C++ opt::getNumOccurrences方法代码示例

void PPCPassConfig::addIRPasses() {
  if (TM->getOptLevel() != CodeGenOpt::None)
    addPass(createPPCBoolRetToIntPass());
  addPass(createAtomicExpandPass(&getPPCTargetMachine()));

  // For the BG/Q (or if explicitly requested), add explicit data prefetch
  // intrinsics.
  bool UsePrefetching = TM->getTargetTriple().getVendor() == Triple::BGQ &&
                        getOptLevel() != CodeGenOpt::None;
  if (EnablePrefetch.getNumOccurrences() > 0)
    UsePrefetching = EnablePrefetch;
  if (UsePrefetching)
    addPass(createPPCLoopDataPrefetchPass());

  if (TM->getOptLevel() == CodeGenOpt::Aggressive && EnableGEPOpt) {
    // Call SeparateConstOffsetFromGEP pass to extract constants within indices
    // and lower a GEP with multiple indices to either arithmetic operations or
    // multiple GEPs with single index.
    addPass(createSeparateConstOffsetFromGEPPass(TM, true));
    // Call EarlyCSE pass to find and remove subexpressions in the lowered
    // result.
    addPass(createEarlyCSEPass());
    // Do loop invariant code motion in case part of the lowered result is
    // invariant.
    addPass(createLICMPass());
  }

  TargetPassConfig::addIRPasses();
}

/// This routine adds optimization passes based on selected optimization level,
/// OptLevel.
///
/// OptLevel - Optimization Level
static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
                                  unsigned OptLevel, unsigned SizeLevel) {
  FPM.add(createVerifierPass());          // Verify that input is correct
  MPM.add(createDebugInfoVerifierPass()); // Verify that debug info is correct

  PassManagerBuilder Builder;
  Builder.OptLevel = OptLevel;
  Builder.SizeLevel = SizeLevel;

  if (DisableInline) {
    // No inlining pass
  } else if (OptLevel > 1) {
    Builder.Inliner = createFunctionInliningPass(OptLevel, SizeLevel);
  } else {
    Builder.Inliner = createAlwaysInlinerPass();
  }
  Builder.DisableUnitAtATime = !UnitAtATime;
  Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
                               DisableLoopUnrolling : OptLevel == 0;

  // This is final, unless there is a #pragma vectorize enable
  if (DisableLoopVectorization)
    Builder.LoopVectorize = false;
  // If option wasn't forced via cmd line (-vectorize-loops, -loop-vectorize)
  else if (!Builder.LoopVectorize)
    Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;

  // When #pragma vectorize is on for SLP, do the same as above
  Builder.SLPVectorize =
      DisableSLPVectorization ? false : OptLevel > 1 && SizeLevel < 2;

  Builder.populateFunctionPassManager(FPM);
  Builder.populateModulePassManager(MPM);
}

int main(int argc, char **argv) {
  llvm::cl::ParseCommandLineOptions(argc, argv);
  if (Input.getNumOccurrences()) {
    OwningPtr<MemoryBuffer> Buf;
    if (MemoryBuffer::getFileOrSTDIN(Input, Buf))
      return 1;

    llvm::SourceMgr sm;
    if (DumpTokens) {
      yaml::dumpTokens(Buf->getBuffer(), outs());
    }

    if (DumpCanonical) {
      yaml::Stream stream(Buf->getBuffer(), sm);
      dumpStream(stream);
    }
  }

  if (Verify) {
    llvm::TimerGroup Group("YAML parser benchmark");
    benchmark(Group, "Fast", createJSONText(10, 500));
  } else if (!DumpCanonical && !DumpTokens) {
    llvm::TimerGroup Group("YAML parser benchmark");
    benchmark(Group, "Small Values", createJSONText(MemoryLimitMB, 5));
    benchmark(Group, "Medium Values", createJSONText(MemoryLimitMB, 500));
    benchmark(Group, "Large Values", createJSONText(MemoryLimitMB, 50000));
  }

  return 0;
}

/// AddOptimizationPasses - This routine adds optimization passes
/// based on selected optimization level, OptLevel. This routine
/// duplicates llvm-gcc behaviour.
///
/// OptLevel - Optimization Level
static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
                                  unsigned OptLevel, unsigned SizeLevel) {
  FPM.add(createVerifierPass());                  // Verify that input is correct

  PassManagerBuilder Builder;
  Builder.OptLevel = OptLevel;
  Builder.SizeLevel = SizeLevel;

  if (DisableInline) {
    // No inlining pass
  } else if (OptLevel > 1) {
    unsigned Threshold = 225;
    if (SizeLevel == 1)      // -Os
      Threshold = 75;
    else if (SizeLevel == 2) // -Oz
      Threshold = 25;
    if (OptLevel > 2)
      Threshold = 275;
    Builder.Inliner = createFunctionInliningPass(Threshold);
  } else {
    Builder.Inliner = createAlwaysInlinerPass();
  }
  Builder.DisableUnitAtATime = !UnitAtATime;
  Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
                               DisableLoopUnrolling : OptLevel == 0;

  Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;
  Builder.SLPVectorize = true;

  Builder.populateFunctionPassManager(FPM);
  Builder.populateModulePassManager(MPM);
}

unsigned Inliner::getInlineThreshold(CallSite CS) const {
  int thres = InlineThreshold; // -inline-threshold or else selected by
                               // overall opt level

  // If -inline-threshold is not given, listen to the optsize attribute when it
  // would decrease the threshold.
  Function *Caller = CS.getCaller();
  bool OptSize = Caller && !Caller->isDeclaration() &&
    Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                         Attribute::OptimizeForSize);
  if (!(InlineLimit.getNumOccurrences() > 0) && OptSize &&
      OptSizeThreshold < thres)
    thres = OptSizeThreshold;

  // Listen to the inlinehint attribute when it would increase the threshold
  // and the caller does not need to minimize its size.
  Function *Callee = CS.getCalledFunction();
  bool InlineHint = Callee && !Callee->isDeclaration() &&
    Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                         Attribute::InlineHint);
  if (InlineHint && HintThreshold > thres
      && !Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                               Attribute::MinSize))
    thres = HintThreshold;

  // Listen to the cold attribute when it would decrease the threshold.
  bool ColdCallee = Callee && !Callee->isDeclaration() &&
    Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                         Attribute::Cold);
  if (ColdCallee && ColdThreshold < thres)
    thres = ColdThreshold;

  return thres;
}

thinlto_code_gen_t thinlto_create_codegen(void) {
  lto_initialize();
  ThinLTOCodeGenerator *CodeGen = new ThinLTOCodeGenerator();
  CodeGen->setTargetOptions(InitTargetOptionsFromCodeGenFlags());

  if (OptLevel.getNumOccurrences()) {
    if (OptLevel < '0' || OptLevel > '3')
      report_fatal_error("Optimization level must be between 0 and 3");
    CodeGen->setOptLevel(OptLevel - '0');
    switch (OptLevel) {
    case '0':
      CodeGen->setCodeGenOptLevel(CodeGenOpt::None);
      break;
    case '1':
      CodeGen->setCodeGenOptLevel(CodeGenOpt::Less);
      break;
    case '2':
      CodeGen->setCodeGenOptLevel(CodeGenOpt::Default);
      break;
    case '3':
      CodeGen->setCodeGenOptLevel(CodeGenOpt::Aggressive);
      break;
    }
  }
  return wrap(CodeGen);
}

// Helper function to handle -of, -od, etc.
static void initFromString(char*& dest, const cl::opt<std::string>& src) {
    dest = 0;
    if (src.getNumOccurrences() != 0) {
        if (src.empty())
            error("Expected argument to '-%s'", src.ArgStr);
        dest = mem.strdup(src.c_str());
    }
}

RegBankSelect::RegBankSelect(Mode RunningMode)
    : MachineFunctionPass(ID), OptMode(RunningMode) {
  initializeRegBankSelectPass(*PassRegistry::getPassRegistry());
  if (RegBankSelectMode.getNumOccurrences() != 0) {
    OptMode = RegBankSelectMode;
    if (RegBankSelectMode != RunningMode)
      LLVM_DEBUG(dbgs() << "RegBankSelect mode overrided by command line\n");
  }
}

TargetMachine::TargetMachine(const Target &T, StringRef DataLayoutString,
                             const Triple &TT, StringRef CPU, StringRef FS,
                             const TargetOptions &Options)
    : TheTarget(T), DL(DataLayoutString), TargetTriple(TT), TargetCPU(CPU),
      TargetFS(FS), AsmInfo(nullptr), MRI(nullptr), MII(nullptr), STI(nullptr),
      RequireStructuredCFG(false), Options(Options) {
  if (EnableIPRA.getNumOccurrences())
    this->Options.EnableIPRA = EnableIPRA;
}

void BasicTTI::getUnrollingPreferences(Loop *L,
                                       UnrollingPreferences &UP) const {
  // This unrolling functionality is target independent, but to provide some
  // motivation for its intended use, for x86:

  // According to the Intel 64 and IA-32 Architectures Optimization Reference
  // Manual, Intel Core models and later have a loop stream detector
  // (and associated uop queue) that can benefit from partial unrolling.
  // The relevant requirements are:
  //  - The loop must have no more than 4 (8 for Nehalem and later) branches
  //    taken, and none of them may be calls.
  //  - The loop can have no more than 18 (28 for Nehalem and later) uops.

  // According to the Software Optimization Guide for AMD Family 15h Processors,
  // models 30h-4fh (Steamroller and later) have a loop predictor and loop
  // buffer which can benefit from partial unrolling.
  // The relevant requirements are:
  //  - The loop must have fewer than 16 branches
  //  - The loop must have less than 40 uops in all executed loop branches

  // The number of taken branches in a loop is hard to estimate here, and
  // benchmarking has revealed that it is better not to be conservative when
  // estimating the branch count. As a result, we'll ignore the branch limits
  // until someone finds a case where it matters in practice.

  unsigned MaxOps;
  const TargetSubtargetInfo *ST = &TM->getSubtarget<TargetSubtargetInfo>();
  if (PartialUnrollingThreshold.getNumOccurrences() > 0)
    MaxOps = PartialUnrollingThreshold;
  else if (ST->getSchedModel().LoopMicroOpBufferSize > 0)
    MaxOps = ST->getSchedModel().LoopMicroOpBufferSize;
  else
    return;

  // Scan the loop: don't unroll loops with calls.
  for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
       I != E; ++I) {
    BasicBlock *BB = *I;

    for (BasicBlock::iterator J = BB->begin(), JE = BB->end(); J != JE; ++J)
      if (isa<CallInst>(J) || isa<InvokeInst>(J)) {
        ImmutableCallSite CS(J);
        if (const Function *F = CS.getCalledFunction()) {
          if (!TopTTI->isLoweredToCall(F))
            continue;
        }

        return;
      }
  }

  // Enable runtime and partial unrolling up to the specified size.
  UP.Partial = UP.Runtime = true;
  UP.PartialThreshold = UP.PartialOptSizeThreshold = MaxOps;
}

static CodeGenOpt::Level GetCodeGenOptLevel() {
  if (CodeGenOptLevel.getNumOccurrences())
    return static_cast<CodeGenOpt::Level>(unsigned(CodeGenOptLevel));
  if (OptLevelO1)
    return CodeGenOpt::Less;
  if (OptLevelO2)
    return CodeGenOpt::Default;
  if (OptLevelO3)
    return CodeGenOpt::Aggressive;
  return CodeGenOpt::None;
}

static void processViewOptions() {
  if (!EnableAllViews.getNumOccurrences() &&
      !EnableAllStats.getNumOccurrences())
    return;

  if (EnableAllViews.getNumOccurrences()) {
    processOptionImpl(PrintSummaryView, EnableAllViews);
    processOptionImpl(PrintResourcePressureView, EnableAllViews);
    processOptionImpl(PrintTimelineView, EnableAllViews);
    processOptionImpl(PrintInstructionInfoView, EnableAllViews);
  }

  const cl::opt<bool> &Default =
      EnableAllViews.getPosition() < EnableAllStats.getPosition()
          ? EnableAllStats
          : EnableAllViews;
  processOptionImpl(PrintRegisterFileStats, Default);
  processOptionImpl(PrintDispatchStats, Default);
  processOptionImpl(PrintSchedulerStats, Default);
  processOptionImpl(PrintRetireStats, Default);
}

unsigned PPCTTIImpl::getCacheLineSize() {
  // Check first if the user specified a custom line size.
  if (CacheLineSize.getNumOccurrences() > 0)
    return CacheLineSize;

  // On P7, P8 or P9 we have a cache line size of 128.
  unsigned Directive = ST->getDarwinDirective();
  if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 ||
      Directive == PPC::DIR_PWR9)
    return 128;

  // On other processors return a default of 64 bytes.
  return 64;
}

R600TargetMachine::R600TargetMachine(const Target &T, const Triple &TT,
                                     StringRef CPU, StringRef FS,
                                     TargetOptions Options,
                                     Optional<Reloc::Model> RM,
                                     Optional<CodeModel::Model> CM,
                                     CodeGenOpt::Level OL, bool JIT)
    : AMDGPUTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL) {
  setRequiresStructuredCFG(true);

  // Override the default since calls aren't supported for r600.
  if (EnableFunctionCalls &&
      EnableAMDGPUFunctionCallsOpt.getNumOccurrences() == 0)
    EnableFunctionCalls = false;
}

/// Returns true if we can profitably unroll the multi-exit loop L. Currently,
/// we return true only if UnrollRuntimeMultiExit is set to true.
static bool canProfitablyUnrollMultiExitLoop(
    Loop *L, SmallVectorImpl<BasicBlock *> &OtherExits, BasicBlock *LatchExit,
    bool PreserveLCSSA, bool UseEpilogRemainder) {

#if !defined(NDEBUG)
  SmallVector<BasicBlock *, 8> OtherExitsDummyCheck;
  assert(canSafelyUnrollMultiExitLoop(L, OtherExitsDummyCheck, LatchExit,
                                      PreserveLCSSA, UseEpilogRemainder) &&
         "Should be safe to unroll before checking profitability!");
#endif
  // Priority goes to UnrollRuntimeMultiExit if it's supplied.
  return UnrollRuntimeMultiExit.getNumOccurrences() ? UnrollRuntimeMultiExit
                                                    : false;
}