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

[David Green via llvm-commits]

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@@ -7951,6 +7951,10 @@ static bool IsQRMVEInstruction(const SDNode *N, const SDNode *Op) {
   case ISD::MUL:
   case ISD::SADDSAT:
   case ISD::UADDSAT:
+  case ISD::AVGFLOORS:
+  case ISD::AVGFLOORU:
+  case ISD::AVGCEILS:
+  case ISD::AVGCEILU:
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davemgreen wrote:

Just floor, not ceil for these I believe.

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