[NewPM] Move debugging log printing after PassInstrumentation before-pass-callbacks

[ychen]

Summary

For passes got skipped, this is confusing because the log said it is running pass
but it is skipped later.

[asbirlea]

LGTM.

[ychen]

• Missed two more similar cases.

[asbirlea]

Thank you!

llvm/include/llvm/IR/PassManager.h

PassInstrumentation PI =
         detail::getAnalysisResult<PassInstrumentationAnalysis>(
             AM, IR, std::tuple<ExtraArgTs...>(ExtraArgs...));
 
     if (DebugLogging)
       dbgs() << "Starting " << getTypeName<IRUnitT>() << " pass manager run.\n";
 
     for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) {
       auto *P = Passes[Idx].get();
-      if (DebugLogging)
-        dbgs() << "Running pass: " << P->name() << " on " << IR.getName()
-               << "\n";
 
       // Check the PassInstrumentation's BeforePass callbacks before running the
       // pass, skip its execution completely if asked to (callback returns
       // false).
       if (!PI.runBeforePass<IRUnitT>(*P, IR))
         continue;
 
+      if (DebugLogging)
+        dbgs() << "Running pass: " << P->name() << " on " << IR.getName()
+               << "\n";
+
       PreservedAnalyses PassPA;
       {
         TimeTraceScope TimeScope(P->name(), IR.getName());
         PassPA = P->run(IR, AM, ExtraArgs...);
       }
 
       // Call onto PassInstrumentation's AfterPass callbacks immediately after
       // running the pass.

llvm/lib/Analysis/CGSCCPassManager.cpp

PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
   // a pointer that we can update.
   LazyCallGraph::SCC *C = &InitialC;
 
   // Get Function analysis manager from its proxy.
   FunctionAnalysisManager &FAM =
       AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(*C)->getManager();
 
   for (auto &Pass : Passes) {
-    if (DebugLogging)
-      dbgs() << "Running pass: " << Pass->name() << " on " << *C << "\n";
-
     // Check the PassInstrumentation's BeforePass callbacks before running the
     // pass, skip its execution completely if asked to (callback returns false).
     if (!PI.runBeforePass(*Pass, *C))
       continue;
 
+    if (DebugLogging)
+      dbgs() << "Running pass: " << Pass->name() << " on " << *C << "\n";
+
     PreservedAnalyses PassPA;
     {
       TimeTraceScope TimeScope(Pass->name());
       PassPA = Pass->run(*C, AM, G, UR);
     }
 
     if (UR.InvalidatedSCCs.count(C))
       PI.runAfterPassInvalidated<LazyCallGraph::SCC>(*Pass);

llvm/lib/Transforms/Scalar/LoopPassManager.cpp

PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
 
   if (DebugLogging)
     dbgs() << "Starting Loop pass manager run.\n";
 
   // Request PassInstrumentation from analysis manager, will use it to run
   // instrumenting callbacks for the passes later.
   PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
   for (auto &Pass : Passes) {
-    if (DebugLogging)
-      dbgs() << "Running pass: " << Pass->name() << " on " << L;
-
     // Check the PassInstrumentation's BeforePass callbacks before running the
     // pass, skip its execution completely if asked to (callback returns false).
     if (!PI.runBeforePass<Loop>(*Pass, L))
       continue;
 
+    if (DebugLogging)
+      dbgs() << "Running pass: " << Pass->name() << " on " << L;
+
     PreservedAnalyses PassPA;
     {
       TimeTraceScope TimeScope(Pass->name(), L.getName());
       PassPA = Pass->run(L, AM, AR, U);
     }
 
     // do not pass deleted Loop into the instrumentation
     if (U.skipCurrentLoop())