[llvm] [CostModel][AArch64] Make extractelement, with fmul user, free whenev… (PR #111479)

[David Sherwood via llvm-commits]

================
@@ -11739,8 +11750,9 @@ InstructionCost BoUpSLP::getTreeCost(ArrayRef<Value *> VectorizedVals) {
       ExtraCost = TTI->getExtractWithExtendCost(Extend, EU.Scalar->getType(),
                                                 VecTy, EU.Lane);
     } else {
-      ExtraCost = TTI->getVectorInstrCost(Instruction::ExtractElement, VecTy,
-                                          CostKind, EU.Lane);
+      ExtraCost = TTI->getVectorInstrCost(
+          Instruction::ExtractElement, VecTy, CostKind, EU.Lane, nullptr,
----------------
david-arm wrote:

Oh ok, I looked at all calls to getVectorInstrCost outside of the TargetTransformInfo files (which simply pass through the operands in a chain) and it wasn't obvious to me where we passed in non-null. I can see examples like this:

```
InstructionCost TargetTransformInfo::getVectorInstrCost
```

but these pass the same operands from one interface to another.

https://github.com/llvm/llvm-project/pull/111479