diff options
| -rw-r--r-- | include/llvm/CodeGen/LiveVariables.h | 2 | ||||
| -rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 21 |
2 files changed, 19 insertions, 4 deletions
diff --git a/include/llvm/CodeGen/LiveVariables.h b/include/llvm/CodeGen/LiveVariables.h index 3a5a583c43..c1a4f4e881 100644 --- a/include/llvm/CodeGen/LiveVariables.h +++ b/include/llvm/CodeGen/LiveVariables.h @@ -283,6 +283,8 @@ public: VarInfo &getVarInfo(unsigned RegIdx); void MarkVirtRegAliveInBlock(VarInfo &VRInfo, MachineBasicBlock *BB); + void MarkVirtRegAliveInBlock(VarInfo &VRInfo, MachineBasicBlock *BB, + std::vector<MachineBasicBlock*> &WorkList); void HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB, MachineInstr *MI); }; diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index 4afeb28b1a..9d2d29057d 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -112,7 +112,8 @@ bool LiveVariables::ModifiesRegister(MachineInstr *MI, unsigned Reg) const { } void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo, - MachineBasicBlock *MBB) { + MachineBasicBlock *MBB, + std::vector<MachineBasicBlock*> &WorkList) { unsigned BBNum = MBB->getNumber(); // Check to see if this basic block is one of the killing blocks. If so, @@ -131,11 +132,23 @@ void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo, // Mark the variable known alive in this bb VRInfo.AliveBlocks[BBNum] = true; - for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), - E = MBB->pred_end(); PI != E; ++PI) - MarkVirtRegAliveInBlock(VRInfo, *PI); + for (MachineBasicBlock::const_pred_reverse_iterator PI = MBB->pred_rbegin(), + E = MBB->pred_rend(); PI != E; ++PI) + WorkList.push_back(*PI); +} + +void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo, + MachineBasicBlock *MBB) { + std::vector<MachineBasicBlock*> WorkList; + MarkVirtRegAliveInBlock(VRInfo, MBB, WorkList); + while (!WorkList.empty()) { + MachineBasicBlock *Pred = WorkList.back(); + WorkList.pop_back(); + MarkVirtRegAliveInBlock(VRInfo, Pred, WorkList); + } } + void LiveVariables::HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB, MachineInstr *MI) { assert(VRInfo.DefInst && "Register use before def!"); |