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DAGCombiner: Use isNullConstant() where possible

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237643 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Matthias Braun 2015-05-19 00:25:17 +00:00
parent a641a4a89e
commit a6698bb5d4
1 changed files with 13 additions and 19 deletions
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32
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -1702,24 +1702,18 @@ SDValue DAGCombiner::visitADD(SDNode *N) {
}
// fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
if (N1.getOpcode() == ISD::SHL &&
N1.getOperand(0).getOpcode() == ISD::SUB)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
if (C->getAPIntValue() == 0)
return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
DAG.getNode(ISD::SHL, SDLoc(N), VT,
N1.getOperand(0).getOperand(1),
N1.getOperand(1)));
if (N0.getOpcode() == ISD::SHL &&
N0.getOperand(0).getOpcode() == ISD::SUB)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
if (C->getAPIntValue() == 0)
return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
DAG.getNode(ISD::SHL, SDLoc(N), VT,
N0.getOperand(0).getOperand(1),
N0.getOperand(1)));
if (N1.getOpcode() == ISD::SHL && N1.getOperand(0).getOpcode() == ISD::SUB &&
isNullConstant(N1.getOperand(0).getOperand(0)))
return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
DAG.getNode(ISD::SHL, SDLoc(N), VT,
N1.getOperand(0).getOperand(1),
N1.getOperand(1)));
if (N0.getOpcode() == ISD::SHL && N0.getOperand(0).getOpcode() == ISD::SUB &&
isNullConstant(N0.getOperand(0).getOperand(0)))
return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
DAG.getNode(ISD::SHL, SDLoc(N), VT,
N0.getOperand(0).getOperand(1),
N0.getOperand(1)));
if (N1.getOpcode() == ISD::AND) {
SDValue AndOp0 = N1.getOperand(0);
@ -4898,7 +4892,7 @@ SDValue DAGCombiner::visitSELECT(SDNode *N) {
return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
// fold (select X, Y, X) -> (and X, Y)
// fold (select X, Y, 0) -> (and X, Y)
if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
if (VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
// If we can fold this based on the true/false value, do so.