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[DAG] Move simplification of SADDSAT/SSUBSAT/UADDSAT/USUBSAT of vXi1 to getNode() 

As discussed on D97276 we should be able to always do this in node creation, we don't need a combine.
This commit is contained in:
Simon Pilgrim 2021-02-25 17:49:01 +00:00
parent 29e2d9461a
commit 9490b9f14b
2 changed files with 8 additions and 8 deletions
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8
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
View File

@ -2540,10 +2540,6 @@ SDValue DAGCombiner::visitADDSAT(SDNode *N) {
if (isNullConstant(N1))
return N0;
// fold (add_sat x, y) -> (or x, y) for bool types.
if (VT.getScalarType() == MVT::i1)
return DAG.getNode(ISD::OR, DL, VT, N0, N1);
// If it cannot overflow, transform into an add.
if (Opcode == ISD::UADDSAT)
if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never)
@ -3581,10 +3577,6 @@ SDValue DAGCombiner::visitSUBSAT(SDNode *N) {
if (isNullConstant(N1))
return N0;
// fold (sub_sat x, y) -> (and x, ~y) for bool types.
if (VT.getScalarType() == MVT::i1)
return DAG.getNode(ISD::AND, DL, VT, N0, DAG.getNOT(DL, N1, VT));
return SDValue();
}

8
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -5342,6 +5342,14 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
assert(VT.isInteger() && "This operator does not apply to FP types!");
assert(N1.getValueType() == N2.getValueType() &&
N1.getValueType() == VT && "Binary operator types must match!");
if (VT.isVector() && VT.getVectorElementType() == MVT::i1) {
// fold (add_sat x, y) -> (or x, y) for bool types.
if (Opcode == ISD::SADDSAT || Opcode == ISD::UADDSAT)
return getNode(ISD::OR, DL, VT, N1, N2);
// fold (sub_sat x, y) -> (and x, ~y) for bool types.
if (Opcode == ISD::SSUBSAT || Opcode == ISD::USUBSAT)
return getNode(ISD::AND, DL, VT, N1, getNOT(DL, N2, VT));
}
break;
case ISD::SMIN:
case ISD::UMAX: