C++ ManagedStatic::empty方法代码示例

/// Return true if the specified string is the debug type
/// specified on the command line, or if none was specified on the command line
/// with the -debug-only=X option.
bool isCurrentDebugType(const char *DebugType) {
  if (CurrentDebugType->empty())
    return true;
  // See if DebugType is in list. Note: do not use find() as that forces us to
  // unnecessarily create an std::string instance.
  for (auto &d : *CurrentDebugType) {
    if (d == DebugType)
      return true;
  }
  return false;
}

// GetLibSupportInfoOutputFile - Return a file stream to print our output on...
std::ostream *
llvm::GetLibSupportInfoOutputFile() {
  std::string &LibSupportInfoOutputFilename = getLibSupportInfoOutputFilename();
  if (LibSupportInfoOutputFilename.empty())
    return cerr.stream();
  if (LibSupportInfoOutputFilename == "-")
    return cout.stream();

  std::ostream *Result = new std::ofstream(LibSupportInfoOutputFilename.c_str(),
                                           std::ios::app);
  if (!Result->good()) {
    cerr << "Error opening info-output-file '"
         << LibSupportInfoOutputFilename << " for appending!\n";
    delete Result;
    return cerr.stream();
  }
  return Result;
}

// GetLibSupportInfoOutputFile - Return a file stream to print our output on...
raw_ostream *
llvm::GetLibSupportInfoOutputFile() {
    std::string &LibSupportInfoOutputFilename = getLibSupportInfoOutputFilename();
    if (LibSupportInfoOutputFilename.empty())
        return &errs();
    if (LibSupportInfoOutputFilename == "-")
        return &outs();


    std::string Error;
    raw_ostream *Result = new raw_fd_ostream(LibSupportInfoOutputFilename.c_str(),
            Error, raw_fd_ostream::F_Append);
    if (Error.empty())
        return Result;

    errs() << "Error opening info-output-file '"
           << LibSupportInfoOutputFilename << " for appending!\n";
    delete Result;
    return &errs();
}

void PassManagerBuilder::populateModulePassManager(
    legacy::PassManagerBase &MPM) {
  // Allow forcing function attributes as a debugging and tuning aid.
  MPM.add(createForceFunctionAttrsLegacyPass());

  // If all optimizations are disabled, just run the always-inline pass and,
  // if enabled, the function merging pass.
  if (OptLevel == 0) {
    addPGOInstrPasses(MPM);
    if (Inliner) {
      MPM.add(Inliner);
      Inliner = nullptr;
    }

    // FIXME: The BarrierNoopPass is a HACK! The inliner pass above implicitly
    // creates a CGSCC pass manager, but we don't want to add extensions into
    // that pass manager. To prevent this we insert a no-op module pass to reset
    // the pass manager to get the same behavior as EP_OptimizerLast in non-O0
    // builds. The function merging pass is
    if (MergeFunctions)
      MPM.add(createMergeFunctionsPass());
    else if (!GlobalExtensions->empty() || !Extensions.empty())
      MPM.add(createBarrierNoopPass());

    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
    return;
  }

  // Add LibraryInfo if we have some.
  if (LibraryInfo)
    MPM.add(new TargetLibraryInfoWrapperPass(*LibraryInfo));

  addInitialAliasAnalysisPasses(MPM);

  if (!DisableUnitAtATime) {
    // Infer attributes about declarations if possible.
    MPM.add(createInferFunctionAttrsLegacyPass());

    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);

    MPM.add(createIPSCCPPass());          // IP SCCP
    MPM.add(createGlobalOptimizerPass()); // Optimize out global vars
    // Promote any localized global vars.
    MPM.add(createPromoteMemoryToRegisterPass());

    MPM.add(createDeadArgEliminationPass()); // Dead argument elimination

    addInstructionCombiningPass(MPM); // Clean up after IPCP & DAE
    addExtensionsToPM(EP_Peephole, MPM);
    MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE
  }

  if (!PerformThinLTO)
    /// PGO instrumentation is added during the compile phase for ThinLTO, do
    /// not run it a second time
    addPGOInstrPasses(MPM);

  if (EnableNonLTOGlobalsModRef)
    // We add a module alias analysis pass here. In part due to bugs in the
    // analysis infrastructure this "works" in that the analysis stays alive
    // for the entire SCC pass run below.
    MPM.add(createGlobalsAAWrapperPass());

  // Start of CallGraph SCC passes.
  if (!DisableUnitAtATime)
    MPM.add(createPruneEHPass()); // Remove dead EH info
  if (Inliner) {
    MPM.add(Inliner);
    Inliner = nullptr;
  }
  if (!DisableUnitAtATime)
    MPM.add(createPostOrderFunctionAttrsLegacyPass());
  if (OptLevel > 2)
    MPM.add(createArgumentPromotionPass()); // Scalarize uninlined fn args

  addFunctionSimplificationPasses(MPM);

  // If we are planning to perform ThinLTO later, let's not bloat the code with
  // unrolling/vectorization/... now. We'll first run the inliner + CGSCC passes
  // during ThinLTO and perform the rest of the optimizations afterward.
  if (PrepareForThinLTO)
    return;

  // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
  // pass manager that we are specifically trying to avoid. To prevent this
  // we must insert a no-op module pass to reset the pass manager.
  MPM.add(createBarrierNoopPass());

  // Scheduling LoopVersioningLICM when inlining is over, because after that
  // we may see more accurate aliasing. Reason to run this late is that too
  // early versioning may prevent further inlining due to increase of code
  // size. By placing it just after inlining other optimizations which runs 
  // later might get benefit of no-alias assumption in clone loop. 
  if (UseLoopVersioningLICM) {
    MPM.add(createLoopVersioningLICMPass());    // Do LoopVersioningLICM
    MPM.add(createLICMPass());                  // Hoist loop invariants
  }

  if (!DisableUnitAtATime)
    MPM.add(createReversePostOrderFunctionAttrsPass());
//.........这里部分代码省略.........

void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
  // If all optimizations are disabled, just run the always-inline pass.
  if (OptLevel == 0) {
    if (Inliner) {
      MPM.add(Inliner);
      Inliner = 0;
    }

    // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
    // pass manager, but we don't want to add extensions into that pass manager.
    // To prevent this we must insert a no-op module pass to reset the pass
    // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
    if (!GlobalExtensions->empty() || !Extensions.empty())
      MPM.add(createBarrierNoopPass());

    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
    return;
  }

  // Add LibraryInfo if we have some.
  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));

  addInitialAliasAnalysisPasses(MPM);

  if (!DisableUnitAtATime) {
    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);

    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars

    MPM.add(createIPSCCPPass());              // IP SCCP
    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination

    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
  }

  // Start of CallGraph SCC passes.
  if (!DisableUnitAtATime)
    MPM.add(createPruneEHPass());             // Remove dead EH info
  if (Inliner) {
    MPM.add(Inliner);
    Inliner = 0;
  }
  if (!DisableUnitAtATime)
    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
  if (OptLevel > 2)
    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args

  // Start of function pass.
  // Break up aggregate allocas, using SSAUpdater.
  if (UseNewSROA)
    MPM.add(createSROAPass(/*RequiresDomTree*/ false));
  else
    MPM.add(createScalarReplAggregatesPass(-1, false));
  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
  if (!DisableSimplifyLibCalls)
    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
  MPM.add(createJumpThreadingPass());         // Thread jumps.
  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createInstructionCombiningPass());  // Combine silly seq's

  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createReassociatePass());           // Reassociate expressions
  MPM.add(createLoopRotatePass());            // Rotate Loop
  MPM.add(createLICMPass());                  // Hoist loop invariants
  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
  MPM.add(createInstructionCombiningPass());
  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
  MPM.add(createLoopDeletionPass());          // Delete dead loops

  if (LoopVectorize && OptLevel > 1 && SizeLevel < 2)
    MPM.add(createLoopVectorizePass());

  if (!DisableUnrollLoops)
    MPM.add(createLoopUnrollPass());          // Unroll small loops
  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);

  if (OptLevel > 1)
    MPM.add(createGVNPass());                 // Remove redundancies
  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
  MPM.add(createSCCPPass());                  // Constant prop with SCCP

  // Run instcombine after redundancy elimination to exploit opportunities
  // opened up by them.
  MPM.add(createInstructionCombiningPass());
  MPM.add(createJumpThreadingPass());         // Thread jumps
  MPM.add(createCorrelatedValuePropagationPass());
  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores

  addExtensionsToPM(EP_ScalarOptimizerLate, MPM);

  if (SLPVectorize)
    MPM.add(createSLPVectorizerPass());     // Vectorize parallel scalar chains.

  if (BBVectorize) {
    MPM.add(createBBVectorizePass());
    MPM.add(createInstructionCombiningPass());
//.........这里部分代码省略.........

/// Check if GlobalExtensions is constructed and not empty.
/// Since GlobalExtensions is a managed static, calling 'empty()' will trigger
/// the construction of the object.
static bool GlobalExtensionsNotEmpty() {
  return GlobalExtensions.isConstructed() && !GlobalExtensions->empty();
}

void PassManagerBuilder::populateModulePassManager(
    legacy::PassManagerBase &MPM) {
  // If all optimizations are disabled, just run the always-inline pass and,
  // if enabled, the function merging pass.
  if (OptLevel == 0) {
    if (Inliner) {
      MPM.add(Inliner);
      Inliner = nullptr;
    }

    // FIXME: The BarrierNoopPass is a HACK! The inliner pass above implicitly
    // creates a CGSCC pass manager, but we don't want to add extensions into
    // that pass manager. To prevent this we insert a no-op module pass to reset
    // the pass manager to get the same behavior as EP_OptimizerLast in non-O0
    // builds. The function merging pass is 
    if (MergeFunctions)
      MPM.add(createMergeFunctionsPass());
    else if (!GlobalExtensions->empty() || !Extensions.empty())
      MPM.add(createBarrierNoopPass());

    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
    return;
  }

  // Add LibraryInfo if we have some.
  if (LibraryInfo)
    MPM.add(new TargetLibraryInfoWrapperPass(*LibraryInfo));

  addInitialAliasAnalysisPasses(MPM);

  if (!DisableUnitAtATime) {
    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);

    MPM.add(createIPSCCPPass());              // IP SCCP
    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars

    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination

    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
    addExtensionsToPM(EP_Peephole, MPM);
    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
  }

  // Start of CallGraph SCC passes.
  if (!DisableUnitAtATime)
    MPM.add(createPruneEHPass());             // Remove dead EH info
  if (Inliner) {
    MPM.add(Inliner);
    Inliner = nullptr;
  }
  if (!DisableUnitAtATime)
    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
  if (OptLevel > 2)
    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args

  // Start of function pass.
  // Break up aggregate allocas, using SSAUpdater.
  if (UseNewSROA)
    MPM.add(createSROAPass(/*RequiresDomTree*/ false));
  else
    MPM.add(createScalarReplAggregatesPass(-1, false));
  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
  MPM.add(createJumpThreadingPass());         // Thread jumps.
  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
  addExtensionsToPM(EP_Peephole, MPM);

  MPM.add(createTailCallEliminationPass()); // Eliminate tail calls
  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
  MPM.add(createReassociatePass());           // Reassociate expressions
  // Rotate Loop - disable header duplication at -Oz
  MPM.add(createLoopRotatePass(SizeLevel == 2 ? 0 : -1));
  MPM.add(createLICMPass());                  // Hoist loop invariants
  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
  MPM.add(createInstructionCombiningPass());
  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
  MPM.add(createLoopDeletionPass());          // Delete dead loops
  if (EnableLoopInterchange) {
    MPM.add(createLoopInterchangePass()); // Interchange loops
    MPM.add(createCFGSimplificationPass());
  }
  if (!DisableUnrollLoops)
    MPM.add(createSimpleLoopUnrollPass());    // Unroll small loops
  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);

  if (OptLevel > 1) {
    if (EnableMLSM)
      MPM.add(createMergedLoadStoreMotionPass()); // Merge ld/st in diamonds
    MPM.add(createGVNPass(DisableGVNLoadPRE));  // Remove redundancies
  }
  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
  MPM.add(createSCCPPass());                  // Constant prop with SCCP

  // Delete dead bit computations (instcombine runs after to fold away the dead
  // computations, and then ADCE will run later to exploit any new DCE
  // opportunities that creates).
  MPM.add(createBitTrackingDCEPass());        // Delete dead bit computations

//.........这里部分代码省略.........