[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, 49 insertions, 21 deletions

diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 90c3cfc..95f900d0 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -1271,46 +1271,44 @@ void annotateValueSite(Module &M, Instruction &Inst,
   Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
 }
 
-bool getValueProfDataFromInst(const Instruction &Inst,
-                              InstrProfValueKind ValueKind,
-                              uint32_t MaxNumValueData,
-                              InstrProfValueData ValueData[],
-                              uint32_t &ActualNumValueData, uint64_t &TotalC,
-                              bool GetNoICPValue) {
+MDNode *mayHaveValueProfileOfKind(const Instruction &Inst,
+                                  InstrProfValueKind ValueKind) {
   MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
   if (!MD)
-    return false;
+    return nullptr;
 
-  unsigned NOps = MD->getNumOperands();
+  if (MD->getNumOperands() < 5)
+    return nullptr;
 
-  if (NOps < 5)
-    return false;
-
-  // Operand 0 is a string tag "VP":
   MDString *Tag = cast<MDString>(MD->getOperand(0));
-  if (!Tag)
-    return false;
-
-  if (!Tag->getString().equals("VP"))
-    return false;
+  if (!Tag || !Tag->getString().equals("VP"))
+    return nullptr;
 
   // Now check kind:
   ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
   if (!KindInt)
-    return false;
+    return nullptr;
   if (KindInt->getZExtValue() != ValueKind)
-    return false;
+    return nullptr;
+
+  return MD;
+}
 
+static bool getValueProfDataFromInstImpl(const MDNode *const MD,
+                                         const uint32_t MaxNumDataWant,
+                                         InstrProfValueData ValueData[],
+                                         uint32_t &ActualNumValueData,
+                                         uint64_t &TotalC, bool GetNoICPValue) {
+  const unsigned NOps = MD->getNumOperands();
   // Get total count
   ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
   if (!TotalCInt)
     return false;
   TotalC = TotalCInt->getZExtValue();
-
   ActualNumValueData = 0;
 
   for (unsigned I = 3; I < NOps; I += 2) {
-    if (ActualNumValueData >= MaxNumValueData)
+    if (ActualNumValueData >= MaxNumDataWant)
       break;
     ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
     ConstantInt *Count =
@@ -1327,6 +1325,36 @@ bool getValueProfDataFromInst(const Instruction &Inst,
   return true;
 }
 
+std::unique_ptr<InstrProfValueData[]>
+getValueProfDataFromInst(const Instruction &Inst, InstrProfValueKind ValueKind,
+                         uint32_t MaxNumValueData, uint32_t &ActualNumValueData,
+                         uint64_t &TotalC, bool GetNoICPValue) {
+  MDNode *MD = mayHaveValueProfileOfKind(Inst, ValueKind);
+  if (!MD)
+    return nullptr;
+  auto ValueDataArray = std::make_unique<InstrProfValueData[]>(MaxNumValueData);
+  if (!getValueProfDataFromInstImpl(MD, MaxNumValueData, ValueDataArray.get(),
+                                    ActualNumValueData, TotalC, GetNoICPValue))
+    return nullptr;
+  return ValueDataArray;
+}
+
+// FIXME: Migrate existing callers to the function above that returns an
+// array.
+bool getValueProfDataFromInst(const Instruction &Inst,
+                              InstrProfValueKind ValueKind,
+                              uint32_t MaxNumValueData,
+                              InstrProfValueData ValueData[],
+                              uint32_t &ActualNumValueData, uint64_t &TotalC,
+                              bool GetNoICPValue) {
+  MDNode *MD = mayHaveValueProfileOfKind(Inst, ValueKind);
+  if (!MD)
+    return false;
+  return getValueProfDataFromInstImpl(MD, MaxNumValueData, ValueData,
+                                      ActualNumValueData, TotalC,
+                                      GetNoICPValue);
+}
+
 MDNode *getPGOFuncNameMetadata(const Function &F) {
   return F.getMetadata(getPGOFuncNameMetadataName());
 }