diff options
Diffstat (limited to 'include/llvm/CodeGen/DAGISelHeader.h')
| -rw-r--r-- | include/llvm/CodeGen/DAGISelHeader.h | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/include/llvm/CodeGen/DAGISelHeader.h b/include/llvm/CodeGen/DAGISelHeader.h index f3eccf0..8cd11f6 100644 --- a/include/llvm/CodeGen/DAGISelHeader.h +++ b/include/llvm/CodeGen/DAGISelHeader.h @@ -26,9 +26,8 @@ /// node list. SelectionDAG::allnodes_iterator ISelPosition; -/// IsChainCompatible - Returns true if Chain is Op or Chain does -/// not reach Op. -static bool IsChainCompatible(SDNode *Chain, SDNode *Op) { +/// ChainNotReachable - Returns true if Chain does not reach Op. +static bool ChainNotReachable(SDNode *Chain, SDNode *Op) { if (Chain->getOpcode() == ISD::EntryToken) return true; if (Chain->getOpcode() == ISD::TokenFactor) @@ -36,11 +35,20 @@ static bool IsChainCompatible(SDNode *Chain, SDNode *Op) { if (Chain->getNumOperands() > 0) { SDValue C0 = Chain->getOperand(0); if (C0.getValueType() == MVT::Other) - return C0.getNode() != Op && IsChainCompatible(C0.getNode(), Op); + return C0.getNode() != Op && ChainNotReachable(C0.getNode(), Op); } return true; } +/// IsChainCompatible - Returns true if Chain is Op or Chain does not reach Op. +/// This is used to ensure that there are no nodes trapped between Chain, which +/// is the first chain node discovered in a pattern and Op, a later node, that +/// will not be selected into the pattern. +static bool IsChainCompatible(SDNode *Chain, SDNode *Op) { + return Chain == Op || ChainNotReachable(Chain, Op); +} + + /// ISelUpdater - helper class to handle updates of the /// instruciton selection graph. class VISIBILITY_HIDDEN ISelUpdater : public SelectionDAG::DAGUpdateListener { |