[llvm] [SelectionDAG] Use unaligned store to move AVX registers onto stack for `extractelement` (PR #78422)

[Danila Malyutin via llvm-commits]

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@@ -1377,6 +1378,19 @@ void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
   }
 }
 
+// Helper function that generates an MMO that considers the alignment of the
+// stack, and the size of the stack object
+MachineMemOperand *getStackAlignedMMO(SDValue &StackPtr, MachineFunction &MF) {
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danilaml wrote:

Also this function should be `static`

https://github.com/llvm/llvm-project/pull/78422