[llvm] [PPC] Add custom lowering for uaddo (PR #110137)

[via llvm-commits]

================
@@ -11967,11 +11969,45 @@ SDValue PPCTargetLowering::LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const {
   llvm_unreachable("ERROR:Should return for all cases within swtich.");
 }
 
+SDValue PPCTargetLowering::LowerUaddo(SDValue Op, SelectionDAG &DAG) const {
+  // Default to target independent lowering if there is a logical user of the
+  // carry-bit.
+  for (SDNode *U : Op->uses()) {
+    if (U->getOpcode() == ISD::SELECT || ISD::isBitwiseLogicOp(U->getOpcode()))
+      return SDValue();
----------------
RolandF77 wrote:

IIUC this patch doesn't make the long long case worse, it just doesn't make it better. Maybe long long can be addressed in a separate patch? Seems hard to tell that case apart from the condition use case - may want to handle the full 64 bit operation in 32 bit mode for long long.

https://github.com/llvm/llvm-project/pull/110137