Revert 72707 and 72709, for the moment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72712 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index e1554bf..4c1710d 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1085,7 +1085,8 @@
// If the flag result is dead, turn this into an ADD.
if (N->hasNUsesOfValue(0, 1))
return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0),
- DAG.getConstant(0, N->getValueType(1)));
+ DAG.getNode(ISD::CARRY_FALSE,
+ N->getDebugLoc(), MVT::Flag));
// canonicalize constant to RHS.
if (N0C && !N1C)
@@ -1093,9 +1094,10 @@
// fold (addc x, 0) -> x + no carry out
if (N1C && N1C->isNullValue())
- return CombineTo(N, N0, DAG.getConstant(0, N1.getValueType()));
+ return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
+ N->getDebugLoc(), MVT::Flag));
- // fold (addc a, b) -> (or a, b), 0 iff a and b share no bits.
+ // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
APInt LHSZero, LHSOne;
APInt RHSZero, RHSOne;
APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits());
@@ -1109,7 +1111,8 @@
if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
(LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
- DAG.getConstant(0, N1.getValueType()));
+ DAG.getNode(ISD::CARRY_FALSE,
+ N->getDebugLoc(), MVT::Flag));
}
return SDValue();
@@ -1128,9 +1131,8 @@
N1, N0, CarryIn);
// fold (adde x, y, false) -> (addc x, y)
- if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(CarryIn))
- if (N2C->getAPIntValue()==0)
- return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
+ if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
+ return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
return SDValue();
}