Changes in directory llvm/lib/CodeGen/SelectionDAG:
DAGCombiner.cpp updated: 1.96 -> 1.97 --- Log message: Handle urem by shifted powers of 2. --- Diffs of the changes: (+15 -4) DAGCombiner.cpp | 19 +++++++++++++++---- 1 files changed, 15 insertions(+), 4 deletions(-) Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp diff -u llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.96 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.97 --- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.96 Sun Feb 5 01:20:23 2006 +++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Sun Feb 5 01:36:48 2006 @@ -786,10 +786,11 @@ if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) { if (isPowerOf2_64(SHC->getValue())) { MVT::ValueType ADDVT = N1.getOperand(1).getValueType(); - return DAG.getNode(ISD::SRL, VT, N0, - DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1), - DAG.getConstant(Log2_64(SHC->getValue()), - ADDVT))); + SDOperand Add = DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1), + DAG.getConstant(Log2_64(SHC->getValue()), + ADDVT)); + WorkList.push_back(Add.Val); + return DAG.getNode(ISD::SRL, VT, N0, Add); } } } @@ -833,6 +834,16 @@ // fold (urem x, pow2) -> (and x, pow2-1) if (N1C && !N1C->isNullValue() && isPowerOf2_64(N1C->getValue())) return DAG.getNode(ISD::AND, VT, N0, DAG.getConstant(N1C->getValue()-1,VT)); + // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1)) + if (N1.getOpcode() == ISD::SHL) { + if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) { + if (isPowerOf2_64(SHC->getValue())) { + SDOperand Add = DAG.getNode(ISD::ADD, VT, N1, DAG.getConstant(-1, VT)); + WorkList.push_back(Add.Val); + return DAG.getNode(ISD::AND, VT, N0, Add); + } + } + } return SDOperand(); } _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits