diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 3bae15c6aa..3ebaaa465f 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -853,6 +853,23 @@ SDOperand SelectionDAG::SimplifySelectCC(SDOperand N1, SDOperand N2, } } + // Check to see if this is the equivalent of seteq X, 0. + // select_cc seteq X, 0, 1, 0 -> setcc X, 0, seteq -> srl (ctlz X), size(X)-1 + if (N2C && N2C->isNullValue() && N4C && N4C->isNullValue() && + N3C && (N3C->getValue() == 1)) { + MVT::ValueType XType = N1.getValueType(); + if (TLI.getOperationAction(ISD::SETCC, TLI.getSetCCResultTy()) == + TargetLowering::Legal) { + return getSetCC(TLI.getSetCCResultTy(), N1, N2, ISD::SETEQ); + } + if (TLI.getOperationAction(ISD::CTLZ, XType) == TargetLowering::Legal) { + SDOperand Ctlz = getNode(ISD::CTLZ, XType, N1); + return getNode(ISD::SRL, XType, Ctlz, + getConstant(MVT::getSizeInBits(XType)-1, + TLI.getShiftAmountTy())); + } + } + // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X -> // Y = sra (X, size(X)-1); xor (add (X, Y), Y) if (N2C && N2C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) && |