << '$';
 239     O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
 240       << MO.getJumpTableIndex();
 241
 242     if (TM.getRelocationModel() == Reloc::PIC_) {
 243       if (Subtarget->isPICStyleStub())
 244         O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
 245           << "$pb\"";
 246       else if (Subtarget->isPICStyleGOT())
 247         O << "@GOTOFF";
 248     }
 249
 250     if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
 251       O << "(%rip)";
 252     return;
 253   }
 254   case MachineOperand::MO_ConstantPoolIndex: {
 255     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 256     if (!isMemOp) O << '$';
 257     O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
 258       << MO.getConstantPoolIndex();
 259
 260     if (TM.getRelocationModel() == Reloc::PIC_) {
 261       if (Subtarget->isPICStyleStub())
 262         O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
 263           << "$pb\"";
 264       else if (Subtarget->isPICStyleGOT())
 265         O << "@GOTOFF";
 266     }
 267
 268     int Offset = MO.getOffset();
 269     if (Offset > 0)
 270       O << "+" << Offset;
 271     else if (Offset < 0)
 272       O << Offset;
 273
 274     if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
 275       O << "(%rip)";
 276     return;
 277   }
 278   case MachineOperand::MO_GlobalAddress: {
 279     bool isCallOp = Modifier && !strcmp(Modifier, "call");
 280     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 281     bool needCloseParen = false;
 282
 283     GlobalValue *GV = MO.getGlobal();
 284     GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
 285     bool isThreadLocal = GVar && GVar->isThreadLocal();
 286
 287     std::string Name = Mang->getValueName(GV);
 288     X86SharedAsmPrinter::decorateName(Name, GV);
 289
 290     if (!isMemOp && !isCallOp)
 291       O << '$';
 292     else if (Name[0] == '$') {
 293       // The name begins with a dollar-sign. In order to avoid having it look
 294       // like an integer immediate to the assembler, enclose it in parens.
 295       O << '(';
 296       needCloseParen = true;
 297     }
 298
 299     if (printStub(TM, Subtarget)) {
 300       // Link-once, declaration, or Weakly-linked global variables need
 301       // non-lazily-resolved stubs
 302       if (GV->isDeclaration() ||
 303           GV->hasWeakLinkage() ||
 304           GV->hasLinkOnceLinkage()) {
 305         // Dynamically-resolved functions need a stub for the function.
 306         if (isCallOp && isa<Function>(GV)) {
 307           FnStubs.insert(Name);
 308           O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
 309         } else {
 310           GVStubs.insert(Name);
 311           O << TAI->getPrivateGlobalPrefix() << Name << "$non_lazy_ptr";
 312         }
 313       } else {
 314         if (GV->hasDLLImportLinkage())
 315           O << "__imp_";
 316         O << Name;
 317       }
 318
 319       if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
 320         O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
 321           << "$pb\"";
 322     } else {
 323       if (GV->hasDLLImportLinkage()) {
 324         O << "__imp_";
 325       }
 326       O << Name;
 327
 328       if (isCallOp && isa<Function>(GV)) {
 329         if (printGOT(TM, Subtarget)) {
 330           // Assemble call via PLT for non-local symbols
 331           if (!(GV->hasHiddenVisibility() || GV->hasProtectedVisibility()) ||
 332               GV->isDeclaration())
 333             O << "@PLT";
 334         }
 335         if (Subtarget->isTargetCygMing() && GV->isDeclaration())
 336           // Save function name for later type emission
 337           FnStubs.insert(Name);
 338       }
 339     }
 340
 341     if (GV->hasExternalWeakLinkage())
 342       ExtWeakSymbols.insert(GV);
 343
 344     int Offset = MO.getOffset();
 345     if (Offset > 0)
 346       O << "+" << Offset;
 347     else if (Offset < 0)
 348       O << Offset;
 349
 350     if (isThreadLocal) {
 351       if (TM.getRelocationModel() == Reloc::PIC_)
 352         O << "@TLSGD"; // general dynamic TLS model
 353       else
 354         if (GV->isDeclaration())
 355           O << "@INDNTPOFF"; // initial exec TLS model
 356         else
 357           O << "@NTPOFF"; // local exec TLS model
 358     } else if (isMemOp) {
 359       if (printGOT(TM, Subtarget)) {
 360         if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
 361           O << "@GOT";
 362         else
 363           O << "@GOTOFF";
 364       } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel) {
 365         if ((GV->isDeclaration() ||
 366              GV->hasWeakLinkage() ||
 367              GV->hasLinkOnceLinkage()) &&
 368             TM.getRelocationModel() != Reloc::Static)
 369           O << "@GOTPCREL";
 370
 371         if (needCloseParen) {
 372           needCloseParen = false;
 373           O << ')';
 374         }
 375
 376         // Use rip when possible to reduce code size, except when
 377         // index or base register are also part of the address. e.g.
 378         // foo(%rip)(%rcx,%rax,4) is not legal
 379         O << "(%rip)";
 380       }
 381     }
 382
 383     if (needCloseParen)
 384       O << ')';
 385
 386     return;
 387   }
 388   case MachineOperand::MO_ExternalSymbol: {
 389     bool isCallOp = Modifier && !strcmp(Modifier, "call");
 390     bool needCloseParen = false;
 391     std::string Name(TAI->getGlobalPrefix());
 392     Name += MO.getSymbolName();
 393     if (isCallOp && printStub(TM, Subtarget)) {
 394       FnStubs.insert(Name);
 395       O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
 396       return;
 397     }
 398     if (!isCallOp)
 399       O << '$';
 400     else if (Name[0] == '$') {
 401       // The name begins with a dollar-sign. In order to avoid having it look
 402       // like an integer immediate to the assembler, enclose it in parens.
 403       O << '(';
 404       needCloseParen = true;
 405     }
 406
 407     O << Name;
 408
 409     if (printGOT(TM, Subtarget)) {
 410       std::string GOTName(TAI->getGlobalPrefix());
 411       GOTName+="_GLOBAL_OFFSET_TABLE_";
 412       if (Name == GOTName)
 413         // HACK! Emit extra offset to PC during printing GOT offset to
 414         // compensate for the size of popl instruction. The resulting code
 415         // should look like:
 416         //   call .piclabel
 417         // piclabel:
 418         //   popl %some_register
 419         //   addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
 420         O << " + [.-"
 421           << computePICLabel(getFunctionNumber(), TAI, Subtarget) << "]";
 422
 423       if (isCallOp)
 424         O << "@PLT";
 425     }
 426
 427     if (needCloseParen)
 428       O << ')';
 429
 430     if (!isCallOp && Subtarget->isPICStyleRIPRel())
 431       O << "(%rip)";
 432
 433     return;
 434   }
 435   default:
 436     O << "<unknown operand type>"; return;
 437   }
 438 }
 439
 440 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
 441   unsigned char value = MI->getOperand(Op).getImmedValue();
 442   assert(value <= 7 && "Invalid ssecc argument!");
 443   switch (value) {
 444   case 0: O << "eq"; break;
 445   case 1: O << "lt"; break;
 446   case 2: O << "le"; break;
 447   case 3: O << "unord"; break;
 448   case 4: O << "neq"; break;
 449   case 5: O << "nlt"; break;
 450   case 6: O << "nle"; break;
 451   case 7: O << "ord"; break;
 452   }
 453 }
 454
 455 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
 456                                          const char *Modifier){
 457   assert(isMem(MI, Op) && "Invalid memory reference!");
 458   MachineOperand BaseReg  = MI->getOperand(Op);
 459   MachineOperand IndexReg = MI->getOperand(Op+2);
 460   const MachineOperand &DispSpec = MI->getOperand(Op+3);
 461
 462   bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
 463   if (DispSpec.isGlobalAddress() ||
 464       DispSpec.isConstantPoolIndex() ||
 465       DispSpec.isJumpTableIndex()) {
 466     printOperand(MI, Op+3, "mem", NotRIPRel);
 467   } else {
 468     int DispVal = DispSpec.getImmedValue();
 469     if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
 470       O << DispVal;
 471   }
 472
 473   if (IndexReg.getReg() || BaseReg.getReg()) {
 474     unsigned ScaleVal = MI->getOperand(Op+1).getImmedValue();
 475     unsigned BaseRegOperand = 0, IndexRegOperand = 2;
 476
 477     // There are cases where we can end up with ESP/RSP in the indexreg slot.
 478     // If this happens, swap the base/index register to support assemblers that
 479     // don't work when the index is *SP.
 480     if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
 481       assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
 482       std::swap(BaseReg, IndexReg);
 483       std::swap(BaseRegOperand, IndexRegOperand);
 484     }
 485
 486     O << "(";
 487     if (BaseReg.getReg())
 488       printOperand(MI, Op+BaseRegOperand, Modifier);
 489
 490     if (IndexReg.getReg()) {
 491       O << ",";
 492       printOperand(MI, Op+IndexRegOperand, Modifier);
 493       if (ScaleVal != 1)
 494         O << "," << ScaleVal;
 495     }
 496     O << ")";
 497   }
 498 }
 499
 500 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
 501   std::string label = computePICLabel(getFunctionNumber(), TAI, Subtarget);
 502   O << label << "\n" << label << ":";
 503 }
 504
 505
 506 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
 507                                          const char Mode) {
 508   const MRegisterInfo &RI = *TM.getRegisterInfo();
 509   unsigned Reg = MO.getReg();
 510   switch (Mode) {
 511   default: return true;  // Unknown mode.
 512   case 'b': // Print QImode register
 513     Reg = getX86SubSuperRegister(Reg, MVT::i8);
 514     break;
 515   case 'h': // Print QImode high register
 516     Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
 517     break;
 518   case 'w': // Print HImode register
 519     Reg = getX86SubSuperRegister(Reg, MVT::i16);
 520     break;
 521   case 'k': // Print SImode register
 522     Reg = getX86SubSuperRegister(Reg, MVT::i32);
 523     break;
 524   }
 525
 526   O << '%';
 527   for (const char *Name = RI.get(Reg).Name; *Name; ++Name)
 528     O << (char)tolower(*Name);
 529   return false;
 530 }
 531
 532 /// PrintAsmOperand - Print out an operand for an inline asm expression.
 533 ///
 534 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
 535                                        unsigned AsmVariant,
 536                                        const char *ExtraCode) {
 537   // Does this asm operand have a single letter operand modifier?
 538   if (ExtraCode && ExtraCode[0]) {
 539     if (ExtraCode[1] != 0) return true; // Unknown modifier.
 540
 541     switch (ExtraCode[0]) {
 542     default: return true;  // Unknown modifier.
 543     case 'c': // Don't print "$" before a global var name or constant.
 544       printOperand(MI, OpNo, "mem");
 545       return false;
 546     case 'b': // Print QImode register
 547     case 'h': // Print QImode high register
 548     case 'w': // Print HImode register
 549     case 'k': // Print SImode register
 550       if (MI->getOperand(OpNo).isRegister())
 551         return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
 552       printOperand(MI, OpNo);
 553       return false;
 554
 555     case 'P': // Don't print @PLT, but do print as memory.
 556       printOperand(MI, OpNo, "mem");
 557       return false;
 558     }
 559   }
 560
 561   printOperand(MI, OpNo);
 562   return false;
 563 }
 564
 565 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
 566                                              unsigned OpNo,
 567                                              unsigned AsmVariant,
 568                                              const char *ExtraCode) {
 569   if (ExtraCode && ExtraCode[0])
 570     return true; // Unknown modifier.
 571   printMemReference(MI, OpNo);
 572   return false;
 573 }
 574
 575 /// printMachineInstruction -- Print out a single X86 LLVM instruction
 576 /// MI in AT&T syntax to the current output stream.
 577 ///
 578 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 579   ++EmittedInsts;
 580
 581   // See if a truncate instruction can be turned into a nop.
 582   switch (MI->getOpcode()) {
 583   default: break;
 584   case X86::PsMOVZX64rr32:
 585     O << TAI->getCommentString() << " ZERO-EXTEND " << "\n\t";
 586     break;
 587   }
 588
 589   // Call the autogenerated instruction printer routines.
 590   printInstruction(MI);
 591 }
 592
 593 // Include the auto-generated portion of the assembly writer.
 594 #include "X86GenAsmWriter.inc"
 595