[CSSPGO] Turn on profi and ext-tsp when using probe-based profile.

[hoy]

Summary

Probe-based profile leads to a better performance when combined with profi and ext-tsp block layout. I'm turning them on by default.

[wenlei]

llvm/lib/Transforms/IPO/SampleProfile.cpp

2037–2044

I would structure it slightly differently..

if (Reader->profileIsCSFlat() || Reader->profileIsCSNested() || Reader->profileIsProbeBased()) {
    // Enable iterative-BFI by default for CSSPGO.
    if (!UseIterativeBFIInference.getNumOccurrences())
      UseIterativeBFIInference = true;
    // Enable Profi by default for CSSPGO.
    if (!SampleProfileUseProfi.getNumOccurrences())
      SampleProfileUseProfi = true;

    // Enable EXT-TSP block layout for CSSPGO.
    if (!EnableExtTspBlockPlacement.getNumOccurrences())
      EnableExtTspBlockPlacement = true;
}
else if (Reader->profileIsCSNested() || Reader->profileIsProbeBased()) {
  ...
}

[hoy]

Updating D122442: [CSSPGO] Turn on profi and ext-tsp when using probe-based profile.

[hoy]

llvm/lib/Transforms/IPO/SampleProfile.cpp

2037–2044

Sounds good without the else.

[wenlei]

lgtm, thanks.

[hoy]

Fixing test failures by explictly turning off profi.

llvm/lib/Transforms/IPO/SampleProfile.cpp

if (Reader->profileIsCSFlat() || Reader->profileIsCSNested()) {
     if (!EnableExtTspBlockPlacement.getNumOccurrences())
       EnableExtTspBlockPlacement = true;
 
     if (FunctionSamples::ProfileIsCSFlat) {
       // Tracker for profiles under different context
       ContextTracker = std::make_unique<SampleContextTracker>(
           Reader->getProfiles(), &GUIDToFuncNameMap);
     }
+  } else if (Reader->profileIsProbeBased()) {
+    if (!UseIterativeBFIInference.getNumOccurrences())
+      UseIterativeBFIInference = true;
+    if (!SampleProfileUseProfi.getNumOccurrences())
+      SampleProfileUseProfi = true;
+    if (!EnableExtTspBlockPlacement.getNumOccurrences())
+      EnableExtTspBlockPlacement = true;
   }
 
   // Load pseudo probe descriptors for probe-based function samples.
   if (Reader->profileIsProbeBased()) {
     ProbeManager = std::make_unique<PseudoProbeManager>(M);
     if (!ProbeManager->moduleIsProbed(M)) {
       const char *Msg =
           "Pseudo-probe-based profile requires SampleProfileProbePass";
       Ctx.diagnose(DiagnosticInfoSampleProfile(M.getModuleIdentifier(), Msg,