[llvm] [LegalizeDAG][X86][AArch64][LoongArch] Freeze index when converting extract_elt/extract_subvector to load/store on stack. (PR #88985)

[Matt Arsenault via llvm-commits]

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@@ -1405,6 +1405,9 @@ SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, StoreMMO);
   }
 
+  // Freeze the index so we don't poison the clamping code we're about to emit.
+  Idx = DAG.getFreeze(Idx);
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arsenm wrote:

I believe GlobalIsel has the same issue 

https://github.com/llvm/llvm-project/pull/88985