[llvm] [FuncSpec] Only compute Latency bonus when necessary (PR #113159)

[Hari Limaye via llvm-commits]

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@@ -154,37 +154,55 @@ static Constant *findConstantFor(Value *V, ConstMap &KnownConstants) {
   return KnownConstants.lookup(V);
 }
 
-Bonus InstCostVisitor::getBonusFromPendingPHIs() {
-  Bonus B;
+Cost InstCostVisitor::getCodeSizeBonusFromPendingPHIs() {
+  Cost CodeSize;
   while (!PendingPHIs.empty()) {
     Instruction *Phi = PendingPHIs.pop_back_val();
     // The pending PHIs could have been proven dead by now.
     if (isBlockExecutable(Phi->getParent()))
-      B += getUserBonus(Phi);
+      CodeSize += getUserCodeSizeBonus(Phi);
   }
-  return B;
+  return CodeSize;
 }
 
-/// Compute a bonus for replacing argument \p A with constant \p C.
-Bonus InstCostVisitor::getSpecializationBonus(Argument *A, Constant *C) {
+/// Compute the codesize savings for replacing argument \p A with constant \p C.
+Cost InstCostVisitor::getCodeSizeBonus(Argument *A, Constant *C) {
   LLVM_DEBUG(dbgs() << "FnSpecialization: Analysing bonus for constant: "
                     << C->getNameOrAsOperand() << "\n");
-  Bonus B;
+  Cost CodeSize;
   for (auto *U : A->users())
     if (auto *UI = dyn_cast<Instruction>(U))
       if (isBlockExecutable(UI->getParent()))
-        B += getUserBonus(UI, A, C);
+        CodeSize += getUserCodeSizeBonus(UI, A, C);
 
   LLVM_DEBUG(dbgs() << "FnSpecialization:   Accumulated bonus {CodeSize = "
-                    << B.CodeSize << ", Latency = " << B.Latency
-                    << "} for argument " << *A << "\n");
-  return B;
+                    << CodeSize << "} for argument " << *A << "\n");
+  return CodeSize;
+}
+
+Cost InstCostVisitor::getLatencyBonus() {
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hazzlim wrote:

Good point - I have added an explanatory comment.

https://github.com/llvm/llvm-project/pull/113159