Revert D84057 "[PGO][PGSO] Remove a temporary flag used for gradual r…

…ollout."

This reverts commit e64afef. It caused
a PGO bootstrapped clang to crash on many source files.

`__llvm_profile_instrument_range` seems to trigger a null pointer dereference.

Call stack:
__llvm_profile_instrument_range
llvm::APInt::udiv(llvm::APInt const&) const
getRangeForAffineARHelper

llvm/include/llvm/Transforms/Utils/SizeOpts.h

@@ -19,6 +19,7 @@
 
 extern llvm::cl::opt<bool> EnablePGSO;
 extern llvm::cl::opt<bool> PGSOLargeWorkingSetSizeOnly;
+extern llvm::cl::opt<bool> PGSOIRPassOrTestOnly;
 extern llvm::cl::opt<bool> PGSOColdCodeOnly;
 extern llvm::cl::opt<bool> PGSOColdCodeOnlyForInstrPGO;
 extern llvm::cl::opt<bool> PGSOColdCodeOnlyForSamplePGO;
@@ -59,6 +60,11 @@ bool shouldFuncOptimizeForSizeImpl(const FuncT *F, ProfileSummaryInfo *PSI,
     return true;
   if (!EnablePGSO)
     return false;
+  // Temporarily enable size optimizations only for the IR pass or test query
+  // sites for gradual commit/rollout. This is to be removed later.
+  if (PGSOIRPassOrTestOnly && !(QueryType == PGSOQueryType::IRPass ||
+                                QueryType == PGSOQueryType::Test))
+    return false;
   if (isPGSOColdCodeOnly(PSI))
     return AdapterT::isFunctionColdInCallGraph(F, PSI, *BFI);
   if (PSI->hasSampleProfile())
@@ -79,6 +85,11 @@ bool shouldOptimizeForSizeImpl(BlockTOrBlockFreq BBOrBlockFreq, ProfileSummaryIn
     return true;
   if (!EnablePGSO)
     return false;
+  // Temporarily enable size optimizations only for the IR pass or test query
+  // sites for gradual commit/rollout. This is to be removed later.
+  if (PGSOIRPassOrTestOnly && !(QueryType == PGSOQueryType::IRPass ||
+                                QueryType == PGSOQueryType::Test))
+    return false;
   if (isPGSOColdCodeOnly(PSI))
     return AdapterT::isColdBlock(BBOrBlockFreq, PSI, BFI);
   if (PSI->hasSampleProfile())

llvm/lib/Transforms/Utils/SizeOpts.cpp

@@ -43,6 +43,11 @@ cl::opt<bool> PGSOColdCodeOnlyForPartialSamplePGO(
     cl::desc("Apply the profile guided size optimizations only "
              "to cold code under partial-profile sample PGO."));
 
+cl::opt<bool> PGSOIRPassOrTestOnly(
+    "pgso-ir-pass-or-test-only", cl::Hidden, cl::init(false),
+    cl::desc("Apply the profile guided size optimizations only"
+             "to the IR passes or tests."));
+
 cl::opt<bool> ForcePGSO(
     "force-pgso", cl::Hidden, cl::init(false),
     cl::desc("Force the (profiled-guided) size optimizations. "));