[llvm] [ARM][Codegen] Fix vector data miscompilation in arm32be (PR #105519)

[David Green via llvm-commits]

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@@ -7966,7 +7953,7 @@ SDValue ARMTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
 
       if (Val.getNode()) {
         SDValue Vmov = DAG.getNode(ARMISD::VMOVIMM, dl, VmovVT, Val);
-        return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
+        return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, Vmov);
       }
 
       // Try an immediate VMVN.
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davemgreen wrote:

Can you change the MVN below too (and maybe make sure there are tests to ensure it is correct).

https://github.com/llvm/llvm-project/pull/105519