[PATCH] D32755: [DAGCombine] (addcarry (add|uaddo X, Y), 0, Carry) -> (addcarry X, Y, Carry)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:2158
+  // If the flag result is dead, we can do transform that invalidate it.
+  if (!N->hasAnyUseOfValue(1)) {
+    // (addcarry (add|uaddo X, Y), 0, Carry) -> (addcarry X, Y, Carry)
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Might it be quicker if we check for ISD::ADD/ISD::UADDO first before calling the heavier isNullConstan/hasAnyUseOfValue checks?


https://reviews.llvm.org/D32755