diff options
Diffstat (limited to 'lib/CodeGen/VirtRegMap.cpp')
| -rw-r--r-- | lib/CodeGen/VirtRegMap.cpp | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp index 5650e3d01f..a375a7b498 100644 --- a/lib/CodeGen/VirtRegMap.cpp +++ b/lib/CodeGen/VirtRegMap.cpp @@ -271,7 +271,7 @@ namespace { MachineBasicBlock::iterator &MII, int Idx, unsigned PhysReg, int StackSlot, const TargetRegisterClass *RC, - MachineInstr *&LastStore, + bool isAvailable, MachineInstr *&LastStore, AvailableSpills &Spills, SmallSet<MachineInstr*, 4> &ReMatDefs, BitVector &RegKills, @@ -357,7 +357,7 @@ public: "Value not available!"); return SpillSlotsOrReMatsAvailable.find(SlotOrReMat)->second & 1; } - + /// disallowClobberPhysReg - Unset the CanClobber bit of the specified /// stackslot register. The register is still available but is no longer /// allowed to be modifed. @@ -855,7 +855,7 @@ void LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MII, int Idx, unsigned PhysReg, int StackSlot, const TargetRegisterClass *RC, - MachineInstr *&LastStore, + bool isAvailable, MachineInstr *&LastStore, AvailableSpills &Spills, SmallSet<MachineInstr*, 4> &ReMatDefs, BitVector &RegKills, @@ -903,7 +903,7 @@ void LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB, // in PhysReg. Spills.ModifyStackSlotOrReMat(StackSlot); Spills.ClobberPhysReg(PhysReg); - Spills.addAvailable(StackSlot, LastStore, PhysReg); + Spills.addAvailable(StackSlot, LastStore, PhysReg, isAvailable); ++NumStores; } @@ -984,9 +984,9 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { const TargetRegisterClass *RC = RegMap->getRegClass(VirtReg); unsigned Phys = VRM.getPhys(VirtReg); int StackSlot = VRM.getStackSlot(VirtReg); - MachineInstr *&LastStore = MaybeDeadStores[StackSlot]; - SpillRegToStackSlot(MBB, MII, i, Phys, StackSlot, RC, LastStore, - Spills, ReMatDefs, RegKills, KillOps, VRM); + MRI->storeRegToStackSlot(MBB, next(MII), Phys, StackSlot, RC); + DOUT << "Store:\t" << *next(MII); + VRM.virtFolded(VirtReg, next(MII), VirtRegMap::isMod); } NextMII = next(MII); } @@ -1303,7 +1303,12 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { if (MR & VirtRegMap::isModRef) { unsigned PhysReg = Spills.getSpillSlotOrReMatPhysReg(SS); SmallVector<MachineInstr*, 4> NewMIs; + // We can reuse this physreg as long as we are allowed to clobber + // the value and there isn't an earlier def that has already clobbered the + // physreg. if (PhysReg && + Spills.canClobberPhysReg(SS) && + !ReusedOperands.isClobbered(PhysReg) && DeadStore->findRegisterUseOperandIdx(PhysReg, true) != -1 && MRI->unfoldMemoryOperand(MF, &MI, PhysReg, false, true, NewMIs)) { MBB.insert(MII, NewMIs[0]); @@ -1446,8 +1451,8 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { if (!MO.isDead()) { MachineInstr *&LastStore = MaybeDeadStores[StackSlot]; - SpillRegToStackSlot(MBB, MII, -1, PhysReg, StackSlot, RC, LastStore, - Spills, ReMatDefs, RegKills, KillOps, VRM); + SpillRegToStackSlot(MBB, MII, -1, PhysReg, StackSlot, RC, true, + LastStore, Spills, ReMatDefs, RegKills, KillOps, VRM); NextMII = next(MII); // Check to see if this is a noop copy. If so, eliminate the @@ -1467,9 +1472,10 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) { } } ProcessNextInst: - if (!Erased && !BackTracked) + if (!Erased && !BackTracked) { for (MachineBasicBlock::iterator II = MI; II != NextMII; ++II) UpdateKills(*II, RegKills, KillOps); + } MII = NextMII; } } |