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/MCStreamer.h"
  27 #include "llvm/MC/MCSubtargetInfo.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/FormattedStream.h"
  31 #include "llvm/Support/TargetRegistry.h"
  32 #include "llvm/Target/TargetLoweringObjectFile.h"
  33 #include "llvm/Target/TargetMachine.h"
  34 #include "llvm/Target/TargetOptions.h"
  35 using namespace llvm;
  36
  37 static cl::opt<bool> EnableTrapUnreachable("trap-unreachable",
  38   cl::Hidden, cl::ZeroOrMore, cl::init(false),
  39   cl::desc("Enable generating trap for unreachable"));
  40
  41 void LLVMTargetMachine::initAsmInfo() {
  42   MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str()));
  43   MII.reset(TheTarget.createMCInstrInfo());
  44   // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
  45   // to some backends having subtarget feature dependent module level
  46   // code generation. This is similar to the hack in the AsmPrinter for
  47   // module level assembly etc.
  48   STI.reset(TheTarget.createMCSubtargetInfo(
  49       getTargetTriple().str(), getTargetCPU(), getTargetFeatureString()));
  50
  51   MCAsmInfo *TmpAsmInfo =
  52       TheTarget.createMCAsmInfo(*MRI, getTargetTriple().str());
  53   // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
  54   // and if the old one gets included then MCAsmInfo will be NULL and
  55   // we'll crash later.
  56   // Provide the user with a useful error message about what's wrong.
  57   assert(TmpAsmInfo && "MCAsmInfo not initialized. "
  58          "Make sure you include the correct TargetSelect.h"
  59          "and that InitializeAllTargetMCs() is being invoked!");
  60
  61   if (Options.DisableIntegratedAS)
  62     TmpAsmInfo->setUseIntegratedAssembler(false);
  63
  64   TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments);
  65
  66   TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections);
  67
  68   TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations);
  69
  70   if (Options.ExceptionModel != ExceptionHandling::None)
  71     TmpAsmInfo->setExceptionsType(Options.ExceptionModel);
  72
  73   AsmInfo.reset(TmpAsmInfo);
  74 }
  75
  76 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
  77                                      StringRef DataLayoutString,
  78                                      const Triple &TT, StringRef CPU,
  79                                      StringRef FS, const TargetOptions &Options,
  80                                      Reloc::Model RM, CodeModel::Model CM,
  81                                      CodeGenOpt::Level OL)
  82     : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) {
  83   this->RM = RM;
  84   this->CMModel = CM;
  85   this->OptLevel = OL;
  86
  87   if (EnableTrapUnreachable)
  88     this->Options.TrapUnreachable = true;
  89 }
  90
  91 TargetTransformInfo
  92 LLVMTargetMachine::getTargetTransformInfo(const Function &F) {
  93   return TargetTransformInfo(BasicTTIImpl(this, F));
  94 }
  95
  96 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
  97 static TargetPassConfig *
  98 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM,
  99                         bool DisableVerify,
 100                         MachineModuleInfoWrapperPass &MMIWP) {
 101   // Targets may override createPassConfig to provide a target-specific
 102   // subclass.
 103   TargetPassConfig *PassConfig = TM.createPassConfig(PM);
 104   // Set PassConfig options provided by TargetMachine.
 105   PassConfig->setDisableVerify(DisableVerify);
 106   PM.add(PassConfig);
 107   PM.add(&MMIWP);
 108
 109   if (PassConfig->addISelPasses())
 110     return nullptr;
 111   PassConfig->addMachinePasses();
 112   PassConfig->setInitialized();
 113   return PassConfig;
 114 }
 115
 116 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
 117                                       raw_pwrite_stream &Out,
 118                                       raw_pwrite_stream *DwoOut,
 119                                       CodeGenFileType FileType,
 120                                       MCContext &Context) {
 121   if (Options.MCOptions.MCSaveTempLabels)
 122     Context.setAllowTemporaryLabels(false);
 123
 124   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 125   const MCAsmInfo &MAI = *getMCAsmInfo();
 126   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 127   const MCInstrInfo &MII = *getMCInstrInfo();
 128
 129   std::unique_ptr<MCStreamer> AsmStreamer;
 130
 131   switch (FileType) {
 132   case CGFT_AssemblyFile: {
 133     MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
 134         getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI);
 135
 136     // Create a code emitter if asked to show the encoding.
 137     std::unique_ptr<MCCodeEmitter> MCE;
 138     if (Options.MCOptions.ShowMCEncoding)
 139       MCE.reset(getTarget().createMCCodeEmitter(MII, MRI, Context));
 140
 141     std::unique_ptr<MCAsmBackend> MAB(
 142         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 143     auto FOut = std::make_unique<formatted_raw_ostream>(Out);
 144     MCStreamer *S = getTarget().createAsmStreamer(
 145         Context, std::move(FOut), Options.MCOptions.AsmVerbose,
 146         Options.MCOptions.MCUseDwarfDirectory, InstPrinter, std::move(MCE),
 147         std::move(MAB), Options.MCOptions.ShowMCInst);
 148     AsmStreamer.reset(S);
 149     break;
 150   }
 151   case CGFT_ObjectFile: {
 152     // Create the code emitter for the target if it exists.  If not, .o file
 153     // emission fails.
 154     MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, Context);
 155     MCAsmBackend *MAB =
 156         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 157     if (!MCE || !MAB)
 158       return true;
 159
 160     // Don't waste memory on names of temp labels.
 161     Context.setUseNamesOnTempLabels(false);
 162
 163     Triple T(getTargetTriple().str());
 164     AsmStreamer.reset(getTarget().createMCObjectStreamer(
 165         T, Context, std::unique_ptr<MCAsmBackend>(MAB),
 166         DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut)
 167                : MAB->createObjectWriter(Out),
 168         std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 169         Options.MCOptions.MCIncrementalLinkerCompatible,
 170         /*DWARFMustBeAtTheEnd*/ true));
 171     break;
 172   }
 173   case CGFT_Null:
 174     // The Null output is intended for use for performance analysis and testing,
 175     // not real users.
 176     AsmStreamer.reset(getTarget().createNullStreamer(Context));
 177     break;
 178   }
 179
 180   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 181   FunctionPass *Printer =
 182       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 183   if (!Printer)
 184     return true;
 185
 186   PM.add(Printer);
 187   return false;
 188 }
 189
 190 bool LLVMTargetMachine::addPassesToEmitFile(
 191     PassManagerBase &PM, raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
 192     CodeGenFileType FileType, bool DisableVerify,
 193     MachineModuleInfoWrapperPass *MMIWP) {
 194   // Add common CodeGen passes.
 195   if (!MMIWP)
 196     MMIWP = new MachineModuleInfoWrapperPass(this);
 197   TargetPassConfig *PassConfig =
 198       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 199   if (!PassConfig)
 200     return true;
 201
 202   if (!TargetPassConfig::willCompleteCodeGenPipeline()) {
 203     if (this->getTargetTriple().isOSAIX()) {
 204       // On AIX, we might manifest MCSymbols during SDAG lowering. For MIR
 205       // testing to be meaningful, we need to ensure that the symbols created
 206       // are MCSymbolXCOFF variants, which requires that
 207       // the TargetLoweringObjectFile instance has been initialized.
 208       MCContext &Ctx = MMIWP->getMMI().getContext();
 209       const_cast<TargetLoweringObjectFile &>(*this->getObjFileLowering())
 210           .Initialize(Ctx, *this);
 211     }
 212     PM.add(createPrintMIRPass(Out));
 213   } else if (addAsmPrinter(PM, Out, DwoOut, FileType,
 214                            MMIWP->getMMI().getContext()))
 215     return true;
 216
 217   PM.add(createFreeMachineFunctionPass());
 218   return false;
 219 }
 220
 221 /// addPassesToEmitMC - Add passes to the specified pass manager to get
 222 /// machine code emitted with the MCJIT. This method returns true if machine
 223 /// code is not supported. It fills the MCContext Ctx pointer which can be
 224 /// used to build custom MCStreamer.
 225 ///
 226 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
 227                                           raw_pwrite_stream &Out,
 228                                           bool DisableVerify) {
 229   // Add common CodeGen passes.
 230   MachineModuleInfoWrapperPass *MMIWP = new MachineModuleInfoWrapperPass(this);
 231   TargetPassConfig *PassConfig =
 232       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 233   if (!PassConfig)
 234     return true;
 235   assert(TargetPassConfig::willCompleteCodeGenPipeline() &&
 236          "Cannot emit MC with limited codegen pipeline");
 237
 238   Ctx = &MMIWP->getMMI().getContext();
 239   if (Options.MCOptions.MCSaveTempLabels)
 240     Ctx->setAllowTemporaryLabels(false);
 241
 242   // Create the code emitter for the target if it exists.  If not, .o file
 243   // emission fails.
 244   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 245   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 246   MCCodeEmitter *MCE =
 247       getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx);
 248   MCAsmBackend *MAB =
 249       getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 250   if (!MCE || !MAB)
 251     return true;
 252
 253   const Triple &T = getTargetTriple();
 254   std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
 255       T, *Ctx, std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(Out),
 256       std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 257       Options.MCOptions.MCIncrementalLinkerCompatible,
 258       /*DWARFMustBeAtTheEnd*/ true));
 259
 260   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 261   FunctionPass *Printer =
 262       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 263   if (!Printer)
 264     return true;
 265
 266   PM.add(Printer);
 267   PM.add(createFreeMachineFunctionPass());
 268
 269   return false; // success!
 270 }