diff options
Diffstat (limited to 'lib/CodeGen/SplitKit.h')
| -rw-r--r-- | lib/CodeGen/SplitKit.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h index 9ba7cbeb10..9a7fa5388a 100644 --- a/lib/CodeGen/SplitKit.h +++ b/lib/CodeGen/SplitKit.h @@ -22,7 +22,6 @@ class LiveInterval; class LiveIntervals; class LiveRangeEdit; class MachineInstr; -class MachineDominatorTree; class MachineLoop; class MachineLoopInfo; class MachineRegisterInfo; @@ -31,6 +30,11 @@ class VirtRegMap; class VNInfo; class raw_ostream; +/// At some point we should just include MachineDominators.h: +class MachineDominatorTree; +template <class NodeT> class DomTreeNodeBase; +typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode; + /// SplitAnalysis - Analyze a LiveInterval, looking for live range splitting /// opportunities. class SplitAnalysis { @@ -171,6 +175,24 @@ class LiveIntervalMap { // values not present (unknown/unmapped). ValueMap valueMap_; + typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair; + typedef DenseMap<MachineBasicBlock*,LiveOutPair> LiveOutMap; + + // liveOutCache_ - Map each basic block where li_ is live out to the live-out + // value and its defining block. One of these conditions shall be true: + // + // 1. !liveOutCache_.count(MBB) + // 2. liveOutCache_[MBB].second.getNode() == MBB + // 3. forall P in preds(MBB): liveOutCache_[P] == liveOutCache_[MBB] + // + // This is only a cache, the values can be computed as: + // + // VNI = li_->getVNInfoAt(lis_.getMBBEndIdx(MBB)) + // Node = mbt_[lis_.getMBBFromIndex(VNI->def)] + // + // The cache is also used as a visiteed set by mapValue(). + LiveOutMap liveOutCache_; + public: LiveIntervalMap(LiveIntervals &lis, MachineDominatorTree &mdt, |