diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 4ff2a3aded..370054d296 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2475,15 +2475,18 @@ SDValue DAGCombiner::visitSHL(SDNode *N) { if (N1C && N0.getOpcode() == ISD::SRL && N0.getOperand(1).getOpcode() == ISD::Constant) { uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue(); - uint64_t c2 = N1C->getZExtValue(); - SDValue Mask = DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, N0.getOperand(0), - DAG.getConstant(~0ULL << c1, VT)); - if (c2 > c1) - return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, Mask, - DAG.getConstant(c2-c1, N1.getValueType())); - else - return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Mask, - DAG.getConstant(c1-c2, N1.getValueType())); + if (c1 < VT.getSizeInBits()) { + uint64_t c2 = N1C->getZExtValue(); + SDValue Mask = DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, + N0.getOperand(0), + DAG.getConstant(~0ULL << c1, VT)); + if (c2 > c1) + return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, Mask, + DAG.getConstant(c2-c1, N1.getValueType())); + else + return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Mask, + DAG.getConstant(c1-c2, N1.getValueType())); + } } // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1)) if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) |