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| author | Wei Ding <wei.ding2@amd.com> | 2017-10-12 19:37:14 +0000 |
|---|---|---|
| committer | Wei Ding <wei.ding2@amd.com> | 2017-10-12 19:37:14 +0000 |
| commit | 5676acad9e0b530aae507e0b1482cc87c949b762 (patch) | |
| tree | ff0f17fe3a809f5c402d4e0c61de1ec73c5d75ca /llvm/lib/CodeGen/SelectionDAG | |
| parent | ca05b6fb798f2eed32756c7dfc8886411609bdd8 (diff) | |
| download | bcm5719-llvm-5676acad9e0b530aae507e0b1482cc87c949b762.tar.gz bcm5719-llvm-5676acad9e0b530aae507e0b1482cc87c949b762.zip | |
Implement custom lowering for ISD::CTTZ_ZERO_UNDEF and ISD::CTTZ.
Differential Revision: http://reviews.llvm.org/D37348
llvm-svn: 315610
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 3d320a9dda7..bbee69fb656 100644 --- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -2773,7 +2773,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op, return DAG.getNode(ISD::CTLZ, dl, Op.getValueType(), Op); case ISD::CTLZ: { EVT VT = Op.getValueType(); - unsigned len = VT.getSizeInBits(); + unsigned Len = VT.getSizeInBits(); if (TLI.isOperationLegalOrCustom(ISD::CTLZ_ZERO_UNDEF, VT)) { EVT SetCCVT = getSetCCResultType(VT); @@ -2781,7 +2781,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op, SDValue Zero = DAG.getConstant(0, dl, VT); SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ); return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero, - DAG.getConstant(len, dl, VT), CTLZ); + DAG.getConstant(Len, dl, VT), CTLZ); } // for now, we do this: @@ -2794,7 +2794,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op, // // Ref: "Hacker's Delight" by Henry Warren EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout()); - for (unsigned i = 0; (1U << i) <= (len / 2); ++i) { + for (unsigned i = 0; (1U << i) <= (Len / 2); ++i) { SDValue Tmp3 = DAG.getConstant(1ULL << i, dl, ShVT); Op = DAG.getNode(ISD::OR, dl, VT, Op, DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3)); @@ -2806,11 +2806,22 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op, // This trivially expands to CTTZ. return DAG.getNode(ISD::CTTZ, dl, Op.getValueType(), Op); case ISD::CTTZ: { + EVT VT = Op.getValueType(); + unsigned Len = VT.getSizeInBits(); + + if (TLI.isOperationLegalOrCustom(ISD::CTTZ_ZERO_UNDEF, VT)) { + EVT SetCCVT = getSetCCResultType(VT); + SDValue CTTZ = DAG.getNode(ISD::CTTZ_ZERO_UNDEF, dl, VT, Op); + SDValue Zero = DAG.getConstant(0, dl, VT); + SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ); + return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero, + DAG.getConstant(Len, dl, VT), CTTZ); + } + // for now, we use: { return popcount(~x & (x - 1)); } // unless the target has ctlz but not ctpop, in which case we use: // { return 32 - nlz(~x & (x-1)); } // Ref: "Hacker's Delight" by Henry Warren - EVT VT = Op.getValueType(); SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT, DAG.getNOT(dl, Op, VT), DAG.getNode(ISD::SUB, dl, VT, Op, |
