return SDValue();
}
-/// isCarryMaterialization - Returns true if V is an ADDE node that is known to
-/// return 0 or 1 depending on the carry flag.
-static bool isCarryMaterialization(SDValue V) {
- if (V.getOpcode() != ISD::ADDE)
- return false;
-
- ConstantSDNode *C = dyn_cast<ConstantSDNode>(V.getOperand(0));
- return C && C->isNullValue() && V.getOperand(0) == V.getOperand(1);
-}
-
SDValue DAGCombiner::visitADD(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
}
- // add (adde 0, 0, glue), X -> adde X, 0, glue
- if (N0->hasOneUse() && isCarryMaterialization(N0))
- return DAG.getNode(ISD::ADDE, N->getDebugLoc(),
- DAG.getVTList(VT, MVT::Glue), N1, N0.getOperand(0),
- N0.getOperand(2));
-
- // add X, (adde 0, 0, glue) -> adde X, 0, glue
- if (N1->hasOneUse() && isCarryMaterialization(N1))
- return DAG.getNode(ISD::ADDE, N->getDebugLoc(),
- DAG.getVTList(VT, MVT::Glue), N0, N1.getOperand(0),
- N1.getOperand(2));
-
return SDValue();
}
N->getDebugLoc(), MVT::Glue));
}
- // addc (adde 0, 0, glue), X -> adde X, 0, glue
- if (N0->hasOneUse() && isCarryMaterialization(N0))
- return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(), N1,
- DAG.getConstant(0, VT), N0.getOperand(2));
-
- // addc X, (adde 0, 0, glue) -> adde X, 0, glue
- if (N1->hasOneUse() && isCarryMaterialization(N1))
- return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(), N0,
- DAG.getConstant(0, VT), N1.getOperand(2));
-
return SDValue();
}