[llvm] [SelectionDAG] Use unaligned store/load to move AVX registers onto stack for `insertelement` (PR #82130)

[Matt Arsenault via llvm-commits]

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@@ -1474,7 +1474,10 @@ SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
 
   // First store the whole vector.
-  SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
+  Align ElementAlignment =
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arsenm wrote:

This is not the element alignment, this is the alignment of the base vector

https://github.com/llvm/llvm-project/pull/82130