1 //===-- ARMAsmPrinter.cpp - Print machine code to an ARM .s file ----------===//
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 GAS-format ARM assembly language.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #define DEBUG_TYPE "asm-printer"
16 #include "ARM.h"
17 #include "ARMAsmPrinter.h"
18 #include "ARMBuildAttrs.h"
19 #include "ARMBaseRegisterInfo.h"
20 #include "ARMConstantPoolValue.h"
21 #include "ARMMachineFunctionInfo.h"
22 #include "ARMTargetMachine.h"
23 #include "ARMTargetObjectFile.h"
24 #include "InstPrinter/ARMInstPrinter.h"
25 #include "MCTargetDesc/ARMAddressingModes.h"
26 #include "MCTargetDesc/ARMMCExpr.h"
27 #include "llvm/Analysis/DebugInfo.h"
28 #include "llvm/Constants.h"
29 #include "llvm/Module.h"
30 #include "llvm/Type.h"
31 #include "llvm/Assembly/Writer.h"
32 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
33 #include "llvm/CodeGen/MachineFunctionPass.h"
34 #include "llvm/CodeGen/MachineJumpTableInfo.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCAssembler.h"
37 #include "llvm/MC/MCContext.h"
38 #include "llvm/MC/MCExpr.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/MC/MCSectionMachO.h"
41 #include "llvm/MC/MCObjectStreamer.h"
42 #include "llvm/MC/MCStreamer.h"
43 #include "llvm/MC/MCSymbol.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetData.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include "llvm/ADT/SmallPtrSet.h"
49 #include "llvm/ADT/SmallString.h"
50 #include "llvm/Support/CommandLine.h"
51 #include "llvm/Support/Debug.h"
52 #include "llvm/Support/ErrorHandling.h"
53 #include "llvm/Support/TargetRegistry.h"
54 #include "llvm/Support/raw_ostream.h"
55 #include <cctype>
56 using namespace llvm;
57 
58 namespace {
59 
60   // Per section and per symbol attributes are not supported.
61   // To implement them we would need the ability to delay this emission
62   // until the assembly file is fully parsed/generated as only then do we
63   // know the symbol and section numbers.
64   class AttributeEmitter {
65   public:
66     virtual void MaybeSwitchVendor(StringRef Vendor) = 0;
67     virtual void EmitAttribute(unsigned Attribute, unsigned Value) = 0;
68     virtual void EmitTextAttribute(unsigned Attribute, StringRef String) = 0;
69     virtual void Finish() = 0;
70     virtual ~AttributeEmitter() {}
71   };
72 
73   class AsmAttributeEmitter : public AttributeEmitter {
74     MCStreamer &Streamer;
75 
76   public:
77     AsmAttributeEmitter(MCStreamer &Streamer_) : Streamer(Streamer_) {}
78     void MaybeSwitchVendor(StringRef Vendor) { }
79 
80     void EmitAttribute(unsigned Attribute, unsigned Value) {
81       Streamer.EmitRawText("\t.eabi_attribute " +
82                            Twine(Attribute) + ", " + Twine(Value));
83     }
84 
85     void EmitTextAttribute(unsigned Attribute, StringRef String) {
86       switch (Attribute) {
87       case ARMBuildAttrs::CPU_name:
88         Streamer.EmitRawText(StringRef("\t.cpu ") + String.lower());
89         break;
90       /* GAS requires .fpu to be emitted regardless of EABI attribute */
91       case ARMBuildAttrs::Advanced_SIMD_arch:
92       case ARMBuildAttrs::VFP_arch:
93         Streamer.EmitRawText(StringRef("\t.fpu ") + String.lower());
94         break;
95       default: assert(0 && "Unsupported Text attribute in ASM Mode"); break;
96       }
97     }
98     void Finish() { }
99   };
100 
101   class ObjectAttributeEmitter : public AttributeEmitter {
102     // This structure holds all attributes, accounting for
103     // their string/numeric value, so we can later emmit them
104     // in declaration order, keeping all in the same vector
105     struct AttributeItemType {
106       enum {
107         HiddenAttribute = 0,
108         NumericAttribute,
109         TextAttribute
110       } Type;
111       unsigned Tag;
112       unsigned IntValue;
113       StringRef StringValue;
114     } AttributeItem;
115 
116     MCObjectStreamer &Streamer;
117     StringRef CurrentVendor;
118     SmallVector<AttributeItemType, 64> Contents;
119 
120     // Account for the ULEB/String size of each item,
121     // not just the number of items
122     size_t ContentsSize;
123     // FIXME: this should be in a more generic place, but
124     // getULEBSize() is in MCAsmInfo and will be moved to MCDwarf
125     size_t getULEBSize(int Value) {
126       size_t Size = 0;
127       do {
128         Value >>= 7;
129         Size += sizeof(int8_t); // Is this really necessary?
130       } while (Value);
131       return Size;
132     }
133 
134   public:
135     ObjectAttributeEmitter(MCObjectStreamer &Streamer_) :
136       Streamer(Streamer_), CurrentVendor(""), ContentsSize(0) { }
137 
138     void MaybeSwitchVendor(StringRef Vendor) {
139       assert(!Vendor.empty() && "Vendor cannot be empty.");
140 
141       if (CurrentVendor.empty())
142         CurrentVendor = Vendor;
143       else if (CurrentVendor == Vendor)
144         return;
145       else
146         Finish();
147 
148       CurrentVendor = Vendor;
149 
150       assert(Contents.size() == 0);
151     }
152 
153     void EmitAttribute(unsigned Attribute, unsigned Value) {
154       AttributeItemType attr = {
155         AttributeItemType::NumericAttribute,
156         Attribute,
157         Value,
158         StringRef("")
159       };
160       ContentsSize += getULEBSize(Attribute);
161       ContentsSize += getULEBSize(Value);
162       Contents.push_back(attr);
163     }
164 
165     void EmitTextAttribute(unsigned Attribute, StringRef String) {
166       AttributeItemType attr = {
167         AttributeItemType::TextAttribute,
168         Attribute,
169         0,
170         String
171       };
172       ContentsSize += getULEBSize(Attribute);
173       // String + \0
174       ContentsSize += String.size()+1;
175 
176       Contents.push_back(attr);
177     }
178 
179     void Finish() {
180       // Vendor size + Vendor name + '\0'
181       const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
182 
183       // Tag + Tag Size
184       const size_t TagHeaderSize = 1 + 4;
185 
186       Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
187       Streamer.EmitBytes(CurrentVendor, 0);
188       Streamer.EmitIntValue(0, 1); // '\0'
189 
190       Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
191       Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
192 
193       // Size should have been accounted for already, now
194       // emit each field as its type (ULEB or String)
195       for (unsigned int i=0; i<Contents.size(); ++i) {
196         AttributeItemType item = Contents[i];
197         Streamer.EmitULEB128IntValue(item.Tag, 0);
198         switch (item.Type) {
199         case AttributeItemType::NumericAttribute:
200           Streamer.EmitULEB128IntValue(item.IntValue, 0);
201           break;
202         case AttributeItemType::TextAttribute:
203           Streamer.EmitBytes(item.StringValue.upper(), 0);
204           Streamer.EmitIntValue(0, 1); // '\0'
205           break;
206         default:
207           assert(0 && "Invalid attribute type");
208         }
209       }
210 
211       Contents.clear();
212     }
213   };
214 
215 } // end of anonymous namespace
216 
217 MachineLocation ARMAsmPrinter::
218 getDebugValueLocation(const MachineInstr *MI) const {
219   MachineLocation Location;
220   assert(MI->getNumOperands() == 4 && "Invalid no. of machine operands!");
221   // Frame address.  Currently handles register +- offset only.
222   if (MI->getOperand(0).isReg() && MI->getOperand(1).isImm())
223     Location.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
224   else {
225     DEBUG(dbgs() << "DBG_VALUE instruction ignored! " << *MI << "\n");
226   }
227   return Location;
228 }
229 
230 /// EmitDwarfRegOp - Emit dwarf register operation.
231 void ARMAsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
232   const TargetRegisterInfo *RI = TM.getRegisterInfo();
233   if (RI->getDwarfRegNum(MLoc.getReg(), false) != -1)
234     AsmPrinter::EmitDwarfRegOp(MLoc);
235   else {
236     unsigned Reg = MLoc.getReg();
237     if (Reg >= ARM::S0 && Reg <= ARM::S31) {
238       assert(ARM::S0 + 31 == ARM::S31 && "Unexpected ARM S register numbering");
239       // S registers are described as bit-pieces of a register
240       // S[2x] = DW_OP_regx(256 + (x>>1)) DW_OP_bit_piece(32, 0)
241       // S[2x+1] = DW_OP_regx(256 + (x>>1)) DW_OP_bit_piece(32, 32)
242 
243       unsigned SReg = Reg - ARM::S0;
244       bool odd = SReg & 0x1;
245       unsigned Rx = 256 + (SReg >> 1);
246 
247       OutStreamer.AddComment("DW_OP_regx for S register");
248       EmitInt8(dwarf::DW_OP_regx);
249 
250       OutStreamer.AddComment(Twine(SReg));
251       EmitULEB128(Rx);
252 
253       if (odd) {
254         OutStreamer.AddComment("DW_OP_bit_piece 32 32");
255         EmitInt8(dwarf::DW_OP_bit_piece);
256         EmitULEB128(32);
257         EmitULEB128(32);
258       } else {
259         OutStreamer.AddComment("DW_OP_bit_piece 32 0");
260         EmitInt8(dwarf::DW_OP_bit_piece);
261         EmitULEB128(32);
262         EmitULEB128(0);
263       }
264     } else if (Reg >= ARM::Q0 && Reg <= ARM::Q15) {
265       assert(ARM::Q0 + 15 == ARM::Q15 && "Unexpected ARM Q register numbering");
266       // Q registers Q0-Q15 are described by composing two D registers together.
267       // Qx = DW_OP_regx(256+2x) DW_OP_piece(8) DW_OP_regx(256+2x+1)
268       // DW_OP_piece(8)
269 
270       unsigned QReg = Reg - ARM::Q0;
271       unsigned D1 = 256 + 2 * QReg;
272       unsigned D2 = D1 + 1;
273 
274       OutStreamer.AddComment("DW_OP_regx for Q register: D1");
275       EmitInt8(dwarf::DW_OP_regx);
276       EmitULEB128(D1);
277       OutStreamer.AddComment("DW_OP_piece 8");
278       EmitInt8(dwarf::DW_OP_piece);
279       EmitULEB128(8);
280 
281       OutStreamer.AddComment("DW_OP_regx for Q register: D2");
282       EmitInt8(dwarf::DW_OP_regx);
283       EmitULEB128(D2);
284       OutStreamer.AddComment("DW_OP_piece 8");
285       EmitInt8(dwarf::DW_OP_piece);
286       EmitULEB128(8);
287     }
288   }
289 }
290 
291 void ARMAsmPrinter::EmitFunctionEntryLabel() {
292   OutStreamer.ForceCodeRegion();
293 
294   if (AFI->isThumbFunction()) {
295     OutStreamer.EmitAssemblerFlag(MCAF_Code16);
296     OutStreamer.EmitThumbFunc(CurrentFnSym);
297   }
298 
299   OutStreamer.EmitLabel(CurrentFnSym);
300 }
301 
302 /// runOnMachineFunction - This uses the EmitInstruction()
303 /// method to print assembly for each instruction.
304 ///
305 bool ARMAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
306   AFI = MF.getInfo<ARMFunctionInfo>();
307   MCP = MF.getConstantPool();
308 
309   return AsmPrinter::runOnMachineFunction(MF);
310 }
311 
312 void ARMAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
313                                  raw_ostream &O, const char *Modifier) {
314   const MachineOperand &MO = MI->getOperand(OpNum);
315   unsigned TF = MO.getTargetFlags();
316 
317   switch (MO.getType()) {
318   default:
319     assert(0 && "<unknown operand type>");
320   case MachineOperand::MO_Register: {
321     unsigned Reg = MO.getReg();
322     assert(TargetRegisterInfo::isPhysicalRegister(Reg));
323     assert(!MO.getSubReg() && "Subregs should be eliminated!");
324     O << ARMInstPrinter::getRegisterName(Reg);
325     break;
326   }
327   case MachineOperand::MO_Immediate: {
328     int64_t Imm = MO.getImm();
329     O << '#';
330     if ((Modifier && strcmp(Modifier, "lo16") == 0) ||
331         (TF == ARMII::MO_LO16))
332       O << ":lower16:";
333     else if ((Modifier && strcmp(Modifier, "hi16") == 0) ||
334              (TF == ARMII::MO_HI16))
335       O << ":upper16:";
336     O << Imm;
337     break;
338   }
339   case MachineOperand::MO_MachineBasicBlock:
340     O << *MO.getMBB()->getSymbol();
341     return;
342   case MachineOperand::MO_GlobalAddress: {
343     const GlobalValue *GV = MO.getGlobal();
344     if ((Modifier && strcmp(Modifier, "lo16") == 0) ||
345         (TF & ARMII::MO_LO16))
346       O << ":lower16:";
347     else if ((Modifier && strcmp(Modifier, "hi16") == 0) ||
348              (TF & ARMII::MO_HI16))
349       O << ":upper16:";
350     O << *Mang->getSymbol(GV);
351 
352     printOffset(MO.getOffset(), O);
353     if (TF == ARMII::MO_PLT)
354       O << "(PLT)";
355     break;
356   }
357   case MachineOperand::MO_ExternalSymbol: {
358     O << *GetExternalSymbolSymbol(MO.getSymbolName());
359     if (TF == ARMII::MO_PLT)
360       O << "(PLT)";
361     break;
362   }
363   case MachineOperand::MO_ConstantPoolIndex:
364     O << *GetCPISymbol(MO.getIndex());
365     break;
366   case MachineOperand::MO_JumpTableIndex:
367     O << *GetJTISymbol(MO.getIndex());
368     break;
369   }
370 }
371 
372 //===--------------------------------------------------------------------===//
373 
374 MCSymbol *ARMAsmPrinter::
375 GetARMSetPICJumpTableLabel2(unsigned uid, unsigned uid2,
376                             const MachineBasicBlock *MBB) const {
377   SmallString<60> Name;
378   raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
379     << getFunctionNumber() << '_' << uid << '_' << uid2
380     << "_set_" << MBB->getNumber();
381   return OutContext.GetOrCreateSymbol(Name.str());
382 }
383 
384 MCSymbol *ARMAsmPrinter::
385 GetARMJTIPICJumpTableLabel2(unsigned uid, unsigned uid2) const {
386   SmallString<60> Name;
387   raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "JTI"
388     << getFunctionNumber() << '_' << uid << '_' << uid2;
389   return OutContext.GetOrCreateSymbol(Name.str());
390 }
391 
392 
393 MCSymbol *ARMAsmPrinter::GetARMSJLJEHLabel(void) const {
394   SmallString<60> Name;
395   raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "SJLJEH"
396     << getFunctionNumber();
397   return OutContext.GetOrCreateSymbol(Name.str());
398 }
399 
400 bool ARMAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
401                                     unsigned AsmVariant, const char *ExtraCode,
402                                     raw_ostream &O) {
403   // Does this asm operand have a single letter operand modifier?
404   if (ExtraCode && ExtraCode[0]) {
405     if (ExtraCode[1] != 0) return true; // Unknown modifier.
406 
407     switch (ExtraCode[0]) {
408     default: return true;  // Unknown modifier.
409     case 'a': // Print as a memory address.
410       if (MI->getOperand(OpNum).isReg()) {
411         O << "["
412           << ARMInstPrinter::getRegisterName(MI->getOperand(OpNum).getReg())
413           << "]";
414         return false;
415       }
416       // Fallthrough
417     case 'c': // Don't print "#" before an immediate operand.
418       if (!MI->getOperand(OpNum).isImm())
419         return true;
420       O << MI->getOperand(OpNum).getImm();
421       return false;
422     case 'P': // Print a VFP double precision register.
423     case 'q': // Print a NEON quad precision register.
424       printOperand(MI, OpNum, O);
425       return false;
426     case 'y': // Print a VFP single precision register as indexed double.
427       // This uses the ordering of the alias table to get the first 'd' register
428       // that overlaps the 's' register. Also, s0 is an odd register, hence the
429       // odd modulus check below.
430       if (MI->getOperand(OpNum).isReg()) {
431         unsigned Reg = MI->getOperand(OpNum).getReg();
432         const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
433         O << ARMInstPrinter::getRegisterName(TRI->getAliasSet(Reg)[0]) <<
434         (((Reg % 2) == 1) ? "[0]" : "[1]");
435         return false;
436       }
437       return true;
438     case 'B': // Bitwise inverse of integer or symbol without a preceding #.
439       if (!MI->getOperand(OpNum).isImm())
440         return true;
441       O << ~(MI->getOperand(OpNum).getImm());
442       return false;
443     case 'L': // The low 16 bits of an immediate constant.
444       if (!MI->getOperand(OpNum).isImm())
445         return true;
446       O << (MI->getOperand(OpNum).getImm() & 0xffff);
447       return false;
448     case 'M': { // A register range suitable for LDM/STM.
449       if (!MI->getOperand(OpNum).isReg())
450         return true;
451       const MachineOperand &MO = MI->getOperand(OpNum);
452       unsigned RegBegin = MO.getReg();
453       // This takes advantage of the 2 operand-ness of ldm/stm and that we've
454       // already got the operands in registers that are operands to the
455       // inline asm statement.
456 
457       O << "{" << ARMInstPrinter::getRegisterName(RegBegin);
458 
459       // FIXME: The register allocator not only may not have given us the
460       // registers in sequence, but may not be in ascending registers. This
461       // will require changes in the register allocator that'll need to be
462       // propagated down here if the operands change.
463       unsigned RegOps = OpNum + 1;
464       while (MI->getOperand(RegOps).isReg()) {
465         O << ", "
466           << ARMInstPrinter::getRegisterName(MI->getOperand(RegOps).getReg());
467         RegOps++;
468       }
469 
470       O << "}";
471 
472       return false;
473     }
474     case 'R': // The most significant register of a pair.
475     case 'Q': { // The least significant register of a pair.
476       if (OpNum == 0)
477         return true;
478       const MachineOperand &FlagsOP = MI->getOperand(OpNum - 1);
479       if (!FlagsOP.isImm())
480         return true;
481       unsigned Flags = FlagsOP.getImm();
482       unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
483       if (NumVals != 2)
484         return true;
485       unsigned RegOp = ExtraCode[0] == 'Q' ? OpNum : OpNum + 1;
486       if (RegOp >= MI->getNumOperands())
487         return true;
488       const MachineOperand &MO = MI->getOperand(RegOp);
489       if (!MO.isReg())
490         return true;
491       unsigned Reg = MO.getReg();
492       O << ARMInstPrinter::getRegisterName(Reg);
493       return false;
494     }
495 
496     case 'e': // The low doubleword register of a NEON quad register.
497     case 'f': { // The high doubleword register of a NEON quad register.
498       if (!MI->getOperand(OpNum).isReg())
499         return true;
500       unsigned Reg = MI->getOperand(OpNum).getReg();
501       if (!ARM::QPRRegClass.contains(Reg))
502         return true;
503       const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
504       unsigned SubReg = TRI->getSubReg(Reg, ExtraCode[0] == 'e' ?
505                                        ARM::dsub_0 : ARM::dsub_1);
506       O << ARMInstPrinter::getRegisterName(SubReg);
507       return false;
508     }
509 
510     // These modifiers are not yet supported.
511     case 'h': // A range of VFP/NEON registers suitable for VLD1/VST1.
512     case 'H': // The highest-numbered register of a pair.
513       return true;
514     }
515   }
516 
517   printOperand(MI, OpNum, O);
518   return false;
519 }
520 
521 bool ARMAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
522                                           unsigned OpNum, unsigned AsmVariant,
523                                           const char *ExtraCode,
524                                           raw_ostream &O) {
525   // Does this asm operand have a single letter operand modifier?
526   if (ExtraCode && ExtraCode[0]) {
527     if (ExtraCode[1] != 0) return true; // Unknown modifier.
528 
529     switch (ExtraCode[0]) {
530       case 'A': // A memory operand for a VLD1/VST1 instruction.
531       default: return true;  // Unknown modifier.
532       case 'm': // The base register of a memory operand.
533         if (!MI->getOperand(OpNum).isReg())
534           return true;
535         O << ARMInstPrinter::getRegisterName(MI->getOperand(OpNum).getReg());
536         return false;
537     }
538   }
539 
540   const MachineOperand &MO = MI->getOperand(OpNum);
541   assert(MO.isReg() && "unexpected inline asm memory operand");
542   O << "[" << ARMInstPrinter::getRegisterName(MO.getReg()) << "]";
543   return false;
544 }
545 
546 void ARMAsmPrinter::EmitStartOfAsmFile(Module &M) {
547   if (Subtarget->isTargetDarwin()) {
548     Reloc::Model RelocM = TM.getRelocationModel();
549     if (RelocM == Reloc::PIC_ || RelocM == Reloc::DynamicNoPIC) {
550       // Declare all the text sections up front (before the DWARF sections
551       // emitted by AsmPrinter::doInitialization) so the assembler will keep
552       // them together at the beginning of the object file.  This helps
553       // avoid out-of-range branches that are due a fundamental limitation of
554       // the way symbol offsets are encoded with the current Darwin ARM
555       // relocations.
556       const TargetLoweringObjectFileMachO &TLOFMacho =
557         static_cast<const TargetLoweringObjectFileMachO &>(
558           getObjFileLowering());
559       OutStreamer.SwitchSection(TLOFMacho.getTextSection());
560       OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
561       OutStreamer.SwitchSection(TLOFMacho.getConstTextCoalSection());
562       if (RelocM == Reloc::DynamicNoPIC) {
563         const MCSection *sect =
564           OutContext.getMachOSection("__TEXT", "__symbol_stub4",
565                                      MCSectionMachO::S_SYMBOL_STUBS,
566                                      12, SectionKind::getText());
567         OutStreamer.SwitchSection(sect);
568       } else {
569         const MCSection *sect =
570           OutContext.getMachOSection("__TEXT", "__picsymbolstub4",
571                                      MCSectionMachO::S_SYMBOL_STUBS,
572                                      16, SectionKind::getText());
573         OutStreamer.SwitchSection(sect);
574       }
575       const MCSection *StaticInitSect =
576         OutContext.getMachOSection("__TEXT", "__StaticInit",
577                                    MCSectionMachO::S_REGULAR |
578                                    MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
579                                    SectionKind::getText());
580       OutStreamer.SwitchSection(StaticInitSect);
581     }
582   }
583 
584   // Use unified assembler syntax.
585   OutStreamer.EmitAssemblerFlag(MCAF_SyntaxUnified);
586 
587   // Emit ARM Build Attributes
588   if (Subtarget->isTargetELF()) {
589 
590     emitAttributes();
591   }
592 }
593 
594 
595 void ARMAsmPrinter::EmitEndOfAsmFile(Module &M) {
596   if (Subtarget->isTargetDarwin()) {
597     // All darwin targets use mach-o.
598     const TargetLoweringObjectFileMachO &TLOFMacho =
599       static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
600     MachineModuleInfoMachO &MMIMacho =
601       MMI->getObjFileInfo<MachineModuleInfoMachO>();
602 
603     // Output non-lazy-pointers for external and common global variables.
604     MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetGVStubList();
605 
606     if (!Stubs.empty()) {
607       // Switch with ".non_lazy_symbol_pointer" directive.
608       OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
609       EmitAlignment(2);
610       for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
611         // L_foo$stub:
612         OutStreamer.EmitLabel(Stubs[i].first);
613         //   .indirect_symbol _foo
614         MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
615         OutStreamer.EmitSymbolAttribute(MCSym.getPointer(),MCSA_IndirectSymbol);
616 
617         if (MCSym.getInt())
618           // External to current translation unit.
619           OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
620         else
621           // Internal to current translation unit.
622           //
623           // When we place the LSDA into the TEXT section, the type info
624           // pointers need to be indirect and pc-rel. We accomplish this by
625           // using NLPs; however, sometimes the types are local to the file.
626           // We need to fill in the value for the NLP in those cases.
627           OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
628                                                         OutContext),
629                                 4/*size*/, 0/*addrspace*/);
630       }
631 
632       Stubs.clear();
633       OutStreamer.AddBlankLine();
634     }
635 
636     Stubs = MMIMacho.GetHiddenGVStubList();
637     if (!Stubs.empty()) {
638       OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
639       EmitAlignment(2);
640       for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
641         // L_foo$stub:
642         OutStreamer.EmitLabel(Stubs[i].first);
643         //   .long _foo
644         OutStreamer.EmitValue(MCSymbolRefExpr::
645                               Create(Stubs[i].second.getPointer(),
646                                      OutContext),
647                               4/*size*/, 0/*addrspace*/);
648       }
649 
650       Stubs.clear();
651       OutStreamer.AddBlankLine();
652     }
653 
654     // Funny Darwin hack: This flag tells the linker that no global symbols
655     // contain code that falls through to other global symbols (e.g. the obvious
656     // implementation of multiple entry points).  If this doesn't occur, the
657     // linker can safely perform dead code stripping.  Since LLVM never
658     // generates code that does this, it is always safe to set.
659     OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
660   }
661 }
662 
663 //===----------------------------------------------------------------------===//
664 // Helper routines for EmitStartOfAsmFile() and EmitEndOfAsmFile()
665 // FIXME:
666 // The following seem like one-off assembler flags, but they actually need
667 // to appear in the .ARM.attributes section in ELF.
668 // Instead of subclassing the MCELFStreamer, we do the work here.
669 
670 void ARMAsmPrinter::emitAttributes() {
671 
672   emitARMAttributeSection();
673 
674   /* GAS expect .fpu to be emitted, regardless of VFP build attribute */
675   bool emitFPU = false;
676   AttributeEmitter *AttrEmitter;
677   if (OutStreamer.hasRawTextSupport()) {
678     AttrEmitter = new AsmAttributeEmitter(OutStreamer);
679     emitFPU = true;
680   } else {
681     MCObjectStreamer &O = static_cast<MCObjectStreamer&>(OutStreamer);
682     AttrEmitter = new ObjectAttributeEmitter(O);
683   }
684 
685   AttrEmitter->MaybeSwitchVendor("aeabi");
686 
687   std::string CPUString = Subtarget->getCPUString();
688 
689   if (CPUString == "cortex-a8" ||
690       Subtarget->isCortexA8()) {
691     AttrEmitter->EmitTextAttribute(ARMBuildAttrs::CPU_name, "cortex-a8");
692     AttrEmitter->EmitAttribute(ARMBuildAttrs::CPU_arch, ARMBuildAttrs::v7);
693     AttrEmitter->EmitAttribute(ARMBuildAttrs::CPU_arch_profile,
694                                ARMBuildAttrs::ApplicationProfile);
695     AttrEmitter->EmitAttribute(ARMBuildAttrs::ARM_ISA_use,
696                                ARMBuildAttrs::Allowed);
697     AttrEmitter->EmitAttribute(ARMBuildAttrs::THUMB_ISA_use,
698                                ARMBuildAttrs::AllowThumb32);
699     // Fixme: figure out when this is emitted.
700     //AttrEmitter->EmitAttribute(ARMBuildAttrs::WMMX_arch,
701     //                           ARMBuildAttrs::AllowWMMXv1);
702     //
703 
704     /// ADD additional Else-cases here!
705   } else if (CPUString == "xscale") {
706     AttrEmitter->EmitAttribute(ARMBuildAttrs::CPU_arch, ARMBuildAttrs::v5TEJ);
707     AttrEmitter->EmitAttribute(ARMBuildAttrs::ARM_ISA_use,
708                                ARMBuildAttrs::Allowed);
709     AttrEmitter->EmitAttribute(ARMBuildAttrs::THUMB_ISA_use,
710                                ARMBuildAttrs::Allowed);
711   } else if (CPUString == "generic") {
712     // FIXME: Why these defaults?
713     AttrEmitter->EmitAttribute(ARMBuildAttrs::CPU_arch, ARMBuildAttrs::v4T);
714     AttrEmitter->EmitAttribute(ARMBuildAttrs::ARM_ISA_use,
715                                ARMBuildAttrs::Allowed);
716     AttrEmitter->EmitAttribute(ARMBuildAttrs::THUMB_ISA_use,
717                                ARMBuildAttrs::Allowed);
718   }
719 
720   if (Subtarget->hasNEON() && emitFPU) {
721     /* NEON is not exactly a VFP architecture, but GAS emit one of
722      * neon/vfpv3/vfpv2 for .fpu parameters */
723     AttrEmitter->EmitTextAttribute(ARMBuildAttrs::Advanced_SIMD_arch, "neon");
724     /* If emitted for NEON, omit from VFP below, since you can have both
725      * NEON and VFP in build attributes but only one .fpu */
726     emitFPU = false;
727   }
728 
729   /* VFPv3 + .fpu */
730   if (Subtarget->hasVFP3()) {
731     AttrEmitter->EmitAttribute(ARMBuildAttrs::VFP_arch,
732                                ARMBuildAttrs::AllowFPv3A);
733     if (emitFPU)
734       AttrEmitter->EmitTextAttribute(ARMBuildAttrs::VFP_arch, "vfpv3");
735 
736   /* VFPv2 + .fpu */
737   } else if (Subtarget->hasVFP2()) {
738     AttrEmitter->EmitAttribute(ARMBuildAttrs::VFP_arch,
739                                ARMBuildAttrs::AllowFPv2);
740     if (emitFPU)
741       AttrEmitter->EmitTextAttribute(ARMBuildAttrs::VFP_arch, "vfpv2");
742   }
743 
744   /* TODO: ARMBuildAttrs::Allowed is not completely accurate,
745    * since NEON can have 1 (allowed) or 2 (MAC operations) */
746   if (Subtarget->hasNEON()) {
747     AttrEmitter->EmitAttribute(ARMBuildAttrs::Advanced_SIMD_arch,
748                                ARMBuildAttrs::Allowed);
749   }
750 
751   // Signal various FP modes.
752   if (!TM.Options.UnsafeFPMath) {
753     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_FP_denormal,
754                                ARMBuildAttrs::Allowed);
755     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_FP_exceptions,
756                                ARMBuildAttrs::Allowed);
757   }
758 
759   if (TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath)
760     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_FP_number_model,
761                                ARMBuildAttrs::Allowed);
762   else
763     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_FP_number_model,
764                                ARMBuildAttrs::AllowIEE754);
765 
766   // FIXME: add more flags to ARMBuildAttrs.h
767   // 8-bytes alignment stuff.
768   AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_align8_needed, 1);
769   AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_align8_preserved, 1);
770 
771   // Hard float.  Use both S and D registers and conform to AAPCS-VFP.
772   if (Subtarget->isAAPCS_ABI() && TM.Options.FloatABIType == FloatABI::Hard) {
773     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_HardFP_use, 3);
774     AttrEmitter->EmitAttribute(ARMBuildAttrs::ABI_VFP_args, 1);
775   }
776   // FIXME: Should we signal R9 usage?
777 
778   if (Subtarget->hasDivide())
779     AttrEmitter->EmitAttribute(ARMBuildAttrs::DIV_use, 1);
780 
781   AttrEmitter->Finish();
782   delete AttrEmitter;
783 }
784 
785 void ARMAsmPrinter::emitARMAttributeSection() {
786   // <format-version>
787   // [ <section-length> "vendor-name"
788   // [ <file-tag> <size> <attribute>*
789   //   | <section-tag> <size> <section-number>* 0 <attribute>*
790   //   | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
791   //   ]+
792   // ]*
793 
794   if (OutStreamer.hasRawTextSupport())
795     return;
796 
797   const ARMElfTargetObjectFile &TLOFELF =
798     static_cast<const ARMElfTargetObjectFile &>
799     (getObjFileLowering());
800 
801   OutStreamer.SwitchSection(TLOFELF.getAttributesSection());
802 
803   // Format version
804   OutStreamer.EmitIntValue(0x41, 1);
805 }
806 
807 //===----------------------------------------------------------------------===//
808 
809 static MCSymbol *getPICLabel(const char *Prefix, unsigned FunctionNumber,
810                              unsigned LabelId, MCContext &Ctx) {
811 
812   MCSymbol *Label = Ctx.GetOrCreateSymbol(Twine(Prefix)
813                        + "PC" + Twine(FunctionNumber) + "_" + Twine(LabelId));
814   return Label;
815 }
816 
817 static MCSymbolRefExpr::VariantKind
818 getModifierVariantKind(ARMCP::ARMCPModifier Modifier) {
819   switch (Modifier) {
820   case ARMCP::no_modifier: return MCSymbolRefExpr::VK_None;
821   case ARMCP::TLSGD:       return MCSymbolRefExpr::VK_ARM_TLSGD;
822   case ARMCP::TPOFF:       return MCSymbolRefExpr::VK_ARM_TPOFF;
823   case ARMCP::GOTTPOFF:    return MCSymbolRefExpr::VK_ARM_GOTTPOFF;
824   case ARMCP::GOT:         return MCSymbolRefExpr::VK_ARM_GOT;
825   case ARMCP::GOTOFF:      return MCSymbolRefExpr::VK_ARM_GOTOFF;
826   }
827   return MCSymbolRefExpr::VK_None;
828 }
829 
830 MCSymbol *ARMAsmPrinter::GetARMGVSymbol(const GlobalValue *GV) {
831   bool isIndirect = Subtarget->isTargetDarwin() &&
832     Subtarget->GVIsIndirectSymbol(GV, TM.getRelocationModel());
833   if (!isIndirect)
834     return Mang->getSymbol(GV);
835 
836   // FIXME: Remove this when Darwin transition to @GOT like syntax.
837   MCSymbol *MCSym = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
838   MachineModuleInfoMachO &MMIMachO =
839     MMI->getObjFileInfo<MachineModuleInfoMachO>();
840   MachineModuleInfoImpl::StubValueTy &StubSym =
841     GV->hasHiddenVisibility() ? MMIMachO.getHiddenGVStubEntry(MCSym) :
842     MMIMachO.getGVStubEntry(MCSym);
843   if (StubSym.getPointer() == 0)
844     StubSym = MachineModuleInfoImpl::
845       StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
846   return MCSym;
847 }
848 
849 void ARMAsmPrinter::
850 EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
851   int Size = TM.getTargetData()->getTypeAllocSize(MCPV->getType());
852 
853   ARMConstantPoolValue *ACPV = static_cast<ARMConstantPoolValue*>(MCPV);
854 
855   MCSymbol *MCSym;
856   if (ACPV->isLSDA()) {
857     SmallString<128> Str;
858     raw_svector_ostream OS(Str);
859     OS << MAI->getPrivateGlobalPrefix() << "_LSDA_" << getFunctionNumber();
860     MCSym = OutContext.GetOrCreateSymbol(OS.str());
861   } else if (ACPV->isBlockAddress()) {
862     const BlockAddress *BA =
863       cast<ARMConstantPoolConstant>(ACPV)->getBlockAddress();
864     MCSym = GetBlockAddressSymbol(BA);
865   } else if (ACPV->isGlobalValue()) {
866     const GlobalValue *GV = cast<ARMConstantPoolConstant>(ACPV)->getGV();
867     MCSym = GetARMGVSymbol(GV);
868   } else if (ACPV->isMachineBasicBlock()) {
869     const MachineBasicBlock *MBB = cast<ARMConstantPoolMBB>(ACPV)->getMBB();
870     MCSym = MBB->getSymbol();
871   } else {
872     assert(ACPV->isExtSymbol() && "unrecognized constant pool value");
873     const char *Sym = cast<ARMConstantPoolSymbol>(ACPV)->getSymbol();
874     MCSym = GetExternalSymbolSymbol(Sym);
875   }
876 
877   // Create an MCSymbol for the reference.
878   const MCExpr *Expr =
879     MCSymbolRefExpr::Create(MCSym, getModifierVariantKind(ACPV->getModifier()),
880                             OutContext);
881 
882   if (ACPV->getPCAdjustment()) {
883     MCSymbol *PCLabel = getPICLabel(MAI->getPrivateGlobalPrefix(),
884                                     getFunctionNumber(),
885                                     ACPV->getLabelId(),
886                                     OutContext);
887     const MCExpr *PCRelExpr = MCSymbolRefExpr::Create(PCLabel, OutContext);
888     PCRelExpr =
889       MCBinaryExpr::CreateAdd(PCRelExpr,
890                               MCConstantExpr::Create(ACPV->getPCAdjustment(),
891                                                      OutContext),
892                               OutContext);
893     if (ACPV->mustAddCurrentAddress()) {
894       // We want "(<expr> - .)", but MC doesn't have a concept of the '.'
895       // label, so just emit a local label end reference that instead.
896       MCSymbol *DotSym = OutContext.CreateTempSymbol();
897       OutStreamer.EmitLabel(DotSym);
898       const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext);
899       PCRelExpr = MCBinaryExpr::CreateSub(PCRelExpr, DotExpr, OutContext);
900     }
901     Expr = MCBinaryExpr::CreateSub(Expr, PCRelExpr, OutContext);
902   }
903   OutStreamer.EmitValue(Expr, Size);
904 }
905 
906 void ARMAsmPrinter::EmitJumpTable(const MachineInstr *MI) {
907   unsigned Opcode = MI->getOpcode();
908   int OpNum = 1;
909   if (Opcode == ARM::BR_JTadd)
910     OpNum = 2;
911   else if (Opcode == ARM::BR_JTm)
912     OpNum = 3;
913 
914   const MachineOperand &MO1 = MI->getOperand(OpNum);
915   const MachineOperand &MO2 = MI->getOperand(OpNum+1); // Unique Id
916   unsigned JTI = MO1.getIndex();
917 
918   // Tag the jump table appropriately for precise disassembly.
919   OutStreamer.EmitJumpTable32Region();
920 
921   // Emit a label for the jump table.
922   MCSymbol *JTISymbol = GetARMJTIPICJumpTableLabel2(JTI, MO2.getImm());
923   OutStreamer.EmitLabel(JTISymbol);
924 
925   // Emit each entry of the table.
926   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
927   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
928   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
929 
930   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
931     MachineBasicBlock *MBB = JTBBs[i];
932     // Construct an MCExpr for the entry. We want a value of the form:
933     // (BasicBlockAddr - TableBeginAddr)
934     //
935     // For example, a table with entries jumping to basic blocks BB0 and BB1
936     // would look like:
937     // LJTI_0_0:
938     //    .word (LBB0 - LJTI_0_0)
939     //    .word (LBB1 - LJTI_0_0)
940     const MCExpr *Expr = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
941 
942     if (TM.getRelocationModel() == Reloc::PIC_)
943       Expr = MCBinaryExpr::CreateSub(Expr, MCSymbolRefExpr::Create(JTISymbol,
944                                                                    OutContext),
945                                      OutContext);
946     // If we're generating a table of Thumb addresses in static relocation
947     // model, we need to add one to keep interworking correctly.
948     else if (AFI->isThumbFunction())
949       Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(1,OutContext),
950                                      OutContext);
951     OutStreamer.EmitValue(Expr, 4);
952   }
953 }
954 
955 void ARMAsmPrinter::EmitJump2Table(const MachineInstr *MI) {
956   unsigned Opcode = MI->getOpcode();
957   int OpNum = (Opcode == ARM::t2BR_JT) ? 2 : 1;
958   const MachineOperand &MO1 = MI->getOperand(OpNum);
959   const MachineOperand &MO2 = MI->getOperand(OpNum+1); // Unique Id
960   unsigned JTI = MO1.getIndex();
961 
962   // Emit a label for the jump table.
963   if (MI->getOpcode() == ARM::t2TBB_JT) {
964     OutStreamer.EmitJumpTable8Region();
965   } else if (MI->getOpcode() == ARM::t2TBH_JT) {
966     OutStreamer.EmitJumpTable16Region();
967   } else {
968     OutStreamer.EmitJumpTable32Region();
969   }
970 
971   MCSymbol *JTISymbol = GetARMJTIPICJumpTableLabel2(JTI, MO2.getImm());
972   OutStreamer.EmitLabel(JTISymbol);
973 
974   // Emit each entry of the table.
975   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
976   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
977   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
978   unsigned OffsetWidth = 4;
979   if (MI->getOpcode() == ARM::t2TBB_JT)
980     OffsetWidth = 1;
981   else if (MI->getOpcode() == ARM::t2TBH_JT)
982     OffsetWidth = 2;
983 
984   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
985     MachineBasicBlock *MBB = JTBBs[i];
986     const MCExpr *MBBSymbolExpr = MCSymbolRefExpr::Create(MBB->getSymbol(),
987                                                       OutContext);
988     // If this isn't a TBB or TBH, the entries are direct branch instructions.
989     if (OffsetWidth == 4) {
990       MCInst BrInst;
991       BrInst.setOpcode(ARM::t2B);
992       BrInst.addOperand(MCOperand::CreateExpr(MBBSymbolExpr));
993       BrInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
994       BrInst.addOperand(MCOperand::CreateReg(0));
995       OutStreamer.EmitInstruction(BrInst);
996       continue;
997     }
998     // Otherwise it's an offset from the dispatch instruction. Construct an
999     // MCExpr for the entry. We want a value of the form:
1000     // (BasicBlockAddr - TableBeginAddr) / 2
1001     //
1002     // For example, a TBB table with entries jumping to basic blocks BB0 and BB1
1003     // would look like:
1004     // LJTI_0_0:
1005     //    .byte (LBB0 - LJTI_0_0) / 2
1006     //    .byte (LBB1 - LJTI_0_0) / 2
1007     const MCExpr *Expr =
1008       MCBinaryExpr::CreateSub(MBBSymbolExpr,
1009                               MCSymbolRefExpr::Create(JTISymbol, OutContext),
1010                               OutContext);
1011     Expr = MCBinaryExpr::CreateDiv(Expr, MCConstantExpr::Create(2, OutContext),
1012                                    OutContext);
1013     OutStreamer.EmitValue(Expr, OffsetWidth);
1014   }
1015 }
1016 
1017 void ARMAsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
1018                                            raw_ostream &OS) {
1019   unsigned NOps = MI->getNumOperands();
1020   assert(NOps==4);
1021   OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
1022   // cast away const; DIetc do not take const operands for some reason.
1023   DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps-1).getMetadata()));
1024   OS << V.getName();
1025   OS << " <- ";
1026   // Frame address.  Currently handles register +- offset only.
1027   assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
1028   OS << '['; printOperand(MI, 0, OS); OS << '+'; printOperand(MI, 1, OS);
1029   OS << ']';
1030   OS << "+";
1031   printOperand(MI, NOps-2, OS);
1032 }
1033 
1034 static void populateADROperands(MCInst &Inst, unsigned Dest,
1035                                 const MCSymbol *Label,
1036                                 unsigned pred, unsigned ccreg,
1037                                 MCContext &Ctx) {
1038   const MCExpr *SymbolExpr = MCSymbolRefExpr::Create(Label, Ctx);
1039   Inst.addOperand(MCOperand::CreateReg(Dest));
1040   Inst.addOperand(MCOperand::CreateExpr(SymbolExpr));
1041   // Add predicate operands.
1042   Inst.addOperand(MCOperand::CreateImm(pred));
1043   Inst.addOperand(MCOperand::CreateReg(ccreg));
1044 }
1045 
1046 void ARMAsmPrinter::EmitPatchedInstruction(const MachineInstr *MI,
1047                                            unsigned Opcode) {
1048   MCInst TmpInst;
1049 
1050   // Emit the instruction as usual, just patch the opcode.
1051   LowerARMMachineInstrToMCInst(MI, TmpInst, *this);
1052   TmpInst.setOpcode(Opcode);
1053   OutStreamer.EmitInstruction(TmpInst);
1054 }
1055 
1056 void ARMAsmPrinter::EmitUnwindingInstruction(const MachineInstr *MI) {
1057   assert(MI->getFlag(MachineInstr::FrameSetup) &&
1058       "Only instruction which are involved into frame setup code are allowed");
1059 
1060   const MachineFunction &MF = *MI->getParent()->getParent();
1061   const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
1062   const ARMFunctionInfo &AFI = *MF.getInfo<ARMFunctionInfo>();
1063 
1064   unsigned FramePtr = RegInfo->getFrameRegister(MF);
1065   unsigned Opc = MI->getOpcode();
1066   unsigned SrcReg, DstReg;
1067 
1068   if (Opc == ARM::tPUSH || Opc == ARM::tLDRpci) {
1069     // Two special cases:
1070     // 1) tPUSH does not have src/dst regs.
1071     // 2) for Thumb1 code we sometimes materialize the constant via constpool
1072     // load. Yes, this is pretty fragile, but for now I don't see better
1073     // way... :(
1074     SrcReg = DstReg = ARM::SP;
1075   } else {
1076     SrcReg = MI->getOperand(1).getReg();
1077     DstReg = MI->getOperand(0).getReg();
1078   }
1079 
1080   // Try to figure out the unwinding opcode out of src / dst regs.
1081   if (MI->mayStore()) {
1082     // Register saves.
1083     assert(DstReg == ARM::SP &&
1084            "Only stack pointer as a destination reg is supported");
1085 
1086     SmallVector<unsigned, 4> RegList;
1087     // Skip src & dst reg, and pred ops.
1088     unsigned StartOp = 2 + 2;
1089     // Use all the operands.
1090     unsigned NumOffset = 0;
1091 
1092     switch (Opc) {
1093     default:
1094       MI->dump();
1095       assert(0 && "Unsupported opcode for unwinding information");
1096     case ARM::tPUSH:
1097       // Special case here: no src & dst reg, but two extra imp ops.
1098       StartOp = 2; NumOffset = 2;
1099     case ARM::STMDB_UPD:
1100     case ARM::t2STMDB_UPD:
1101     case ARM::VSTMDDB_UPD:
1102       assert(SrcReg == ARM::SP &&
1103              "Only stack pointer as a source reg is supported");
1104       for (unsigned i = StartOp, NumOps = MI->getNumOperands() - NumOffset;
1105            i != NumOps; ++i)
1106         RegList.push_back(MI->getOperand(i).getReg());
1107       break;
1108     case ARM::STR_PRE_IMM:
1109     case ARM::STR_PRE_REG:
1110       assert(MI->getOperand(2).getReg() == ARM::SP &&
1111              "Only stack pointer as a source reg is supported");
1112       RegList.push_back(SrcReg);
1113       break;
1114     }
1115     OutStreamer.EmitRegSave(RegList, Opc == ARM::VSTMDDB_UPD);
1116   } else {
1117     // Changes of stack / frame pointer.
1118     if (SrcReg == ARM::SP) {
1119       int64_t Offset = 0;
1120       switch (Opc) {
1121       default:
1122         MI->dump();
1123         assert(0 && "Unsupported opcode for unwinding information");
1124       case ARM::MOVr:
1125         Offset = 0;
1126         break;
1127       case ARM::ADDri:
1128         Offset = -MI->getOperand(2).getImm();
1129         break;
1130       case ARM::SUBri:
1131         Offset = MI->getOperand(2).getImm();
1132         break;
1133       case ARM::tSUBspi:
1134         Offset = MI->getOperand(2).getImm()*4;
1135         break;
1136       case ARM::tADDspi:
1137       case ARM::tADDrSPi:
1138         Offset = -MI->getOperand(2).getImm()*4;
1139         break;
1140       case ARM::tLDRpci: {
1141         // Grab the constpool index and check, whether it corresponds to
1142         // original or cloned constpool entry.
1143         unsigned CPI = MI->getOperand(1).getIndex();
1144         const MachineConstantPool *MCP = MF.getConstantPool();
1145         if (CPI >= MCP->getConstants().size())
1146           CPI = AFI.getOriginalCPIdx(CPI);
1147         assert(CPI != -1U && "Invalid constpool index");
1148 
1149         // Derive the actual offset.
1150         const MachineConstantPoolEntry &CPE = MCP->getConstants()[CPI];
1151         assert(!CPE.isMachineConstantPoolEntry() && "Invalid constpool entry");
1152         // FIXME: Check for user, it should be "add" instruction!
1153         Offset = -cast<ConstantInt>(CPE.Val.ConstVal)->getSExtValue();
1154         break;
1155       }
1156       }
1157 
1158       if (DstReg == FramePtr && FramePtr != ARM::SP)
1159         // Set-up of the frame pointer. Positive values correspond to "add"
1160         // instruction.
1161         OutStreamer.EmitSetFP(FramePtr, ARM::SP, -Offset);
1162       else if (DstReg == ARM::SP) {
1163         // Change of SP by an offset. Positive values correspond to "sub"
1164         // instruction.
1165         OutStreamer.EmitPad(Offset);
1166       } else {
1167         MI->dump();
1168         assert(0 && "Unsupported opcode for unwinding information");
1169       }
1170     } else if (DstReg == ARM::SP) {
1171       // FIXME: .movsp goes here
1172       MI->dump();
1173       assert(0 && "Unsupported opcode for unwinding information");
1174     }
1175     else {
1176       MI->dump();
1177       assert(0 && "Unsupported opcode for unwinding information");
1178     }
1179   }
1180 }
1181 
1182 extern cl::opt<bool> EnableARMEHABI;
1183 
1184 // Simple pseudo-instructions have their lowering (with expansion to real
1185 // instructions) auto-generated.
1186 #include "ARMGenMCPseudoLowering.inc"
1187 
1188 void ARMAsmPrinter::EmitInstruction(const MachineInstr *MI) {
1189   if (MI->getOpcode() != ARM::CONSTPOOL_ENTRY)
1190     OutStreamer.EmitCodeRegion();
1191 
1192   // Emit unwinding stuff for frame-related instructions
1193   if (EnableARMEHABI && MI->getFlag(MachineInstr::FrameSetup))
1194     EmitUnwindingInstruction(MI);
1195 
1196   // Do any auto-generated pseudo lowerings.
1197   if (emitPseudoExpansionLowering(OutStreamer, MI))
1198     return;
1199 
1200   assert(!convertAddSubFlagsOpcode(MI->getOpcode()) &&
1201          "Pseudo flag setting opcode should be expanded early");
1202 
1203   // Check for manual lowerings.
1204   unsigned Opc = MI->getOpcode();
1205   switch (Opc) {
1206   case ARM::t2MOVi32imm: assert(0 && "Should be lowered by thumb2it pass");
1207   case ARM::DBG_VALUE: {
1208     if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1209       SmallString<128> TmpStr;
1210       raw_svector_ostream OS(TmpStr);
1211       PrintDebugValueComment(MI, OS);
1212       OutStreamer.EmitRawText(StringRef(OS.str()));
1213     }
1214     return;
1215   }
1216   case ARM::LEApcrel:
1217   case ARM::tLEApcrel:
1218   case ARM::t2LEApcrel: {
1219     // FIXME: Need to also handle globals and externals
1220     MCInst TmpInst;
1221     TmpInst.setOpcode(MI->getOpcode() == ARM::t2LEApcrel ? ARM::t2ADR
1222                       : (MI->getOpcode() == ARM::tLEApcrel ? ARM::tADR
1223                          : ARM::ADR));
1224     populateADROperands(TmpInst, MI->getOperand(0).getReg(),
1225                         GetCPISymbol(MI->getOperand(1).getIndex()),
1226                         MI->getOperand(2).getImm(), MI->getOperand(3).getReg(),
1227                         OutContext);
1228     OutStreamer.EmitInstruction(TmpInst);
1229     return;
1230   }
1231   case ARM::LEApcrelJT:
1232   case ARM::tLEApcrelJT:
1233   case ARM::t2LEApcrelJT: {
1234     MCInst TmpInst;
1235     TmpInst.setOpcode(MI->getOpcode() == ARM::t2LEApcrelJT ? ARM::t2ADR
1236                       : (MI->getOpcode() == ARM::tLEApcrelJT ? ARM::tADR
1237                          : ARM::ADR));
1238     populateADROperands(TmpInst, MI->getOperand(0).getReg(),
1239                       GetARMJTIPICJumpTableLabel2(MI->getOperand(1).getIndex(),
1240                                                   MI->getOperand(2).getImm()),
1241                       MI->getOperand(3).getImm(), MI->getOperand(4).getReg(),
1242                       OutContext);
1243     OutStreamer.EmitInstruction(TmpInst);
1244     return;
1245   }
1246   // Darwin call instructions are just normal call instructions with different
1247   // clobber semantics (they clobber R9).
1248   case ARM::BXr9_CALL:
1249   case ARM::BX_CALL: {
1250     {
1251       MCInst TmpInst;
1252       TmpInst.setOpcode(ARM::MOVr);
1253       TmpInst.addOperand(MCOperand::CreateReg(ARM::LR));
1254       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1255       // Add predicate operands.
1256       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1257       TmpInst.addOperand(MCOperand::CreateReg(0));
1258       // Add 's' bit operand (always reg0 for this)
1259       TmpInst.addOperand(MCOperand::CreateReg(0));
1260       OutStreamer.EmitInstruction(TmpInst);
1261     }
1262     {
1263       MCInst TmpInst;
1264       TmpInst.setOpcode(ARM::BX);
1265       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1266       OutStreamer.EmitInstruction(TmpInst);
1267     }
1268     return;
1269   }
1270   case ARM::tBXr9_CALL:
1271   case ARM::tBX_CALL: {
1272     {
1273       MCInst TmpInst;
1274       TmpInst.setOpcode(ARM::tMOVr);
1275       TmpInst.addOperand(MCOperand::CreateReg(ARM::LR));
1276       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1277       // Add predicate operands.
1278       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1279       TmpInst.addOperand(MCOperand::CreateReg(0));
1280       OutStreamer.EmitInstruction(TmpInst);
1281     }
1282     {
1283       MCInst TmpInst;
1284       TmpInst.setOpcode(ARM::tBX);
1285       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1286       // Add predicate operands.
1287       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1288       TmpInst.addOperand(MCOperand::CreateReg(0));
1289       OutStreamer.EmitInstruction(TmpInst);
1290     }
1291     return;
1292   }
1293   case ARM::BMOVPCRXr9_CALL:
1294   case ARM::BMOVPCRX_CALL: {
1295     {
1296       MCInst TmpInst;
1297       TmpInst.setOpcode(ARM::MOVr);
1298       TmpInst.addOperand(MCOperand::CreateReg(ARM::LR));
1299       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1300       // Add predicate operands.
1301       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1302       TmpInst.addOperand(MCOperand::CreateReg(0));
1303       // Add 's' bit operand (always reg0 for this)
1304       TmpInst.addOperand(MCOperand::CreateReg(0));
1305       OutStreamer.EmitInstruction(TmpInst);
1306     }
1307     {
1308       MCInst TmpInst;
1309       TmpInst.setOpcode(ARM::MOVr);
1310       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1311       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1312       // Add predicate operands.
1313       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1314       TmpInst.addOperand(MCOperand::CreateReg(0));
1315       // Add 's' bit operand (always reg0 for this)
1316       TmpInst.addOperand(MCOperand::CreateReg(0));
1317       OutStreamer.EmitInstruction(TmpInst);
1318     }
1319     return;
1320   }
1321   case ARM::MOVi16_ga_pcrel:
1322   case ARM::t2MOVi16_ga_pcrel: {
1323     MCInst TmpInst;
1324     TmpInst.setOpcode(Opc == ARM::MOVi16_ga_pcrel? ARM::MOVi16 : ARM::t2MOVi16);
1325     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1326 
1327     unsigned TF = MI->getOperand(1).getTargetFlags();
1328     bool isPIC = TF == ARMII::MO_LO16_NONLAZY_PIC;
1329     const GlobalValue *GV = MI->getOperand(1).getGlobal();
1330     MCSymbol *GVSym = GetARMGVSymbol(GV);
1331     const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
1332     if (isPIC) {
1333       MCSymbol *LabelSym = getPICLabel(MAI->getPrivateGlobalPrefix(),
1334                                        getFunctionNumber(),
1335                                        MI->getOperand(2).getImm(), OutContext);
1336       const MCExpr *LabelSymExpr= MCSymbolRefExpr::Create(LabelSym, OutContext);
1337       unsigned PCAdj = (Opc == ARM::MOVi16_ga_pcrel) ? 8 : 4;
1338       const MCExpr *PCRelExpr =
1339         ARMMCExpr::CreateLower16(MCBinaryExpr::CreateSub(GVSymExpr,
1340                                   MCBinaryExpr::CreateAdd(LabelSymExpr,
1341                                       MCConstantExpr::Create(PCAdj, OutContext),
1342                                           OutContext), OutContext), OutContext);
1343       TmpInst.addOperand(MCOperand::CreateExpr(PCRelExpr));
1344     } else {
1345       const MCExpr *RefExpr= ARMMCExpr::CreateLower16(GVSymExpr, OutContext);
1346       TmpInst.addOperand(MCOperand::CreateExpr(RefExpr));
1347     }
1348 
1349     // Add predicate operands.
1350     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1351     TmpInst.addOperand(MCOperand::CreateReg(0));
1352     // Add 's' bit operand (always reg0 for this)
1353     TmpInst.addOperand(MCOperand::CreateReg(0));
1354     OutStreamer.EmitInstruction(TmpInst);
1355     return;
1356   }
1357   case ARM::MOVTi16_ga_pcrel:
1358   case ARM::t2MOVTi16_ga_pcrel: {
1359     MCInst TmpInst;
1360     TmpInst.setOpcode(Opc == ARM::MOVTi16_ga_pcrel
1361                       ? ARM::MOVTi16 : ARM::t2MOVTi16);
1362     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1363     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1364 
1365     unsigned TF = MI->getOperand(2).getTargetFlags();
1366     bool isPIC = TF == ARMII::MO_HI16_NONLAZY_PIC;
1367     const GlobalValue *GV = MI->getOperand(2).getGlobal();
1368     MCSymbol *GVSym = GetARMGVSymbol(GV);
1369     const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
1370     if (isPIC) {
1371       MCSymbol *LabelSym = getPICLabel(MAI->getPrivateGlobalPrefix(),
1372                                        getFunctionNumber(),
1373                                        MI->getOperand(3).getImm(), OutContext);
1374       const MCExpr *LabelSymExpr= MCSymbolRefExpr::Create(LabelSym, OutContext);
1375       unsigned PCAdj = (Opc == ARM::MOVTi16_ga_pcrel) ? 8 : 4;
1376       const MCExpr *PCRelExpr =
1377         ARMMCExpr::CreateUpper16(MCBinaryExpr::CreateSub(GVSymExpr,
1378                                    MCBinaryExpr::CreateAdd(LabelSymExpr,
1379                                       MCConstantExpr::Create(PCAdj, OutContext),
1380                                           OutContext), OutContext), OutContext);
1381       TmpInst.addOperand(MCOperand::CreateExpr(PCRelExpr));
1382     } else {
1383       const MCExpr *RefExpr= ARMMCExpr::CreateUpper16(GVSymExpr, OutContext);
1384       TmpInst.addOperand(MCOperand::CreateExpr(RefExpr));
1385     }
1386     // Add predicate operands.
1387     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1388     TmpInst.addOperand(MCOperand::CreateReg(0));
1389     // Add 's' bit operand (always reg0 for this)
1390     TmpInst.addOperand(MCOperand::CreateReg(0));
1391     OutStreamer.EmitInstruction(TmpInst);
1392     return;
1393   }
1394   case ARM::tPICADD: {
1395     // This is a pseudo op for a label + instruction sequence, which looks like:
1396     // LPC0:
1397     //     add r0, pc
1398     // This adds the address of LPC0 to r0.
1399 
1400     // Emit the label.
1401     OutStreamer.EmitLabel(getPICLabel(MAI->getPrivateGlobalPrefix(),
1402                           getFunctionNumber(), MI->getOperand(2).getImm(),
1403                           OutContext));
1404 
1405     // Form and emit the add.
1406     MCInst AddInst;
1407     AddInst.setOpcode(ARM::tADDhirr);
1408     AddInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1409     AddInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1410     AddInst.addOperand(MCOperand::CreateReg(ARM::PC));
1411     // Add predicate operands.
1412     AddInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1413     AddInst.addOperand(MCOperand::CreateReg(0));
1414     OutStreamer.EmitInstruction(AddInst);
1415     return;
1416   }
1417   case ARM::PICADD: {
1418     // This is a pseudo op for a label + instruction sequence, which looks like:
1419     // LPC0:
1420     //     add r0, pc, r0
1421     // This adds the address of LPC0 to r0.
1422 
1423     // Emit the label.
1424     OutStreamer.EmitLabel(getPICLabel(MAI->getPrivateGlobalPrefix(),
1425                           getFunctionNumber(), MI->getOperand(2).getImm(),
1426                           OutContext));
1427 
1428     // Form and emit the add.
1429     MCInst AddInst;
1430     AddInst.setOpcode(ARM::ADDrr);
1431     AddInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1432     AddInst.addOperand(MCOperand::CreateReg(ARM::PC));
1433     AddInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1434     // Add predicate operands.
1435     AddInst.addOperand(MCOperand::CreateImm(MI->getOperand(3).getImm()));
1436     AddInst.addOperand(MCOperand::CreateReg(MI->getOperand(4).getReg()));
1437     // Add 's' bit operand (always reg0 for this)
1438     AddInst.addOperand(MCOperand::CreateReg(0));
1439     OutStreamer.EmitInstruction(AddInst);
1440     return;
1441   }
1442   case ARM::PICSTR:
1443   case ARM::PICSTRB:
1444   case ARM::PICSTRH:
1445   case ARM::PICLDR:
1446   case ARM::PICLDRB:
1447   case ARM::PICLDRH:
1448   case ARM::PICLDRSB:
1449   case ARM::PICLDRSH: {
1450     // This is a pseudo op for a label + instruction sequence, which looks like:
1451     // LPC0:
1452     //     OP r0, [pc, r0]
1453     // The LCP0 label is referenced by a constant pool entry in order to get
1454     // a PC-relative address at the ldr instruction.
1455 
1456     // Emit the label.
1457     OutStreamer.EmitLabel(getPICLabel(MAI->getPrivateGlobalPrefix(),
1458                           getFunctionNumber(), MI->getOperand(2).getImm(),
1459                           OutContext));
1460 
1461     // Form and emit the load
1462     unsigned Opcode;
1463     switch (MI->getOpcode()) {
1464     default:
1465       llvm_unreachable("Unexpected opcode!");
1466     case ARM::PICSTR:   Opcode = ARM::STRrs; break;
1467     case ARM::PICSTRB:  Opcode = ARM::STRBrs; break;
1468     case ARM::PICSTRH:  Opcode = ARM::STRH; break;
1469     case ARM::PICLDR:   Opcode = ARM::LDRrs; break;
1470     case ARM::PICLDRB:  Opcode = ARM::LDRBrs; break;
1471     case ARM::PICLDRH:  Opcode = ARM::LDRH; break;
1472     case ARM::PICLDRSB: Opcode = ARM::LDRSB; break;
1473     case ARM::PICLDRSH: Opcode = ARM::LDRSH; break;
1474     }
1475     MCInst LdStInst;
1476     LdStInst.setOpcode(Opcode);
1477     LdStInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1478     LdStInst.addOperand(MCOperand::CreateReg(ARM::PC));
1479     LdStInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1480     LdStInst.addOperand(MCOperand::CreateImm(0));
1481     // Add predicate operands.
1482     LdStInst.addOperand(MCOperand::CreateImm(MI->getOperand(3).getImm()));
1483     LdStInst.addOperand(MCOperand::CreateReg(MI->getOperand(4).getReg()));
1484     OutStreamer.EmitInstruction(LdStInst);
1485 
1486     return;
1487   }
1488   case ARM::CONSTPOOL_ENTRY: {
1489     /// CONSTPOOL_ENTRY - This instruction represents a floating constant pool
1490     /// in the function.  The first operand is the ID# for this instruction, the
1491     /// second is the index into the MachineConstantPool that this is, the third
1492     /// is the size in bytes of this constant pool entry.
1493     /// The required alignment is specified on the basic block holding this MI.
1494     unsigned LabelId = (unsigned)MI->getOperand(0).getImm();
1495     unsigned CPIdx   = (unsigned)MI->getOperand(1).getIndex();
1496 
1497     // Mark the constant pool entry as data if we're not already in a data
1498     // region.
1499     OutStreamer.EmitDataRegion();
1500     OutStreamer.EmitLabel(GetCPISymbol(LabelId));
1501 
1502     const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPIdx];
1503     if (MCPE.isMachineConstantPoolEntry())
1504       EmitMachineConstantPoolValue(MCPE.Val.MachineCPVal);
1505     else
1506       EmitGlobalConstant(MCPE.Val.ConstVal);
1507     return;
1508   }
1509   case ARM::t2BR_JT: {
1510     // Lower and emit the instruction itself, then the jump table following it.
1511     MCInst TmpInst;
1512     TmpInst.setOpcode(ARM::tMOVr);
1513     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1514     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1515     // Add predicate operands.
1516     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1517     TmpInst.addOperand(MCOperand::CreateReg(0));
1518     OutStreamer.EmitInstruction(TmpInst);
1519     // Output the data for the jump table itself
1520     EmitJump2Table(MI);
1521     return;
1522   }
1523   case ARM::t2TBB_JT: {
1524     // Lower and emit the instruction itself, then the jump table following it.
1525     MCInst TmpInst;
1526 
1527     TmpInst.setOpcode(ARM::t2TBB);
1528     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1529     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1530     // Add predicate operands.
1531     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1532     TmpInst.addOperand(MCOperand::CreateReg(0));
1533     OutStreamer.EmitInstruction(TmpInst);
1534     // Output the data for the jump table itself
1535     EmitJump2Table(MI);
1536     // Make sure the next instruction is 2-byte aligned.
1537     EmitAlignment(1);
1538     return;
1539   }
1540   case ARM::t2TBH_JT: {
1541     // Lower and emit the instruction itself, then the jump table following it.
1542     MCInst TmpInst;
1543 
1544     TmpInst.setOpcode(ARM::t2TBH);
1545     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1546     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1547     // Add predicate operands.
1548     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1549     TmpInst.addOperand(MCOperand::CreateReg(0));
1550     OutStreamer.EmitInstruction(TmpInst);
1551     // Output the data for the jump table itself
1552     EmitJump2Table(MI);
1553     return;
1554   }
1555   case ARM::tBR_JTr:
1556   case ARM::BR_JTr: {
1557     // Lower and emit the instruction itself, then the jump table following it.
1558     // mov pc, target
1559     MCInst TmpInst;
1560     unsigned Opc = MI->getOpcode() == ARM::BR_JTr ?
1561       ARM::MOVr : ARM::tMOVr;
1562     TmpInst.setOpcode(Opc);
1563     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1564     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1565     // Add predicate operands.
1566     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1567     TmpInst.addOperand(MCOperand::CreateReg(0));
1568     // Add 's' bit operand (always reg0 for this)
1569     if (Opc == ARM::MOVr)
1570       TmpInst.addOperand(MCOperand::CreateReg(0));
1571     OutStreamer.EmitInstruction(TmpInst);
1572 
1573     // Make sure the Thumb jump table is 4-byte aligned.
1574     if (Opc == ARM::tMOVr)
1575       EmitAlignment(2);
1576 
1577     // Output the data for the jump table itself
1578     EmitJumpTable(MI);
1579     return;
1580   }
1581   case ARM::BR_JTm: {
1582     // Lower and emit the instruction itself, then the jump table following it.
1583     // ldr pc, target
1584     MCInst TmpInst;
1585     if (MI->getOperand(1).getReg() == 0) {
1586       // literal offset
1587       TmpInst.setOpcode(ARM::LDRi12);
1588       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1589       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1590       TmpInst.addOperand(MCOperand::CreateImm(MI->getOperand(2).getImm()));
1591     } else {
1592       TmpInst.setOpcode(ARM::LDRrs);
1593       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1594       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1595       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1596       TmpInst.addOperand(MCOperand::CreateImm(0));
1597     }
1598     // Add predicate operands.
1599     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1600     TmpInst.addOperand(MCOperand::CreateReg(0));
1601     OutStreamer.EmitInstruction(TmpInst);
1602 
1603     // Output the data for the jump table itself
1604     EmitJumpTable(MI);
1605     return;
1606   }
1607   case ARM::BR_JTadd: {
1608     // Lower and emit the instruction itself, then the jump table following it.
1609     // add pc, target, idx
1610     MCInst TmpInst;
1611     TmpInst.setOpcode(ARM::ADDrr);
1612     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1613     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1614     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1615     // Add predicate operands.
1616     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1617     TmpInst.addOperand(MCOperand::CreateReg(0));
1618     // Add 's' bit operand (always reg0 for this)
1619     TmpInst.addOperand(MCOperand::CreateReg(0));
1620     OutStreamer.EmitInstruction(TmpInst);
1621 
1622     // Output the data for the jump table itself
1623     EmitJumpTable(MI);
1624     return;
1625   }
1626   case ARM::TRAP: {
1627     // Non-Darwin binutils don't yet support the "trap" mnemonic.
1628     // FIXME: Remove this special case when they do.
1629     if (!Subtarget->isTargetDarwin()) {
1630       //.long 0xe7ffdefe @ trap
1631       uint32_t Val = 0xe7ffdefeUL;
1632       OutStreamer.AddComment("trap");
1633       OutStreamer.EmitIntValue(Val, 4);
1634       return;
1635     }
1636     break;
1637   }
1638   case ARM::tTRAP: {
1639     // Non-Darwin binutils don't yet support the "trap" mnemonic.
1640     // FIXME: Remove this special case when they do.
1641     if (!Subtarget->isTargetDarwin()) {
1642       //.short 57086 @ trap
1643       uint16_t Val = 0xdefe;
1644       OutStreamer.AddComment("trap");
1645       OutStreamer.EmitIntValue(Val, 2);
1646       return;
1647     }
1648     break;
1649   }
1650   case ARM::t2Int_eh_sjlj_setjmp:
1651   case ARM::t2Int_eh_sjlj_setjmp_nofp:
1652   case ARM::tInt_eh_sjlj_setjmp: {
1653     // Two incoming args: GPR:$src, GPR:$val
1654     // mov $val, pc
1655     // adds $val, #7
1656     // str $val, [$src, #4]
1657     // movs r0, #0
1658     // b 1f
1659     // movs r0, #1
1660     // 1:
1661     unsigned SrcReg = MI->getOperand(0).getReg();
1662     unsigned ValReg = MI->getOperand(1).getReg();
1663     MCSymbol *Label = GetARMSJLJEHLabel();
1664     {
1665       MCInst TmpInst;
1666       TmpInst.setOpcode(ARM::tMOVr);
1667       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1668       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1669       // Predicate.
1670       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1671       TmpInst.addOperand(MCOperand::CreateReg(0));
1672       OutStreamer.AddComment("eh_setjmp begin");
1673       OutStreamer.EmitInstruction(TmpInst);
1674     }
1675     {
1676       MCInst TmpInst;
1677       TmpInst.setOpcode(ARM::tADDi3);
1678       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1679       // 's' bit operand
1680       TmpInst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1681       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1682       TmpInst.addOperand(MCOperand::CreateImm(7));
1683       // Predicate.
1684       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1685       TmpInst.addOperand(MCOperand::CreateReg(0));
1686       OutStreamer.EmitInstruction(TmpInst);
1687     }
1688     {
1689       MCInst TmpInst;
1690       TmpInst.setOpcode(ARM::tSTRi);
1691       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1692       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1693       // The offset immediate is #4. The operand value is scaled by 4 for the
1694       // tSTR instruction.
1695       TmpInst.addOperand(MCOperand::CreateImm(1));
1696       // Predicate.
1697       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1698       TmpInst.addOperand(MCOperand::CreateReg(0));
1699       OutStreamer.EmitInstruction(TmpInst);
1700     }
1701     {
1702       MCInst TmpInst;
1703       TmpInst.setOpcode(ARM::tMOVi8);
1704       TmpInst.addOperand(MCOperand::CreateReg(ARM::R0));
1705       TmpInst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1706       TmpInst.addOperand(MCOperand::CreateImm(0));
1707       // Predicate.
1708       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1709       TmpInst.addOperand(MCOperand::CreateReg(0));
1710       OutStreamer.EmitInstruction(TmpInst);
1711     }
1712     {
1713       const MCExpr *SymbolExpr = MCSymbolRefExpr::Create(Label, OutContext);
1714       MCInst TmpInst;
1715       TmpInst.setOpcode(ARM::tB);
1716       TmpInst.addOperand(MCOperand::CreateExpr(SymbolExpr));
1717       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1718       TmpInst.addOperand(MCOperand::CreateReg(0));
1719       OutStreamer.EmitInstruction(TmpInst);
1720     }
1721     {
1722       MCInst TmpInst;
1723       TmpInst.setOpcode(ARM::tMOVi8);
1724       TmpInst.addOperand(MCOperand::CreateReg(ARM::R0));
1725       TmpInst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1726       TmpInst.addOperand(MCOperand::CreateImm(1));
1727       // Predicate.
1728       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1729       TmpInst.addOperand(MCOperand::CreateReg(0));
1730       OutStreamer.AddComment("eh_setjmp end");
1731       OutStreamer.EmitInstruction(TmpInst);
1732     }
1733     OutStreamer.EmitLabel(Label);
1734     return;
1735   }
1736 
1737   case ARM::Int_eh_sjlj_setjmp_nofp:
1738   case ARM::Int_eh_sjlj_setjmp: {
1739     // Two incoming args: GPR:$src, GPR:$val
1740     // add $val, pc, #8
1741     // str $val, [$src, #+4]
1742     // mov r0, #0
1743     // add pc, pc, #0
1744     // mov r0, #1
1745     unsigned SrcReg = MI->getOperand(0).getReg();
1746     unsigned ValReg = MI->getOperand(1).getReg();
1747 
1748     {
1749       MCInst TmpInst;
1750       TmpInst.setOpcode(ARM::ADDri);
1751       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1752       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1753       TmpInst.addOperand(MCOperand::CreateImm(8));
1754       // Predicate.
1755       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1756       TmpInst.addOperand(MCOperand::CreateReg(0));
1757       // 's' bit operand (always reg0 for this).
1758       TmpInst.addOperand(MCOperand::CreateReg(0));
1759       OutStreamer.AddComment("eh_setjmp begin");
1760       OutStreamer.EmitInstruction(TmpInst);
1761     }
1762     {
1763       MCInst TmpInst;
1764       TmpInst.setOpcode(ARM::STRi12);
1765       TmpInst.addOperand(MCOperand::CreateReg(ValReg));
1766       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1767       TmpInst.addOperand(MCOperand::CreateImm(4));
1768       // Predicate.
1769       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1770       TmpInst.addOperand(MCOperand::CreateReg(0));
1771       OutStreamer.EmitInstruction(TmpInst);
1772     }
1773     {
1774       MCInst TmpInst;
1775       TmpInst.setOpcode(ARM::MOVi);
1776       TmpInst.addOperand(MCOperand::CreateReg(ARM::R0));
1777       TmpInst.addOperand(MCOperand::CreateImm(0));
1778       // Predicate.
1779       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1780       TmpInst.addOperand(MCOperand::CreateReg(0));
1781       // 's' bit operand (always reg0 for this).
1782       TmpInst.addOperand(MCOperand::CreateReg(0));
1783       OutStreamer.EmitInstruction(TmpInst);
1784     }
1785     {
1786       MCInst TmpInst;
1787       TmpInst.setOpcode(ARM::ADDri);
1788       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1789       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1790       TmpInst.addOperand(MCOperand::CreateImm(0));
1791       // Predicate.
1792       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1793       TmpInst.addOperand(MCOperand::CreateReg(0));
1794       // 's' bit operand (always reg0 for this).
1795       TmpInst.addOperand(MCOperand::CreateReg(0));
1796       OutStreamer.EmitInstruction(TmpInst);
1797     }
1798     {
1799       MCInst TmpInst;
1800       TmpInst.setOpcode(ARM::MOVi);
1801       TmpInst.addOperand(MCOperand::CreateReg(ARM::R0));
1802       TmpInst.addOperand(MCOperand::CreateImm(1));
1803       // Predicate.
1804       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1805       TmpInst.addOperand(MCOperand::CreateReg(0));
1806       // 's' bit operand (always reg0 for this).
1807       TmpInst.addOperand(MCOperand::CreateReg(0));
1808       OutStreamer.AddComment("eh_setjmp end");
1809       OutStreamer.EmitInstruction(TmpInst);
1810     }
1811     return;
1812   }
1813   case ARM::Int_eh_sjlj_longjmp: {
1814     // ldr sp, [$src, #8]
1815     // ldr $scratch, [$src, #4]
1816     // ldr r7, [$src]
1817     // bx $scratch
1818     unsigned SrcReg = MI->getOperand(0).getReg();
1819     unsigned ScratchReg = MI->getOperand(1).getReg();
1820     {
1821       MCInst TmpInst;
1822       TmpInst.setOpcode(ARM::LDRi12);
1823       TmpInst.addOperand(MCOperand::CreateReg(ARM::SP));
1824       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1825       TmpInst.addOperand(MCOperand::CreateImm(8));
1826       // Predicate.
1827       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1828       TmpInst.addOperand(MCOperand::CreateReg(0));
1829       OutStreamer.EmitInstruction(TmpInst);
1830     }
1831     {
1832       MCInst TmpInst;
1833       TmpInst.setOpcode(ARM::LDRi12);
1834       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1835       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1836       TmpInst.addOperand(MCOperand::CreateImm(4));
1837       // Predicate.
1838       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1839       TmpInst.addOperand(MCOperand::CreateReg(0));
1840       OutStreamer.EmitInstruction(TmpInst);
1841     }
1842     {
1843       MCInst TmpInst;
1844       TmpInst.setOpcode(ARM::LDRi12);
1845       TmpInst.addOperand(MCOperand::CreateReg(ARM::R7));
1846       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1847       TmpInst.addOperand(MCOperand::CreateImm(0));
1848       // Predicate.
1849       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1850       TmpInst.addOperand(MCOperand::CreateReg(0));
1851       OutStreamer.EmitInstruction(TmpInst);
1852     }
1853     {
1854       MCInst TmpInst;
1855       TmpInst.setOpcode(ARM::BX);
1856       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1857       // Predicate.
1858       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1859       TmpInst.addOperand(MCOperand::CreateReg(0));
1860       OutStreamer.EmitInstruction(TmpInst);
1861     }
1862     return;
1863   }
1864   case ARM::tInt_eh_sjlj_longjmp: {
1865     // ldr $scratch, [$src, #8]
1866     // mov sp, $scratch
1867     // ldr $scratch, [$src, #4]
1868     // ldr r7, [$src]
1869     // bx $scratch
1870     unsigned SrcReg = MI->getOperand(0).getReg();
1871     unsigned ScratchReg = MI->getOperand(1).getReg();
1872     {
1873       MCInst TmpInst;
1874       TmpInst.setOpcode(ARM::tLDRi);
1875       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1876       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1877       // The offset immediate is #8. The operand value is scaled by 4 for the
1878       // tLDR instruction.
1879       TmpInst.addOperand(MCOperand::CreateImm(2));
1880       // Predicate.
1881       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1882       TmpInst.addOperand(MCOperand::CreateReg(0));
1883       OutStreamer.EmitInstruction(TmpInst);
1884     }
1885     {
1886       MCInst TmpInst;
1887       TmpInst.setOpcode(ARM::tMOVr);
1888       TmpInst.addOperand(MCOperand::CreateReg(ARM::SP));
1889       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1890       // Predicate.
1891       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1892       TmpInst.addOperand(MCOperand::CreateReg(0));
1893       OutStreamer.EmitInstruction(TmpInst);
1894     }
1895     {
1896       MCInst TmpInst;
1897       TmpInst.setOpcode(ARM::tLDRi);
1898       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1899       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1900       TmpInst.addOperand(MCOperand::CreateImm(1));
1901       // Predicate.
1902       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1903       TmpInst.addOperand(MCOperand::CreateReg(0));
1904       OutStreamer.EmitInstruction(TmpInst);
1905     }
1906     {
1907       MCInst TmpInst;
1908       TmpInst.setOpcode(ARM::tLDRr);
1909       TmpInst.addOperand(MCOperand::CreateReg(ARM::R7));
1910       TmpInst.addOperand(MCOperand::CreateReg(SrcReg));
1911       TmpInst.addOperand(MCOperand::CreateReg(0));
1912       // Predicate.
1913       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1914       TmpInst.addOperand(MCOperand::CreateReg(0));
1915       OutStreamer.EmitInstruction(TmpInst);
1916     }
1917     {
1918       MCInst TmpInst;
1919       TmpInst.setOpcode(ARM::tBX);
1920       TmpInst.addOperand(MCOperand::CreateReg(ScratchReg));
1921       // Predicate.
1922       TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1923       TmpInst.addOperand(MCOperand::CreateReg(0));
1924       OutStreamer.EmitInstruction(TmpInst);
1925     }
1926     return;
1927   }
1928   }
1929 
1930   MCInst TmpInst;
1931   LowerARMMachineInstrToMCInst(MI, TmpInst, *this);
1932 
1933   OutStreamer.EmitInstruction(TmpInst);
1934 }
1935 
1936 //===----------------------------------------------------------------------===//
1937 // Target Registry Stuff
1938 //===----------------------------------------------------------------------===//
1939 
1940 // Force static initialization.
1941 extern "C" void LLVMInitializeARMAsmPrinter() {
1942   RegisterAsmPrinter<ARMAsmPrinter> X(TheARMTarget);
1943   RegisterAsmPrinter<ARMAsmPrinter> Y(TheThumbTarget);
1944 }
1945