[llvm] [DAGCombiner] Add sra-xor-sra pattern fold (PR #166777)

[Simon Pilgrim via llvm-commits]

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@@ -10968,6 +10968,28 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
     }
   }
 
+  // fold (sra (xor (sra x, c1), -1), c2) -> (sra (xor x, -1), c3)
+  if (N0.getOpcode() == ISD::XOR && N0.hasOneUse() &&
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RKSimon wrote:

use sd_match patterns?

https://github.com/llvm/llvm-project/pull/166777