[llvm] [DAG] MatchLoadCombine - match swapped loads (PR #167416)

[Simon Pilgrim via llvm-commits]

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@@ -9803,8 +9832,12 @@ SDValue DAGCombiner::MatchLoadCombine(SDNode *N) {
       !TLI.isOperationLegal(ISD::BSWAP, VT))
     return SDValue();
 
-  // If we need to bswap and zero extend, we have to insert a shift. Check that
-  // it is legal.
+  // If we need to rotate make sure that is legal.
+  if (IsRotated && LegalOperations && !TLI.isOperationLegal(ISD::ROTR, VT))
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RKSimon wrote:

we'll either have to not support NeedsZext for rotation cases or add more test coverage - happy with a TODO comment for now

https://github.com/llvm/llvm-project/pull/167416