[llvm] [VectorCombine] Scalarize binop-like intrinsics (PR #138095)

[Yingwei Zheng via llvm-commits]

================
@@ -1085,15 +1099,24 @@ bool VectorCombine::scalarizeBinopOrCmp(Instruction &I) {
 
   unsigned Opcode = I.getOpcode();
   InstructionCost ScalarOpCost, VectorOpCost;
-  if (IsCmp) {
+  if (isa<CmpInst>(I)) {
     CmpInst::Predicate Pred = cast<CmpInst>(I).getPredicate();
     ScalarOpCost = TTI.getCmpSelInstrCost(
         Opcode, ScalarTy, CmpInst::makeCmpResultType(ScalarTy), Pred, CostKind);
     VectorOpCost = TTI.getCmpSelInstrCost(
         Opcode, VecTy, CmpInst::makeCmpResultType(VecTy), Pred, CostKind);
-  } else {
+  } else if (isa<BinaryOperator>(I)) {
     ScalarOpCost = TTI.getArithmeticInstrCost(Opcode, ScalarTy, CostKind);
     VectorOpCost = TTI.getArithmeticInstrCost(Opcode, VecTy, CostKind);
+  } else if (auto *II = dyn_cast<IntrinsicInst>(&I)) {
+    IntrinsicCostAttributes ScalarICA(
+        II->getIntrinsicID(), ScalarTy,
+        SmallVector<Type *>(II->arg_size(), ScalarTy));
+    ScalarOpCost = TTI.getIntrinsicInstrCost(ScalarICA, CostKind);
+    IntrinsicCostAttributes VectorICA(
+        II->getIntrinsicID(), VecTy,
+        SmallVector<Type *>(II->arg_size(), VecTy));
+    VectorOpCost = TTI.getIntrinsicInstrCost(ScalarICA, CostKind);
----------------
dtcxzyw wrote:

```suggestion
    VectorOpCost = TTI.getIntrinsicInstrCost(VectorICA, CostKind);
```


https://github.com/llvm/llvm-project/pull/138095