diff options
| -rw-r--r-- | lib/CodeGen/VirtRegMap.cpp | 54 | ||||
| -rw-r--r-- | lib/CodeGen/VirtRegMap.h | 4 |
2 files changed, 54 insertions, 4 deletions
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp index ebdbb86..d6dc92a 100644 --- a/lib/CodeGen/VirtRegMap.cpp +++ b/lib/CodeGen/VirtRegMap.cpp @@ -139,6 +139,11 @@ void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI, MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo))); } +void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo) { + MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(MI); + MI2VirtMap.insert(IP, std::make_pair(MI, std::make_pair(VirtReg, MRInfo))); +} + void VirtRegMap::print(std::ostream &OS) const { const MRegisterInfo* MRI = MF.getTarget().getRegisterInfo(); @@ -1059,6 +1064,19 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { Erased = true; goto ProcessNextInst; } + } else { + unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS); + SmallVector<MachineInstr*, 4> NewMIs; + if (PhysReg && + MRI->unfoldMemoryOperand(MF, &MI, PhysReg, false, false, NewMIs)) { + MBB.insert(MII, NewMIs[0]); + VRM.RemoveFromFoldedVirtMap(&MI); + MBB.erase(&MI); + Erased = true; + --NextMII; // backtrack to the unfolded instruction. + BackTracked = true; + goto ProcessNextInst; + } } } @@ -1066,16 +1084,44 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { // Otherwise, the store to this stack slot is not dead anymore. MachineInstr* DeadStore = MaybeDeadStores[SS]; if (DeadStore) { - if (!(MR & VirtRegMap::isRef)) { // Previous store is dead. + bool isDead = true; + MachineInstr *NewStore = NULL; + if (MR & VirtRegMap::isRef) { + unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS); + SmallVector<MachineInstr*, 4> NewMIs; + if (PhysReg && + DeadStore->findRegisterUseOperandIdx(PhysReg, true) != -1 && + MRI->unfoldMemoryOperand(MF, &MI, PhysReg, false, true, NewMIs)) { + MBB.insert(MII, NewMIs[0]); + NewStore = NewMIs[1]; + MBB.insert(MII, NewStore); + VRM.RemoveFromFoldedVirtMap(&MI); + MBB.erase(&MI); + Erased = true; + --NextMII; + --NextMII; // backtrack to the unfolded instruction. + BackTracked = true; + } else + isDead = false; + } + + if (isDead) { // Previous store is dead. // If we get here, the store is dead, nuke it now. - assert(VirtRegMap::isMod && "Can't be modref!"); DOUT << "Removed dead store:\t" << *DeadStore; InvalidateKills(*DeadStore, RegKills, KillOps); - MBB.erase(DeadStore); VRM.RemoveFromFoldedVirtMap(DeadStore); - ++NumDSE; + MBB.erase(DeadStore); + if (!NewStore) + ++NumDSE; } + MaybeDeadStores[SS] = NULL; + if (NewStore) { + // Treat this store as a spill merged into a copy. That makes the + // stack slot value available. + VRM.virtFolded(VirtReg, NewStore, VirtRegMap::isMod); + goto ProcessNextInst; + } } // If the spill slot value is available, and this is a new definition of diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h index 8385f3d..f6d305e 100644 --- a/lib/CodeGen/VirtRegMap.h +++ b/lib/CodeGen/VirtRegMap.h @@ -181,6 +181,10 @@ namespace llvm { void virtFolded(unsigned VirtReg, MachineInstr *OldMI, unsigned OpNum, MachineInstr *NewMI); + /// @brief Updates information about the specified virtual register's value + /// folded into the specified machine instruction. + void virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo); + /// @brief returns the virtual registers' values folded in memory /// operands of this instruction std::pair<MI2VirtMapTy::const_iterator, MI2VirtMapTy::const_iterator> |