diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 688a4c4b137..a06932b0521 100644 --- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -4010,18 +4010,20 @@ void SelectionDAGLegalize::PromoteNode(SDNode *Node) { case ISD::CTPOP: // Zero extend the argument. Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0)); + if (Node->getOpcode() == ISD::CTTZ) { + // The count is the same in the promoted type except if the original + // value was zero. This can be handled by setting the bit just off + // the top of the original type. + auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(), + OVT.getSizeInBits()); + Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1, + DAG.getConstant(TopBit, dl, NVT)); + } // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is // already the correct result. Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1); - if (Node->getOpcode() == ISD::CTTZ) { - // FIXME: This should set a bit in the zero extended value instead. - Tmp2 = DAG.getSetCC(dl, getSetCCResultType(NVT), - Tmp1, DAG.getConstant(NVT.getSizeInBits(), dl, NVT), - ISD::SETEQ); - Tmp1 = DAG.getSelect(dl, NVT, Tmp2, - DAG.getConstant(OVT.getSizeInBits(), dl, NVT), Tmp1); - } else if (Node->getOpcode() == ISD::CTLZ || - Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) { + if (Node->getOpcode() == ISD::CTLZ || + Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) { // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT)) Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1, DAG.getConstant(NVT.getSizeInBits() - |
