static void VerifyPHIs(MachineFunction &MF, bool CheckExtra) {
for (MachineFunction::iterator I = ++MF.begin(), E = MF.end(); I != E; ++I) {
- MachineBasicBlock *MBB = I;
+ MachineBasicBlock *MBB = &*I;
SmallSetVector<MachineBasicBlock*, 8> Preds(MBB->pred_begin(),
MBB->pred_end());
MachineBasicBlock::iterator MI = MBB->begin();
}
for (MachineFunction::iterator I = ++MF.begin(), E = MF.end(); I != E; ) {
- MachineBasicBlock *MBB = I++;
+ MachineBasicBlock *MBB = &*I++;
if (NumTails == TailDupLimit)
break;
// Check the instructions in the block to determine whether tail-duplication
// is invalid or unlikely to be profitable.
unsigned InstrCount = 0;
- for (MachineBasicBlock::iterator I = TailBB.begin(); I != TailBB.end(); ++I) {
+ for (MachineInstr &MI : TailBB) {
// Non-duplicable things shouldn't be tail-duplicated.
- if (I->isNotDuplicable())
+ if (MI.isNotDuplicable())
return false;
// Do not duplicate 'return' instructions if this is a pre-regalloc run.
// A return may expand into a lot more instructions (e.g. reload of callee
// saved registers) after PEI.
- if (PreRegAlloc && I->isReturn())
+ if (PreRegAlloc && MI.isReturn())
return false;
// Avoid duplicating calls before register allocation. Calls presents a
// barrier to register allocation so duplicating them may end up increasing
// spills.
- if (PreRegAlloc && I->isCall())
+ if (PreRegAlloc && MI.isCall())
return false;
- if (!I->isPHI() && !I->isDebugValue())
+ if (!MI.isPHI() && !MI.isDebugValue())
InstrCount += 1;
if (InstrCount > MaxDuplicateCount)
return false;
}
+ // Check if any of the successors of TailBB has a PHI node in which the
+ // value corresponding to TailBB uses a subregister.
+ // If a phi node uses a register paired with a subregister, the actual
+ // "value type" of the phi may differ from the type of the register without
+ // any subregisters. Due to a bug, tail duplication may add a new operand
+ // without a necessary subregister, producing an invalid code. This is
+ // demonstrated by test/CodeGen/Hexagon/tail-dup-subreg-abort.ll.
+ // Disable tail duplication for this case for now, until the problem is
+ // fixed.
+ for (auto SB : TailBB.successors()) {
+ for (auto &I : *SB) {
+ if (!I.isPHI())
+ break;
+ unsigned Idx = getPHISrcRegOpIdx(&I, &TailBB);
+ assert(Idx != 0);
+ MachineOperand &PU = I.getOperand(Idx);
+ if (PU.getSubReg() != 0)
+ return false;
+ }
+ }
+
if (HasIndirectbr && PreRegAlloc)
return true;
static bool
bothUsedInPHI(const MachineBasicBlock &A,
SmallPtrSet<MachineBasicBlock*, 8> SuccsB) {
- for (MachineBasicBlock::const_succ_iterator SI = A.succ_begin(),
- SE = A.succ_end(); SI != SE; ++SI) {
- MachineBasicBlock *BB = *SI;
+ for (MachineBasicBlock *BB : A.successors())
if (SuccsB.count(BB) && !BB->empty() && BB->begin()->isPHI())
return true;
- }
return false;
}
bool
TailDuplicatePass::canCompletelyDuplicateBB(MachineBasicBlock &BB) {
- for (MachineBasicBlock::pred_iterator PI = BB.pred_begin(),
- PE = BB.pred_end(); PI != PE; ++PI) {
- MachineBasicBlock *PredBB = *PI;
-
+ for (MachineBasicBlock *PredBB : BB.predecessors()) {
if (PredBB->succ_size() > 1)
return false;
PE = Preds.end(); PI != PE; ++PI) {
MachineBasicBlock *PredBB = *PI;
- if (PredBB->getLandingPadSuccessor())
+ if (PredBB->hasEHPadSuccessor())
continue;
if (bothUsedInPHI(*PredBB, Succs))
<< "From simple Succ: " << *TailBB);
MachineBasicBlock *NewTarget = *TailBB->succ_begin();
- MachineBasicBlock *NextBB = std::next(MachineFunction::iterator(PredBB));
+ MachineBasicBlock *NextBB = &*std::next(PredBB->getIterator());
// Make PredFBB explicit.
if (PredCond.empty())
if (PredTBB)
TII->InsertBranch(*PredBB, PredTBB, PredFBB, PredCond, DebugLoc());
- uint32_t Weight = MBPI->getEdgeWeight(PredBB, TailBB);
+ auto Prob = MBPI->getEdgeProbability(PredBB, TailBB);
PredBB->removeSuccessor(TailBB);
unsigned NumSuccessors = PredBB->succ_size();
assert(NumSuccessors <= 1);
if (NumSuccessors == 0 || *PredBB->succ_begin() != NewTarget)
- PredBB->addSuccessor(NewTarget, Weight);
+ PredBB->addSuccessor(NewTarget, Prob);
TDBBs.push_back(PredBB);
}
RS->enterBasicBlock(PredBB);
if (!PredBB->empty())
RS->forward(std::prev(PredBB->end()));
- for (MachineBasicBlock::livein_iterator I = TailBB->livein_begin(),
- E = TailBB->livein_end(); I != E; ++I) {
- if (!RS->isRegUsed(*I, false))
+ for (const auto &LI : TailBB->liveins()) {
+ if (!RS->isRegUsed(LI.PhysReg, false))
// If a register is previously livein to the tail but it's not live
// at the end of predecessor BB, then it should be added to its
// livein list.
- PredBB->addLiveIn(*I);
+ PredBB->addLiveIn(LI);
}
}
"TailDuplicate called on block with multiple successors!");
for (MachineBasicBlock::succ_iterator I = TailBB->succ_begin(),
E = TailBB->succ_end(); I != E; ++I)
- PredBB->addSuccessor(*I, MBPI->getEdgeWeight(TailBB, I));
+ PredBB->addSuccessor(*I, MBPI->getEdgeProbability(TailBB, I));
Changed = true;
++NumTailDups;
// If TailBB was duplicated into all its predecessors except for the prior
// block, which falls through unconditionally, move the contents of this
// block into the prior block.
- MachineBasicBlock *PrevBB = std::prev(MachineFunction::iterator(TailBB));
+ MachineBasicBlock *PrevBB = &*std::prev(TailBB->getIterator());
MachineBasicBlock *PriorTBB = nullptr, *PriorFBB = nullptr;
SmallVector<MachineOperand, 4> PriorCond;
// This has to check PrevBB->succ_size() because EH edges are ignored by