src/llvm/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/Target/TargetMachine.h"
  15 #include "llvm/Analysis/JumpInstrTableInfo.h"
  16 #include "llvm/Analysis/Passes.h"
  17 #include "llvm/CodeGen/AsmPrinter.h"
  18 #include "llvm/CodeGen/ForwardControlFlowIntegrity.h"
  19 #include "llvm/CodeGen/JumpInstrTables.h"
  20 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
  21 #include "llvm/CodeGen/MachineModuleInfo.h"
  22 #include "llvm/CodeGen/Passes.h"
  23 #include "llvm/IR/IRPrintingPasses.h"
  24 #include "llvm/IR/Verifier.h"
  25 #include "llvm/MC/MCAsmInfo.h"
  26 #include "llvm/MC/MCContext.h"
  27 #include "llvm/MC/MCInstrInfo.h"
  28 #include "llvm/MC/MCStreamer.h"
  29 #include "llvm/MC/MCSubtargetInfo.h"
  30 #include "llvm/PassManager.h"
  31 #include "llvm/Support/CommandLine.h"
  32 #include "llvm/Support/ErrorHandling.h"
  33 #include "llvm/Support/FormattedStream.h"
  34 #include "llvm/Support/TargetRegistry.h"
  35 #include "llvm/Target/TargetInstrInfo.h"
  36 #include "llvm/Target/TargetLowering.h"
  37 #include "llvm/Target/TargetLoweringObjectFile.h"
  38 #include "llvm/Target/TargetOptions.h"
  39 #include "llvm/Target/TargetRegisterInfo.h"
  40 #include "llvm/Target/TargetSubtargetInfo.h"
  41 #include "llvm/Transforms/Scalar.h"
  42 using namespace llvm;
  43
  44 // Enable or disable FastISel. Both options are needed, because
  45 // FastISel is enabled by default with -fast, and we wish to be
  46 // able to enable or disable fast-isel independently from -O0.
  47 static cl::opt<cl::boolOrDefault>
  48 EnableFastISelOption("fast-isel", cl::Hidden,
  49   cl::desc("Enable the \"fast\" instruction selector"));
  50
  51 void LLVMTargetMachine::initAsmInfo() {
  52   MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo(
  53       *getSubtargetImpl()->getRegisterInfo(), getTargetTriple());
  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   if (Options.CompressDebugSections)
  66     TmpAsmInfo->setCompressDebugSections(true);
  67
  68   AsmInfo = TmpAsmInfo;
  69 }
  70
  71 LLVMTargetMachine::LLVMTargetMachine(const Target &T, StringRef Triple,
  72                                      StringRef CPU, StringRef FS,
  73                                      TargetOptions Options,
  74                                      Reloc::Model RM, CodeModel::Model CM,
  75                                      CodeGenOpt::Level OL)
  76   : TargetMachine(T, Triple, CPU, FS, Options) {
  77   CodeGenInfo = T.createMCCodeGenInfo(Triple, RM, CM, OL);
  78 }
  79
  80 void LLVMTargetMachine::addAnalysisPasses(PassManagerBase &PM) {
  81   PM.add(createBasicTargetTransformInfoPass(this));
  82 }
  83
  84 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
  85 static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
  86                                           PassManagerBase &PM,
  87                                           bool DisableVerify,
  88                                           AnalysisID StartAfter,
  89                                           AnalysisID StopAfter) {
  90
  91   // Add internal analysis passes from the target machine.
  92   TM->addAnalysisPasses(PM);
  93
  94   // Targets may override createPassConfig to provide a target-specific
  95   // subclass.
  96   TargetPassConfig *PassConfig = TM->createPassConfig(PM);
  97   PassConfig->setStartStopPasses(StartAfter, StopAfter);
  98
  99   // Set PassConfig options provided by TargetMachine.
 100   PassConfig->setDisableVerify(DisableVerify);
 101
 102   PM.add(PassConfig);
 103
 104   PassConfig->addIRPasses();
 105
 106   PassConfig->addCodeGenPrepare();
 107
 108   PassConfig->addPassesToHandleExceptions();
 109
 110   PassConfig->addISelPrepare();
 111
 112   // Install a MachineModuleInfo class, which is an immutable pass that holds
 113   // all the per-module stuff we're generating, including MCContext.
 114   MachineModuleInfo *MMI = new MachineModuleInfo(
 115       *TM->getMCAsmInfo(), *TM->getSubtargetImpl()->getRegisterInfo(),
 116       &TM->getSubtargetImpl()->getTargetLowering()->getObjFileLowering());
 117   PM.add(MMI);
 118
 119   // Set up a MachineFunction for the rest of CodeGen to work on.
 120   PM.add(new MachineFunctionAnalysis(*TM));
 121
 122   // Enable FastISel with -fast, but allow that to be overridden.
 123   if (EnableFastISelOption == cl::BOU_TRUE ||
 124       (TM->getOptLevel() == CodeGenOpt::None &&
 125        EnableFastISelOption != cl::BOU_FALSE))
 126     TM->setFastISel(true);
 127
 128   // Ask the target for an isel.
 129   if (PassConfig->addInstSelector())
 130     return nullptr;
 131
 132   PassConfig->addMachinePasses();
 133
 134   PassConfig->setInitialized();
 135
 136   return &MMI->getContext();
 137 }
 138
 139 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
 140                                             formatted_raw_ostream &Out,
 141                                             CodeGenFileType FileType,
 142                                             bool DisableVerify,
 143                                             AnalysisID StartAfter,
 144                                             AnalysisID StopAfter) {
 145   // Passes to handle jumptable function annotations. These can't be handled at
 146   // JIT time, so we don't add them directly to addPassesToGenerateCode.
 147   PM.add(createJumpInstrTableInfoPass(
 148       getSubtargetImpl()->getInstrInfo()->getJumpInstrTableEntryBound()));
 149   PM.add(createJumpInstrTablesPass(Options.JTType));
 150   if (Options.FCFI)
 151     PM.add(createForwardControlFlowIntegrityPass(
 152         Options.JTType, Options.CFIType, Options.CFIEnforcing,
 153         Options.getCFIFuncName()));
 154
 155   // Add common CodeGen passes.
 156   MCContext *Context = addPassesToGenerateCode(this, PM, DisableVerify,
 157                                                StartAfter, StopAfter);
 158   if (!Context)
 159     return true;
 160
 161   if (StopAfter) {
 162     // FIXME: The intent is that this should eventually write out a YAML file,
 163     // containing the LLVM IR, the machine-level IR (when stopping after a
 164     // machine-level pass), and whatever other information is needed to
 165     // deserialize the code and resume compilation.  For now, just write the
 166     // LLVM IR.
 167     PM.add(createPrintModulePass(Out));
 168     return false;
 169   }
 170
 171   if (Options.MCOptions.MCSaveTempLabels)
 172     Context->setAllowTemporaryLabels(false);
 173
 174   const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
 175   const MCAsmInfo &MAI = *getMCAsmInfo();
 176   const MCRegisterInfo &MRI = *getSubtargetImpl()->getRegisterInfo();
 177   const MCInstrInfo &MII = *getSubtargetImpl()->getInstrInfo();
 178   std::unique_ptr<MCStreamer> AsmStreamer;
 179
 180   switch (FileType) {
 181   case CGFT_AssemblyFile: {
 182     MCInstPrinter *InstPrinter =
 183       getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI,
 184                                       MII, MRI, STI);
 185
 186     // Create a code emitter if asked to show the encoding.
 187     MCCodeEmitter *MCE = nullptr;
 188     if (Options.MCOptions.ShowMCEncoding)
 189       MCE = getTarget().createMCCodeEmitter(MII, MRI, STI, *Context);
 190
 191     MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
 192                                                        TargetCPU);
 193     MCStreamer *S = getTarget().createAsmStreamer(
 194         *Context, Out, Options.MCOptions.AsmVerbose,
 195         Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
 196         Options.MCOptions.ShowMCInst);
 197     AsmStreamer.reset(S);
 198     break;
 199   }
 200   case CGFT_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, MRI, STI,
 204                                                          *Context);
 205     MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
 206                                                        TargetCPU);
 207     if (!MCE || !MAB)
 208       return true;
 209
 210     AsmStreamer.reset(
 211         getTarget()
 212             .createMCObjectStreamer(getTargetTriple(), *Context, *MAB, Out, MCE,
 213                                     STI, Options.MCOptions.MCRelaxAll));
 214     break;
 215   }
 216   case CGFT_Null:
 217     // The Null output is intended for use for performance analysis and testing,
 218     // not real users.
 219     AsmStreamer.reset(getTarget().createNullStreamer(*Context));
 220     break;
 221   }
 222
 223   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 224   FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
 225   if (!Printer)
 226     return true;
 227
 228   // If successful, createAsmPrinter took ownership of AsmStreamer.
 229   AsmStreamer.release();
 230
 231   PM.add(Printer);
 232
 233   return false;
 234 }
 235
 236 /// addPassesToEmitMC - Add passes to the specified pass manager to get
 237 /// machine code emitted with the MCJIT. This method returns true if machine
 238 /// code is not supported. It fills the MCContext Ctx pointer which can be
 239 /// used to build custom MCStreamer.
 240 ///
 241 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM,
 242                                           MCContext *&Ctx,
 243                                           raw_ostream &Out,
 244                                           bool DisableVerify) {
 245   // Add common CodeGen passes.
 246   Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr);
 247   if (!Ctx)
 248     return true;
 249
 250   if (Options.MCOptions.MCSaveTempLabels)
 251     Ctx->setAllowTemporaryLabels(false);
 252
 253   // Create the code emitter for the target if it exists.  If not, .o file
 254   // emission fails.
 255   const MCRegisterInfo &MRI = *getSubtargetImpl()->getRegisterInfo();
 256   const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
 257   MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(
 258       *getSubtargetImpl()->getInstrInfo(), MRI, STI, *Ctx);
 259   MCAsmBackend *MAB = getTarget().createMCAsmBackend(MRI, getTargetTriple(),
 260                                                      TargetCPU);
 261   if (!MCE || !MAB)
 262     return true;
 263
 264   std::unique_ptr<MCStreamer> AsmStreamer;
 265   AsmStreamer.reset(getTarget()
 266                         .createMCObjectStreamer(getTargetTriple(), *Ctx, *MAB,
 267                                                 Out, MCE, STI,
 268                                                 Options.MCOptions.MCRelaxAll));
 269
 270   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 271   FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
 272   if (!Printer)
 273     return true;
 274
 275   // If successful, createAsmPrinter took ownership of AsmStreamer.
 276   AsmStreamer.release();
 277
 278   PM.add(Printer);
 279
 280   return false; // success!
 281 }