[PATCH] D38942: [DAG] Promote ADDCARRY / SUBCARRY

[Roger Ferrer Ibanez via Phabricator via llvm-commits]

rogfer01 added inline comments.


================
Comment at: lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp:777-787
+  SDValue LHS = GetPromotedInteger(N->getOperand(0));
+  SDValue RHS = GetPromotedInteger(N->getOperand(1));
+
+  EVT ValueVTs[] = { LHS.getValueType(), N->getValueType(1) };
+
+  SDValue Res = DAG.getNode(N->getOpcode(), SDLoc(N),
+                     DAG.getVTList(ValueVTs), LHS, RHS, N->getOperand(2));
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This looks like a lot like the "dual" of `PromoteIntRes_Overflow` but replacing the users of `:1` (instead of `:0`). It generates correct code in Arm but I may be missing some subtlety here.


https://reviews.llvm.org/D38942