diff options
Diffstat (limited to 'lib/CodeGen/PreAllocSplitting.cpp')
-rw-r--r-- | lib/CodeGen/PreAllocSplitting.cpp | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp index 8f223b36..f09ea23 100644 --- a/lib/CodeGen/PreAllocSplitting.cpp +++ b/lib/CodeGen/PreAllocSplitting.cpp @@ -17,6 +17,7 @@ #define DEBUG_TYPE "pre-alloc-split" #include "llvm/CodeGen/LiveIntervalAnalysis.h" #include "llvm/CodeGen/LiveStackAnalysis.h" +#include "llvm/CodeGen/MachineDominators.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/MachineLoopInfo.h" @@ -89,6 +90,10 @@ namespace { AU.addPreservedID(StrongPHIEliminationID); else AU.addPreservedID(PHIEliminationID); + AU.addRequired<MachineDominatorTree>(); + AU.addRequired<MachineLoopInfo>(); + AU.addPreserved<MachineDominatorTree>(); + AU.addPreserved<MachineLoopInfo>(); MachineFunctionPass::getAnalysisUsage(AU); } @@ -145,6 +150,9 @@ namespace { bool SplitRegLiveInterval(LiveInterval*); bool SplitRegLiveIntervals(const TargetRegisterClass **); + + bool createsNewJoin(LiveRange* LR, MachineBasicBlock* DefMBB, + MachineBasicBlock* BarrierMBB); }; } // end anonymous namespace @@ -817,6 +825,71 @@ PreAllocSplitting::SplitRegLiveIntervals(const TargetRegisterClass **RCs) { return Change; } +bool PreAllocSplitting::createsNewJoin(LiveRange* LR, + MachineBasicBlock* DefMBB, + MachineBasicBlock* BarrierMBB) { + if (DefMBB == BarrierMBB) + return false; + + if (LR->valno->hasPHIKill) + return false; + + unsigned MBBEnd = LIs->getMBBEndIdx(BarrierMBB); + if (LR->end < MBBEnd) + return false; + + MachineLoopInfo& MLI = getAnalysis<MachineLoopInfo>(); + if (MLI.getLoopFor(DefMBB) != MLI.getLoopFor(BarrierMBB)) + return true; + + MachineDominatorTree& MDT = getAnalysis<MachineDominatorTree>(); + SmallPtrSet<MachineBasicBlock*, 4> Visited; + typedef std::pair<MachineBasicBlock*, + MachineBasicBlock::succ_iterator> ItPair; + SmallVector<ItPair, 4> Stack; + Stack.push_back(std::make_pair(BarrierMBB, BarrierMBB->succ_begin())); + + while (!Stack.empty()) { + ItPair P = Stack.back(); + Stack.pop_back(); + + MachineBasicBlock* PredMBB = P.first; + MachineBasicBlock::succ_iterator S = P.second; + + if (S == PredMBB->succ_end()) + continue; + else if (Visited.count(*S)) { + Stack.push_back(std::make_pair(PredMBB, ++S)); + continue; + } else + Stack.push_back(std::make_pair(PredMBB, ++S)); + + MachineBasicBlock* MBB = *S; + Visited.insert(MBB); + + if (MBB == BarrierMBB) + return true; + + MachineDomTreeNode* DefMDTN = MDT.getNode(DefMBB); + MachineDomTreeNode* BarrierMDTN = MDT.getNode(BarrierMBB); + MachineDomTreeNode* MDTN = MDT.getNode(MBB)->getIDom(); + while (MDTN) { + if (MDTN == DefMDTN) + return true; + else if (MDTN == BarrierMDTN) + break; + MDTN = MDTN->getIDom(); + } + + MBBEnd = LIs->getMBBEndIdx(MBB); + if (LR->end > MBBEnd) + Stack.push_back(std::make_pair(MBB, MBB->succ_begin())); + } + + return false; +} + + bool PreAllocSplitting::runOnMachineFunction(MachineFunction &MF) { CurrMF = &MF; TM = &MF.getTarget(); |