diff options
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 4d1e39359ba..7eeb1003599 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -208,6 +208,7 @@ namespace { SDOperand visitBRCOND(SDNode *N); SDOperand visitBR_CC(SDNode *N); SDOperand visitLOAD(SDNode *N); + SDOperand visitXEXTLOAD(SDNode *N); SDOperand visitSTORE(SDNode *N); SDOperand visitINSERT_VECTOR_ELT(SDNode *N); SDOperand visitVINSERT_VECTOR_ELT(SDNode *N); @@ -643,6 +644,9 @@ SDOperand DAGCombiner::visit(SDNode *N) { case ISD::BRCOND: return visitBRCOND(N); case ISD::BR_CC: return visitBR_CC(N); case ISD::LOAD: return visitLOAD(N); + case ISD::EXTLOAD: + case ISD::SEXTLOAD: + case ISD::ZEXTLOAD: return visitXEXTLOAD(N); case ISD::STORE: return visitSTORE(N); case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N); case ISD::VINSERT_VECTOR_ELT: return visitVINSERT_VECTOR_ELT(N); @@ -2278,6 +2282,21 @@ SDOperand DAGCombiner::visitLOAD(SDNode *N) { return SDOperand(); } +/// visitXEXTLOAD - Handle EXTLOAD/ZEXTLOAD/SEXTLOAD. +SDOperand DAGCombiner::visitXEXTLOAD(SDNode *N) { + SDOperand Chain = N->getOperand(0); + SDOperand Ptr = N->getOperand(1); + SDOperand SrcValue = N->getOperand(2); + SDOperand EVT = N->getOperand(3); + + // If there are no uses of the loaded value, change uses of the chain value + // into uses of the chain input (i.e. delete the dead load). + if (N->hasNUsesOfValue(0, 0)) + return CombineTo(N, DAG.getNode(ISD::UNDEF, N->getValueType(0)), Chain); + + return SDOperand(); +} + SDOperand DAGCombiner::visitSTORE(SDNode *N) { SDOperand Chain = N->getOperand(0); SDOperand Value = N->getOperand(1); |
