6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-08 21:32:39 +00:00
Code Issues Projects Releases Wiki Activity

Spiller unfold optimization bug: do not clobber a reusable stack slot value unless it can be modified.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44575 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2007-12-04 19:19:45 +00:00
parent eb1819d1e5
commit 35a3e4abb9
1 changed files with 16 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
lib/CodeGen/VirtRegMap.cpp
View File

@ -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;
}
}