llvm/lib/CodeGen/LLVMTargetMachine.cpp

   1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the LLVMTargetMachine class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Analysis/Passes.h"
  14 #include "llvm/CodeGen/AsmPrinter.h"
  15 #include "llvm/CodeGen/BasicTTIImpl.h"
  16 #include "llvm/CodeGen/MachineModuleInfo.h"
  17 #include "llvm/CodeGen/Passes.h"
  18 #include "llvm/CodeGen/TargetPassConfig.h"
  19 #include "llvm/IR/LegacyPassManager.h"
  20 #include "llvm/MC/MCAsmBackend.h"
  21 #include "llvm/MC/MCAsmInfo.h"
  22 #include "llvm/MC/MCCodeEmitter.h"
  23 #include "llvm/MC/MCContext.h"
  24 #include "llvm/MC/MCInstrInfo.h"
  25 #include "llvm/MC/MCObjectWriter.h"
  26 #include "llvm/MC/MCRegisterInfo.h"
  27 #include "llvm/MC/MCStreamer.h"
  28 #include "llvm/MC/MCSubtargetInfo.h"
  29 #include "llvm/MC/TargetRegistry.h"
  30 #include "llvm/Support/CommandLine.h"
  31 #include "llvm/Support/FormattedStream.h"
  32 #include "llvm/Target/TargetMachine.h"
  33 #include "llvm/Target/TargetOptions.h"
  34 using namespace llvm;
  35
  36 static cl::opt<bool>
  37     EnableTrapUnreachable("trap-unreachable", cl::Hidden,
  38                           cl::desc("Enable generating trap for unreachable"));
  39
  40 static cl::opt<bool> EnableNoTrapAfterNoreturn(
  41     "no-trap-after-noreturn", cl::Hidden,
  42     cl::desc("Do not emit a trap instruction for 'unreachable' IR instructions "
  43              "after noreturn calls, even if --trap-unreachable is set."));
  44
  45 void LLVMTargetMachine::initAsmInfo() {
  46   MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str()));
  47   assert(MRI && "Unable to create reg info");
  48   MII.reset(TheTarget.createMCInstrInfo());
  49   assert(MII && "Unable to create instruction info");
  50   // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
  51   // to some backends having subtarget feature dependent module level
  52   // code generation. This is similar to the hack in the AsmPrinter for
  53   // module level assembly etc.
  54   STI.reset(TheTarget.createMCSubtargetInfo(
  55       getTargetTriple().str(), getTargetCPU(), getTargetFeatureString()));
  56   assert(STI && "Unable to create subtarget info");
  57
  58   MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo(
  59       *MRI, getTargetTriple().str(), Options.MCOptions);
  60   // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
  61   // and if the old one gets included then MCAsmInfo will be NULL and
  62   // we'll crash later.
  63   // Provide the user with a useful error message about what's wrong.
  64   assert(TmpAsmInfo && "MCAsmInfo not initialized. "
  65          "Make sure you include the correct TargetSelect.h"
  66          "and that InitializeAllTargetMCs() is being invoked!");
  67
  68   if (Options.BinutilsVersion.first > 0)
  69     TmpAsmInfo->setBinutilsVersion(Options.BinutilsVersion);
  70
  71   if (Options.DisableIntegratedAS) {
  72     TmpAsmInfo->setUseIntegratedAssembler(false);
  73     // If there is explict option disable integratedAS, we can't use it for
  74     // inlineasm either.
  75     TmpAsmInfo->setParseInlineAsmUsingAsmParser(false);
  76   }
  77
  78   TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments);
  79
  80   TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections);
  81
  82   TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations);
  83
  84   TmpAsmInfo->setFullRegisterNames(Options.MCOptions.PPCUseFullRegisterNames);
  85
  86   if (Options.ExceptionModel != ExceptionHandling::None)
  87     TmpAsmInfo->setExceptionsType(Options.ExceptionModel);
  88
  89   AsmInfo.reset(TmpAsmInfo);
  90 }
  91
  92 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
  93                                      StringRef DataLayoutString,
  94                                      const Triple &TT, StringRef CPU,
  95                                      StringRef FS, const TargetOptions &Options,
  96                                      Reloc::Model RM, CodeModel::Model CM,
  97                                      CodeGenOptLevel OL)
  98     : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) {
  99   this->RM = RM;
 100   this->CMModel = CM;
 101   this->OptLevel = OL;
 102
 103   if (EnableTrapUnreachable)
 104     this->Options.TrapUnreachable = true;
 105   if (EnableNoTrapAfterNoreturn)
 106     this->Options.NoTrapAfterNoreturn = true;
 107 }
 108
 109 TargetTransformInfo
 110 LLVMTargetMachine::getTargetTransformInfo(const Function &F) const {
 111   return TargetTransformInfo(BasicTTIImpl(this, F));
 112 }
 113
 114 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
 115 static TargetPassConfig *
 116 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM,
 117                         bool DisableVerify,
 118                         MachineModuleInfoWrapperPass &MMIWP) {
 119   // Targets may override createPassConfig to provide a target-specific
 120   // subclass.
 121   TargetPassConfig *PassConfig = TM.createPassConfig(PM);
 122   // Set PassConfig options provided by TargetMachine.
 123   PassConfig->setDisableVerify(DisableVerify);
 124   PM.add(PassConfig);
 125   PM.add(&MMIWP);
 126
 127   if (PassConfig->addISelPasses())
 128     return nullptr;
 129   PassConfig->addMachinePasses();
 130   PassConfig->setInitialized();
 131   return PassConfig;
 132 }
 133
 134 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
 135                                       raw_pwrite_stream &Out,
 136                                       raw_pwrite_stream *DwoOut,
 137                                       CodeGenFileType FileType,
 138                                       MCContext &Context) {
 139   Expected<std::unique_ptr<MCStreamer>> MCStreamerOrErr =
 140       createMCStreamer(Out, DwoOut, FileType, Context);
 141   if (auto Err = MCStreamerOrErr.takeError())
 142     return true;
 143
 144   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 145   FunctionPass *Printer =
 146       getTarget().createAsmPrinter(*this, std::move(*MCStreamerOrErr));
 147   if (!Printer)
 148     return true;
 149
 150   PM.add(Printer);
 151   return false;
 152 }
 153
 154 Expected<std::unique_ptr<MCStreamer>> LLVMTargetMachine::createMCStreamer(
 155     raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, CodeGenFileType FileType,
 156     MCContext &Context) {
 157   if (Options.MCOptions.MCSaveTempLabels)
 158     Context.setAllowTemporaryLabels(false);
 159
 160   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 161   const MCAsmInfo &MAI = *getMCAsmInfo();
 162   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 163   const MCInstrInfo &MII = *getMCInstrInfo();
 164
 165   std::unique_ptr<MCStreamer> AsmStreamer;
 166
 167   switch (FileType) {
 168   case CodeGenFileType::AssemblyFile: {
 169     MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
 170         getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI);
 171
 172     // Create a code emitter if asked to show the encoding.
 173     std::unique_ptr<MCCodeEmitter> MCE;
 174     if (Options.MCOptions.ShowMCEncoding)
 175       MCE.reset(getTarget().createMCCodeEmitter(MII, Context));
 176
 177     bool UseDwarfDirectory = false;
 178     switch (Options.MCOptions.MCUseDwarfDirectory) {
 179     case MCTargetOptions::DisableDwarfDirectory:
 180       UseDwarfDirectory = false;
 181       break;
 182     case MCTargetOptions::EnableDwarfDirectory:
 183       UseDwarfDirectory = true;
 184       break;
 185     case MCTargetOptions::DefaultDwarfDirectory:
 186       UseDwarfDirectory = MAI.enableDwarfFileDirectoryDefault();
 187       break;
 188     }
 189
 190     std::unique_ptr<MCAsmBackend> MAB(
 191         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 192     auto FOut = std::make_unique<formatted_raw_ostream>(Out);
 193     MCStreamer *S = getTarget().createAsmStreamer(
 194         Context, std::move(FOut), Options.MCOptions.AsmVerbose,
 195         UseDwarfDirectory, InstPrinter, std::move(MCE), std::move(MAB),
 196         Options.MCOptions.ShowMCInst);
 197     AsmStreamer.reset(S);
 198     break;
 199   }
 200   case CodeGenFileType::ObjectFile: {
 201     // Create the code emitter for the target if it exists.  If not, .o file
 202     // emission fails.
 203     MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, Context);
 204     if (!MCE)
 205       return make_error<StringError>("createMCCodeEmitter failed",
 206                                      inconvertibleErrorCode());
 207     MCAsmBackend *MAB =
 208         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 209     if (!MAB)
 210       return make_error<StringError>("createMCAsmBackend failed",
 211                                      inconvertibleErrorCode());
 212
 213     Triple T(getTargetTriple().str());
 214     AsmStreamer.reset(getTarget().createMCObjectStreamer(
 215         T, Context, std::unique_ptr<MCAsmBackend>(MAB),
 216         DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut)
 217                : MAB->createObjectWriter(Out),
 218         std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 219         Options.MCOptions.MCIncrementalLinkerCompatible,
 220         /*DWARFMustBeAtTheEnd*/ true));
 221     break;
 222   }
 223   case CodeGenFileType::Null:
 224     // The Null output is intended for use for performance analysis and testing,
 225     // not real users.
 226     AsmStreamer.reset(getTarget().createNullStreamer(Context));
 227     break;
 228   }
 229
 230   return std::move(AsmStreamer);
 231 }
 232
 233 bool LLVMTargetMachine::addPassesToEmitFile(
 234     PassManagerBase &PM, raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
 235     CodeGenFileType FileType, bool DisableVerify,
 236     MachineModuleInfoWrapperPass *MMIWP) {
 237   // Add common CodeGen passes.
 238   if (!MMIWP)
 239     MMIWP = new MachineModuleInfoWrapperPass(this);
 240   TargetPassConfig *PassConfig =
 241       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 242   if (!PassConfig)
 243     return true;
 244
 245   if (TargetPassConfig::willCompleteCodeGenPipeline()) {
 246     if (addAsmPrinter(PM, Out, DwoOut, FileType, MMIWP->getMMI().getContext()))
 247       return true;
 248   } else {
 249     // MIR printing is redundant with -filetype=null.
 250     if (FileType != CodeGenFileType::Null)
 251       PM.add(createPrintMIRPass(Out));
 252   }
 253
 254   PM.add(createFreeMachineFunctionPass());
 255   return false;
 256 }
 257
 258 /// addPassesToEmitMC - Add passes to the specified pass manager to get
 259 /// machine code emitted with the MCJIT. This method returns true if machine
 260 /// code is not supported. It fills the MCContext Ctx pointer which can be
 261 /// used to build custom MCStreamer.
 262 ///
 263 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
 264                                           raw_pwrite_stream &Out,
 265                                           bool DisableVerify) {
 266   // Add common CodeGen passes.
 267   MachineModuleInfoWrapperPass *MMIWP = new MachineModuleInfoWrapperPass(this);
 268   TargetPassConfig *PassConfig =
 269       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 270   if (!PassConfig)
 271     return true;
 272   assert(TargetPassConfig::willCompleteCodeGenPipeline() &&
 273          "Cannot emit MC with limited codegen pipeline");
 274
 275   Ctx = &MMIWP->getMMI().getContext();
 276   // libunwind is unable to load compact unwind dynamically, so we must generate
 277   // DWARF unwind info for the JIT.
 278   Options.MCOptions.EmitDwarfUnwind = EmitDwarfUnwindType::Always;
 279   if (Options.MCOptions.MCSaveTempLabels)
 280     Ctx->setAllowTemporaryLabels(false);
 281
 282   // Create the code emitter for the target if it exists.  If not, .o file
 283   // emission fails.
 284   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 285   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 286   std::unique_ptr<MCCodeEmitter> MCE(
 287       getTarget().createMCCodeEmitter(*getMCInstrInfo(), *Ctx));
 288   std::unique_ptr<MCAsmBackend> MAB(
 289       getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 290   if (!MCE || !MAB)
 291     return true;
 292
 293   const Triple &T = getTargetTriple();
 294   std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
 295       T, *Ctx, std::move(MAB), MAB->createObjectWriter(Out), std::move(MCE),
 296       STI, Options.MCOptions.MCRelaxAll,
 297       Options.MCOptions.MCIncrementalLinkerCompatible,
 298       /*DWARFMustBeAtTheEnd*/ true));
 299
 300   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 301   FunctionPass *Printer =
 302       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 303   if (!Printer)
 304     return true;
 305
 306   PM.add(Printer);
 307   PM.add(createFreeMachineFunctionPass());
 308
 309   return false; // success!
 310 }