diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index f67cd3e270..05a58b1c1b 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -205,6 +205,7 @@ namespace { SDValue visitCTTZ_ZERO_UNDEF(SDNode *N); SDValue visitCTPOP(SDNode *N); SDValue visitSELECT(SDNode *N); + SDValue visitVSELECT(SDNode *N); SDValue visitSELECT_CC(SDNode *N); SDValue visitSETCC(SDNode *N); SDValue visitSIGN_EXTEND(SDNode *N); @@ -1126,6 +1127,7 @@ SDValue DAGCombiner::visit(SDNode *N) { case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N); case ISD::CTPOP: return visitCTPOP(N); case ISD::SELECT: return visitSELECT(N); + case ISD::VSELECT: return visitVSELECT(N); case ISD::SELECT_CC: return visitSELECT_CC(N); case ISD::SETCC: return visitSETCC(N); case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N); @@ -4162,6 +4164,46 @@ SDValue DAGCombiner::visitSELECT(SDNode *N) { return SDValue(); } +SDValue DAGCombiner::visitVSELECT(SDNode *N) { + SDValue N0 = N->getOperand(0); + SDValue N1 = N->getOperand(1); + SDValue N2 = N->getOperand(2); + DebugLoc DL = N->getDebugLoc(); + + // Canonicalize integer abs. + // vselect (setg[te] X, 0), X, -X -> + // vselect (setgt X, -1), X, -X -> + // vselect (setl[te] X, 0), -X, X -> + // Y = sra (X, size(X)-1); xor (add (X, Y), Y) + if (N0.getOpcode() == ISD::SETCC) { + SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1); + ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get(); + bool isAbs = false; + bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode()); + + if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) || + (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) && + N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1)) + isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode()); + else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) && + N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1)) + isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode()); + + if (isAbs) { + EVT VT = LHS.getValueType(); + SDValue Shift = DAG.getNode( + ISD::SRA, DL, VT, LHS, + DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, VT)); + SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift); + AddToWorkList(Shift.getNode()); + AddToWorkList(Add.getNode()); + return DAG.getNode(ISD::XOR, DL, VT, Add, Shift); + } + } + + return SDValue(); +} + SDValue DAGCombiner::visitSELECT_CC(SDNode *N) { SDValue N0 = N->getOperand(0); SDValue N1 = N->getOperand(1); |