[SampleFDO] Make FSDiscriminator flag part of function parameters

Add a parameter of IsFSDiscriminator to function
getBaseDiscriminatorFromDiscriminator().

This function currently checks the internal flag of
--enable-fs-discriminator. This is not good because we might
change the default value of the internal flag.

Note that we have a default parameter. This is just
because create_afdo_tool has a call-site to it.
I will remove the default parameter in a later patch.

Differential Revision: https://reviews.llvm.org/D104584

Author: xur-llvm

llvm/include/llvm/IR/DebugInfoMetadata.h

@@ -1744,8 +1744,10 @@ class DILocation : public MDNode {
   static unsigned getBaseDiscriminatorBits() { return getBaseFSBitEnd(); }
 
   /// Returns the base discriminator for a given encoded discriminator \p D.
-  static unsigned getBaseDiscriminatorFromDiscriminator(unsigned D) {
-    if (EnableFSDiscriminator)
+  static unsigned
+  getBaseDiscriminatorFromDiscriminator(unsigned D,
+                                        bool IsFSDiscriminator = false) {
+    if (IsFSDiscriminator)
       return getMaskedDiscriminator(D, getBaseDiscriminatorBits());
     return getUnsignedFromPrefixEncoding(D);
   }
@@ -2198,7 +2200,8 @@ DILocation::cloneWithDiscriminator(unsigned Discriminator) const {
 }
 
 unsigned DILocation::getBaseDiscriminator() const {
-  return getBaseDiscriminatorFromDiscriminator(getDiscriminator());
+  return getBaseDiscriminatorFromDiscriminator(getDiscriminator(),
+                                               EnableFSDiscriminator);
 }
 
 unsigned DILocation::getDuplicationFactor() const {

llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseImpl.h

@@ -279,7 +279,12 @@ SampleProfileLoaderBaseImpl<BT>::getInstWeightImpl(const InstructionT &Inst) {
 
   const DILocation *DIL = DLoc;
   uint32_t LineOffset = FunctionSamples::getOffset(DIL);
-  uint32_t Discriminator = DIL->getBaseDiscriminator();
+  uint32_t Discriminator;
+  if (EnableFSDiscriminator)
+    Discriminator = DIL->getDiscriminator();
+  else
+    Discriminator = DIL->getBaseDiscriminator();
+
   ErrorOr<uint64_t> R = FS->findSamplesAt(LineOffset, Discriminator);
   if (R) {
     bool FirstMark =
@@ -298,11 +303,9 @@ SampleProfileLoaderBaseImpl<BT>::getInstWeightImpl(const InstructionT &Inst) {
         return Remark;
       });
     }
-    LLVM_DEBUG(dbgs() << "    " << DLoc.getLine() << "."
-                      << DIL->getBaseDiscriminator() << ":" << Inst
-                      << " (line offset: " << LineOffset << "."
-                      << DIL->getBaseDiscriminator() << " - weight: " << R.get()
-                      << ")\n");
+    LLVM_DEBUG(dbgs() << "    " << DLoc.getLine() << "." << Discriminator << ":"
+                      << Inst << " (line offset: " << LineOffset << "."
+                      << Discriminator << " - weight: " << R.get() << ")\n");
   }
   return R;
 }

llvm/tools/llvm-profgen/ProfiledBinary.cpp

@@ -440,7 +440,8 @@ FrameLocationStack ProfiledBinary::symbolize(const InstructionPointer &IP,
       FunctionName = FunctionSamples::getCanonicalFnName(FunctionName);
     LineLocation Line(CallerFrame.Line - CallerFrame.StartLine,
                       DILocation::getBaseDiscriminatorFromDiscriminator(
-                          CallerFrame.Discriminator));
+                          CallerFrame.Discriminator,
+                          /* IsFSDiscriminator */ false));
     FrameLocation Callsite(FunctionName.str(), Line);
     CallStack.push_back(Callsite);
   }