[llvm] [DAGCombiner] Add combine avg from shifts (PR #113909)

[David Green via llvm-commits]

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@@ -10626,6 +10649,9 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
   if (SDValue NarrowLoad = reduceLoadWidth(N))
     return NarrowLoad;
 
+  if (SDValue AVG = combineAVG(N))
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davemgreen wrote:

We have a "foldAddToAvg" already, perhaps we could name this foldAvgFromShift or combineAvgFromFlags or something like it?

https://github.com/llvm/llvm-project/pull/113909