llvm.org GIT mirror llvm / release_35@215010 lib / Target / PowerPC / PPCAsmPrinter.cpp
release_35@215010

Tree @release_35@215010 (Download .tar.gz)

PPCAsmPrinter.cpp @release_35@215010raw · history · blame

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
//===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly ------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to PowerPC assembly language. This printer is
// the output mechanism used by `llc'.
//
// Documentation at http://developer.apple.com/documentation/DeveloperTools/
// Reference/Assembler/ASMIntroduction/chapter_1_section_1.html
//
//===----------------------------------------------------------------------===//

#include "PPC.h"
#include "InstPrinter/PPCInstPrinter.h"
#include "PPCMachineFunctionInfo.h"
#include "MCTargetDesc/PPCMCExpr.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "PPCTargetStreamer.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;

#define DEBUG_TYPE "asmprinter"

namespace {
  class PPCAsmPrinter : public AsmPrinter {
  protected:
    MapVector<MCSymbol*, MCSymbol*> TOC;
    const PPCSubtarget &Subtarget;
    uint64_t TOCLabelID;
  public:
    explicit PPCAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
      : AsmPrinter(TM, Streamer),
        Subtarget(TM.getSubtarget<PPCSubtarget>()), TOCLabelID(0) {}

    const char *getPassName() const override {
      return "PowerPC Assembly Printer";
    }

    MCSymbol *lookUpOrCreateTOCEntry(MCSymbol *Sym);

    void EmitInstruction(const MachineInstr *MI) override;

    void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);

    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                         unsigned AsmVariant, const char *ExtraCode,
                         raw_ostream &O) override;
    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                               unsigned AsmVariant, const char *ExtraCode,
                               raw_ostream &O) override;
  };

  /// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
  class PPCLinuxAsmPrinter : public PPCAsmPrinter {
  public:
    explicit PPCLinuxAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
      : PPCAsmPrinter(TM, Streamer) {}

    const char *getPassName() const override {
      return "Linux PPC Assembly Printer";
    }

    bool doFinalization(Module &M) override;
    void EmitStartOfAsmFile(Module &M) override;

    void EmitFunctionEntryLabel() override;

    void EmitFunctionBodyStart() override;
    void EmitFunctionBodyEnd() override;
  };

  /// PPCDarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac
  /// OS X
  class PPCDarwinAsmPrinter : public PPCAsmPrinter {
  public:
    explicit PPCDarwinAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
      : PPCAsmPrinter(TM, Streamer) {}

    const char *getPassName() const override {
      return "Darwin PPC Assembly Printer";
    }

    bool doFinalization(Module &M) override;
    void EmitStartOfAsmFile(Module &M) override;

    void EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs);
  };
} // end of anonymous namespace

/// stripRegisterPrefix - This method strips the character prefix from a
/// register name so that only the number is left.  Used by for linux asm.
static const char *stripRegisterPrefix(const char *RegName) {
  switch (RegName[0]) {
    case 'r':
    case 'f':
    case 'v':
      if (RegName[1] == 's')
        return RegName + 2;
      return RegName + 1;
    case 'c': if (RegName[1] == 'r') return RegName + 2;
  }
  
  return RegName;
}

void PPCAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
                                 raw_ostream &O) {
  const DataLayout *DL = TM.getDataLayout();
  const MachineOperand &MO = MI->getOperand(OpNo);
  
  switch (MO.getType()) {
  case MachineOperand::MO_Register: {
    const char *RegName = PPCInstPrinter::getRegisterName(MO.getReg());
    // Linux assembler (Others?) does not take register mnemonics.
    // FIXME - What about special registers used in mfspr/mtspr?
    if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
    O << RegName;
    return;
  }
  case MachineOperand::MO_Immediate:
    O << MO.getImm();
    return;

  case MachineOperand::MO_MachineBasicBlock:
    O << *MO.getMBB()->getSymbol();
    return;
  case MachineOperand::MO_ConstantPoolIndex:
    O << DL->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
      << '_' << MO.getIndex();
    return;
  case MachineOperand::MO_BlockAddress:
    O << *GetBlockAddressSymbol(MO.getBlockAddress());
    return;
  case MachineOperand::MO_GlobalAddress: {
    // Computing the address of a global symbol, not calling it.
    const GlobalValue *GV = MO.getGlobal();
    MCSymbol *SymToPrint;

    // External or weakly linked global variables need non-lazily-resolved stubs
    if (TM.getRelocationModel() != Reloc::Static &&
        (GV->isDeclaration() || GV->isWeakForLinker())) {
      if (!GV->hasHiddenVisibility()) {
        SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
        MachineModuleInfoImpl::StubValueTy &StubSym = 
          MMI->getObjFileInfo<MachineModuleInfoMachO>()
            .getGVStubEntry(SymToPrint);
        if (!StubSym.getPointer())
          StubSym = MachineModuleInfoImpl::
            StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
      } else if (GV->isDeclaration() || GV->hasCommonLinkage() ||
                 GV->hasAvailableExternallyLinkage()) {
        SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
        
        MachineModuleInfoImpl::StubValueTy &StubSym = 
          MMI->getObjFileInfo<MachineModuleInfoMachO>().
                    getHiddenGVStubEntry(SymToPrint);
        if (!StubSym.getPointer())
          StubSym = MachineModuleInfoImpl::
            StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
      } else {
        SymToPrint = getSymbol(GV);
      }
    } else {
      SymToPrint = getSymbol(GV);
    }
    
    O << *SymToPrint;

    printOffset(MO.getOffset(), O);
    return;
  }

  default:
    O << "<unknown operand type: " << (unsigned)MO.getType() << ">";
    return;
  }
}

/// PrintAsmOperand - Print out an operand for an inline asm expression.
///
bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                                    unsigned AsmVariant,
                                    const char *ExtraCode, raw_ostream &O) {
  // Does this asm operand have a single letter operand modifier?
  if (ExtraCode && ExtraCode[0]) {
    if (ExtraCode[1] != 0) return true; // Unknown modifier.

    switch (ExtraCode[0]) {
    default:
      // See if this is a generic print operand
      return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
    case 'c': // Don't print "$" before a global var name or constant.
      break; // PPC never has a prefix.
    case 'L': // Write second word of DImode reference.
      // Verify that this operand has two consecutive registers.
      if (!MI->getOperand(OpNo).isReg() ||
          OpNo+1 == MI->getNumOperands() ||
          !MI->getOperand(OpNo+1).isReg())
        return true;
      ++OpNo;   // Return the high-part.
      break;
    case 'I':
      // Write 'i' if an integer constant, otherwise nothing.  Used to print
      // addi vs add, etc.
      if (MI->getOperand(OpNo).isImm())
        O << "i";
      return false;
    }
  }

  printOperand(MI, OpNo, O);
  return false;
}

// At the moment, all inline asm memory operands are a single register.
// In any case, the output of this routine should always be just one
// assembler operand.

bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                                          unsigned AsmVariant,
                                          const char *ExtraCode,
                                          raw_ostream &O) {
  if (ExtraCode && ExtraCode[0]) {
    if (ExtraCode[1] != 0) return true; // Unknown modifier.

    switch (ExtraCode[0]) {
    default: return true;  // Unknown modifier.
    case 'y': // A memory reference for an X-form instruction
      {
        const char *RegName = "r0";
        if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
        O << RegName << ", ";
        printOperand(MI, OpNo, O);
        return false;
      }
    }
  }

  assert(MI->getOperand(OpNo).isReg());
  O << "0(";
  printOperand(MI, OpNo, O);
  O << ")";
  return false;
}


/// lookUpOrCreateTOCEntry -- Given a symbol, look up whether a TOC entry
/// exists for it.  If not, create one.  Then return a symbol that references
/// the TOC entry.
MCSymbol *PPCAsmPrinter::lookUpOrCreateTOCEntry(MCSymbol *Sym) {
  const DataLayout *DL = TM.getDataLayout();
  MCSymbol *&TOCEntry = TOC[Sym];

  // To avoid name clash check if the name already exists.
  while (!TOCEntry) {
    if (OutContext.LookupSymbol(Twine(DL->getPrivateGlobalPrefix()) +
                                "C" + Twine(TOCLabelID++)) == nullptr) {
      TOCEntry = GetTempSymbol("C", TOCLabelID);
    }
  }

  return TOCEntry;
}


/// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
/// the current output stream.
///
void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
  MCInst TmpInst;
  bool isPPC64 = Subtarget.isPPC64();
  
  // Lower multi-instruction pseudo operations.
  switch (MI->getOpcode()) {
  default: break;
  case TargetOpcode::DBG_VALUE:
    llvm_unreachable("Should be handled target independently");
  case PPC::MovePCtoLR:
  case PPC::MovePCtoLR8: {
    // Transform %LR = MovePCtoLR
    // Into this, where the label is the PIC base: 
    //     bl L1$pb
    // L1$pb:
    MCSymbol *PICBase = MF->getPICBaseSymbol();
    
    // Emit the 'bl'.
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL)
      // FIXME: We would like an efficient form for this, so we don't have to do
      // a lot of extra uniquing.
      .addExpr(MCSymbolRefExpr::Create(PICBase, OutContext)));
    
    // Emit the label.
    OutStreamer.EmitLabel(PICBase);
    return;
  }
  case PPC::GetGBRO: {
    // Get the offset from the GOT Base Register to the GOT
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
    MCSymbol *PICOffset = MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol();
    TmpInst.setOpcode(PPC::LWZ);
    const MCExpr *Exp =
      MCSymbolRefExpr::Create(PICOffset, MCSymbolRefExpr::VK_None, OutContext);
    const MCExpr *PB =
      MCSymbolRefExpr::Create(MF->getPICBaseSymbol(),
                              MCSymbolRefExpr::VK_None,
                              OutContext);
    const MCOperand MO = TmpInst.getOperand(1);
    TmpInst.getOperand(1) = MCOperand::CreateExpr(MCBinaryExpr::CreateSub(Exp,
                                                                          PB,
                                                                          OutContext));
    TmpInst.addOperand(MO);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::UpdateGBR: {
    // Update the GOT Base Register to point to the GOT.  It may be possible to
    // merge this with the PPC::GetGBRO, doing it all in one step.
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
    TmpInst.setOpcode(PPC::ADD4);
    TmpInst.addOperand(TmpInst.getOperand(0));
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::LWZtoc: {
    // Transform %X3 = LWZtoc <ga:@min1>, %X2
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to LWZ, and the global address operand to be a
    // reference to the GOT entry we will synthesize later.
    TmpInst.setOpcode(PPC::LWZ);
    const MachineOperand &MO = MI->getOperand(1);

    // Map symbol -> label of TOC entry
    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI());
    MCSymbol *MOSymbol = nullptr;
    if (MO.isGlobal())
      MOSymbol = getSymbol(MO.getGlobal());
    else if (MO.isCPI())
      MOSymbol = GetCPISymbol(MO.getIndex());
    else if (MO.isJTI())
      MOSymbol = GetJTISymbol(MO.getIndex());

    MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);

    const MCExpr *Exp =
      MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_None,
                              OutContext);
    const MCExpr *PB =
      MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".L.TOC.")),
                                                           OutContext);
    Exp = MCBinaryExpr::CreateSub(Exp, PB, OutContext);
    TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::LDtocJTI:
  case PPC::LDtocCPT:
  case PPC::LDtoc: {
    // Transform %X3 = LDtoc <ga:@min1>, %X2
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to LD, and the global address operand to be a
    // reference to the TOC entry we will synthesize later.
    TmpInst.setOpcode(PPC::LD);
    const MachineOperand &MO = MI->getOperand(1);

    // Map symbol -> label of TOC entry
    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI());
    MCSymbol *MOSymbol = nullptr;
    if (MO.isGlobal())
      MOSymbol = getSymbol(MO.getGlobal());
    else if (MO.isCPI())
      MOSymbol = GetCPISymbol(MO.getIndex());
    else if (MO.isJTI())
      MOSymbol = GetJTISymbol(MO.getIndex());

    MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);

    const MCExpr *Exp =
      MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_PPC_TOC,
                              OutContext);
    TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
      
  case PPC::ADDIStocHA: {
    // Transform %Xd = ADDIStocHA %X2, <ga:@sym>
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to ADDIS8.  If the global address is external, has
    // common linkage, is a non-local function address, or is a jump table
    // address, then generate a TOC entry and reference that.  Otherwise
    // reference the symbol directly.
    TmpInst.setOpcode(PPC::ADDIS8);
    const MachineOperand &MO = MI->getOperand(2);
    assert((MO.isGlobal() || MO.isCPI() || MO.isJTI()) &&
           "Invalid operand for ADDIStocHA!");
    MCSymbol *MOSymbol = nullptr;
    bool IsExternal = false;
    bool IsNonLocalFunction = false;
    bool IsCommon = false;
    bool IsAvailExt = false;

    if (MO.isGlobal()) {
      const GlobalValue *GV = MO.getGlobal();
      MOSymbol = getSymbol(GV);
      IsExternal = GV->isDeclaration();
      IsCommon = GV->hasCommonLinkage();
      IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
        (GV->isDeclaration() || GV->isWeakForLinker());
      IsAvailExt = GV->hasAvailableExternallyLinkage();
    } else if (MO.isCPI())
      MOSymbol = GetCPISymbol(MO.getIndex());
    else if (MO.isJTI())
      MOSymbol = GetJTISymbol(MO.getIndex());

    if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
        MO.isJTI() || TM.getCodeModel() == CodeModel::Large)
      MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);

    const MCExpr *Exp =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_HA,
                              OutContext);
    TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::LDtocL: {
    // Transform %Xd = LDtocL <ga:@sym>, %Xs
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to LD.  If the global address is external, has
    // common linkage, or is a jump table address, then reference the
    // associated TOC entry.  Otherwise reference the symbol directly.
    TmpInst.setOpcode(PPC::LD);
    const MachineOperand &MO = MI->getOperand(1);
    assert((MO.isGlobal() || MO.isJTI() || MO.isCPI()) &&
           "Invalid operand for LDtocL!");
    MCSymbol *MOSymbol = nullptr;

    if (MO.isJTI())
      MOSymbol = lookUpOrCreateTOCEntry(GetJTISymbol(MO.getIndex()));
    else if (MO.isCPI()) {
      MOSymbol = GetCPISymbol(MO.getIndex());
      if (TM.getCodeModel() == CodeModel::Large)
        MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
    }
    else if (MO.isGlobal()) {
      const GlobalValue *GValue = MO.getGlobal();
      MOSymbol = getSymbol(GValue);
      if (GValue->getType()->getElementType()->isFunctionTy() ||
          GValue->isDeclaration() || GValue->hasCommonLinkage() ||
          GValue->hasAvailableExternallyLinkage() ||
          TM.getCodeModel() == CodeModel::Large)
        MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
    }

    const MCExpr *Exp =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
                              OutContext);
    TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::ADDItocL: {
    // Transform %Xd = ADDItocL %Xs, <ga:@sym>
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to ADDI8.  If the global address is external, then
    // generate a TOC entry and reference that.  Otherwise reference the
    // symbol directly.
    TmpInst.setOpcode(PPC::ADDI8);
    const MachineOperand &MO = MI->getOperand(2);
    assert((MO.isGlobal() || MO.isCPI()) && "Invalid operand for ADDItocL");
    MCSymbol *MOSymbol = nullptr;
    bool IsExternal = false;
    bool IsNonLocalFunction = false;

    if (MO.isGlobal()) {
      const GlobalValue *GV = MO.getGlobal();
      MOSymbol = getSymbol(GV);
      IsExternal = GV->isDeclaration();
      IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
        (GV->isDeclaration() || GV->isWeakForLinker());
    } else if (MO.isCPI())
      MOSymbol = GetCPISymbol(MO.getIndex());

    if (IsNonLocalFunction || IsExternal ||
        TM.getCodeModel() == CodeModel::Large)
      MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);

    const MCExpr *Exp =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
                              OutContext);
    TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }
  case PPC::ADDISgotTprelHA: {
    // Transform: %Xd = ADDISgotTprelHA %X2, <ga:@sym>
    // Into:      %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymGotTprel =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(PPC::X2)
                                .addExpr(SymGotTprel));
    return;
  }
  case PPC::LDgotTprelL:
  case PPC::LDgotTprelL32: {
    // Transform %Xd = LDgotTprelL <ga:@sym>, %Xs
    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());

    // Change the opcode to LD.
    TmpInst.setOpcode(isPPC64 ? PPC::LD : PPC::LWZ);
    const MachineOperand &MO = MI->getOperand(1);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *Exp =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO,
                              OutContext);
    TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
    EmitToStreamer(OutStreamer, TmpInst);
    return;
  }

  case PPC::PPC32GOT: {
    MCSymbol *GOTSymbol = OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
    const MCExpr *SymGotTlsL =
      MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_LO,
                              OutContext);
    const MCExpr *SymGotTlsHA =                               
      MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_HA,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI)
                                .addReg(MI->getOperand(0).getReg())
                                .addExpr(SymGotTlsL));
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(MI->getOperand(0).getReg())
                                .addExpr(SymGotTlsHA));
    return;
  }
  case PPC::ADDIStlsgdHA: {
    // Transform: %Xd = ADDIStlsgdHA %X2, <ga:@sym>
    // Into:      %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymGotTlsGD =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(PPC::X2)
                                .addExpr(SymGotTlsGD));
    return;
  }
  case PPC::ADDItlsgdL: {
    // Transform: %Xd = ADDItlsgdL %Xs, <ga:@sym>
    // Into:      %Xd = ADDI8 %Xs, sym@got@tlsgd@l
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymGotTlsGD =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(MI->getOperand(1).getReg())
                                .addExpr(SymGotTlsGD));
    return;
  }
  case PPC::GETtlsADDR: {
    // Transform: %X3 = GETtlsADDR %X3, <ga:@sym>
    // Into:      BL8_NOP_TLS __tls_get_addr(sym@tlsgd)
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");

    StringRef Name = "__tls_get_addr";
    MCSymbol *TlsGetAddr = OutContext.GetOrCreateSymbol(Name);
    const MCSymbolRefExpr *TlsRef = 
      MCSymbolRefExpr::Create(TlsGetAddr, MCSymbolRefExpr::VK_None, OutContext);
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymVar =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TLSGD,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL8_NOP_TLS)
                                .addExpr(TlsRef)
                                .addExpr(SymVar));
    return;
  }
  case PPC::ADDIStlsldHA: {
    // Transform: %Xd = ADDIStlsldHA %X2, <ga:@sym>
    // Into:      %Xd = ADDIS8 %X2, sym@got@tlsld@ha
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymGotTlsLD =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(PPC::X2)
                                .addExpr(SymGotTlsLD));
    return;
  }
  case PPC::ADDItlsldL: {
    // Transform: %Xd = ADDItlsldL %Xs, <ga:@sym>
    // Into:      %Xd = ADDI8 %Xs, sym@got@tlsld@l
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymGotTlsLD =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(MI->getOperand(1).getReg())
                                .addExpr(SymGotTlsLD));
    return;
  }
  case PPC::GETtlsldADDR: {
    // Transform: %X3 = GETtlsldADDR %X3, <ga:@sym>
    // Into:      BL8_NOP_TLS __tls_get_addr(sym@tlsld)
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");

    StringRef Name = "__tls_get_addr";
    MCSymbol *TlsGetAddr = OutContext.GetOrCreateSymbol(Name);
    const MCSymbolRefExpr *TlsRef = 
      MCSymbolRefExpr::Create(TlsGetAddr, MCSymbolRefExpr::VK_None, OutContext);
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymVar =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TLSLD,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL8_NOP_TLS)
                                .addExpr(TlsRef)
                                .addExpr(SymVar));
    return;
  }
  case PPC::ADDISdtprelHA: {
    // Transform: %Xd = ADDISdtprelHA %X3, <ga:@sym>
    // Into:      %Xd = ADDIS8 %X3, sym@dtprel@ha
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymDtprel =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_HA,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(PPC::X3)
                                .addExpr(SymDtprel));
    return;
  }
  case PPC::ADDIdtprelL: {
    // Transform: %Xd = ADDIdtprelL %Xs, <ga:@sym>
    // Into:      %Xd = ADDI8 %Xs, sym@dtprel@l
    assert(Subtarget.isPPC64() && "Not supported for 32-bit PowerPC");
    const MachineOperand &MO = MI->getOperand(2);
    const GlobalValue *GValue = MO.getGlobal();
    MCSymbol *MOSymbol = getSymbol(GValue);
    const MCExpr *SymDtprel =
      MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_LO,
                              OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI8)
                                .addReg(MI->getOperand(0).getReg())
                                .addReg(MI->getOperand(1).getReg())
                                .addExpr(SymDtprel));
    return;
  }
  case PPC::MFOCRF:
  case PPC::MFOCRF8:
    if (!Subtarget.hasMFOCRF()) {
      // Transform: %R3 = MFOCRF %CR7
      // Into:      %R3 = MFCR   ;; cr7
      unsigned NewOpcode =
        MI->getOpcode() == PPC::MFOCRF ? PPC::MFCR : PPC::MFCR8;
      OutStreamer.AddComment(PPCInstPrinter::
                             getRegisterName(MI->getOperand(1).getReg()));
      EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
                                  .addReg(MI->getOperand(0).getReg()));
      return;
    }
    break;
  case PPC::MTOCRF:
  case PPC::MTOCRF8:
    if (!Subtarget.hasMFOCRF()) {
      // Transform: %CR7 = MTOCRF %R3
      // Into:      MTCRF mask, %R3 ;; cr7
      unsigned NewOpcode =
        MI->getOpcode() == PPC::MTOCRF ? PPC::MTCRF : PPC::MTCRF8;
      unsigned Mask = 0x80 >> OutContext.getRegisterInfo()
                              ->getEncodingValue(MI->getOperand(0).getReg());
      OutStreamer.AddComment(PPCInstPrinter::
                             getRegisterName(MI->getOperand(0).getReg()));
      EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
                                  .addImm(Mask)
                                  .addReg(MI->getOperand(1).getReg()));
      return;
    }
    break;
  case PPC::LD:
  case PPC::STD:
  case PPC::LWA_32:
  case PPC::LWA: {
    // Verify alignment is legal, so we don't create relocations
    // that can't be supported.
    // FIXME:  This test is currently disabled for Darwin.  The test
    // suite shows a handful of test cases that fail this check for
    // Darwin.  Those need to be investigated before this sanity test
    // can be enabled for those subtargets.
    if (!Subtarget.isDarwin()) {
      unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
      const MachineOperand &MO = MI->getOperand(OpNum);
      if (MO.isGlobal() && MO.getGlobal()->getAlignment() < 4)
        llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
    }
    // Now process the instruction normally.
    break;
  }
  }

  LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
  EmitToStreamer(OutStreamer, TmpInst);
}

void PPCLinuxAsmPrinter::EmitStartOfAsmFile(Module &M) {
  if (Subtarget.isELFv2ABI()) {
    PPCTargetStreamer *TS =
      static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());

    if (TS)
      TS->emitAbiVersion(2);
  }

  if (Subtarget.isPPC64() || TM.getRelocationModel() != Reloc::PIC_)
    return AsmPrinter::EmitStartOfAsmFile(M);

  // FIXME: The use of .got2 assumes large GOT model (-fPIC), which is not
  // optimal for some cases.  We should consider supporting small model (-fpic)
  // as well in the future.
  assert(TM.getCodeModel() != CodeModel::Small &&
         "Small code model PIC is currently unsupported.");
  OutStreamer.SwitchSection(OutContext.getELFSection(".got2",
         ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
         SectionKind::getReadOnly()));

  MCSymbol *TOCSym = OutContext.GetOrCreateSymbol(Twine(".L.TOC."));
  MCSymbol *CurrentPos = OutContext.CreateTempSymbol();

  OutStreamer.EmitLabel(CurrentPos);

  // The GOT pointer points to the middle of the GOT, in order to reference the
  // entire 64kB range.  0x8000 is the midpoint.
  const MCExpr *tocExpr =
    MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(CurrentPos, OutContext),
                            MCConstantExpr::Create(0x8000, OutContext),
                            OutContext);

  OutStreamer.EmitAssignment(TOCSym, tocExpr);

  OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
}

void PPCLinuxAsmPrinter::EmitFunctionEntryLabel() {
  // linux/ppc32 - Normal entry label.
  if (!Subtarget.isPPC64() && TM.getRelocationModel() != Reloc::PIC_)
    return AsmPrinter::EmitFunctionEntryLabel();

  if (!Subtarget.isPPC64()) {
    const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
  	if (PPCFI->usesPICBase()) {
      MCSymbol *RelocSymbol = PPCFI->getPICOffsetSymbol();
      MCSymbol *PICBase = MF->getPICBaseSymbol();
      OutStreamer.EmitLabel(RelocSymbol);

      const MCExpr *OffsExpr =
        MCBinaryExpr::CreateSub(
          MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".L.TOC.")),
                                                               OutContext),
                                  MCSymbolRefExpr::Create(PICBase, OutContext),
          OutContext);
      OutStreamer.EmitValue(OffsExpr, 4);
      OutStreamer.EmitLabel(CurrentFnSym);
      return;
    } else
      return AsmPrinter::EmitFunctionEntryLabel();
  }

  // ELFv2 ABI - Normal entry label.
  if (Subtarget.isELFv2ABI())
    return AsmPrinter::EmitFunctionEntryLabel();

  // Emit an official procedure descriptor.
  MCSectionSubPair Current = OutStreamer.getCurrentSection();
  const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".opd",
      ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
      SectionKind::getReadOnly());
  OutStreamer.SwitchSection(Section);
  OutStreamer.EmitLabel(CurrentFnSym);
  OutStreamer.EmitValueToAlignment(8);
  MCSymbol *Symbol1 = 
    OutContext.GetOrCreateSymbol(".L." + Twine(CurrentFnSym->getName()));
  // Generates a R_PPC64_ADDR64 (from FK_DATA_8) relocation for the function
  // entry point.
  OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol1, OutContext),
			8 /*size*/);
  MCSymbol *Symbol2 = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
  // Generates a R_PPC64_TOC relocation for TOC base insertion.
  OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol2,
                        MCSymbolRefExpr::VK_PPC_TOCBASE, OutContext),
                        8/*size*/);
  // Emit a null environment pointer.
  OutStreamer.EmitIntValue(0, 8 /* size */);
  OutStreamer.SwitchSection(Current.first, Current.second);

  MCSymbol *RealFnSym = OutContext.GetOrCreateSymbol(
                          ".L." + Twine(CurrentFnSym->getName()));
  OutStreamer.EmitLabel(RealFnSym);
  CurrentFnSymForSize = RealFnSym;
}


bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
  const DataLayout *TD = TM.getDataLayout();

  bool isPPC64 = TD->getPointerSizeInBits() == 64;

  PPCTargetStreamer &TS =
      static_cast<PPCTargetStreamer &>(*OutStreamer.getTargetStreamer());

  if (!TOC.empty()) {
    const MCSectionELF *Section;
    
    if (isPPC64)
      Section = OutStreamer.getContext().getELFSection(".toc",
        ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
        SectionKind::getReadOnly());
	else
      Section = OutStreamer.getContext().getELFSection(".got2",
        ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
        SectionKind::getReadOnly());
    OutStreamer.SwitchSection(Section);

    for (MapVector<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
         E = TOC.end(); I != E; ++I) {
      OutStreamer.EmitLabel(I->second);
      MCSymbol *S = OutContext.GetOrCreateSymbol(I->first->getName());
      if (isPPC64)
        TS.emitTCEntry(*S);
      else
        OutStreamer.EmitSymbolValue(S, 4);
    }
  }

  MachineModuleInfoELF &MMIELF =
    MMI->getObjFileInfo<MachineModuleInfoELF>();

  MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
  if (!Stubs.empty()) {
    OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
    for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
      // L_foo$stub:
      OutStreamer.EmitLabel(Stubs[i].first);
      //   .long _foo
      OutStreamer.EmitValue(MCSymbolRefExpr::Create(Stubs[i].second.getPointer(),
                                                    OutContext),
                            isPPC64 ? 8 : 4/*size*/);
    }

    Stubs.clear();
    OutStreamer.AddBlankLine();
  }

  return AsmPrinter::doFinalization(M);
}

/// EmitFunctionBodyStart - Emit a global entry point prefix for ELFv2.
void PPCLinuxAsmPrinter::EmitFunctionBodyStart() {
  // In the ELFv2 ABI, in functions that use the TOC register, we need to
  // provide two entry points.  The ABI guarantees that when calling the
  // local entry point, r2 is set up by the caller to contain the TOC base
  // for this function, and when calling the global entry point, r12 is set
  // up by the caller to hold the address of the global entry point.  We
  // thus emit a prefix sequence along the following lines:
  //
  // func:
  //         # global entry point
  //         addis r2,r12,(.TOC.-func)@ha
  //         addi  r2,r2,(.TOC.-func)@l
  //         .localentry func, .-func
  //         # local entry point, followed by function body
  //
  // This ensures we have r2 set up correctly while executing the function
  // body, no matter which entry point is called.
  if (Subtarget.isELFv2ABI()
      // Only do all that if the function uses r2 in the first place.
      && !MF->getRegInfo().use_empty(PPC::X2)) {

    MCSymbol *GlobalEntryLabel = OutContext.CreateTempSymbol();
    OutStreamer.EmitLabel(GlobalEntryLabel);
    const MCSymbolRefExpr *GlobalEntryLabelExp =
      MCSymbolRefExpr::Create(GlobalEntryLabel, OutContext);

    MCSymbol *TOCSymbol = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
    const MCExpr *TOCDeltaExpr =
      MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(TOCSymbol, OutContext),
                              GlobalEntryLabelExp, OutContext);

    const MCExpr *TOCDeltaHi =
      PPCMCExpr::CreateHa(TOCDeltaExpr, false, OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
                                .addReg(PPC::X2)
                                .addReg(PPC::X12)
                                .addExpr(TOCDeltaHi));

    const MCExpr *TOCDeltaLo =
      PPCMCExpr::CreateLo(TOCDeltaExpr, false, OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI)
                                .addReg(PPC::X2)
                                .addReg(PPC::X2)
                                .addExpr(TOCDeltaLo));

    MCSymbol *LocalEntryLabel = OutContext.CreateTempSymbol();
    OutStreamer.EmitLabel(LocalEntryLabel);
    const MCSymbolRefExpr *LocalEntryLabelExp =
       MCSymbolRefExpr::Create(LocalEntryLabel, OutContext);
    const MCExpr *LocalOffsetExp =
      MCBinaryExpr::CreateSub(LocalEntryLabelExp,
                              GlobalEntryLabelExp, OutContext);

    PPCTargetStreamer *TS =
      static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());

    if (TS)
      TS->emitLocalEntry(CurrentFnSym, LocalOffsetExp);
  }
}

/// EmitFunctionBodyEnd - Print the traceback table before the .size
/// directive.
///
void PPCLinuxAsmPrinter::EmitFunctionBodyEnd() {
  // Only the 64-bit target requires a traceback table.  For now,
  // we only emit the word of zeroes that GDB requires to find
  // the end of the function, and zeroes for the eight-byte
  // mandatory fields.
  // FIXME: We should fill in the eight-byte mandatory fields as described in
  // the PPC64 ELF ABI (this is a low-priority item because GDB does not
  // currently make use of these fields).
  if (Subtarget.isPPC64()) {
    OutStreamer.EmitIntValue(0, 4/*size*/);
    OutStreamer.EmitIntValue(0, 8/*size*/);
  }
}

void PPCDarwinAsmPrinter::EmitStartOfAsmFile(Module &M) {
  static const char *const CPUDirectives[] = {
    "",
    "ppc",
    "ppc440",
    "ppc601",
    "ppc602",
    "ppc603",
    "ppc7400",
    "ppc750",
    "ppc970",
    "ppcA2",
    "ppce500mc",
    "ppce5500",
    "power3",
    "power4",
    "power5",
    "power5x",
    "power6",
    "power6x",
    "power7",
    "ppc64",
    "ppc64le"
  };

  unsigned Directive = Subtarget.getDarwinDirective();
  if (Subtarget.hasMFOCRF() && Directive < PPC::DIR_970)
    Directive = PPC::DIR_970;
  if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
    Directive = PPC::DIR_7400;
  if (Subtarget.isPPC64() && Directive < PPC::DIR_64)
    Directive = PPC::DIR_64;
  assert(Directive <= PPC::DIR_64 && "Directive out of range.");

  assert(Directive < array_lengthof(CPUDirectives) &&
         "CPUDirectives[] might not be up-to-date!");
  PPCTargetStreamer &TStreamer =
      *static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
  TStreamer.emitMachine(CPUDirectives[Directive]);

  // Prime text sections so they are adjacent.  This reduces the likelihood a
  // large data or debug section causes a branch to exceed 16M limit.
  const TargetLoweringObjectFileMachO &TLOFMacho = 
    static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
  OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
  if (TM.getRelocationModel() == Reloc::PIC_) {
    OutStreamer.SwitchSection(
           OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
                                      MachO::S_SYMBOL_STUBS |
                                      MachO::S_ATTR_PURE_INSTRUCTIONS,
                                      32, SectionKind::getText()));
  } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
    OutStreamer.SwitchSection(
           OutContext.getMachOSection("__TEXT","__symbol_stub1",
                                      MachO::S_SYMBOL_STUBS |
                                      MachO::S_ATTR_PURE_INSTRUCTIONS,
                                      16, SectionKind::getText()));
  }
  OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
}

static MCSymbol *GetLazyPtr(MCSymbol *Sym, MCContext &Ctx) {
  // Remove $stub suffix, add $lazy_ptr.
  StringRef NoStub = Sym->getName().substr(0, Sym->getName().size()-5);
  return Ctx.GetOrCreateSymbol(NoStub + "$lazy_ptr");
}

static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
  // Add $tmp suffix to $stub, yielding $stub$tmp.
  return Ctx.GetOrCreateSymbol(Sym->getName() + "$tmp");
}

void PPCDarwinAsmPrinter::
EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
  bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
  bool isDarwin = Subtarget.isDarwin();
  
  const TargetLoweringObjectFileMachO &TLOFMacho = 
    static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());

  // .lazy_symbol_pointer
  const MCSection *LSPSection = TLOFMacho.getLazySymbolPointerSection();
  
  // Output stubs for dynamically-linked functions
  if (TM.getRelocationModel() == Reloc::PIC_) {
    const MCSection *StubSection = 
    OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
                               MachO::S_SYMBOL_STUBS |
                               MachO::S_ATTR_PURE_INSTRUCTIONS,
                               32, SectionKind::getText());
    for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
      OutStreamer.SwitchSection(StubSection);
      EmitAlignment(4);
      
      MCSymbol *Stub = Stubs[i].first;
      MCSymbol *RawSym = Stubs[i].second.getPointer();
      MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
      MCSymbol *AnonSymbol = GetAnonSym(Stub, OutContext);
                                           
      OutStreamer.EmitLabel(Stub);
      OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);

      const MCExpr *Anon = MCSymbolRefExpr::Create(AnonSymbol, OutContext);
      const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);
      const MCExpr *Sub =
        MCBinaryExpr::CreateSub(LazyPtrExpr, Anon, OutContext);

      // mflr r0
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R0));
      // bcl 20, 31, AnonSymbol
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCLalways).addExpr(Anon));
      OutStreamer.EmitLabel(AnonSymbol);
      // mflr r11
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R11));
      // addis r11, r11, ha16(LazyPtr - AnonSymbol)
      const MCExpr *SubHa16 = PPCMCExpr::CreateHa(Sub, isDarwin, OutContext);
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
        .addReg(PPC::R11)
        .addReg(PPC::R11)
        .addExpr(SubHa16));
      // mtlr r0
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTLR).addReg(PPC::R0));

      // ldu r12, lo16(LazyPtr - AnonSymbol)(r11)
      // lwzu r12, lo16(LazyPtr - AnonSymbol)(r11)
      const MCExpr *SubLo16 = PPCMCExpr::CreateLo(Sub, isDarwin, OutContext);
      EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
        .addReg(PPC::R12)
        .addExpr(SubLo16).addExpr(SubLo16)
        .addReg(PPC::R11));
      // mtctr r12
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
      // bctr
      EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));

      OutStreamer.SwitchSection(LSPSection);
      OutStreamer.EmitLabel(LazyPtr);
      OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);

      MCSymbol *DyldStubBindingHelper =
        OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
      if (isPPC64) {
        // .quad dyld_stub_binding_helper
        OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
      } else {
        // .long dyld_stub_binding_helper
        OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
      }
    }
    OutStreamer.AddBlankLine();
    return;
  }
  
  const MCSection *StubSection =
    OutContext.getMachOSection("__TEXT","__symbol_stub1",
                               MachO::S_SYMBOL_STUBS |
                               MachO::S_ATTR_PURE_INSTRUCTIONS,
                               16, SectionKind::getText());
  for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
    MCSymbol *Stub = Stubs[i].first;
    MCSymbol *RawSym = Stubs[i].second.getPointer();
    MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
    const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);

    OutStreamer.SwitchSection(StubSection);
    EmitAlignment(4);
    OutStreamer.EmitLabel(Stub);
    OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);

    // lis r11, ha16(LazyPtr)
    const MCExpr *LazyPtrHa16 =
      PPCMCExpr::CreateHa(LazyPtrExpr, isDarwin, OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LIS)
      .addReg(PPC::R11)
      .addExpr(LazyPtrHa16));

    // ldu r12, lo16(LazyPtr)(r11)
    // lwzu r12, lo16(LazyPtr)(r11)
    const MCExpr *LazyPtrLo16 =
      PPCMCExpr::CreateLo(LazyPtrExpr, isDarwin, OutContext);
    EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
      .addReg(PPC::R12)
      .addExpr(LazyPtrLo16).addExpr(LazyPtrLo16)
      .addReg(PPC::R11));

    // mtctr r12
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
    // bctr
    EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));

    OutStreamer.SwitchSection(LSPSection);
    OutStreamer.EmitLabel(LazyPtr);
    OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);

    MCSymbol *DyldStubBindingHelper =
      OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
    if (isPPC64) {
      // .quad dyld_stub_binding_helper
      OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
    } else {
      // .long dyld_stub_binding_helper
      OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
    }
  }
  
  OutStreamer.AddBlankLine();
}


bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
  bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;

  // Darwin/PPC always uses mach-o.
  const TargetLoweringObjectFileMachO &TLOFMacho = 
    static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
  MachineModuleInfoMachO &MMIMacho =
    MMI->getObjFileInfo<MachineModuleInfoMachO>();
  
  MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetFnStubList();
  if (!Stubs.empty())
    EmitFunctionStubs(Stubs);

  if (MAI->doesSupportExceptionHandling() && MMI) {
    // Add the (possibly multiple) personalities to the set of global values.
    // Only referenced functions get into the Personalities list.
    const std::vector<const Function*> &Personalities = MMI->getPersonalities();
    for (std::vector<const Function*>::const_iterator I = Personalities.begin(),
         E = Personalities.end(); I != E; ++I) {
      if (*I) {
        MCSymbol *NLPSym = getSymbolWithGlobalValueBase(*I, "$non_lazy_ptr");
        MachineModuleInfoImpl::StubValueTy &StubSym =
          MMIMacho.getGVStubEntry(NLPSym);
        StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(*I), true);
      }
    }
  }

  // Output stubs for dynamically-linked functions.
  Stubs = MMIMacho.GetGVStubList();
  
  // Output macho stubs for external and common global variables.
  if (!Stubs.empty()) {
    // Switch with ".non_lazy_symbol_pointer" directive.
    OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
    EmitAlignment(isPPC64 ? 3 : 2);
    
    for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
      // L_foo$stub:
      OutStreamer.EmitLabel(Stubs[i].first);
      //   .indirect_symbol _foo
      MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
      OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);

      if (MCSym.getInt())
        // External to current translation unit.
        OutStreamer.EmitIntValue(0, isPPC64 ? 8 : 4/*size*/);
      else
        // Internal to current translation unit.
        //
        // When we place the LSDA into the TEXT section, the type info pointers
        // need to be indirect and pc-rel. We accomplish this by using NLPs.
        // However, sometimes the types are local to the file. So we need to
        // fill in the value for the NLP in those cases.
        OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
                                                      OutContext),
                              isPPC64 ? 8 : 4/*size*/);
    }

    Stubs.clear();
    OutStreamer.AddBlankLine();
  }

  Stubs = MMIMacho.GetHiddenGVStubList();
  if (!Stubs.empty()) {
    OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
    EmitAlignment(isPPC64 ? 3 : 2);
    
    for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
      // L_foo$stub:
      OutStreamer.EmitLabel(Stubs[i].first);
      //   .long _foo
      OutStreamer.EmitValue(MCSymbolRefExpr::
                            Create(Stubs[i].second.getPointer(),
                                   OutContext),
                            isPPC64 ? 8 : 4/*size*/);
    }

    Stubs.clear();
    OutStreamer.AddBlankLine();
  }

  // Funny Darwin hack: This flag tells the linker that no global symbols
  // contain code that falls through to other global symbols (e.g. the obvious
  // implementation of multiple entry points).  If this doesn't occur, the
  // linker can safely perform dead code stripping.  Since LLVM never generates
  // code that does this, it is always safe to set.
  OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);

  return AsmPrinter::doFinalization(M);
}

/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
/// for a MachineFunction to the given output stream, in a format that the
/// Darwin assembler can deal with.
///
static AsmPrinter *createPPCAsmPrinterPass(TargetMachine &tm,
                                           MCStreamer &Streamer) {
  const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();

  if (Subtarget->isDarwin())
    return new PPCDarwinAsmPrinter(tm, Streamer);
  return new PPCLinuxAsmPrinter(tm, Streamer);
}

// Force static initialization.
extern "C" void LLVMInitializePowerPCAsmPrinter() { 
  TargetRegistry::RegisterAsmPrinter(ThePPC32Target, createPPCAsmPrinterPass);
  TargetRegistry::RegisterAsmPrinter(ThePPC64Target, createPPCAsmPrinterPass);
  TargetRegistry::RegisterAsmPrinter(ThePPC64LETarget, createPPCAsmPrinterPass);
}