Inliner.cpp

  if (!Changed)
    return PreservedAnalyses::all();

  // Even if we change the IR, we update the core CGSCC data structures and so
  // can preserve the proxy to the function analysis manager.
  PreservedAnalyses PA;
  PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
  return PA;
}

ModuleInlinerWrapperPass::ModuleInlinerWrapperPass(InlineParams Params,
                                                   bool MandatoryFirst,
                                                   InliningAdvisorMode Mode,
                                                   unsigned MaxDevirtIterations)
    : Params(Params), Mode(Mode), MaxDevirtIterations(MaxDevirtIterations),
      PM(), MPM() {
  // Run the inliner first. The theory is that we are walking bottom-up and so
  // the callees have already been fully optimized, and we want to inline them
  // into the callers so that our optimizations can reflect that.
  // For PreLinkThinLTO pass, we disable hot-caller heuristic for sample PGO
  // because it makes profile annotation in the backend inaccurate.
  if (MandatoryFirst)
    PM.addPass(InlinerPass(/*OnlyMandatory*/ true));
  PM.addPass(InlinerPass());
}

PreservedAnalyses ModuleInlinerWrapperPass::run(Module &M,
                                                ModuleAnalysisManager &MAM) {
  auto &IAA = MAM.getResult<InlineAdvisorAnalysis>(M);
  if (!IAA.tryCreate(Params, Mode, CGSCCInlineReplayFile)) {
    M.getContext().emitError(
        "Could not setup Inlining Advisor for the requested "
        "mode and/or options");
    return PreservedAnalyses::all();
  }

  // We wrap the CGSCC pipeline in a devirtualization repeater. This will try
  // to detect when we devirtualize indirect calls and iterate the SCC passes
  // in that case to try and catch knock-on inlining or function attrs
  // opportunities. Then we add it to the module pipeline by walking the SCCs
  // in postorder (or bottom-up).
  // If MaxDevirtIterations is 0, we just don't use the devirtualization
  // wrapper.
  if (MaxDevirtIterations == 0)
    MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(PM)));
  else
    MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
        createDevirtSCCRepeatedPass(std::move(PM), MaxDevirtIterations)));
  MPM.run(M, MAM);

  IAA.clear();

  // The ModulePassManager has already taken care of invalidating analyses.
  return PreservedAnalyses::all();
}