[clang] [compiler-rt] [llvm] [TypeProf][InstrFDO]Implement more efficient comparison sequence for indirect-call-promotion with vtable profiles. (PR #81442)

[Mingming Liu via cfe-commits]

================
@@ -322,14 +796,133 @@ bool IndirectCallPromoter::processFunction(ProfileSummaryInfo *PSI) {
     if (!NumCandidates ||
         (PSI && PSI->hasProfileSummary() && !PSI->isHotCount(TotalCount)))
       continue;
+
     auto PromotionCandidates = getPromotionCandidatesForCallSite(
         *CB, ICallProfDataRef, TotalCount, NumCandidates);
-    Changed |= tryToPromoteWithFuncCmp(*CB, PromotionCandidates, TotalCount,
-                                       ICallProfDataRef, NumCandidates);
+
+    VTableGUIDCountsMap VTableGUIDCounts;
+    Instruction *VPtr =
+        computeVTableInfos(CB, VTableGUIDCounts, PromotionCandidates);
+
+    if (isProfitableToCompareVTables(*CB, PromotionCandidates, TotalCount))
+      Changed |= tryToPromoteWithVTableCmp(*CB, VPtr, PromotionCandidates,
+                                           TotalCount, NumCandidates,
+                                           ICallProfDataRef, VTableGUIDCounts);
+    else
+      Changed |= tryToPromoteWithFuncCmp(*CB, VPtr, PromotionCandidates,
+                                         TotalCount, ICallProfDataRef,
+                                         NumCandidates, VTableGUIDCounts);
   }
   return Changed;
 }
 
+// TODO: Returns false if the function addressing and vtable load instructions
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minglotus-6 wrote:

done.

https://github.com/llvm/llvm-project/pull/81442