[PATCH] D89158: [NewPM] Provide method to run all pipeline callbacks, used for -O0

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks added a comment.

With this change in its current state, it's ok to add callbacks, as long as they don't add passes at -O0.
Polly adds some callbacks. When I first submitted this, polly would add some callbacks to VectorizerStartEPCallbacks. Those callbacks didn't actually add any passes (I didn't investigate that, but it makes sense at -O0). However, the previous logic would add a FunctionPassManager if there were any callbacks, so we had an extra empty FunctionPassManager being run, which changed the output of -debug-pass-manager. Now I've changed it so that we check if the FunctionPassManager actually has any passes added to it before adding it to the ModulePassManager.

So previously it was

  if (!VectorizerStartEPCallbacks.empty()) {
    FunctionPassManager FPM(DebugLogging);
    for (auto &C : VectorizerStartEPCallbacks)
      C(FPM, Level);
    MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
  }

Now it is

  if (!VectorizerStartEPCallbacks.empty()) {
    FunctionPassManager FPM(DebugLogging);
    for (auto &C : VectorizerStartEPCallbacks)
      C(FPM, Level);
    if (!FPM.isEmpty())
      MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
  }

which should take care of added registered callbacks that don't actually add anything at -O0.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89158/new/

https://reviews.llvm.org/D89158