[ThinLTO][TypeProf] Implement vtable def import (#79381)

Add annotated vtable GUID as referenced variables in per function
summary, and update bitcode writer to create value-ids for these
referenced vtables.

- This is the part3 of type profiling work, and described in the "Virtual Table Definition Import" [1] section of the
RFC.

[1] https://github.com/llvm/llvm-project/pull/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

1 files changed, 11 insertions, 2 deletions

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 221eeaa..dd554e4 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -203,7 +203,7 @@ public:
     for (const auto &GUIDSummaryLists : *Index)
       // Examine all summaries for this GUID.
       for (auto &Summary : GUIDSummaryLists.second.SummaryList)
-        if (auto FS = dyn_cast<FunctionSummary>(Summary.get()))
+        if (auto FS = dyn_cast<FunctionSummary>(Summary.get())) {
           // For each call in the function summary, see if the call
           // is to a GUID (which means it is for an indirect call,
           // otherwise we would have a Value for it). If so, synthesize
@@ -211,6 +211,15 @@ public:
           for (auto &CallEdge : FS->calls())
             if (!CallEdge.first.haveGVs() || !CallEdge.first.getValue())
               assignValueId(CallEdge.first.getGUID());
+
+          // For each referenced variables in the function summary, see if the
+          // variable is represented by a GUID (as opposed to a symbol to
+          // declarations or definitions in the module). If so, synthesize a
+          // value id.
+          for (auto &RefEdge : FS->refs())
+            if (!RefEdge.haveGVs() || !RefEdge.getValue())
+              assignValueId(RefEdge.getGUID());
+        }
   }
 
 protected:
@@ -4188,7 +4197,7 @@ void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
   NameVals.push_back(SpecialRefCnts.second); // worefcnt
 
   for (auto &RI : FS->refs())
-    NameVals.push_back(VE.getValueID(RI.getValue()));
+    NameVals.push_back(getValueId(RI));
 
   const bool UseRelBFRecord =
       WriteRelBFToSummary && !F.hasProfileData() &&