[llvm] [X86] Optimized ADD + ADC to ADC (PR #173543)

[Sebastian Buchwald via llvm-commits]

================
@@ -58164,6 +58164,13 @@ static SDValue combineX86AddSub(SDNode *N, SelectionDAG &DAG,
     }
   }
 
+  // Fold ADD(ADC(Y,0,CF), C) -> ADC(Y, C, CF)
----------------
UniQP wrote:

There is another way to generalize the example: `ADD(ADC(Y,0,CF), X) -> ADC(Y, X, CF)`.

For instance: https://godbolt.org/z/o5h9rTvan.

https://github.com/llvm/llvm-project/pull/173543