bool IsSimple, MachineBasicBlock &TailBB);
bool isSimpleBB(MachineBasicBlock *TailBB);
bool canCompletelyDuplicateBB(MachineBasicBlock &BB, bool IsSimple);
- void duplicateSimpleBB(MachineBasicBlock *TailBB,
+ bool duplicateSimpleBB(MachineBasicBlock *TailBB,
SmallVector<MachineBasicBlock*, 8> &TDBBs,
const DenseSet<unsigned> &RegsUsedByPhi,
SmallVector<MachineInstr*, 16> &Copies);
return true;
if (IsSimple)
- return canCompletelyDuplicateBB(TailBB, IsSimple);
+ return true;
if (!PreRegAlloc)
return true;
return true;
}
-void
+bool
TailDuplicatePass::duplicateSimpleBB(MachineBasicBlock *TailBB,
SmallVector<MachineBasicBlock*, 8> &TDBBs,
const DenseSet<unsigned> &UsedByPhi,
SmallVector<MachineInstr*, 16> &Copies) {
+ SmallPtrSet<MachineBasicBlock*, 8> Succs(TailBB->succ_begin(),
+ TailBB->succ_end());
SmallVector<MachineBasicBlock*, 8> Preds(TailBB->pred_begin(),
TailBB->pred_end());
+ bool Changed = false;
for (SmallSetVector<MachineBasicBlock *, 8>::iterator PI = Preds.begin(),
PE = Preds.end(); PI != PE; ++PI) {
MachineBasicBlock *PredBB = *PI;
+ if (PredBB->getLandingPadSuccessor())
+ continue;
+
+ if (bothUsedInPHI(*PredBB, Succs))
+ continue;
+
MachineBasicBlock *PredTBB = NULL, *PredFBB = NULL;
SmallVector<MachineOperand, 4> PredCond;
- bool NotAnalyzable =
- TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true);
- (void)NotAnalyzable;
- assert(!NotAnalyzable && "Cannot duplicate this!");
+ if (TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true))
+ continue;
+ Changed = true;
DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB
<< "From simple Succ: " << *TailBB);
TDBBs.push_back(PredBB);
}
+ return Changed;
}
/// TailDuplicate - If it is profitable, duplicate TailBB's contents in each
DenseSet<unsigned> UsedByPhi;
getRegsUsedByPHIs(*TailBB, &UsedByPhi);
- if (IsSimple) {
- duplicateSimpleBB(TailBB, TDBBs, UsedByPhi, Copies);
- return true;
- }
-
+ if (IsSimple)
+ return duplicateSimpleBB(TailBB, TDBBs, UsedByPhi, Copies);
// Iterate through all the unique predecessors and tail-duplicate this
// block into them, if possible. Copying the list ahead of time also