RS_Done
};
+#ifndef NDEBUG
static const char *const StageName[];
+#endif
// RegInfo - Keep additional information about each live range.
struct RegInfo {
void setStage(Iterator Begin, Iterator End, LiveRangeStage NewStage) {
ExtraRegInfo.resize(MRI->getNumVirtRegs());
for (;Begin != End; ++Begin) {
- unsigned Reg = (*Begin)->reg;
+ unsigned Reg = *Begin;
if (ExtraRegInfo[Reg].Stage == RS_New)
ExtraRegInfo[Reg].Stage = NewStage;
}
EvictionCost(unsigned B = 0) : BrokenHints(B), MaxWeight(0) {}
+ bool isMax() const { return BrokenHints == ~0u; }
+
bool operator<(const EvictionCost &O) const {
if (BrokenHints != O.BrokenHints)
return BrokenHints < O.BrokenHints;
virtual void enqueue(LiveInterval *LI);
virtual LiveInterval *dequeue();
virtual unsigned selectOrSplit(LiveInterval&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
/// Perform register allocation.
virtual bool runOnMachineFunction(MachineFunction &mf);
bool calcCompactRegion(GlobalSplitCandidate&);
void splitAroundRegion(LiveRangeEdit&, ArrayRef<unsigned>);
void calcGapWeights(unsigned, SmallVectorImpl<float>&);
+ unsigned canReassign(LiveInterval &VirtReg, unsigned PhysReg);
bool shouldEvict(LiveInterval &A, bool, LiveInterval &B, bool);
bool canEvictInterference(LiveInterval&, unsigned, bool, EvictionCost&);
void evictInterference(LiveInterval&, unsigned,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned tryAssign(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned tryEvict(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&, unsigned = ~0u);
+ SmallVectorImpl<unsigned>&, unsigned = ~0u);
unsigned tryRegionSplit(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned tryBlockSplit(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned tryInstructionSplit(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned tryLocalSplit(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
unsigned trySplit(LiveInterval&, AllocationOrder&,
- SmallVectorImpl<LiveInterval*>&);
+ SmallVectorImpl<unsigned>&);
};
} // end anonymous namespace
// everything else has been allocated.
Prio = Size;
} else {
- // Everything is allocated in long->short order. Long ranges that don't fit
- // should be spilled (or split) ASAP so they don't create interference.
- Prio = (1u << 31) + Size;
+ if (ExtraRegInfo[Reg].Stage == RS_Assign && !LI->empty() &&
+ LIS->intervalIsInOneMBB(*LI)) {
+ // Allocate original local ranges in linear instruction order. Since they
+ // are singly defined, this produces optimal coloring in the absence of
+ // global interference and other constraints.
+ Prio = LI->beginIndex().getInstrDistance(Indexes->getLastIndex());
+ }
+ else {
+ // Allocate global and split ranges in long->short order. Long ranges that
+ // don't fit should be spilled (or split) ASAP so they don't create
+ // interference. Mark a bit to prioritize global above local ranges.
+ Prio = (1u << 29) + Size;
+ }
+ // Mark a higher bit to prioritize global and local above RS_Split.
+ Prio |= (1u << 31);
// Boost ranges that have a physical register hint.
if (VRM->hasKnownPreference(Reg))
Prio |= (1u << 30);
}
-
+ // The virtual register number is a tie breaker for same-sized ranges.
+ // Give lower vreg numbers higher priority to assign them first.
Queue.push(std::make_pair(Prio, ~Reg));
}
/// tryAssign - Try to assign VirtReg to an available register.
unsigned RAGreedy::tryAssign(LiveInterval &VirtReg,
AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
Order.rewind();
unsigned PhysReg;
while ((PhysReg = Order.next()))
// Interference eviction
//===----------------------------------------------------------------------===//
+unsigned RAGreedy::canReassign(LiveInterval &VirtReg, unsigned PrevReg) {
+ AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
+ unsigned PhysReg;
+ while ((PhysReg = Order.next())) {
+ if (PhysReg == PrevReg)
+ continue;
+
+ MCRegUnitIterator Units(PhysReg, TRI);
+ for (; Units.isValid(); ++Units) {
+ // Instantiate a "subquery", not to be confused with the Queries array.
+ LiveIntervalUnion::Query subQ(&VirtReg, &Matrix->getLiveUnions()[*Units]);
+ if (subQ.checkInterference())
+ break;
+ }
+ // If no units have interference, break out with the current PhysReg.
+ if (!Units.isValid())
+ break;
+ }
+ if (PhysReg)
+ DEBUG(dbgs() << "can reassign: " << VirtReg << " from "
+ << PrintReg(PrevReg, TRI) << " to " << PrintReg(PhysReg, TRI)
+ << '\n');
+ return PhysReg;
+}
+
/// shouldEvict - determine if A should evict the assigned live range B. The
/// eviction policy defined by this function together with the allocation order
/// defined by enqueue() decides which registers ultimately end up being split
if (Matrix->checkInterference(VirtReg, PhysReg) > LiveRegMatrix::IK_VirtReg)
return false;
+ bool IsLocal = LIS->intervalIsInOneMBB(VirtReg);
+
// Find VirtReg's cascade number. This will be unassigned if VirtReg was never
// involved in an eviction before. If a cascade number was assigned, deny
// evicting anything with the same or a newer cascade number. This prevents
// Abort if this would be too expensive.
if (!(Cost < MaxCost))
return false;
+ if (Urgent)
+ continue;
+ // If !MaxCost.isMax(), then we're just looking for a cheap register.
+ // Evicting another local live range in this case could lead to suboptimal
+ // coloring.
+ if (!MaxCost.isMax() && IsLocal && LIS->intervalIsInOneMBB(*Intf) &&
+ !canReassign(*Intf, PhysReg)) {
+ return false;
+ }
// Finally, apply the eviction policy for non-urgent evictions.
- if (!Urgent && !shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
+ if (!shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
return false;
}
}
/// from being assigned to Physreg. This assumes that canEvictInterference
/// returned true.
void RAGreedy::evictInterference(LiveInterval &VirtReg, unsigned PhysReg,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
// Make sure that VirtReg has a cascade number, and assign that cascade
// number to every evicted register. These live ranges than then only be
// evicted by a newer cascade, preventing infinite loops.
"Cannot decrease cascade number, illegal eviction");
ExtraRegInfo[Intf->reg].Cascade = Cascade;
++NumEvicted;
- NewVRegs.push_back(Intf);
+ NewVRegs.push_back(Intf->reg);
}
}
/// @return Physreg to assign VirtReg, or 0.
unsigned RAGreedy::tryEvict(LiveInterval &VirtReg,
AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs,
+ SmallVectorImpl<unsigned> &NewVRegs,
unsigned CostPerUseLimit) {
NamedRegionTimer T("Evict", TimerGroupName, TimePassesIsEnabled);
SmallVector<unsigned, 8> IntvMap;
SE->finish(&IntvMap);
- DebugVars->splitRegister(Reg, LREdit.regs());
+ DebugVars->splitRegister(Reg, LREdit.regs(), *LIS);
ExtraRegInfo.resize(MRI->getNumVirtRegs());
unsigned OrigBlocks = SA->getNumLiveBlocks();
// - Block-local splits are candidates for local splitting.
// - DCE leftovers should go back on the queue.
for (unsigned i = 0, e = LREdit.size(); i != e; ++i) {
- LiveInterval &Reg = *LREdit.get(i);
+ LiveInterval &Reg = LIS->getInterval(LREdit.get(i));
// Ignore old intervals from DCE.
if (getStage(Reg) != RS_New)
}
unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
unsigned NumCands = 0;
unsigned BestCand = NoCand;
BlockFrequency BestCost;
/// creates a lot of local live ranges, that will be split by tryLocalSplit if
/// they don't allocate.
unsigned RAGreedy::tryBlockSplit(LiveInterval &VirtReg, AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
assert(&SA->getParent() == &VirtReg && "Live range wasn't analyzed");
unsigned Reg = VirtReg.reg;
bool SingleInstrs = RegClassInfo.isProperSubClass(MRI->getRegClass(Reg));
SE->finish(&IntvMap);
// Tell LiveDebugVariables about the new ranges.
- DebugVars->splitRegister(Reg, LREdit.regs());
+ DebugVars->splitRegister(Reg, LREdit.regs(), *LIS);
ExtraRegInfo.resize(MRI->getNumVirtRegs());
// Sort out the new intervals created by splitting. The remainder interval
// goes straight to spilling, the new local ranges get to stay RS_New.
for (unsigned i = 0, e = LREdit.size(); i != e; ++i) {
- LiveInterval &LI = *LREdit.get(i);
+ LiveInterval &LI = LIS->getInterval(LREdit.get(i));
if (getStage(LI) == RS_New && IntvMap[i] == 0)
setStage(LI, RS_Spill);
}
/// This is similar to spilling to a larger register class.
unsigned
RAGreedy::tryInstructionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
// There is no point to this if there are no larger sub-classes.
if (!RegClassInfo.isProperSubClass(MRI->getRegClass(VirtReg.reg)))
return 0;
SmallVector<unsigned, 8> IntvMap;
SE->finish(&IntvMap);
- DebugVars->splitRegister(VirtReg.reg, LREdit.regs());
+ DebugVars->splitRegister(VirtReg.reg, LREdit.regs(), *LIS);
ExtraRegInfo.resize(MRI->getNumVirtRegs());
// Assign all new registers to RS_Spill. This was the last chance.
/// basic block.
///
unsigned RAGreedy::tryLocalSplit(LiveInterval &VirtReg, AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
assert(SA->getUseBlocks().size() == 1 && "Not a local interval");
const SplitAnalysis::BlockInfo &BI = SA->getUseBlocks().front();
SE->useIntv(SegStart, SegStop);
SmallVector<unsigned, 8> IntvMap;
SE->finish(&IntvMap);
- DebugVars->splitRegister(VirtReg.reg, LREdit.regs());
+ DebugVars->splitRegister(VirtReg.reg, LREdit.regs(), *LIS);
// If the new range has the same number of instructions as before, mark it as
// RS_Split2 so the next split will be forced to make progress. Otherwise,
assert(!ProgressRequired && "Didn't make progress when it was required.");
for (unsigned i = 0, e = IntvMap.size(); i != e; ++i)
if (IntvMap[i] == 1) {
- setStage(*LREdit.get(i), RS_Split2);
- DEBUG(dbgs() << PrintReg(LREdit.get(i)->reg));
+ setStage(LIS->getInterval(LREdit.get(i)), RS_Split2);
+ DEBUG(dbgs() << PrintReg(LREdit.get(i)));
}
DEBUG(dbgs() << '\n');
}
/// assignable.
/// @return Physreg when VirtReg may be assigned and/or new NewVRegs.
unsigned RAGreedy::trySplit(LiveInterval &VirtReg, AllocationOrder &Order,
- SmallVectorImpl<LiveInterval*>&NewVRegs) {
+ SmallVectorImpl<unsigned>&NewVRegs) {
// Ranges must be Split2 or less.
if (getStage(VirtReg) >= RS_Spill)
return 0;
//===----------------------------------------------------------------------===//
unsigned RAGreedy::selectOrSplit(LiveInterval &VirtReg,
- SmallVectorImpl<LiveInterval*> &NewVRegs) {
+ SmallVectorImpl<unsigned> &NewVRegs) {
// First try assigning a free register.
AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
if (unsigned PhysReg = tryAssign(VirtReg, Order, NewVRegs))
if (Stage < RS_Split) {
setStage(VirtReg, RS_Split);
DEBUG(dbgs() << "wait for second round\n");
- NewVRegs.push_back(&VirtReg);
+ NewVRegs.push_back(VirtReg.reg);
return 0;
}
projects / oota-llvm.git / blobdiff