Unverified Commit 890335bb authored by Ellis Hoag's avatar Ellis Hoag Committed by GitHub
Browse files

[InstrProf] Do not block functions from PGOUse (#71106) 

The `skipPGO()` function was added in https://reviews.llvm.org/D137184.
Unfortunately, it also blocked functions from being annotated (PGOUse),
which I believe will cause confusion to users if a function has a
profile but it is not PGO'd.

The docs for `noprofile` and `skipprofile` only claim to block
instrumentation, not PGO optimization:
https://llvm.org/docs/LangRef.html
parent 778a4846

llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp

+16 −11
Original line number Diff line number Diff line
@@ -1760,17 +1760,10 @@ static void collectComdatMembers( 
      ComdatMembers.insert(std::make_pair(C, &GA));

}



// Don't perform PGO instrumeatnion / profile-use.

static bool skipPGO(const Function &F) {

// Return true if we should not find instrumentation data for this function

static bool skipPGOUse(const Function &F) {

  if (F.isDeclaration())

    return true;

  if (F.hasFnAttribute(llvm::Attribute::NoProfile))

    return true;

  if (F.hasFnAttribute(llvm::Attribute::SkipProfile))

    return true;

  if (F.getInstructionCount() < PGOFunctionSizeThreshold)

    return true;



  // If there are too many critical edges, PGO might cause

  // compiler time problem. Skip PGO if the number of

  // critical edges execeed the threshold.
@@ -1788,7 +1781,19 @@ static bool skipPGO(const Function &F) { 
                      << " exceed the threshold. Skip PGO.\n");

    return true;

  }

  return false;

}



// Return true if we should not instrument this function

static bool skipPGOGen(const Function &F) {

  if (skipPGOUse(F))

    return true;

  if (F.hasFnAttribute(llvm::Attribute::NoProfile))

    return true;

  if (F.hasFnAttribute(llvm::Attribute::SkipProfile))

    return true;

  if (F.getInstructionCount() < PGOFunctionSizeThreshold)

    return true;

  return false;

}
@@ -1804,7 +1809,7 @@ static bool InstrumentAllFunctions( 
  collectComdatMembers(M, ComdatMembers);



  for (auto &F : M) {

    if (skipPGO(F))

    if (skipPGOGen(F))

      continue;

    auto &TLI = LookupTLI(F);

    auto *BPI = LookupBPI(F);
@@ -2031,7 +2036,7 @@ static bool annotateAllFunctions( 
    InstrumentFuncEntry = PGOInstrumentEntry;

  bool HasSingleByteCoverage = PGOReader->hasSingleByteCoverage();

  for (auto &F : M) {

    if (skipPGO(F))

    if (skipPGOUse(F))

      continue;

    auto &TLI = LookupTLI(F);

    auto *BPI = LookupBPI(F);