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 #include "ARMAsmPrinter.h"
16 #include "ARM.h"
17 #include "ARMConstantPoolValue.h"
18 #include "ARMFPUName.h"
19 #include "ARMArchExtName.h"
20 #include "ARMMachineFunctionInfo.h"
21 #include "ARMTargetMachine.h"
22 #include "ARMTargetObjectFile.h"
23 #include "InstPrinter/ARMInstPrinter.h"
24 #include "MCTargetDesc/ARMAddressingModes.h"
25 #include "MCTargetDesc/ARMMCExpr.h"
26 #include "llvm/ADT/SetVector.h"
27 #include "llvm/ADT/SmallString.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
31 #include "llvm/IR/Constants.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/DebugInfo.h"
34 #include "llvm/IR/Mangler.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/IR/Type.h"
37 #include "llvm/MC/MCAsmInfo.h"
38 #include "llvm/MC/MCAssembler.h"
39 #include "llvm/MC/MCContext.h"
40 #include "llvm/MC/MCELFStreamer.h"
41 #include "llvm/MC/MCInst.h"
42 #include "llvm/MC/MCInstBuilder.h"
43 #include "llvm/MC/MCObjectStreamer.h"
44 #include "llvm/MC/MCSectionMachO.h"
45 #include "llvm/MC/MCStreamer.h"
46 #include "llvm/MC/MCSymbol.h"
47 #include "llvm/Support/ARMBuildAttributes.h"
48 #include "llvm/Support/COFF.h"
49 #include "llvm/Support/CommandLine.h"
50 #include "llvm/Support/Debug.h"
51 #include "llvm/Support/ELF.h"
52 #include "llvm/Support/ErrorHandling.h"
53 #include "llvm/Support/TargetRegistry.h"
54 #include "llvm/Support/raw_ostream.h"
55 #include "llvm/Target/TargetMachine.h"
56 #include <cctype>
57 using namespace llvm;
58 
59 #define DEBUG_TYPE "asm-printer"
60 
ARMAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)61 ARMAsmPrinter::ARMAsmPrinter(TargetMachine &TM,
62                              std::unique_ptr<MCStreamer> Streamer)
63     : AsmPrinter(TM, std::move(Streamer)), AFI(nullptr), MCP(nullptr),
64       InConstantPool(false) {}
65 
EmitFunctionBodyEnd()66 void ARMAsmPrinter::EmitFunctionBodyEnd() {
67   // Make sure to terminate any constant pools that were at the end
68   // of the function.
69   if (!InConstantPool)
70     return;
71   InConstantPool = false;
72   OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
73 }
74 
EmitFunctionEntryLabel()75 void ARMAsmPrinter::EmitFunctionEntryLabel() {
76   if (AFI->isThumbFunction()) {
77     OutStreamer.EmitAssemblerFlag(MCAF_Code16);
78     OutStreamer.EmitThumbFunc(CurrentFnSym);
79   }
80 
81   OutStreamer.EmitLabel(CurrentFnSym);
82 }
83 
EmitXXStructor(const Constant * CV)84 void ARMAsmPrinter::EmitXXStructor(const Constant *CV) {
85   uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
86   assert(Size && "C++ constructor pointer had zero size!");
87 
88   const GlobalValue *GV = dyn_cast<GlobalValue>(CV->stripPointerCasts());
89   assert(GV && "C++ constructor pointer was not a GlobalValue!");
90 
91   const MCExpr *E = MCSymbolRefExpr::Create(GetARMGVSymbol(GV,
92                                                            ARMII::MO_NO_FLAG),
93                                             (Subtarget->isTargetELF()
94                                              ? MCSymbolRefExpr::VK_ARM_TARGET1
95                                              : MCSymbolRefExpr::VK_None),
96                                             OutContext);
97 
98   OutStreamer.EmitValue(E, Size);
99 }
100 
101 /// runOnMachineFunction - This uses the EmitInstruction()
102 /// method to print assembly for each instruction.
103 ///
runOnMachineFunction(MachineFunction & MF)104 bool ARMAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
105   AFI = MF.getInfo<ARMFunctionInfo>();
106   MCP = MF.getConstantPool();
107   Subtarget = &MF.getSubtarget<ARMSubtarget>();
108 
109   SetupMachineFunction(MF);
110 
111   if (Subtarget->isTargetCOFF()) {
112     bool Internal = MF.getFunction()->hasInternalLinkage();
113     COFF::SymbolStorageClass Scl = Internal ? COFF::IMAGE_SYM_CLASS_STATIC
114                                             : COFF::IMAGE_SYM_CLASS_EXTERNAL;
115     int Type = COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT;
116 
117     OutStreamer.BeginCOFFSymbolDef(CurrentFnSym);
118     OutStreamer.EmitCOFFSymbolStorageClass(Scl);
119     OutStreamer.EmitCOFFSymbolType(Type);
120     OutStreamer.EndCOFFSymbolDef();
121   }
122 
123   // Emit the rest of the function body.
124   EmitFunctionBody();
125 
126   // If we need V4T thumb mode Register Indirect Jump pads, emit them.
127   // These are created per function, rather than per TU, since it's
128   // relatively easy to exceed the thumb branch range within a TU.
129   if (! ThumbIndirectPads.empty()) {
130     OutStreamer.EmitAssemblerFlag(MCAF_Code16);
131     EmitAlignment(1);
132     for (unsigned i = 0, e = ThumbIndirectPads.size(); i < e; i++) {
133       OutStreamer.EmitLabel(ThumbIndirectPads[i].second);
134       EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBX)
135         .addReg(ThumbIndirectPads[i].first)
136         // Add predicate operands.
137         .addImm(ARMCC::AL)
138         .addReg(0));
139     }
140     ThumbIndirectPads.clear();
141   }
142 
143   // We didn't modify anything.
144   return false;
145 }
146 
printOperand(const MachineInstr * MI,int OpNum,raw_ostream & O,const char * Modifier)147 void ARMAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
148                                  raw_ostream &O, const char *Modifier) {
149   const MachineOperand &MO = MI->getOperand(OpNum);
150   unsigned TF = MO.getTargetFlags();
151 
152   switch (MO.getType()) {
153   default: llvm_unreachable("<unknown operand type>");
154   case MachineOperand::MO_Register: {
155     unsigned Reg = MO.getReg();
156     assert(TargetRegisterInfo::isPhysicalRegister(Reg));
157     assert(!MO.getSubReg() && "Subregs should be eliminated!");
158     if(ARM::GPRPairRegClass.contains(Reg)) {
159       const MachineFunction &MF = *MI->getParent()->getParent();
160       const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
161       Reg = TRI->getSubReg(Reg, ARM::gsub_0);
162     }
163     O << ARMInstPrinter::getRegisterName(Reg);
164     break;
165   }
166   case MachineOperand::MO_Immediate: {
167     int64_t Imm = MO.getImm();
168     O << '#';
169     if ((Modifier && strcmp(Modifier, "lo16") == 0) ||
170         (TF == ARMII::MO_LO16))
171       O << ":lower16:";
172     else if ((Modifier && strcmp(Modifier, "hi16") == 0) ||
173              (TF == ARMII::MO_HI16))
174       O << ":upper16:";
175     O << Imm;
176     break;
177   }
178   case MachineOperand::MO_MachineBasicBlock:
179     O << *MO.getMBB()->getSymbol();
180     return;
181   case MachineOperand::MO_GlobalAddress: {
182     const GlobalValue *GV = MO.getGlobal();
183     if ((Modifier && strcmp(Modifier, "lo16") == 0) ||
184         (TF & ARMII::MO_LO16))
185       O << ":lower16:";
186     else if ((Modifier && strcmp(Modifier, "hi16") == 0) ||
187              (TF & ARMII::MO_HI16))
188       O << ":upper16:";
189     O << *GetARMGVSymbol(GV, TF);
190 
191     printOffset(MO.getOffset(), O);
192     if (TF == ARMII::MO_PLT)
193       O << "(PLT)";
194     break;
195   }
196   case MachineOperand::MO_ConstantPoolIndex:
197     O << *GetCPISymbol(MO.getIndex());
198     break;
199   }
200 }
201 
202 //===--------------------------------------------------------------------===//
203 
204 MCSymbol *ARMAsmPrinter::
GetARMJTIPICJumpTableLabel2(unsigned uid,unsigned uid2) const205 GetARMJTIPICJumpTableLabel2(unsigned uid, unsigned uid2) const {
206   const DataLayout *DL = TM.getDataLayout();
207   SmallString<60> Name;
208   raw_svector_ostream(Name) << DL->getPrivateGlobalPrefix() << "JTI"
209     << getFunctionNumber() << '_' << uid << '_' << uid2;
210   return OutContext.GetOrCreateSymbol(Name);
211 }
212 
213 
GetARMSJLJEHLabel() const214 MCSymbol *ARMAsmPrinter::GetARMSJLJEHLabel() const {
215   const DataLayout *DL = TM.getDataLayout();
216   SmallString<60> Name;
217   raw_svector_ostream(Name) << DL->getPrivateGlobalPrefix() << "SJLJEH"
218     << getFunctionNumber();
219   return OutContext.GetOrCreateSymbol(Name);
220 }
221 
PrintAsmOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)222 bool ARMAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
223                                     unsigned AsmVariant, const char *ExtraCode,
224                                     raw_ostream &O) {
225   // Does this asm operand have a single letter operand modifier?
226   if (ExtraCode && ExtraCode[0]) {
227     if (ExtraCode[1] != 0) return true; // Unknown modifier.
228 
229     switch (ExtraCode[0]) {
230     default:
231       // See if this is a generic print operand
232       return AsmPrinter::PrintAsmOperand(MI, OpNum, AsmVariant, ExtraCode, O);
233     case 'a': // Print as a memory address.
234       if (MI->getOperand(OpNum).isReg()) {
235         O << "["
236           << ARMInstPrinter::getRegisterName(MI->getOperand(OpNum).getReg())
237           << "]";
238         return false;
239       }
240       // Fallthrough
241     case 'c': // Don't print "#" before an immediate operand.
242       if (!MI->getOperand(OpNum).isImm())
243         return true;
244       O << MI->getOperand(OpNum).getImm();
245       return false;
246     case 'P': // Print a VFP double precision register.
247     case 'q': // Print a NEON quad precision register.
248       printOperand(MI, OpNum, O);
249       return false;
250     case 'y': // Print a VFP single precision register as indexed double.
251       if (MI->getOperand(OpNum).isReg()) {
252         unsigned Reg = MI->getOperand(OpNum).getReg();
253         const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
254         // Find the 'd' register that has this 's' register as a sub-register,
255         // and determine the lane number.
256         for (MCSuperRegIterator SR(Reg, TRI); SR.isValid(); ++SR) {
257           if (!ARM::DPRRegClass.contains(*SR))
258             continue;
259           bool Lane0 = TRI->getSubReg(*SR, ARM::ssub_0) == Reg;
260           O << ARMInstPrinter::getRegisterName(*SR) << (Lane0 ? "[0]" : "[1]");
261           return false;
262         }
263       }
264       return true;
265     case 'B': // Bitwise inverse of integer or symbol without a preceding #.
266       if (!MI->getOperand(OpNum).isImm())
267         return true;
268       O << ~(MI->getOperand(OpNum).getImm());
269       return false;
270     case 'L': // The low 16 bits of an immediate constant.
271       if (!MI->getOperand(OpNum).isImm())
272         return true;
273       O << (MI->getOperand(OpNum).getImm() & 0xffff);
274       return false;
275     case 'M': { // A register range suitable for LDM/STM.
276       if (!MI->getOperand(OpNum).isReg())
277         return true;
278       const MachineOperand &MO = MI->getOperand(OpNum);
279       unsigned RegBegin = MO.getReg();
280       // This takes advantage of the 2 operand-ness of ldm/stm and that we've
281       // already got the operands in registers that are operands to the
282       // inline asm statement.
283       O << "{";
284       if (ARM::GPRPairRegClass.contains(RegBegin)) {
285         const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
286         unsigned Reg0 = TRI->getSubReg(RegBegin, ARM::gsub_0);
287         O << ARMInstPrinter::getRegisterName(Reg0) << ", ";
288         RegBegin = TRI->getSubReg(RegBegin, ARM::gsub_1);
289       }
290       O << ARMInstPrinter::getRegisterName(RegBegin);
291 
292       // FIXME: The register allocator not only may not have given us the
293       // registers in sequence, but may not be in ascending registers. This
294       // will require changes in the register allocator that'll need to be
295       // propagated down here if the operands change.
296       unsigned RegOps = OpNum + 1;
297       while (MI->getOperand(RegOps).isReg()) {
298         O << ", "
299           << ARMInstPrinter::getRegisterName(MI->getOperand(RegOps).getReg());
300         RegOps++;
301       }
302 
303       O << "}";
304 
305       return false;
306     }
307     case 'R': // The most significant register of a pair.
308     case 'Q': { // The least significant register of a pair.
309       if (OpNum == 0)
310         return true;
311       const MachineOperand &FlagsOP = MI->getOperand(OpNum - 1);
312       if (!FlagsOP.isImm())
313         return true;
314       unsigned Flags = FlagsOP.getImm();
315 
316       // This operand may not be the one that actually provides the register. If
317       // it's tied to a previous one then we should refer instead to that one
318       // for registers and their classes.
319       unsigned TiedIdx;
320       if (InlineAsm::isUseOperandTiedToDef(Flags, TiedIdx)) {
321         for (OpNum = InlineAsm::MIOp_FirstOperand; TiedIdx; --TiedIdx) {
322           unsigned OpFlags = MI->getOperand(OpNum).getImm();
323           OpNum += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
324         }
325         Flags = MI->getOperand(OpNum).getImm();
326 
327         // Later code expects OpNum to be pointing at the register rather than
328         // the flags.
329         OpNum += 1;
330       }
331 
332       unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
333       unsigned RC;
334       InlineAsm::hasRegClassConstraint(Flags, RC);
335       if (RC == ARM::GPRPairRegClassID) {
336         if (NumVals != 1)
337           return true;
338         const MachineOperand &MO = MI->getOperand(OpNum);
339         if (!MO.isReg())
340           return true;
341         const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
342         unsigned Reg = TRI->getSubReg(MO.getReg(), ExtraCode[0] == 'Q' ?
343             ARM::gsub_0 : ARM::gsub_1);
344         O << ARMInstPrinter::getRegisterName(Reg);
345         return false;
346       }
347       if (NumVals != 2)
348         return true;
349       unsigned RegOp = ExtraCode[0] == 'Q' ? OpNum : OpNum + 1;
350       if (RegOp >= MI->getNumOperands())
351         return true;
352       const MachineOperand &MO = MI->getOperand(RegOp);
353       if (!MO.isReg())
354         return true;
355       unsigned Reg = MO.getReg();
356       O << ARMInstPrinter::getRegisterName(Reg);
357       return false;
358     }
359 
360     case 'e': // The low doubleword register of a NEON quad register.
361     case 'f': { // The high doubleword register of a NEON quad register.
362       if (!MI->getOperand(OpNum).isReg())
363         return true;
364       unsigned Reg = MI->getOperand(OpNum).getReg();
365       if (!ARM::QPRRegClass.contains(Reg))
366         return true;
367       const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
368       unsigned SubReg = TRI->getSubReg(Reg, ExtraCode[0] == 'e' ?
369                                        ARM::dsub_0 : ARM::dsub_1);
370       O << ARMInstPrinter::getRegisterName(SubReg);
371       return false;
372     }
373 
374     // This modifier is not yet supported.
375     case 'h': // A range of VFP/NEON registers suitable for VLD1/VST1.
376       return true;
377     case 'H': { // The highest-numbered register of a pair.
378       const MachineOperand &MO = MI->getOperand(OpNum);
379       if (!MO.isReg())
380         return true;
381       const MachineFunction &MF = *MI->getParent()->getParent();
382       const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
383       unsigned Reg = MO.getReg();
384       if(!ARM::GPRPairRegClass.contains(Reg))
385         return false;
386       Reg = TRI->getSubReg(Reg, ARM::gsub_1);
387       O << ARMInstPrinter::getRegisterName(Reg);
388       return false;
389     }
390     }
391   }
392 
393   printOperand(MI, OpNum, O);
394   return false;
395 }
396 
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)397 bool ARMAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
398                                           unsigned OpNum, unsigned AsmVariant,
399                                           const char *ExtraCode,
400                                           raw_ostream &O) {
401   // Does this asm operand have a single letter operand modifier?
402   if (ExtraCode && ExtraCode[0]) {
403     if (ExtraCode[1] != 0) return true; // Unknown modifier.
404 
405     switch (ExtraCode[0]) {
406       case 'A': // A memory operand for a VLD1/VST1 instruction.
407       default: return true;  // Unknown modifier.
408       case 'm': // The base register of a memory operand.
409         if (!MI->getOperand(OpNum).isReg())
410           return true;
411         O << ARMInstPrinter::getRegisterName(MI->getOperand(OpNum).getReg());
412         return false;
413     }
414   }
415 
416   const MachineOperand &MO = MI->getOperand(OpNum);
417   assert(MO.isReg() && "unexpected inline asm memory operand");
418   O << "[" << ARMInstPrinter::getRegisterName(MO.getReg()) << "]";
419   return false;
420 }
421 
isThumb(const MCSubtargetInfo & STI)422 static bool isThumb(const MCSubtargetInfo& STI) {
423   return (STI.getFeatureBits() & ARM::ModeThumb) != 0;
424 }
425 
emitInlineAsmEnd(const MCSubtargetInfo & StartInfo,const MCSubtargetInfo * EndInfo) const426 void ARMAsmPrinter::emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
427                                      const MCSubtargetInfo *EndInfo) const {
428   // If either end mode is unknown (EndInfo == NULL) or different than
429   // the start mode, then restore the start mode.
430   const bool WasThumb = isThumb(StartInfo);
431   if (!EndInfo || WasThumb != isThumb(*EndInfo)) {
432     OutStreamer.EmitAssemblerFlag(WasThumb ? MCAF_Code16 : MCAF_Code32);
433   }
434 }
435 
EmitStartOfAsmFile(Module & M)436 void ARMAsmPrinter::EmitStartOfAsmFile(Module &M) {
437   Triple TT(TM.getTargetTriple());
438   // Use unified assembler syntax.
439   OutStreamer.EmitAssemblerFlag(MCAF_SyntaxUnified);
440 
441   // Emit ARM Build Attributes
442   if (TT.isOSBinFormatELF())
443     emitAttributes();
444 
445   // Use the triple's architecture and subarchitecture to determine
446   // if we're thumb for the purposes of the top level code16 assembler
447   // flag.
448   bool isThumb = TT.getArch() == Triple::thumb ||
449                  TT.getArch() == Triple::thumbeb ||
450                  TT.getSubArch() == Triple::ARMSubArch_v7m ||
451                  TT.getSubArch() == Triple::ARMSubArch_v6m;
452   if (!M.getModuleInlineAsm().empty() && isThumb)
453     OutStreamer.EmitAssemblerFlag(MCAF_Code16);
454 }
455 
456 static void
emitNonLazySymbolPointer(MCStreamer & OutStreamer,MCSymbol * StubLabel,MachineModuleInfoImpl::StubValueTy & MCSym)457 emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
458                          MachineModuleInfoImpl::StubValueTy &MCSym) {
459   // L_foo$stub:
460   OutStreamer.EmitLabel(StubLabel);
461   //   .indirect_symbol _foo
462   OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
463 
464   if (MCSym.getInt())
465     // External to current translation unit.
466     OutStreamer.EmitIntValue(0, 4/*size*/);
467   else
468     // Internal to current translation unit.
469     //
470     // When we place the LSDA into the TEXT section, the type info
471     // pointers need to be indirect and pc-rel. We accomplish this by
472     // using NLPs; however, sometimes the types are local to the file.
473     // We need to fill in the value for the NLP in those cases.
474     OutStreamer.EmitValue(
475         MCSymbolRefExpr::Create(MCSym.getPointer(), OutStreamer.getContext()),
476         4 /*size*/);
477 }
478 
479 
EmitEndOfAsmFile(Module & M)480 void ARMAsmPrinter::EmitEndOfAsmFile(Module &M) {
481   Triple TT(TM.getTargetTriple());
482   if (TT.isOSBinFormatMachO()) {
483     // All darwin targets use mach-o.
484     const TargetLoweringObjectFileMachO &TLOFMacho =
485       static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
486     MachineModuleInfoMachO &MMIMacho =
487       MMI->getObjFileInfo<MachineModuleInfoMachO>();
488 
489     // Output non-lazy-pointers for external and common global variables.
490     MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetGVStubList();
491 
492     if (!Stubs.empty()) {
493       // Switch with ".non_lazy_symbol_pointer" directive.
494       OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
495       EmitAlignment(2);
496 
497       for (auto &Stub : Stubs)
498         emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
499 
500       Stubs.clear();
501       OutStreamer.AddBlankLine();
502     }
503 
504     Stubs = MMIMacho.GetHiddenGVStubList();
505     if (!Stubs.empty()) {
506       OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
507       EmitAlignment(2);
508 
509       for (auto &Stub : Stubs)
510         emitNonLazySymbolPointer(OutStreamer, Stub.first, Stub.second);
511 
512       Stubs.clear();
513       OutStreamer.AddBlankLine();
514     }
515 
516     // Funny Darwin hack: This flag tells the linker that no global symbols
517     // contain code that falls through to other global symbols (e.g. the obvious
518     // implementation of multiple entry points).  If this doesn't occur, the
519     // linker can safely perform dead code stripping.  Since LLVM never
520     // generates code that does this, it is always safe to set.
521     OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
522   }
523 }
524 
525 //===----------------------------------------------------------------------===//
526 // Helper routines for EmitStartOfAsmFile() and EmitEndOfAsmFile()
527 // FIXME:
528 // The following seem like one-off assembler flags, but they actually need
529 // to appear in the .ARM.attributes section in ELF.
530 // Instead of subclassing the MCELFStreamer, we do the work here.
531 
getArchForCPU(StringRef CPU,const ARMSubtarget * Subtarget)532 static ARMBuildAttrs::CPUArch getArchForCPU(StringRef CPU,
533                                             const ARMSubtarget *Subtarget) {
534   if (CPU == "xscale")
535     return ARMBuildAttrs::v5TEJ;
536 
537   if (Subtarget->hasV8Ops())
538     return ARMBuildAttrs::v8;
539   else if (Subtarget->hasV7Ops()) {
540     if (Subtarget->isMClass() && Subtarget->hasThumb2DSP())
541       return ARMBuildAttrs::v7E_M;
542     return ARMBuildAttrs::v7;
543   } else if (Subtarget->hasV6T2Ops())
544     return ARMBuildAttrs::v6T2;
545   else if (Subtarget->hasV6MOps())
546     return ARMBuildAttrs::v6S_M;
547   else if (Subtarget->hasV6Ops())
548     return ARMBuildAttrs::v6;
549   else if (Subtarget->hasV5TEOps())
550     return ARMBuildAttrs::v5TE;
551   else if (Subtarget->hasV5TOps())
552     return ARMBuildAttrs::v5T;
553   else if (Subtarget->hasV4TOps())
554     return ARMBuildAttrs::v4T;
555   else
556     return ARMBuildAttrs::v4;
557 }
558 
emitAttributes()559 void ARMAsmPrinter::emitAttributes() {
560   MCTargetStreamer &TS = *OutStreamer.getTargetStreamer();
561   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
562 
563   ATS.emitTextAttribute(ARMBuildAttrs::conformance, "2.09");
564 
565   ATS.switchVendor("aeabi");
566 
567   // Compute ARM ELF Attributes based on the default subtarget that
568   // we'd have constructed. The existing ARM behavior isn't LTO clean
569   // anyhow.
570   // FIXME: For ifunc related functions we could iterate over and look
571   // for a feature string that doesn't match the default one.
572   StringRef TT = TM.getTargetTriple();
573   StringRef CPU = TM.getTargetCPU();
574   StringRef FS = TM.getTargetFeatureString();
575   std::string ArchFS = ARM_MC::ParseARMTriple(TT, CPU);
576   if (!FS.empty()) {
577     if (!ArchFS.empty())
578       ArchFS = (Twine(ArchFS) + "," + FS).str();
579     else
580       ArchFS = FS;
581   }
582   const ARMBaseTargetMachine &ATM =
583       static_cast<const ARMBaseTargetMachine &>(TM);
584   const ARMSubtarget STI(TT, CPU, ArchFS, ATM, ATM.isLittleEndian());
585 
586   std::string CPUString = STI.getCPUString();
587 
588   if (CPUString.find("generic") != 0) { //CPUString doesn't start with "generic"
589     // FIXME: remove krait check when GNU tools support krait cpu
590     if (STI.isKrait()) {
591       ATS.emitTextAttribute(ARMBuildAttrs::CPU_name, "cortex-a9");
592       // We consider krait as a "cortex-a9" + hwdiv CPU
593       // Enable hwdiv through ".arch_extension idiv"
594       if (STI.hasDivide() || STI.hasDivideInARMMode())
595         ATS.emitArchExtension(ARM::HWDIV);
596     } else
597       ATS.emitTextAttribute(ARMBuildAttrs::CPU_name, CPUString);
598   }
599 
600   ATS.emitAttribute(ARMBuildAttrs::CPU_arch, getArchForCPU(CPUString, &STI));
601 
602   // Tag_CPU_arch_profile must have the default value of 0 when "Architecture
603   // profile is not applicable (e.g. pre v7, or cross-profile code)".
604   if (STI.hasV7Ops()) {
605     if (STI.isAClass()) {
606       ATS.emitAttribute(ARMBuildAttrs::CPU_arch_profile,
607                         ARMBuildAttrs::ApplicationProfile);
608     } else if (STI.isRClass()) {
609       ATS.emitAttribute(ARMBuildAttrs::CPU_arch_profile,
610                         ARMBuildAttrs::RealTimeProfile);
611     } else if (STI.isMClass()) {
612       ATS.emitAttribute(ARMBuildAttrs::CPU_arch_profile,
613                         ARMBuildAttrs::MicroControllerProfile);
614     }
615   }
616 
617   ATS.emitAttribute(ARMBuildAttrs::ARM_ISA_use,
618                     STI.hasARMOps() ? ARMBuildAttrs::Allowed
619                                     : ARMBuildAttrs::Not_Allowed);
620   if (STI.isThumb1Only()) {
621     ATS.emitAttribute(ARMBuildAttrs::THUMB_ISA_use, ARMBuildAttrs::Allowed);
622   } else if (STI.hasThumb2()) {
623     ATS.emitAttribute(ARMBuildAttrs::THUMB_ISA_use,
624                       ARMBuildAttrs::AllowThumb32);
625   }
626 
627   if (STI.hasNEON()) {
628     /* NEON is not exactly a VFP architecture, but GAS emit one of
629      * neon/neon-fp-armv8/neon-vfpv4/vfpv3/vfpv2 for .fpu parameters */
630     if (STI.hasFPARMv8()) {
631       if (STI.hasCrypto())
632         ATS.emitFPU(ARM::CRYPTO_NEON_FP_ARMV8);
633       else
634         ATS.emitFPU(ARM::NEON_FP_ARMV8);
635     } else if (STI.hasVFP4())
636       ATS.emitFPU(ARM::NEON_VFPV4);
637     else
638       ATS.emitFPU(ARM::NEON);
639     // Emit Tag_Advanced_SIMD_arch for ARMv8 architecture
640     if (STI.hasV8Ops())
641       ATS.emitAttribute(ARMBuildAttrs::Advanced_SIMD_arch,
642                         STI.hasV8_1aOps() ? ARMBuildAttrs::AllowNeonARMv8_1a:
643                                             ARMBuildAttrs::AllowNeonARMv8);
644   } else {
645     if (STI.hasFPARMv8())
646       // FPv5 and FP-ARMv8 have the same instructions, so are modeled as one
647       // FPU, but there are two different names for it depending on the CPU.
648       ATS.emitFPU(STI.hasD16() ? ARM::FPV5_D16 : ARM::FP_ARMV8);
649     else if (STI.hasVFP4())
650       ATS.emitFPU(STI.hasD16() ? ARM::VFPV4_D16 : ARM::VFPV4);
651     else if (STI.hasVFP3())
652       ATS.emitFPU(STI.hasD16() ? ARM::VFPV3_D16 : ARM::VFPV3);
653     else if (STI.hasVFP2())
654       ATS.emitFPU(ARM::VFPV2);
655   }
656 
657   if (TM.getRelocationModel() == Reloc::PIC_) {
658     // PIC specific attributes.
659     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_RW_data,
660                       ARMBuildAttrs::AddressRWPCRel);
661     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_RO_data,
662                       ARMBuildAttrs::AddressROPCRel);
663     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_GOT_use,
664                       ARMBuildAttrs::AddressGOT);
665   } else {
666     // Allow direct addressing of imported data for all other relocation models.
667     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_GOT_use,
668                       ARMBuildAttrs::AddressDirect);
669   }
670 
671   // Signal various FP modes.
672   if (!TM.Options.UnsafeFPMath) {
673     ATS.emitAttribute(ARMBuildAttrs::ABI_FP_denormal,
674                       ARMBuildAttrs::IEEEDenormals);
675     ATS.emitAttribute(ARMBuildAttrs::ABI_FP_exceptions, ARMBuildAttrs::Allowed);
676 
677     // If the user has permitted this code to choose the IEEE 754
678     // rounding at run-time, emit the rounding attribute.
679     if (TM.Options.HonorSignDependentRoundingFPMathOption)
680       ATS.emitAttribute(ARMBuildAttrs::ABI_FP_rounding, ARMBuildAttrs::Allowed);
681   } else {
682     if (!STI.hasVFP2()) {
683       // When the target doesn't have an FPU (by design or
684       // intention), the assumptions made on the software support
685       // mirror that of the equivalent hardware support *if it
686       // existed*. For v7 and better we indicate that denormals are
687       // flushed preserving sign, and for V6 we indicate that
688       // denormals are flushed to positive zero.
689       if (STI.hasV7Ops())
690         ATS.emitAttribute(ARMBuildAttrs::ABI_FP_denormal,
691                           ARMBuildAttrs::PreserveFPSign);
692     } else if (STI.hasVFP3()) {
693       // In VFPv4, VFPv4U, VFPv3, or VFPv3U, it is preserved. That is,
694       // the sign bit of the zero matches the sign bit of the input or
695       // result that is being flushed to zero.
696       ATS.emitAttribute(ARMBuildAttrs::ABI_FP_denormal,
697                         ARMBuildAttrs::PreserveFPSign);
698     }
699     // For VFPv2 implementations it is implementation defined as
700     // to whether denormals are flushed to positive zero or to
701     // whatever the sign of zero is (ARM v7AR ARM 2.7.5). Historically
702     // LLVM has chosen to flush this to positive zero (most likely for
703     // GCC compatibility), so that's the chosen value here (the
704     // absence of its emission implies zero).
705   }
706 
707   // TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath is the
708   // equivalent of GCC's -ffinite-math-only flag.
709   if (TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath)
710     ATS.emitAttribute(ARMBuildAttrs::ABI_FP_number_model,
711                       ARMBuildAttrs::Allowed);
712   else
713     ATS.emitAttribute(ARMBuildAttrs::ABI_FP_number_model,
714                       ARMBuildAttrs::AllowIEE754);
715 
716   if (STI.allowsUnalignedMem())
717     ATS.emitAttribute(ARMBuildAttrs::CPU_unaligned_access,
718                       ARMBuildAttrs::Allowed);
719   else
720     ATS.emitAttribute(ARMBuildAttrs::CPU_unaligned_access,
721                       ARMBuildAttrs::Not_Allowed);
722 
723   // FIXME: add more flags to ARMBuildAttributes.h
724   // 8-bytes alignment stuff.
725   ATS.emitAttribute(ARMBuildAttrs::ABI_align_needed, 1);
726   ATS.emitAttribute(ARMBuildAttrs::ABI_align_preserved, 1);
727 
728   // ABI_HardFP_use attribute to indicate single precision FP.
729   if (STI.isFPOnlySP())
730     ATS.emitAttribute(ARMBuildAttrs::ABI_HardFP_use,
731                       ARMBuildAttrs::HardFPSinglePrecision);
732 
733   // Hard float.  Use both S and D registers and conform to AAPCS-VFP.
734   if (STI.isAAPCS_ABI() && TM.Options.FloatABIType == FloatABI::Hard)
735     ATS.emitAttribute(ARMBuildAttrs::ABI_VFP_args, ARMBuildAttrs::HardFPAAPCS);
736 
737   // FIXME: Should we signal R9 usage?
738 
739   if (STI.hasFP16())
740     ATS.emitAttribute(ARMBuildAttrs::FP_HP_extension, ARMBuildAttrs::AllowHPFP);
741 
742   // FIXME: To support emitting this build attribute as GCC does, the
743   // -mfp16-format option and associated plumbing must be
744   // supported. For now the __fp16 type is exposed by default, so this
745   // attribute should be emitted with value 1.
746   ATS.emitAttribute(ARMBuildAttrs::ABI_FP_16bit_format,
747                     ARMBuildAttrs::FP16FormatIEEE);
748 
749   if (STI.hasMPExtension())
750     ATS.emitAttribute(ARMBuildAttrs::MPextension_use, ARMBuildAttrs::AllowMP);
751 
752   // Hardware divide in ARM mode is part of base arch, starting from ARMv8.
753   // If only Thumb hwdiv is present, it must also be in base arch (ARMv7-R/M).
754   // It is not possible to produce DisallowDIV: if hwdiv is present in the base
755   // arch, supplying -hwdiv downgrades the effective arch, via ClearImpliedBits.
756   // AllowDIVExt is only emitted if hwdiv isn't available in the base arch;
757   // otherwise, the default value (AllowDIVIfExists) applies.
758   if (STI.hasDivideInARMMode() && !STI.hasV8Ops())
759     ATS.emitAttribute(ARMBuildAttrs::DIV_use, ARMBuildAttrs::AllowDIVExt);
760 
761   if (MMI) {
762     if (const Module *SourceModule = MMI->getModule()) {
763       // ABI_PCS_wchar_t to indicate wchar_t width
764       // FIXME: There is no way to emit value 0 (wchar_t prohibited).
765       if (auto WCharWidthValue = mdconst::extract_or_null<ConstantInt>(
766               SourceModule->getModuleFlag("wchar_size"))) {
767         int WCharWidth = WCharWidthValue->getZExtValue();
768         assert((WCharWidth == 2 || WCharWidth == 4) &&
769                "wchar_t width must be 2 or 4 bytes");
770         ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_wchar_t, WCharWidth);
771       }
772 
773       // ABI_enum_size to indicate enum width
774       // FIXME: There is no way to emit value 0 (enums prohibited) or value 3
775       //        (all enums contain a value needing 32 bits to encode).
776       if (auto EnumWidthValue = mdconst::extract_or_null<ConstantInt>(
777               SourceModule->getModuleFlag("min_enum_size"))) {
778         int EnumWidth = EnumWidthValue->getZExtValue();
779         assert((EnumWidth == 1 || EnumWidth == 4) &&
780                "Minimum enum width must be 1 or 4 bytes");
781         int EnumBuildAttr = EnumWidth == 1 ? 1 : 2;
782         ATS.emitAttribute(ARMBuildAttrs::ABI_enum_size, EnumBuildAttr);
783       }
784     }
785   }
786 
787   // TODO: We currently only support either reserving the register, or treating
788   // it as another callee-saved register, but not as SB or a TLS pointer; It
789   // would instead be nicer to push this from the frontend as metadata, as we do
790   // for the wchar and enum size tags
791   if (STI.isR9Reserved())
792     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_R9_use, ARMBuildAttrs::R9Reserved);
793   else
794     ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_R9_use, ARMBuildAttrs::R9IsGPR);
795 
796   if (STI.hasTrustZone() && STI.hasVirtualization())
797     ATS.emitAttribute(ARMBuildAttrs::Virtualization_use,
798                       ARMBuildAttrs::AllowTZVirtualization);
799   else if (STI.hasTrustZone())
800     ATS.emitAttribute(ARMBuildAttrs::Virtualization_use,
801                       ARMBuildAttrs::AllowTZ);
802   else if (STI.hasVirtualization())
803     ATS.emitAttribute(ARMBuildAttrs::Virtualization_use,
804                       ARMBuildAttrs::AllowVirtualization);
805 
806   ATS.finishAttributeSection();
807 }
808 
809 //===----------------------------------------------------------------------===//
810 
getPICLabel(const char * Prefix,unsigned FunctionNumber,unsigned LabelId,MCContext & Ctx)811 static MCSymbol *getPICLabel(const char *Prefix, unsigned FunctionNumber,
812                              unsigned LabelId, MCContext &Ctx) {
813 
814   MCSymbol *Label = Ctx.GetOrCreateSymbol(Twine(Prefix)
815                        + "PC" + Twine(FunctionNumber) + "_" + Twine(LabelId));
816   return Label;
817 }
818 
819 static MCSymbolRefExpr::VariantKind
getModifierVariantKind(ARMCP::ARMCPModifier Modifier)820 getModifierVariantKind(ARMCP::ARMCPModifier Modifier) {
821   switch (Modifier) {
822   case ARMCP::no_modifier: return MCSymbolRefExpr::VK_None;
823   case ARMCP::TLSGD:       return MCSymbolRefExpr::VK_TLSGD;
824   case ARMCP::TPOFF:       return MCSymbolRefExpr::VK_TPOFF;
825   case ARMCP::GOTTPOFF:    return MCSymbolRefExpr::VK_GOTTPOFF;
826   case ARMCP::GOT:         return MCSymbolRefExpr::VK_GOT;
827   case ARMCP::GOTOFF:      return MCSymbolRefExpr::VK_GOTOFF;
828   }
829   llvm_unreachable("Invalid ARMCPModifier!");
830 }
831 
GetARMGVSymbol(const GlobalValue * GV,unsigned char TargetFlags)832 MCSymbol *ARMAsmPrinter::GetARMGVSymbol(const GlobalValue *GV,
833                                         unsigned char TargetFlags) {
834   if (Subtarget->isTargetMachO()) {
835     bool IsIndirect = (TargetFlags & ARMII::MO_NONLAZY) &&
836       Subtarget->GVIsIndirectSymbol(GV, TM.getRelocationModel());
837 
838     if (!IsIndirect)
839       return getSymbol(GV);
840 
841     // FIXME: Remove this when Darwin transition to @GOT like syntax.
842     MCSymbol *MCSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
843     MachineModuleInfoMachO &MMIMachO =
844       MMI->getObjFileInfo<MachineModuleInfoMachO>();
845     MachineModuleInfoImpl::StubValueTy &StubSym =
846       GV->hasHiddenVisibility() ? MMIMachO.getHiddenGVStubEntry(MCSym)
847                                 : MMIMachO.getGVStubEntry(MCSym);
848     if (!StubSym.getPointer())
849       StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(GV),
850                                                    !GV->hasInternalLinkage());
851     return MCSym;
852   } else if (Subtarget->isTargetCOFF()) {
853     assert(Subtarget->isTargetWindows() &&
854            "Windows is the only supported COFF target");
855 
856     bool IsIndirect = (TargetFlags & ARMII::MO_DLLIMPORT);
857     if (!IsIndirect)
858       return getSymbol(GV);
859 
860     SmallString<128> Name;
861     Name = "__imp_";
862     getNameWithPrefix(Name, GV);
863 
864     return OutContext.GetOrCreateSymbol(Name);
865   } else if (Subtarget->isTargetELF()) {
866     return getSymbol(GV);
867   }
868   llvm_unreachable("unexpected target");
869 }
870 
871 void ARMAsmPrinter::
EmitMachineConstantPoolValue(MachineConstantPoolValue * MCPV)872 EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
873   const DataLayout *DL = TM.getDataLayout();
874   int Size = TM.getDataLayout()->getTypeAllocSize(MCPV->getType());
875 
876   ARMConstantPoolValue *ACPV = static_cast<ARMConstantPoolValue*>(MCPV);
877 
878   MCSymbol *MCSym;
879   if (ACPV->isLSDA()) {
880     MCSym = getCurExceptionSym();
881   } else if (ACPV->isBlockAddress()) {
882     const BlockAddress *BA =
883       cast<ARMConstantPoolConstant>(ACPV)->getBlockAddress();
884     MCSym = GetBlockAddressSymbol(BA);
885   } else if (ACPV->isGlobalValue()) {
886     const GlobalValue *GV = cast<ARMConstantPoolConstant>(ACPV)->getGV();
887 
888     // On Darwin, const-pool entries may get the "FOO$non_lazy_ptr" mangling, so
889     // flag the global as MO_NONLAZY.
890     unsigned char TF = Subtarget->isTargetMachO() ? ARMII::MO_NONLAZY : 0;
891     MCSym = GetARMGVSymbol(GV, TF);
892   } else if (ACPV->isMachineBasicBlock()) {
893     const MachineBasicBlock *MBB = cast<ARMConstantPoolMBB>(ACPV)->getMBB();
894     MCSym = MBB->getSymbol();
895   } else {
896     assert(ACPV->isExtSymbol() && "unrecognized constant pool value");
897     const char *Sym = cast<ARMConstantPoolSymbol>(ACPV)->getSymbol();
898     MCSym = GetExternalSymbolSymbol(Sym);
899   }
900 
901   // Create an MCSymbol for the reference.
902   const MCExpr *Expr =
903     MCSymbolRefExpr::Create(MCSym, getModifierVariantKind(ACPV->getModifier()),
904                             OutContext);
905 
906   if (ACPV->getPCAdjustment()) {
907     MCSymbol *PCLabel = getPICLabel(DL->getPrivateGlobalPrefix(),
908                                     getFunctionNumber(),
909                                     ACPV->getLabelId(),
910                                     OutContext);
911     const MCExpr *PCRelExpr = MCSymbolRefExpr::Create(PCLabel, OutContext);
912     PCRelExpr =
913       MCBinaryExpr::CreateAdd(PCRelExpr,
914                               MCConstantExpr::Create(ACPV->getPCAdjustment(),
915                                                      OutContext),
916                               OutContext);
917     if (ACPV->mustAddCurrentAddress()) {
918       // We want "(<expr> - .)", but MC doesn't have a concept of the '.'
919       // label, so just emit a local label end reference that instead.
920       MCSymbol *DotSym = OutContext.CreateTempSymbol();
921       OutStreamer.EmitLabel(DotSym);
922       const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext);
923       PCRelExpr = MCBinaryExpr::CreateSub(PCRelExpr, DotExpr, OutContext);
924     }
925     Expr = MCBinaryExpr::CreateSub(Expr, PCRelExpr, OutContext);
926   }
927   OutStreamer.EmitValue(Expr, Size);
928 }
929 
EmitJumpTable(const MachineInstr * MI)930 void ARMAsmPrinter::EmitJumpTable(const MachineInstr *MI) {
931   unsigned Opcode = MI->getOpcode();
932   int OpNum = 1;
933   if (Opcode == ARM::BR_JTadd)
934     OpNum = 2;
935   else if (Opcode == ARM::BR_JTm)
936     OpNum = 3;
937 
938   const MachineOperand &MO1 = MI->getOperand(OpNum);
939   const MachineOperand &MO2 = MI->getOperand(OpNum+1); // Unique Id
940   unsigned JTI = MO1.getIndex();
941 
942   // Emit a label for the jump table.
943   MCSymbol *JTISymbol = GetARMJTIPICJumpTableLabel2(JTI, MO2.getImm());
944   OutStreamer.EmitLabel(JTISymbol);
945 
946   // Mark the jump table as data-in-code.
947   OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
948 
949   // Emit each entry of the table.
950   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
951   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
952   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
953 
954   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
955     MachineBasicBlock *MBB = JTBBs[i];
956     // Construct an MCExpr for the entry. We want a value of the form:
957     // (BasicBlockAddr - TableBeginAddr)
958     //
959     // For example, a table with entries jumping to basic blocks BB0 and BB1
960     // would look like:
961     // LJTI_0_0:
962     //    .word (LBB0 - LJTI_0_0)
963     //    .word (LBB1 - LJTI_0_0)
964     const MCExpr *Expr = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
965 
966     if (TM.getRelocationModel() == Reloc::PIC_)
967       Expr = MCBinaryExpr::CreateSub(Expr, MCSymbolRefExpr::Create(JTISymbol,
968                                                                    OutContext),
969                                      OutContext);
970     // If we're generating a table of Thumb addresses in static relocation
971     // model, we need to add one to keep interworking correctly.
972     else if (AFI->isThumbFunction())
973       Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(1,OutContext),
974                                      OutContext);
975     OutStreamer.EmitValue(Expr, 4);
976   }
977   // Mark the end of jump table data-in-code region.
978   OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
979 }
980 
EmitJump2Table(const MachineInstr * MI)981 void ARMAsmPrinter::EmitJump2Table(const MachineInstr *MI) {
982   unsigned Opcode = MI->getOpcode();
983   int OpNum = (Opcode == ARM::t2BR_JT) ? 2 : 1;
984   const MachineOperand &MO1 = MI->getOperand(OpNum);
985   const MachineOperand &MO2 = MI->getOperand(OpNum+1); // Unique Id
986   unsigned JTI = MO1.getIndex();
987 
988   MCSymbol *JTISymbol = GetARMJTIPICJumpTableLabel2(JTI, MO2.getImm());
989   OutStreamer.EmitLabel(JTISymbol);
990 
991   // Emit each entry of the table.
992   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
993   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
994   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
995   unsigned OffsetWidth = 4;
996   if (MI->getOpcode() == ARM::t2TBB_JT) {
997     OffsetWidth = 1;
998     // Mark the jump table as data-in-code.
999     OutStreamer.EmitDataRegion(MCDR_DataRegionJT8);
1000   } else if (MI->getOpcode() == ARM::t2TBH_JT) {
1001     OffsetWidth = 2;
1002     // Mark the jump table as data-in-code.
1003     OutStreamer.EmitDataRegion(MCDR_DataRegionJT16);
1004   }
1005 
1006   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
1007     MachineBasicBlock *MBB = JTBBs[i];
1008     const MCExpr *MBBSymbolExpr = MCSymbolRefExpr::Create(MBB->getSymbol(),
1009                                                           OutContext);
1010     // If this isn't a TBB or TBH, the entries are direct branch instructions.
1011     if (OffsetWidth == 4) {
1012       EmitToStreamer(OutStreamer, MCInstBuilder(ARM::t2B)
1013         .addExpr(MBBSymbolExpr)
1014         .addImm(ARMCC::AL)
1015         .addReg(0));
1016       continue;
1017     }
1018     // Otherwise it's an offset from the dispatch instruction. Construct an
1019     // MCExpr for the entry. We want a value of the form:
1020     // (BasicBlockAddr - TableBeginAddr) / 2
1021     //
1022     // For example, a TBB table with entries jumping to basic blocks BB0 and BB1
1023     // would look like:
1024     // LJTI_0_0:
1025     //    .byte (LBB0 - LJTI_0_0) / 2
1026     //    .byte (LBB1 - LJTI_0_0) / 2
1027     const MCExpr *Expr =
1028       MCBinaryExpr::CreateSub(MBBSymbolExpr,
1029                               MCSymbolRefExpr::Create(JTISymbol, OutContext),
1030                               OutContext);
1031     Expr = MCBinaryExpr::CreateDiv(Expr, MCConstantExpr::Create(2, OutContext),
1032                                    OutContext);
1033     OutStreamer.EmitValue(Expr, OffsetWidth);
1034   }
1035   // Mark the end of jump table data-in-code region. 32-bit offsets use
1036   // actual branch instructions here, so we don't mark those as a data-region
1037   // at all.
1038   if (OffsetWidth != 4)
1039     OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1040 }
1041 
EmitUnwindingInstruction(const MachineInstr * MI)1042 void ARMAsmPrinter::EmitUnwindingInstruction(const MachineInstr *MI) {
1043   assert(MI->getFlag(MachineInstr::FrameSetup) &&
1044       "Only instruction which are involved into frame setup code are allowed");
1045 
1046   MCTargetStreamer &TS = *OutStreamer.getTargetStreamer();
1047   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1048   const MachineFunction &MF = *MI->getParent()->getParent();
1049   const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
1050   const ARMFunctionInfo &AFI = *MF.getInfo<ARMFunctionInfo>();
1051 
1052   unsigned FramePtr = RegInfo->getFrameRegister(MF);
1053   unsigned Opc = MI->getOpcode();
1054   unsigned SrcReg, DstReg;
1055 
1056   if (Opc == ARM::tPUSH || Opc == ARM::tLDRpci) {
1057     // Two special cases:
1058     // 1) tPUSH does not have src/dst regs.
1059     // 2) for Thumb1 code we sometimes materialize the constant via constpool
1060     // load. Yes, this is pretty fragile, but for now I don't see better
1061     // way... :(
1062     SrcReg = DstReg = ARM::SP;
1063   } else {
1064     SrcReg = MI->getOperand(1).getReg();
1065     DstReg = MI->getOperand(0).getReg();
1066   }
1067 
1068   // Try to figure out the unwinding opcode out of src / dst regs.
1069   if (MI->mayStore()) {
1070     // Register saves.
1071     assert(DstReg == ARM::SP &&
1072            "Only stack pointer as a destination reg is supported");
1073 
1074     SmallVector<unsigned, 4> RegList;
1075     // Skip src & dst reg, and pred ops.
1076     unsigned StartOp = 2 + 2;
1077     // Use all the operands.
1078     unsigned NumOffset = 0;
1079 
1080     switch (Opc) {
1081     default:
1082       MI->dump();
1083       llvm_unreachable("Unsupported opcode for unwinding information");
1084     case ARM::tPUSH:
1085       // Special case here: no src & dst reg, but two extra imp ops.
1086       StartOp = 2; NumOffset = 2;
1087     case ARM::STMDB_UPD:
1088     case ARM::t2STMDB_UPD:
1089     case ARM::VSTMDDB_UPD:
1090       assert(SrcReg == ARM::SP &&
1091              "Only stack pointer as a source reg is supported");
1092       for (unsigned i = StartOp, NumOps = MI->getNumOperands() - NumOffset;
1093            i != NumOps; ++i) {
1094         const MachineOperand &MO = MI->getOperand(i);
1095         // Actually, there should never be any impdef stuff here. Skip it
1096         // temporary to workaround PR11902.
1097         if (MO.isImplicit())
1098           continue;
1099         RegList.push_back(MO.getReg());
1100       }
1101       break;
1102     case ARM::STR_PRE_IMM:
1103     case ARM::STR_PRE_REG:
1104     case ARM::t2STR_PRE:
1105       assert(MI->getOperand(2).getReg() == ARM::SP &&
1106              "Only stack pointer as a source reg is supported");
1107       RegList.push_back(SrcReg);
1108       break;
1109     }
1110     if (MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
1111       ATS.emitRegSave(RegList, Opc == ARM::VSTMDDB_UPD);
1112   } else {
1113     // Changes of stack / frame pointer.
1114     if (SrcReg == ARM::SP) {
1115       int64_t Offset = 0;
1116       switch (Opc) {
1117       default:
1118         MI->dump();
1119         llvm_unreachable("Unsupported opcode for unwinding information");
1120       case ARM::MOVr:
1121       case ARM::tMOVr:
1122         Offset = 0;
1123         break;
1124       case ARM::ADDri:
1125         Offset = -MI->getOperand(2).getImm();
1126         break;
1127       case ARM::SUBri:
1128       case ARM::t2SUBri:
1129         Offset = MI->getOperand(2).getImm();
1130         break;
1131       case ARM::tSUBspi:
1132         Offset = MI->getOperand(2).getImm()*4;
1133         break;
1134       case ARM::tADDspi:
1135       case ARM::tADDrSPi:
1136         Offset = -MI->getOperand(2).getImm()*4;
1137         break;
1138       case ARM::tLDRpci: {
1139         // Grab the constpool index and check, whether it corresponds to
1140         // original or cloned constpool entry.
1141         unsigned CPI = MI->getOperand(1).getIndex();
1142         const MachineConstantPool *MCP = MF.getConstantPool();
1143         if (CPI >= MCP->getConstants().size())
1144           CPI = AFI.getOriginalCPIdx(CPI);
1145         assert(CPI != -1U && "Invalid constpool index");
1146 
1147         // Derive the actual offset.
1148         const MachineConstantPoolEntry &CPE = MCP->getConstants()[CPI];
1149         assert(!CPE.isMachineConstantPoolEntry() && "Invalid constpool entry");
1150         // FIXME: Check for user, it should be "add" instruction!
1151         Offset = -cast<ConstantInt>(CPE.Val.ConstVal)->getSExtValue();
1152         break;
1153       }
1154       }
1155 
1156       if (MAI->getExceptionHandlingType() == ExceptionHandling::ARM) {
1157         if (DstReg == FramePtr && FramePtr != ARM::SP)
1158           // Set-up of the frame pointer. Positive values correspond to "add"
1159           // instruction.
1160           ATS.emitSetFP(FramePtr, ARM::SP, -Offset);
1161         else if (DstReg == ARM::SP) {
1162           // Change of SP by an offset. Positive values correspond to "sub"
1163           // instruction.
1164           ATS.emitPad(Offset);
1165         } else {
1166           // Move of SP to a register.  Positive values correspond to an "add"
1167           // instruction.
1168           ATS.emitMovSP(DstReg, -Offset);
1169         }
1170       }
1171     } else if (DstReg == ARM::SP) {
1172       MI->dump();
1173       llvm_unreachable("Unsupported opcode for unwinding information");
1174     }
1175     else {
1176       MI->dump();
1177       llvm_unreachable("Unsupported opcode for unwinding information");
1178     }
1179   }
1180 }
1181 
1182 // Simple pseudo-instructions have their lowering (with expansion to real
1183 // instructions) auto-generated.
1184 #include "ARMGenMCPseudoLowering.inc"
1185 
EmitInstruction(const MachineInstr * MI)1186 void ARMAsmPrinter::EmitInstruction(const MachineInstr *MI) {
1187   const DataLayout *DL = TM.getDataLayout();
1188 
1189   // If we just ended a constant pool, mark it as such.
1190   if (InConstantPool && MI->getOpcode() != ARM::CONSTPOOL_ENTRY) {
1191     OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1192     InConstantPool = false;
1193   }
1194 
1195   // Emit unwinding stuff for frame-related instructions
1196   if (Subtarget->isTargetEHABICompatible() &&
1197        MI->getFlag(MachineInstr::FrameSetup))
1198     EmitUnwindingInstruction(MI);
1199 
1200   // Do any auto-generated pseudo lowerings.
1201   if (emitPseudoExpansionLowering(OutStreamer, MI))
1202     return;
1203 
1204   assert(!convertAddSubFlagsOpcode(MI->getOpcode()) &&
1205          "Pseudo flag setting opcode should be expanded early");
1206 
1207   // Check for manual lowerings.
1208   unsigned Opc = MI->getOpcode();
1209   switch (Opc) {
1210   case ARM::t2MOVi32imm: llvm_unreachable("Should be lowered by thumb2it pass");
1211   case ARM::DBG_VALUE: llvm_unreachable("Should be handled by generic printing");
1212   case ARM::LEApcrel:
1213   case ARM::tLEApcrel:
1214   case ARM::t2LEApcrel: {
1215     // FIXME: Need to also handle globals and externals
1216     MCSymbol *CPISymbol = GetCPISymbol(MI->getOperand(1).getIndex());
1217     EmitToStreamer(OutStreamer, MCInstBuilder(MI->getOpcode() ==
1218                                               ARM::t2LEApcrel ? ARM::t2ADR
1219                   : (MI->getOpcode() == ARM::tLEApcrel ? ARM::tADR
1220                      : ARM::ADR))
1221       .addReg(MI->getOperand(0).getReg())
1222       .addExpr(MCSymbolRefExpr::Create(CPISymbol, OutContext))
1223       // Add predicate operands.
1224       .addImm(MI->getOperand(2).getImm())
1225       .addReg(MI->getOperand(3).getReg()));
1226     return;
1227   }
1228   case ARM::LEApcrelJT:
1229   case ARM::tLEApcrelJT:
1230   case ARM::t2LEApcrelJT: {
1231     MCSymbol *JTIPICSymbol =
1232       GetARMJTIPICJumpTableLabel2(MI->getOperand(1).getIndex(),
1233                                   MI->getOperand(2).getImm());
1234     EmitToStreamer(OutStreamer, MCInstBuilder(MI->getOpcode() ==
1235                                               ARM::t2LEApcrelJT ? ARM::t2ADR
1236                   : (MI->getOpcode() == ARM::tLEApcrelJT ? ARM::tADR
1237                      : ARM::ADR))
1238       .addReg(MI->getOperand(0).getReg())
1239       .addExpr(MCSymbolRefExpr::Create(JTIPICSymbol, OutContext))
1240       // Add predicate operands.
1241       .addImm(MI->getOperand(3).getImm())
1242       .addReg(MI->getOperand(4).getReg()));
1243     return;
1244   }
1245   // Darwin call instructions are just normal call instructions with different
1246   // clobber semantics (they clobber R9).
1247   case ARM::BX_CALL: {
1248     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVr)
1249       .addReg(ARM::LR)
1250       .addReg(ARM::PC)
1251       // Add predicate operands.
1252       .addImm(ARMCC::AL)
1253       .addReg(0)
1254       // Add 's' bit operand (always reg0 for this)
1255       .addReg(0));
1256 
1257     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::BX)
1258       .addReg(MI->getOperand(0).getReg()));
1259     return;
1260   }
1261   case ARM::tBX_CALL: {
1262     if (Subtarget->hasV5TOps())
1263       llvm_unreachable("Expected BLX to be selected for v5t+");
1264 
1265     // On ARM v4t, when doing a call from thumb mode, we need to ensure
1266     // that the saved lr has its LSB set correctly (the arch doesn't
1267     // have blx).
1268     // So here we generate a bl to a small jump pad that does bx rN.
1269     // The jump pads are emitted after the function body.
1270 
1271     unsigned TReg = MI->getOperand(0).getReg();
1272     MCSymbol *TRegSym = nullptr;
1273     for (unsigned i = 0, e = ThumbIndirectPads.size(); i < e; i++) {
1274       if (ThumbIndirectPads[i].first == TReg) {
1275         TRegSym = ThumbIndirectPads[i].second;
1276         break;
1277       }
1278     }
1279 
1280     if (!TRegSym) {
1281       TRegSym = OutContext.CreateTempSymbol();
1282       ThumbIndirectPads.push_back(std::make_pair(TReg, TRegSym));
1283     }
1284 
1285     // Create a link-saving branch to the Reg Indirect Jump Pad.
1286     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBL)
1287         // Predicate comes first here.
1288         .addImm(ARMCC::AL).addReg(0)
1289         .addExpr(MCSymbolRefExpr::Create(TRegSym, OutContext)));
1290     return;
1291   }
1292   case ARM::BMOVPCRX_CALL: {
1293     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVr)
1294       .addReg(ARM::LR)
1295       .addReg(ARM::PC)
1296       // Add predicate operands.
1297       .addImm(ARMCC::AL)
1298       .addReg(0)
1299       // Add 's' bit operand (always reg0 for this)
1300       .addReg(0));
1301 
1302     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVr)
1303       .addReg(ARM::PC)
1304       .addReg(MI->getOperand(0).getReg())
1305       // Add predicate operands.
1306       .addImm(ARMCC::AL)
1307       .addReg(0)
1308       // Add 's' bit operand (always reg0 for this)
1309       .addReg(0));
1310     return;
1311   }
1312   case ARM::BMOVPCB_CALL: {
1313     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVr)
1314       .addReg(ARM::LR)
1315       .addReg(ARM::PC)
1316       // Add predicate operands.
1317       .addImm(ARMCC::AL)
1318       .addReg(0)
1319       // Add 's' bit operand (always reg0 for this)
1320       .addReg(0));
1321 
1322     const MachineOperand &Op = MI->getOperand(0);
1323     const GlobalValue *GV = Op.getGlobal();
1324     const unsigned TF = Op.getTargetFlags();
1325     MCSymbol *GVSym = GetARMGVSymbol(GV, TF);
1326     const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
1327     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::Bcc)
1328       .addExpr(GVSymExpr)
1329       // Add predicate operands.
1330       .addImm(ARMCC::AL)
1331       .addReg(0));
1332     return;
1333   }
1334   case ARM::MOVi16_ga_pcrel:
1335   case ARM::t2MOVi16_ga_pcrel: {
1336     MCInst TmpInst;
1337     TmpInst.setOpcode(Opc == ARM::MOVi16_ga_pcrel? ARM::MOVi16 : ARM::t2MOVi16);
1338     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1339 
1340     unsigned TF = MI->getOperand(1).getTargetFlags();
1341     const GlobalValue *GV = MI->getOperand(1).getGlobal();
1342     MCSymbol *GVSym = GetARMGVSymbol(GV, TF);
1343     const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
1344 
1345     MCSymbol *LabelSym = getPICLabel(DL->getPrivateGlobalPrefix(),
1346                                      getFunctionNumber(),
1347                                      MI->getOperand(2).getImm(), OutContext);
1348     const MCExpr *LabelSymExpr= MCSymbolRefExpr::Create(LabelSym, OutContext);
1349     unsigned PCAdj = (Opc == ARM::MOVi16_ga_pcrel) ? 8 : 4;
1350     const MCExpr *PCRelExpr =
1351       ARMMCExpr::CreateLower16(MCBinaryExpr::CreateSub(GVSymExpr,
1352                                       MCBinaryExpr::CreateAdd(LabelSymExpr,
1353                                       MCConstantExpr::Create(PCAdj, OutContext),
1354                                       OutContext), OutContext), OutContext);
1355       TmpInst.addOperand(MCOperand::CreateExpr(PCRelExpr));
1356 
1357     // Add predicate operands.
1358     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1359     TmpInst.addOperand(MCOperand::CreateReg(0));
1360     // Add 's' bit operand (always reg0 for this)
1361     TmpInst.addOperand(MCOperand::CreateReg(0));
1362     EmitToStreamer(OutStreamer, TmpInst);
1363     return;
1364   }
1365   case ARM::MOVTi16_ga_pcrel:
1366   case ARM::t2MOVTi16_ga_pcrel: {
1367     MCInst TmpInst;
1368     TmpInst.setOpcode(Opc == ARM::MOVTi16_ga_pcrel
1369                       ? ARM::MOVTi16 : ARM::t2MOVTi16);
1370     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1371     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1372 
1373     unsigned TF = MI->getOperand(2).getTargetFlags();
1374     const GlobalValue *GV = MI->getOperand(2).getGlobal();
1375     MCSymbol *GVSym = GetARMGVSymbol(GV, TF);
1376     const MCExpr *GVSymExpr = MCSymbolRefExpr::Create(GVSym, OutContext);
1377 
1378     MCSymbol *LabelSym = getPICLabel(DL->getPrivateGlobalPrefix(),
1379                                      getFunctionNumber(),
1380                                      MI->getOperand(3).getImm(), OutContext);
1381     const MCExpr *LabelSymExpr= MCSymbolRefExpr::Create(LabelSym, OutContext);
1382     unsigned PCAdj = (Opc == ARM::MOVTi16_ga_pcrel) ? 8 : 4;
1383     const MCExpr *PCRelExpr =
1384         ARMMCExpr::CreateUpper16(MCBinaryExpr::CreateSub(GVSymExpr,
1385                                    MCBinaryExpr::CreateAdd(LabelSymExpr,
1386                                       MCConstantExpr::Create(PCAdj, OutContext),
1387                                           OutContext), OutContext), OutContext);
1388       TmpInst.addOperand(MCOperand::CreateExpr(PCRelExpr));
1389     // Add predicate operands.
1390     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1391     TmpInst.addOperand(MCOperand::CreateReg(0));
1392     // Add 's' bit operand (always reg0 for this)
1393     TmpInst.addOperand(MCOperand::CreateReg(0));
1394     EmitToStreamer(OutStreamer, TmpInst);
1395     return;
1396   }
1397   case ARM::tPICADD: {
1398     // This is a pseudo op for a label + instruction sequence, which looks like:
1399     // LPC0:
1400     //     add r0, pc
1401     // This adds the address of LPC0 to r0.
1402 
1403     // Emit the label.
1404     OutStreamer.EmitLabel(getPICLabel(DL->getPrivateGlobalPrefix(),
1405                           getFunctionNumber(), MI->getOperand(2).getImm(),
1406                           OutContext));
1407 
1408     // Form and emit the add.
1409     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tADDhirr)
1410       .addReg(MI->getOperand(0).getReg())
1411       .addReg(MI->getOperand(0).getReg())
1412       .addReg(ARM::PC)
1413       // Add predicate operands.
1414       .addImm(ARMCC::AL)
1415       .addReg(0));
1416     return;
1417   }
1418   case ARM::PICADD: {
1419     // This is a pseudo op for a label + instruction sequence, which looks like:
1420     // LPC0:
1421     //     add r0, pc, r0
1422     // This adds the address of LPC0 to r0.
1423 
1424     // Emit the label.
1425     OutStreamer.EmitLabel(getPICLabel(DL->getPrivateGlobalPrefix(),
1426                           getFunctionNumber(), MI->getOperand(2).getImm(),
1427                           OutContext));
1428 
1429     // Form and emit the add.
1430     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::ADDrr)
1431       .addReg(MI->getOperand(0).getReg())
1432       .addReg(ARM::PC)
1433       .addReg(MI->getOperand(1).getReg())
1434       // Add predicate operands.
1435       .addImm(MI->getOperand(3).getImm())
1436       .addReg(MI->getOperand(4).getReg())
1437       // Add 's' bit operand (always reg0 for this)
1438       .addReg(0));
1439     return;
1440   }
1441   case ARM::PICSTR:
1442   case ARM::PICSTRB:
1443   case ARM::PICSTRH:
1444   case ARM::PICLDR:
1445   case ARM::PICLDRB:
1446   case ARM::PICLDRH:
1447   case ARM::PICLDRSB:
1448   case ARM::PICLDRSH: {
1449     // This is a pseudo op for a label + instruction sequence, which looks like:
1450     // LPC0:
1451     //     OP r0, [pc, r0]
1452     // The LCP0 label is referenced by a constant pool entry in order to get
1453     // a PC-relative address at the ldr instruction.
1454 
1455     // Emit the label.
1456     OutStreamer.EmitLabel(getPICLabel(DL->getPrivateGlobalPrefix(),
1457                           getFunctionNumber(), MI->getOperand(2).getImm(),
1458                           OutContext));
1459 
1460     // Form and emit the load
1461     unsigned Opcode;
1462     switch (MI->getOpcode()) {
1463     default:
1464       llvm_unreachable("Unexpected opcode!");
1465     case ARM::PICSTR:   Opcode = ARM::STRrs; break;
1466     case ARM::PICSTRB:  Opcode = ARM::STRBrs; break;
1467     case ARM::PICSTRH:  Opcode = ARM::STRH; break;
1468     case ARM::PICLDR:   Opcode = ARM::LDRrs; break;
1469     case ARM::PICLDRB:  Opcode = ARM::LDRBrs; break;
1470     case ARM::PICLDRH:  Opcode = ARM::LDRH; break;
1471     case ARM::PICLDRSB: Opcode = ARM::LDRSB; break;
1472     case ARM::PICLDRSH: Opcode = ARM::LDRSH; break;
1473     }
1474     EmitToStreamer(OutStreamer, MCInstBuilder(Opcode)
1475       .addReg(MI->getOperand(0).getReg())
1476       .addReg(ARM::PC)
1477       .addReg(MI->getOperand(1).getReg())
1478       .addImm(0)
1479       // Add predicate operands.
1480       .addImm(MI->getOperand(3).getImm())
1481       .addReg(MI->getOperand(4).getReg()));
1482 
1483     return;
1484   }
1485   case ARM::CONSTPOOL_ENTRY: {
1486     /// CONSTPOOL_ENTRY - This instruction represents a floating constant pool
1487     /// in the function.  The first operand is the ID# for this instruction, the
1488     /// second is the index into the MachineConstantPool that this is, the third
1489     /// is the size in bytes of this constant pool entry.
1490     /// The required alignment is specified on the basic block holding this MI.
1491     unsigned LabelId = (unsigned)MI->getOperand(0).getImm();
1492     unsigned CPIdx   = (unsigned)MI->getOperand(1).getIndex();
1493 
1494     // If this is the first entry of the pool, mark it.
1495     if (!InConstantPool) {
1496       OutStreamer.EmitDataRegion(MCDR_DataRegion);
1497       InConstantPool = true;
1498     }
1499 
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     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVr)
1512       .addReg(ARM::PC)
1513       .addReg(MI->getOperand(0).getReg())
1514       // Add predicate operands.
1515       .addImm(ARMCC::AL)
1516       .addReg(0));
1517 
1518     // Output the data for the jump table itself
1519     EmitJump2Table(MI);
1520     return;
1521   }
1522   case ARM::t2TBB_JT: {
1523     // Lower and emit the instruction itself, then the jump table following it.
1524     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::t2TBB)
1525       .addReg(ARM::PC)
1526       .addReg(MI->getOperand(0).getReg())
1527       // Add predicate operands.
1528       .addImm(ARMCC::AL)
1529       .addReg(0));
1530 
1531     // Output the data for the jump table itself
1532     EmitJump2Table(MI);
1533     // Make sure the next instruction is 2-byte aligned.
1534     EmitAlignment(1);
1535     return;
1536   }
1537   case ARM::t2TBH_JT: {
1538     // Lower and emit the instruction itself, then the jump table following it.
1539     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::t2TBH)
1540       .addReg(ARM::PC)
1541       .addReg(MI->getOperand(0).getReg())
1542       // Add predicate operands.
1543       .addImm(ARMCC::AL)
1544       .addReg(0));
1545 
1546     // Output the data for the jump table itself
1547     EmitJump2Table(MI);
1548     return;
1549   }
1550   case ARM::tBR_JTr:
1551   case ARM::BR_JTr: {
1552     // Lower and emit the instruction itself, then the jump table following it.
1553     // mov pc, target
1554     MCInst TmpInst;
1555     unsigned Opc = MI->getOpcode() == ARM::BR_JTr ?
1556       ARM::MOVr : ARM::tMOVr;
1557     TmpInst.setOpcode(Opc);
1558     TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1559     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1560     // Add predicate operands.
1561     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1562     TmpInst.addOperand(MCOperand::CreateReg(0));
1563     // Add 's' bit operand (always reg0 for this)
1564     if (Opc == ARM::MOVr)
1565       TmpInst.addOperand(MCOperand::CreateReg(0));
1566     EmitToStreamer(OutStreamer, TmpInst);
1567 
1568     // Make sure the Thumb jump table is 4-byte aligned.
1569     if (Opc == ARM::tMOVr)
1570       EmitAlignment(2);
1571 
1572     // Output the data for the jump table itself
1573     EmitJumpTable(MI);
1574     return;
1575   }
1576   case ARM::BR_JTm: {
1577     // Lower and emit the instruction itself, then the jump table following it.
1578     // ldr pc, target
1579     MCInst TmpInst;
1580     if (MI->getOperand(1).getReg() == 0) {
1581       // literal offset
1582       TmpInst.setOpcode(ARM::LDRi12);
1583       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1584       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1585       TmpInst.addOperand(MCOperand::CreateImm(MI->getOperand(2).getImm()));
1586     } else {
1587       TmpInst.setOpcode(ARM::LDRrs);
1588       TmpInst.addOperand(MCOperand::CreateReg(ARM::PC));
1589       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
1590       TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
1591       TmpInst.addOperand(MCOperand::CreateImm(0));
1592     }
1593     // Add predicate operands.
1594     TmpInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
1595     TmpInst.addOperand(MCOperand::CreateReg(0));
1596     EmitToStreamer(OutStreamer, TmpInst);
1597 
1598     // Output the data for the jump table itself
1599     EmitJumpTable(MI);
1600     return;
1601   }
1602   case ARM::BR_JTadd: {
1603     // Lower and emit the instruction itself, then the jump table following it.
1604     // add pc, target, idx
1605     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::ADDrr)
1606       .addReg(ARM::PC)
1607       .addReg(MI->getOperand(0).getReg())
1608       .addReg(MI->getOperand(1).getReg())
1609       // Add predicate operands.
1610       .addImm(ARMCC::AL)
1611       .addReg(0)
1612       // Add 's' bit operand (always reg0 for this)
1613       .addReg(0));
1614 
1615     // Output the data for the jump table itself
1616     EmitJumpTable(MI);
1617     return;
1618   }
1619   case ARM::SPACE:
1620     OutStreamer.EmitZeros(MI->getOperand(1).getImm());
1621     return;
1622   case ARM::TRAP: {
1623     // Non-Darwin binutils don't yet support the "trap" mnemonic.
1624     // FIXME: Remove this special case when they do.
1625     if (!Subtarget->isTargetMachO()) {
1626       //.long 0xe7ffdefe @ trap
1627       uint32_t Val = 0xe7ffdefeUL;
1628       OutStreamer.AddComment("trap");
1629       OutStreamer.EmitIntValue(Val, 4);
1630       return;
1631     }
1632     break;
1633   }
1634   case ARM::TRAPNaCl: {
1635     //.long 0xe7fedef0 @ trap
1636     uint32_t Val = 0xe7fedef0UL;
1637     OutStreamer.AddComment("trap");
1638     OutStreamer.EmitIntValue(Val, 4);
1639     return;
1640   }
1641   case ARM::tTRAP: {
1642     // Non-Darwin binutils don't yet support the "trap" mnemonic.
1643     // FIXME: Remove this special case when they do.
1644     if (!Subtarget->isTargetMachO()) {
1645       //.short 57086 @ trap
1646       uint16_t Val = 0xdefe;
1647       OutStreamer.AddComment("trap");
1648       OutStreamer.EmitIntValue(Val, 2);
1649       return;
1650     }
1651     break;
1652   }
1653   case ARM::t2Int_eh_sjlj_setjmp:
1654   case ARM::t2Int_eh_sjlj_setjmp_nofp:
1655   case ARM::tInt_eh_sjlj_setjmp: {
1656     // Two incoming args: GPR:$src, GPR:$val
1657     // mov $val, pc
1658     // adds $val, #7
1659     // str $val, [$src, #4]
1660     // movs r0, #0
1661     // b 1f
1662     // movs r0, #1
1663     // 1:
1664     unsigned SrcReg = MI->getOperand(0).getReg();
1665     unsigned ValReg = MI->getOperand(1).getReg();
1666     MCSymbol *Label = GetARMSJLJEHLabel();
1667     OutStreamer.AddComment("eh_setjmp begin");
1668     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVr)
1669       .addReg(ValReg)
1670       .addReg(ARM::PC)
1671       // Predicate.
1672       .addImm(ARMCC::AL)
1673       .addReg(0));
1674 
1675     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tADDi3)
1676       .addReg(ValReg)
1677       // 's' bit operand
1678       .addReg(ARM::CPSR)
1679       .addReg(ValReg)
1680       .addImm(7)
1681       // Predicate.
1682       .addImm(ARMCC::AL)
1683       .addReg(0));
1684 
1685     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tSTRi)
1686       .addReg(ValReg)
1687       .addReg(SrcReg)
1688       // The offset immediate is #4. The operand value is scaled by 4 for the
1689       // tSTR instruction.
1690       .addImm(1)
1691       // Predicate.
1692       .addImm(ARMCC::AL)
1693       .addReg(0));
1694 
1695     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVi8)
1696       .addReg(ARM::R0)
1697       .addReg(ARM::CPSR)
1698       .addImm(0)
1699       // Predicate.
1700       .addImm(ARMCC::AL)
1701       .addReg(0));
1702 
1703     const MCExpr *SymbolExpr = MCSymbolRefExpr::Create(Label, OutContext);
1704     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tB)
1705       .addExpr(SymbolExpr)
1706       .addImm(ARMCC::AL)
1707       .addReg(0));
1708 
1709     OutStreamer.AddComment("eh_setjmp end");
1710     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVi8)
1711       .addReg(ARM::R0)
1712       .addReg(ARM::CPSR)
1713       .addImm(1)
1714       // Predicate.
1715       .addImm(ARMCC::AL)
1716       .addReg(0));
1717 
1718     OutStreamer.EmitLabel(Label);
1719     return;
1720   }
1721 
1722   case ARM::Int_eh_sjlj_setjmp_nofp:
1723   case ARM::Int_eh_sjlj_setjmp: {
1724     // Two incoming args: GPR:$src, GPR:$val
1725     // add $val, pc, #8
1726     // str $val, [$src, #+4]
1727     // mov r0, #0
1728     // add pc, pc, #0
1729     // mov r0, #1
1730     unsigned SrcReg = MI->getOperand(0).getReg();
1731     unsigned ValReg = MI->getOperand(1).getReg();
1732 
1733     OutStreamer.AddComment("eh_setjmp begin");
1734     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::ADDri)
1735       .addReg(ValReg)
1736       .addReg(ARM::PC)
1737       .addImm(8)
1738       // Predicate.
1739       .addImm(ARMCC::AL)
1740       .addReg(0)
1741       // 's' bit operand (always reg0 for this).
1742       .addReg(0));
1743 
1744     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::STRi12)
1745       .addReg(ValReg)
1746       .addReg(SrcReg)
1747       .addImm(4)
1748       // Predicate.
1749       .addImm(ARMCC::AL)
1750       .addReg(0));
1751 
1752     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVi)
1753       .addReg(ARM::R0)
1754       .addImm(0)
1755       // Predicate.
1756       .addImm(ARMCC::AL)
1757       .addReg(0)
1758       // 's' bit operand (always reg0 for this).
1759       .addReg(0));
1760 
1761     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::ADDri)
1762       .addReg(ARM::PC)
1763       .addReg(ARM::PC)
1764       .addImm(0)
1765       // Predicate.
1766       .addImm(ARMCC::AL)
1767       .addReg(0)
1768       // 's' bit operand (always reg0 for this).
1769       .addReg(0));
1770 
1771     OutStreamer.AddComment("eh_setjmp end");
1772     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::MOVi)
1773       .addReg(ARM::R0)
1774       .addImm(1)
1775       // Predicate.
1776       .addImm(ARMCC::AL)
1777       .addReg(0)
1778       // 's' bit operand (always reg0 for this).
1779       .addReg(0));
1780     return;
1781   }
1782   case ARM::Int_eh_sjlj_longjmp: {
1783     // ldr sp, [$src, #8]
1784     // ldr $scratch, [$src, #4]
1785     // ldr r7, [$src]
1786     // bx $scratch
1787     unsigned SrcReg = MI->getOperand(0).getReg();
1788     unsigned ScratchReg = MI->getOperand(1).getReg();
1789     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::LDRi12)
1790       .addReg(ARM::SP)
1791       .addReg(SrcReg)
1792       .addImm(8)
1793       // Predicate.
1794       .addImm(ARMCC::AL)
1795       .addReg(0));
1796 
1797     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::LDRi12)
1798       .addReg(ScratchReg)
1799       .addReg(SrcReg)
1800       .addImm(4)
1801       // Predicate.
1802       .addImm(ARMCC::AL)
1803       .addReg(0));
1804 
1805     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::LDRi12)
1806       .addReg(ARM::R7)
1807       .addReg(SrcReg)
1808       .addImm(0)
1809       // Predicate.
1810       .addImm(ARMCC::AL)
1811       .addReg(0));
1812 
1813     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::BX)
1814       .addReg(ScratchReg)
1815       // Predicate.
1816       .addImm(ARMCC::AL)
1817       .addReg(0));
1818     return;
1819   }
1820   case ARM::tInt_eh_sjlj_longjmp: {
1821     // ldr $scratch, [$src, #8]
1822     // mov sp, $scratch
1823     // ldr $scratch, [$src, #4]
1824     // ldr r7, [$src]
1825     // bx $scratch
1826     unsigned SrcReg = MI->getOperand(0).getReg();
1827     unsigned ScratchReg = MI->getOperand(1).getReg();
1828     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tLDRi)
1829       .addReg(ScratchReg)
1830       .addReg(SrcReg)
1831       // The offset immediate is #8. The operand value is scaled by 4 for the
1832       // tLDR instruction.
1833       .addImm(2)
1834       // Predicate.
1835       .addImm(ARMCC::AL)
1836       .addReg(0));
1837 
1838     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVr)
1839       .addReg(ARM::SP)
1840       .addReg(ScratchReg)
1841       // Predicate.
1842       .addImm(ARMCC::AL)
1843       .addReg(0));
1844 
1845     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tLDRi)
1846       .addReg(ScratchReg)
1847       .addReg(SrcReg)
1848       .addImm(1)
1849       // Predicate.
1850       .addImm(ARMCC::AL)
1851       .addReg(0));
1852 
1853     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tLDRi)
1854       .addReg(ARM::R7)
1855       .addReg(SrcReg)
1856       .addImm(0)
1857       // Predicate.
1858       .addImm(ARMCC::AL)
1859       .addReg(0));
1860 
1861     EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBX)
1862       .addReg(ScratchReg)
1863       // Predicate.
1864       .addImm(ARMCC::AL)
1865       .addReg(0));
1866     return;
1867   }
1868   }
1869 
1870   MCInst TmpInst;
1871   LowerARMMachineInstrToMCInst(MI, TmpInst, *this);
1872 
1873   EmitToStreamer(OutStreamer, TmpInst);
1874 }
1875 
1876 //===----------------------------------------------------------------------===//
1877 // Target Registry Stuff
1878 //===----------------------------------------------------------------------===//
1879 
1880 // Force static initialization.
LLVMInitializeARMAsmPrinter()1881 extern "C" void LLVMInitializeARMAsmPrinter() {
1882   RegisterAsmPrinter<ARMAsmPrinter> X(TheARMLETarget);
1883   RegisterAsmPrinter<ARMAsmPrinter> Y(TheARMBETarget);
1884   RegisterAsmPrinter<ARMAsmPrinter> A(TheThumbLETarget);
1885   RegisterAsmPrinter<ARMAsmPrinter> B(TheThumbBETarget);
1886 }
1887