lib/CodeGen/LLVMTargetMachine.cpp

   1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
   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 implements the LLVMTargetMachine class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Analysis/Passes.h"
  15 #include "llvm/CodeGen/AsmPrinter.h"
  16 #include "llvm/CodeGen/BasicTTIImpl.h"
  17 #include "llvm/CodeGen/MachineModuleInfo.h"
  18 #include "llvm/CodeGen/Passes.h"
  19 #include "llvm/CodeGen/TargetPassConfig.h"
  20 #include "llvm/IR/LegacyPassManager.h"
  21 #include "llvm/MC/MCAsmBackend.h"
  22 #include "llvm/MC/MCAsmInfo.h"
  23 #include "llvm/MC/MCCodeEmitter.h"
  24 #include "llvm/MC/MCContext.h"
  25 #include "llvm/MC/MCInstrInfo.h"
  26 #include "llvm/MC/MCObjectWriter.h"
  27 #include "llvm/MC/MCStreamer.h"
  28 #include "llvm/MC/MCSubtargetInfo.h"
  29 #include "llvm/Support/CommandLine.h"
  30 #include "llvm/Support/ErrorHandling.h"
  31 #include "llvm/Support/FormattedStream.h"
  32 #include "llvm/Support/TargetRegistry.h"
  33 #include "llvm/Target/TargetLoweringObjectFile.h"
  34 #include "llvm/Target/TargetMachine.h"
  35 #include "llvm/Target/TargetOptions.h"
  36 using namespace llvm;
  37
  38 static cl::opt<bool> EnableTrapUnreachable("trap-unreachable",
  39   cl::Hidden, cl::ZeroOrMore, cl::init(false),
  40   cl::desc("Enable generating trap for unreachable"));
  41
  42 void LLVMTargetMachine::initAsmInfo() {
  43   MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str()));
  44   MII.reset(TheTarget.createMCInstrInfo());
  45   // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
  46   // to some backends having subtarget feature dependent module level
  47   // code generation. This is similar to the hack in the AsmPrinter for
  48   // module level assembly etc.
  49   STI.reset(TheTarget.createMCSubtargetInfo(
  50       getTargetTriple().str(), getTargetCPU(), getTargetFeatureString()));
  51
  52   MCAsmInfo *TmpAsmInfo =
  53       TheTarget.createMCAsmInfo(*MRI, getTargetTriple().str());
  54   // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
  55   // and if the old one gets included then MCAsmInfo will be NULL and
  56   // we'll crash later.
  57   // Provide the user with a useful error message about what's wrong.
  58   assert(TmpAsmInfo && "MCAsmInfo not initialized. "
  59          "Make sure you include the correct TargetSelect.h"
  60          "and that InitializeAllTargetMCs() is being invoked!");
  61
  62   if (Options.DisableIntegratedAS)
  63     TmpAsmInfo->setUseIntegratedAssembler(false);
  64
  65   TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments);
  66
  67   TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections);
  68
  69   TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations);
  70
  71   if (Options.ExceptionModel != ExceptionHandling::None)
  72     TmpAsmInfo->setExceptionsType(Options.ExceptionModel);
  73
  74   AsmInfo.reset(TmpAsmInfo);
  75 }
  76
  77 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
  78                                      StringRef DataLayoutString,
  79                                      const Triple &TT, StringRef CPU,
  80                                      StringRef FS, const TargetOptions &Options,
  81                                      Reloc::Model RM, CodeModel::Model CM,
  82                                      CodeGenOpt::Level OL)
  83     : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) {
  84   this->RM = RM;
  85   this->CMModel = CM;
  86   this->OptLevel = OL;
  87
  88   if (EnableTrapUnreachable)
  89     this->Options.TrapUnreachable = true;
  90 }
  91
  92 TargetTransformInfo
  93 LLVMTargetMachine::getTargetTransformInfo(const Function &F) {
  94   return TargetTransformInfo(BasicTTIImpl(this, F));
  95 }
  96
  97 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
  98 static MCContext *
  99 addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
 100                         bool DisableVerify, bool &WillCompleteCodeGenPipeline,
 101                         raw_pwrite_stream &Out, MachineModuleInfo *MMI) {
 102   // Targets may override createPassConfig to provide a target-specific
 103   // subclass.
 104   TargetPassConfig *PassConfig = TM->createPassConfig(PM);
 105   // Set PassConfig options provided by TargetMachine.
 106   PassConfig->setDisableVerify(DisableVerify);
 107   WillCompleteCodeGenPipeline = PassConfig->willCompleteCodeGenPipeline();
 108   PM.add(PassConfig);
 109   if (!MMI)
 110     MMI = new MachineModuleInfo(TM);
 111   PM.add(MMI);
 112
 113   if (PassConfig->addISelPasses())
 114     return nullptr;
 115   PassConfig->addMachinePasses();
 116   PassConfig->setInitialized();
 117   if (!WillCompleteCodeGenPipeline)
 118     PM.add(createPrintMIRPass(Out));
 119
 120   return &MMI->getContext();
 121 }
 122
 123 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
 124                                       raw_pwrite_stream &Out,
 125                                       raw_pwrite_stream *DwoOut,
 126                                       CodeGenFileType FileType,
 127                                       MCContext &Context) {
 128   if (Options.MCOptions.MCSaveTempLabels)
 129     Context.setAllowTemporaryLabels(false);
 130
 131   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 132   const MCAsmInfo &MAI = *getMCAsmInfo();
 133   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 134   const MCInstrInfo &MII = *getMCInstrInfo();
 135
 136   std::unique_ptr<MCStreamer> AsmStreamer;
 137
 138   switch (FileType) {
 139   case CGFT_AssemblyFile: {
 140     MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
 141         getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI);
 142
 143     // Create a code emitter if asked to show the encoding.
 144     std::unique_ptr<MCCodeEmitter> MCE;
 145     if (Options.MCOptions.ShowMCEncoding)
 146       MCE.reset(getTarget().createMCCodeEmitter(MII, MRI, Context));
 147
 148     std::unique_ptr<MCAsmBackend> MAB(
 149         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 150     auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
 151     MCStreamer *S = getTarget().createAsmStreamer(
 152         Context, std::move(FOut), Options.MCOptions.AsmVerbose,
 153         Options.MCOptions.MCUseDwarfDirectory, InstPrinter, std::move(MCE),
 154         std::move(MAB), Options.MCOptions.ShowMCInst);
 155     AsmStreamer.reset(S);
 156     break;
 157   }
 158   case CGFT_ObjectFile: {
 159     // Create the code emitter for the target if it exists.  If not, .o file
 160     // emission fails.
 161     MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, Context);
 162     MCAsmBackend *MAB =
 163         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 164     if (!MCE || !MAB)
 165       return true;
 166
 167     // Don't waste memory on names of temp labels.
 168     Context.setUseNamesOnTempLabels(false);
 169
 170     Triple T(getTargetTriple().str());
 171     AsmStreamer.reset(getTarget().createMCObjectStreamer(
 172         T, Context, std::unique_ptr<MCAsmBackend>(MAB),
 173         DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut)
 174                : MAB->createObjectWriter(Out),
 175         std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 176         Options.MCOptions.MCIncrementalLinkerCompatible,
 177         /*DWARFMustBeAtTheEnd*/ true));
 178     break;
 179   }
 180   case CGFT_Null:
 181     // The Null output is intended for use for performance analysis and testing,
 182     // not real users.
 183     AsmStreamer.reset(getTarget().createNullStreamer(Context));
 184     break;
 185   }
 186
 187   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 188   FunctionPass *Printer =
 189       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 190   if (!Printer)
 191     return true;
 192
 193   PM.add(Printer);
 194   return false;
 195 }
 196
 197 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
 198                                             raw_pwrite_stream &Out,
 199                                             raw_pwrite_stream *DwoOut,
 200                                             CodeGenFileType FileType,
 201                                             bool DisableVerify,
 202                                             MachineModuleInfo *MMI) {
 203   // Add common CodeGen passes.
 204   bool WillCompleteCodeGenPipeline = true;
 205   MCContext *Context = addPassesToGenerateCode(
 206       this, PM, DisableVerify, WillCompleteCodeGenPipeline, Out, MMI);
 207   if (!Context)
 208     return true;
 209
 210   if (WillCompleteCodeGenPipeline &&
 211       addAsmPrinter(PM, Out, DwoOut, FileType, *Context))
 212     return true;
 213
 214   PM.add(createFreeMachineFunctionPass());
 215   return false;
 216 }
 217
 218 /// addPassesToEmitMC - Add passes to the specified pass manager to get
 219 /// machine code emitted with the MCJIT. This method returns true if machine
 220 /// code is not supported. It fills the MCContext Ctx pointer which can be
 221 /// used to build custom MCStreamer.
 222 ///
 223 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
 224                                           raw_pwrite_stream &Out,
 225                                           bool DisableVerify) {
 226   // Add common CodeGen passes.
 227   bool WillCompleteCodeGenPipeline = true;
 228   Ctx = addPassesToGenerateCode(this, PM, DisableVerify,
 229                                 WillCompleteCodeGenPipeline, Out,
 230                                 /*MachineModuleInfo*/ nullptr);
 231   if (!Ctx)
 232     return true;
 233   assert(WillCompleteCodeGenPipeline && "CodeGen pipeline has been altered");
 234
 235   if (Options.MCOptions.MCSaveTempLabels)
 236     Ctx->setAllowTemporaryLabels(false);
 237
 238   // Create the code emitter for the target if it exists.  If not, .o file
 239   // emission fails.
 240   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 241   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 242   MCCodeEmitter *MCE =
 243       getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx);
 244   MCAsmBackend *MAB =
 245       getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 246   if (!MCE || !MAB)
 247     return true;
 248
 249   const Triple &T = getTargetTriple();
 250   std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
 251       T, *Ctx, std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(Out),
 252       std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 253       Options.MCOptions.MCIncrementalLinkerCompatible,
 254       /*DWARFMustBeAtTheEnd*/ true));
 255
 256   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 257   FunctionPass *Printer =
 258       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 259   if (!Printer)
 260     return true;
 261
 262   PM.add(Printer);
 263   PM.add(createFreeMachineFunctionPass());
 264
 265   return false; // success!
 266 }