[llvm] [AArch64][SelectionDAG] Add CodeGen support for scalar FEAT_CPA (PR #105669)

[Alexander Richardson via llvm-commits]

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@@ -4473,8 +4478,15 @@ void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {
   // an address inside an alloca.
   SDNodeFlags Flags;
   Flags.setNoUnsignedWrap(true);
-  AllocSize = DAG.getNode(ISD::ADD, dl, AllocSize.getValueType(), AllocSize,
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arichardson wrote:

Actually this one should remain an ADD since we are just working on the size.

https://github.com/llvm/llvm-project/pull/105669